Sync up with Linus #10

dabrace · 2014-11-24T14:51:03Z

No description provided.

The initial state of the device's need_restore flag should'nt depend on the current state of the PM domain. For example it should be perfectly valid to attach an inactive device to a powered PM domain. The pm_genpd_dev_need_restore() API allow us to update the need_restore flag to somewhat cope with such scenarios. Typically that should have been done from drivers/buses ->probe() since it's those that put the requirements on the value of the need_restore flag. Until recently, the Exynos SOCs were the only user of the pm_genpd_dev_need_restore() API, though invoking it from a centralized location while adding devices to their PM domains. Due to that Exynos now have swithed to the generic OF-based PM domain look-up, it's no longer possible to invoke the API from a centralized location. The reason is because devices are now added to their PM domains during the probe sequence. Commit "ARM: exynos: Move to generic PM domain DT bindings" did the switch for Exynos to the generic OF-based PM domain look-up, but it also removed the call to pm_genpd_dev_need_restore(). This caused a regression for some of the Exynos drivers. To handle things more properly in the generic PM domain, let's change the default initial value of the need_restore flag to reflect that the state is unknown. As soon as some of the runtime PM callbacks gets invoked, update the initial value accordingly. Moreover, since the generic PM domain is verifying that all devices are both runtime PM enabled and suspended, using pm_runtime_suspended() while pm_genpd_poweroff() is invoked from the scheduled work, we can be sure of that the PM domain won't be powering off while having active devices. Do note that, the generic PM domain can still only know about active devices which has been activated through invoking its runtime PM resume callback. In other words, buses/drivers using pm_runtime_set_active() during ->probe() will still suffer from a race condition, potentially probing a device without having its PM domain being powered. That issue will have to be solved using a different approach. This a log from the boot regression for Exynos5, which is being fixed in this patch. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 308 at ../drivers/clk/clk.c:851 clk_disable+0x24/0x30() Modules linked in: CPU: 0 PID: 308 Comm: kworker/0:1 Not tainted 3.18.0-rc3-00569-gbd9449f-dirty #10 Workqueue: pm pm_runtime_work [<c0013c64>] (unwind_backtrace) from [<c0010dec>] (show_stack+0x10/0x14) [<c0010dec>] (show_stack) from [<c03ee4cc>] (dump_stack+0x70/0xbc) [<c03ee4cc>] (dump_stack) from [<c0020d34>] (warn_slowpath_common+0x64/0x88) [<c0020d34>] (warn_slowpath_common) from [<c0020d74>] (warn_slowpath_null+0x1c/0x24) [<c0020d74>] (warn_slowpath_null) from [<c03107b0>] (clk_disable+0x24/0x30) [<c03107b0>] (clk_disable) from [<c02cc834>] (gsc_runtime_suspend+0x128/0x160) [<c02cc834>] (gsc_runtime_suspend) from [<c0249024>] (pm_generic_runtime_suspend+0x2c/0x38) [<c0249024>] (pm_generic_runtime_suspend) from [<c024f44c>] (pm_genpd_default_save_state+0x2c/0x8c) [<c024f44c>] (pm_genpd_default_save_state) from [<c024ff2c>] (pm_genpd_poweroff+0x224/0x3ec) [<c024ff2c>] (pm_genpd_poweroff) from [<c02501b4>] (pm_genpd_runtime_suspend+0x9c/0xcc) [<c02501b4>] (pm_genpd_runtime_suspend) from [<c024a4f8>] (__rpm_callback+0x2c/0x60) [<c024a4f8>] (__rpm_callback) from [<c024a54c>] (rpm_callback+0x20/0x74) [<c024a54c>] (rpm_callback) from [<c024a930>] (rpm_suspend+0xd4/0x43c) [<c024a930>] (rpm_suspend) from [<c024bbcc>] (pm_runtime_work+0x80/0x90) [<c024bbcc>] (pm_runtime_work) from [<c0032a9c>] (process_one_work+0x12c/0x314) [<c0032a9c>] (process_one_work) from [<c0032cf4>] (worker_thread+0x3c/0x4b0) [<c0032cf4>] (worker_thread) from [<c003747c>] (kthread+0xcc/0xe8) [<c003747c>] (kthread) from [<c000e738>] (ret_from_fork+0x14/0x3c) ---[ end trace 40cd58bcd6988f12 ]--- Fixes: a4a8c2c (ARM: exynos: Move to generic PM domain DT bindings) Reported-and-tested0by: Sylwester Nawrocki <s.nawrocki@samsung.com> Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

David reported that perf can segfault when adding an uprobe event like this: $ perf probe -x /lib64/libc-2.14.90.so -a 'malloc size=%di' (gdb) bt #0 parse_eh_frame_hdr (hdr=0x0, hdr_size=2596, hdr_vaddr=71788, ehdr=0x7fffffffd390, eh_frame_vaddr= 0x7fffffffd378, table_entries=0x8808d8, table_encoding=0x8808e0 "") at dwarf_getcfi_elf.c:79 #1 0x000000385f81615a in getcfi_scn_eh_frame (hdr_vaddr=71788, hdr_scn=0x8839b0, shdr=0x7fffffffd2f0, scn=<optimized out>, ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:231 #2 getcfi_shdr (ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:283 #3 dwarf_getcfi_elf (elf=0x882b30) at dwarf_getcfi_elf.c:309 #4 0x00000000004d5bac in debuginfo__find_probes (pf=0x7fffffffd4f0, dbg=Unhandled dwarf expression opcode 0xfa) at util/probe-finder.c:993 #5 0x00000000004d634a in debuginfo__find_trace_events (dbg=0x880840, pev=<optimized out>, tevs=0x880f88, max_tevs=<optimized out>) at util/probe-finder.c:1200 #6 0x00000000004aed6b in try_to_find_probe_trace_events (target=0x881b20 "/lib64/libpthread-2.14.90.so", max_tevs=128, tevs=0x880f88, pev=0x859b30) at util/probe-event.c:482 #7 convert_to_probe_trace_events (target=0x881b20 "/lib64/libpthread-2.14.90.so", max_tevs=128, tevs=0x880f88, pev=0x859b30) at util/probe-event.c:2356 #8 add_perf_probe_events (pevs=<optimized out>, npevs=1, max_tevs=128, target=0x881b20 "/lib64/libpthread-2.14.90.so", force_add=false) at util/probe-event.c:2391 #9 0x000000000044014f in __cmd_probe (argc=<optimized out>, argv=0x7fffffffe2f0, prefix=Unhandled dwarf expression opcode 0xfa) at at builtin-probe.c:488 #10 0x0000000000440313 in cmd_probe (argc=5, argv=0x7fffffffe2f0, prefix=<optimized out>) at builtin-probe.c:506 #11 0x000000000041d133 in run_builtin (p=0x805680, argc=5, argv=0x7fffffffe2f0) at perf.c:341 #12 0x000000000041c8b2 in handle_internal_command (argv=<optimized out>, argc=<optimized out>) at perf.c:400 #13 run_argv (argv=<optimized out>, argcp=<optimized out>) at perf.c:444 #14 main (argc=5, argv=0x7fffffffe2f0) at perf.c:559 And I found a related commit (5704c8c4fa71 "getcfi_scn_eh_frame: Don't crash and burn when .eh_frame bits aren't there.") in elfutils that can lead to a unexpected crash like this. To safely use the function, it needs to check the .eh_frame section is a PROGBITS type. Reported-by: David Ahern <dsahern@gmail.com> Tested-by: David Ahern <dsahern@gmail.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: David Ahern <dsahern@gmail.com> Cc: Mark Wielaard <mjw@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/20141230090533.GH6081@sejong Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

At f_audio_free_inst, it tries to access struct gaudio *card which is freed at f_audio_free, it causes below oops if the audio device is not there (do unload module may trigger the same problem). The gaudio_cleanup is related to function, so it is better move to f_audio_free. root@freescale ~$ modprobe g_audio [ 751.968931] g_audio gadget: unable to open sound control device file: /dev/snd/controlC0 [ 751.977134] g_audio gadget: we need at least one control device [ 751.988633] Unable to handle kernel paging request at virtual address 455f448e [ 751.995963] pgd = bd42c00 [ 751.998681] [455f448e] *pgd=00000000 [ 752.002383] Internal error: Oops: 5 [#1] SMP ARM [ 752.007008] Modules linked in: usb_f_uac1 g_audio(+) usb_f_mass_storage libcomposite configfs [last unloaded: g_mass_storage] [ 752.018427] CPU: 0 PID: 692 Comm: modprobe Not tainted 3.18.0-rc4-00345-g842f57b #10 [ 752.026176] task: bdb3ba80 ti: bd41a000 task.ti: bd41a000 [ 752.031590] PC is at filp_close+0xc/0x84 [ 752.035530] LR is at gaudio_cleanup+0x28/0x54 [usb_f_uac1] [ 752.041023] pc : [<800ec94c>] lr : [<7f03c63c>] psr: 20000013 [ 752.041023] sp : bd41bcc8 ip : bd41bce8 fp : bd41bce4 [ 752.052504] r10: 7f036234 r9 : 7f036220 r8 : 7f036500 [ 752.057732] r7 : bd456480 r6 : 7f036500 r5 : 7f03626c r4 : bd441000 [ 752.064264] r3 : 7f03b3dc r2 : 7f03cab0 r1 : 00000000 r0 : 455f4456 [ 752.070798] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 752.077938] Control: 10c5387d Table: bd42c04a DAC: 00000015 [ 752.083688] Process modprobe (pid: 692, stack limit = 0xbd41a240) [ 752.089786] Stack: (0xbd41bcc8 to 0xbd41c000) [ 752.094152] bcc0: 7f03b3dc bd441000 7f03626c 7f036500 bd41bcfc bd41bce8 [ 752.102337] bce0: 7f03c63c 800ec94c 7f03b3dc bdaa6b00 bd41bd14 bd41bd00 7f03b3f4 7f03c620 [ 752.110521] bd00: 7f03b3dc 7f03cbd4 bd41bd2c bd41bd18 7f00f88c 7f03b3e8 00000000 fffffffe [ 752.118705] bd20: bd41bd5c bd41bd30 7f0380d8 7f00f874 7f038000 bd456480 7f036364 be392240 [ 752.126889] bd40: 00000000 7f00f620 7f00f638 bd41a008 bd41bd94 bd41bd60 7f00f6d4 7f03800c [ 752.135073] bd60: 00000001 00000000 8047438c be3a4000 7f036364 7f036364 7f00db28 7f00f620 [ 752.143257] bd80: 7f00f638 bd41a008 bd41bdb4 bd41bd98 804742ac 7f00f644 00000000 809adde0 [ 752.151442] bda0: 7f036364 7f036364 bd41bdcc bd41bdb8 804743c8 80474284 7f03633c 7f036200 [ 752.159626] bdc0: bd41bdf4 bd41bdd0 7f00d5b4 8047435c bd41a000 80974060 7f038158 00000000 [ 752.167811] bde0: 80974060 bdaa9940 bd41be04 bd41bdf8 7f03816c 7f00d518 bd41be8c bd41be08 [ 752.175995] be00: 80008a5c 7f038164 be001f00 7f0363c4 bd41bf48 00000000 bd41be54 bd41be28 [ 752.184179] be20: 800e9498 800e8e74 00000002 00000003 bd4129c0 c0a07000 00000001 7f0363c4 [ 752.192363] be40: bd41bf48 00000000 bd41be74 bd41be58 800de780 800e9320 bd41a000 7f0363d0 [ 752.200547] be60: 00000000 bd41a000 7f0363d0 00000000 bd41beec 7f0363c4 bd41bf48 00000000 [ 752.208731] be80: bd41bf44 bd41be90 80093e5 800089e0 ffff8000 00007fff 80091390 0000065f [ 752.216915] bea0: 00000000 c0a0834c bd41bf7c 00000086 bd41bf50 00000000 7f03651c 00000086 [ 752.225099] bec0: bd41a010 00c28758 800ddcc4 800ddae0 000000d2 bd412a00 bd41bf24 00000000 [ 752.233283] bee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 752.241467] bf00: 00000000 00000000 00000000 00000000 00000000 00000000 bd41bf44 000025b0 [ 752.249651] bf20: 00c28a08 00c28758 00000080 8000edc4 bd41a000 00000000 bd41bfa4 bd41bf48 [ 752.257835] bf40: 800943e4 800932ec c0a07000 000025b0 c0a07f8c c0a07ea4 c0a08e5c 0000051c [ 752.266019] bf60: 0000088c 00000000 00000000 00000000 00000018 00000019 00000010 0000000b [ 752.274203] bf80: 00000009 00000000 00000000 000025b0 00000000 00c28758 00000000 bd41bfa8 [ 752.282387] bfa0: 8000ec00 8009430c 000025b0 00000000 00c28a08 000025b0 00c28758 00c28980 [ 752.290571] bfc0: 000025b0 00000000 00c28758 00000080 000a6a78 00000007 00c28718 00c28980 [ 752.298756] bfe0: 7ebc1af0 7ebc1ae0 0001a32c 76e9c490 60000010 00c28a08 22013510 ecebffff [ 752.306933] Backtrace: [ 752.309414] [<800ec940>] (filp_close) from [<7f03c63c>] (gaudio_cleanup+0x28/0x54 [usb_f_uac1]) [ 752.318115] r6:7f036500 r5:7f03626c r4:bd441000 r3:7f03b3dc [ 752.323851] [<7f03c614>] (gaudio_cleanup [usb_f_uac1]) from [<7f03b3f4>] (f_audio_free_inst+0x18/0x68 [usb_f_uac1]) [ 752.334288] r4:bdaa6b00 r3:7f03b3dc [ 752.337931] [<7f03b3dc>] (f_audio_free_inst [usb_f_uac1]) from [<7f00f88c>] (usb_put_function_instance+0x24/0x30 [libcomposite]) [ 752.349498] r4:7f03cbd4 r3:7f03b3dc [ 752.353127] [<7f00f868>] (usb_put_function_instance [libcomposite]) from [<7f0380d8>] (audio_bind+0xd8/0xfc [g_audio]) [ 752.363824] r4:fffffffe r3:00000000 [ 752.367456] [<7f038000>] (audio_bind [g_audio]) from [<7f00f6d4>] (composite_bind+0x9c/0x1e8 [libcomposite]) [ 752.377284] r10:bd41a008 r9:7f00f638 r8:7f00f620 r7:00000000 r6:be392240 r5:7f036364 [ 752.385193] r4:bd456480 r3:7f038000 [ 752.388825] [<7f00f638>] (composite_bind [libcomposite]) from [<804742ac>] (udc_bind_to_driver+0x34/0xd8) [ 752.398394] r10:bd41a008 r9:7f00f638 r8:7f00f620 r7:7f00db28 r6:7f036364 r5:7f036364 [ 752.406302] r4:be3a4000 [ 752.408860] [<80474278>] (udc_bind_to_driver) from [<804743c8>] (usb_gadget_probe_driver+0x78/0xa8) [ 752.417908] r6:7f036364 r5:7f036364 r4:809adde0 r3:00000000 [ 752.423649] [<80474350>] (usb_gadget_probe_driver) from [<7f00d5b4>] (usb_composite_probe+0xa8/0xd4 [libcomposite]) [ 752.434086] r5:7f036200 r4:7f03633c [ 752.437713] [<7f00d50c>] (usb_composite_probe [libcomposite]) from [<7f03816c>] (audio_driver_init+0x14/0x1c [g_audio]) [ 752.448498] r9:bdaa9940 r8:80974060 r7:00000000 r6:7f038158 r5:80974060 r4:bd41a000 [ 752.456330] [<7f038158>] (audio_driver_init [g_audio]) from [<80008a5c>] (do_one_initcall+0x88/0x1d4) [ 752.465564] [<800089d4>] (do_one_initcall) from [<80093e54>] (load_module+0xb74/0x1020) [ 752.473571] r10:00000000 r9:bd41bf48 r8:7f0363c4 r7:bd41beec r6:00000000 r5:7f0363d0 [ 752.481478] r4:bd41a000 [ 752.484037] [<800932e0>] (load_module) from [<800943e4>] (SyS_init_module+0xe4/0xf8) [ 752.491781] r10:00000000 r9:bd41a000 r8:8000edc4 r7:00000080 r6:00c28758 r5:00c28a08 [ 752.499689] r4:000025b0 [ 752.502252] [<80094300>] (SyS_init_module) from [<8000ec00>] (ret_fast_syscall+0x0/0x48) [ 752.510345] r6:00c28758 r5:00000000 r4:000025b0 [ 752.515013] Code: 808475b4 e1a0c00d e92dd878 e24cb004 (e5904038) [ 752.521223] ---[ end trace 70babe34de4ab99b ]--- Segmentation fault Signed-off-by: Peter Chen <peter.chen@freescale.com> Signed-off-by: Felipe Balbi <balbi@ti.com>

The USB console currently allocates a temporary fake tty which is used to pass terminal settings to the underlying serial driver. The tty struct is not fully initialised, something which can lead to a lockdep warning (or worse) if a serial driver tries to acquire a line-discipline reference: usbserial: USB Serial support registered for pl2303 pl2303 1-2.1:1.0: pl2303 converter detected usb 1-2.1: pl2303 converter now attached to ttyUSB0 INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 0 PID: 68 Comm: udevd Tainted: G W 3.18.0-rc5 #10 [<c0016f04>] (unwind_backtrace) from [<c0013978>] (show_stack+0x20/0x24) [<c0013978>] (show_stack) from [<c0449794>] (dump_stack+0x24/0x28) [<c0449794>] (dump_stack) from [<c006f730>] (__lock_acquire+0x1e50/0x2004) [<c006f730>] (__lock_acquire) from [<c0070128>] (lock_acquire+0xe4/0x18c) [<c0070128>] (lock_acquire) from [<c027c6f8>] (ldsem_down_read_trylock+0x78/0x90) [<c027c6f8>] (ldsem_down_read_trylock) from [<c027a1cc>] (tty_ldisc_ref+0x24/0x58) [<c027a1cc>] (tty_ldisc_ref) from [<c0340760>] (usb_serial_handle_dcd_change+0x48/0xe8) [<c0340760>] (usb_serial_handle_dcd_change) from [<bf000484>] (pl2303_read_int_callback+0x210/0x220 [pl2303]) [<bf000484>] (pl2303_read_int_callback [pl2303]) from [<c031624c>] (__usb_hcd_giveback_urb+0x80/0x140) [<c031624c>] (__usb_hcd_giveback_urb) from [<c0316fc0>] (usb_giveback_urb_bh+0x98/0xd4) [<c0316fc0>] (usb_giveback_urb_bh) from [<c0042e44>] (tasklet_hi_action+0x9c/0x108) [<c0042e44>] (tasklet_hi_action) from [<c0042380>] (__do_softirq+0x148/0x42c) [<c0042380>] (__do_softirq) from [<c00429cc>] (irq_exit+0xd8/0x114) [<c00429cc>] (irq_exit) from [<c007ae58>] (__handle_domain_irq+0x84/0xdc) [<c007ae58>] (__handle_domain_irq) from [<c000879c>] (omap_intc_handle_irq+0xd8/0xe0) [<c000879c>] (omap_intc_handle_irq) from [<c0014544>] (__irq_svc+0x44/0x7c) Exception stack(0xdf4e7f08 to 0xdf4e7f50) 7f00: debc0b80 df4e7f5c 00000000 00000000 debc0b80 be8da96c 7f20: 00000000 00000128 c000fc84 df4e6000 00000000 df4e7f94 00000004 df4e7f50 7f40: c038ebc0 c038d74c 600f0013 ffffffff [<c0014544>] (__irq_svc) from [<c038d74c>] (___sys_sendmsg.part.29+0x0/0x2e0) [<c038d74c>] (___sys_sendmsg.part.29) from [<c038ec08>] (SyS_sendmsg+0x18/0x1c) [<c038ec08>] (SyS_sendmsg) from [<c000fa00>] (ret_fast_syscall+0x0/0x48) console [ttyUSB0] enabled Fixes: 3669752 ("tty: Replace ldisc locking with ldisc_sem") Cc: stable <stable@vger.kernel.org> Signed-off-by: Johan Hovold <johan@kernel.org>

…he maximum open files The soft maximum number of open files for a calling process is 1024, which is defined as INR_OPEN_CUR in include/uapi/linux/fs.h, and the hard maximum number of open files for a calling process is 4096, which is defined as INR_OPEN_MAX in include/uapi/linux/fs.h. Both INR_OPEN_CUR and INR_OPEN_MAX are used to limit the value of RLIMIT_NOFILE in include/asm-generic/resource.h. And the soft maximum number finally decides the limitation of the maximum files which are allowed to be opened. That is to say a process can use at most 1024 file descriptors for its o pened files, or an EMFILE error will happen. This error can be fixed by increasing the soft maximum number, under the constraint that the soft maximum number can not exceed the hard maximum number, or both soft and hard maximum number should be increased simultaneously with privilege. For perf sched replay, it uses sys_perf_event_open to create the file descriptor for each of the tasks in order to handle information of perf events. That is to say each task needs a unique file descriptor. In x86_64, there may be over 1024 or 4096 tasks correspoinding to the record in perf.data, which causes that no enough file descriptors can be used. As a result, EMFILE error happens and stops the replay process. To solve this problem, we adaptively increase the soft and hard maximum number of open files with a '-f' option. Example: Test environment: x86_64 with 160 cores $ cat /proc/sys/kernel/pid_max 163840 $ cat /proc/sys/fs/file-max 6815744 $ ulimit -Sn 1024 $ ulimit -Hn 4096 Before this patch: $ perf sched replay ... task 1549 ( :163132: 163132), nr_events: 1 task 1550 ( :163540: 163540), nr_events: 1 task 1551 ( <unknown>: 0), nr_events: 10 Error: sys_perf_event_open() syscall returned with -1 (Too many open files) After this patch: $ perf sched replay ... task 1549 ( :163132: 163132), nr_events: 1 task 1550 ( :163540: 163540), nr_events: 1 task 1551 ( <unknown>: 0), nr_events: 10 Error: sys_perf_event_open() syscall returned with -1 (Too many open files) Have a try with -f option $ perf sched replay -f ... task 1549 ( :163132: 163132), nr_events: 1 task 1550 ( :163540: 163540), nr_events: 1 task 1551 ( <unknown>: 0), nr_events: 10 ------------------------------------------------------------ #1 : 54.401, ravg: 54.40, cpu: 3285.21 / 3285.21 #2 : 199.548, ravg: 68.92, cpu: 4999.65 / 3456.66 #3 : 170.483, ravg: 79.07, cpu: 1349.94 / 3245.99 #4 : 192.034, ravg: 90.37, cpu: 1322.88 / 3053.67 #5 : 182.929, ravg: 99.62, cpu: 1406.51 / 2888.96 #6 : 152.974, ravg: 104.96, cpu: 1167.54 / 2716.82 #7 : 155.579, ravg: 110.02, cpu: 2992.53 / 2744.39 #8 : 130.557, ravg: 112.08, cpu: 1126.43 / 2582.59 #9 : 138.520, ravg: 114.72, cpu: 1253.22 / 2449.65 #10 : 134.328, ravg: 116.68, cpu: 1587.95 / 2363.48 Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427809596-29559-8-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Enable to use perf.data when it is not owned by current user or root. Example: $ ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 5321918 Mar 25 15:14 perf.data $ sudo id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: $ sudo perf sched replay -f run measurement overhead: 98 nsecs sleep measurement overhead: 52909 nsecs the run test took 1000015 nsecs the sleep test took 1054253 nsecs File perf.data not owned by current user or root (use -f to override) As shown above, the -f option does not work at all. After this patch: $ sudo perf sched replay -f run measurement overhead: 221 nsecs sleep measurement overhead: 40514 nsecs the run test took 1000003 nsecs the sleep test took 1056098 nsecs nr_run_events: 10 nr_sleep_events: 1562 nr_wakeup_events: 5 task 0 ( :1: 1), nr_events: 1 task 1 ( :2: 2), nr_events: 1 task 2 ( :3: 3), nr_events: 1 ... ... task 1549 ( :163132: 163132), nr_events: 1 task 1550 ( :163540: 163540), nr_events: 1 task 1551 ( <unknown>: 0), nr_events: 10 ------------------------------------------------------------ #1 : 50.198, ravg: 50.20, cpu: 2335.18 / 2335.18 #2 : 219.099, ravg: 67.09, cpu: 2835.11 / 2385.17 #3 : 238.626, ravg: 84.24, cpu: 3278.26 / 2474.48 #4 : 200.364, ravg: 95.85, cpu: 2977.41 / 2524.77 #5 : 176.882, ravg: 103.96, cpu: 2801.35 / 2552.43 #6 : 191.093, ravg: 112.67, cpu: 2813.70 / 2578.56 #7 : 189.448, ravg: 120.35, cpu: 2809.21 / 2601.62 #8 : 200.637, ravg: 128.38, cpu: 2849.91 / 2626.45 #9 : 248.338, ravg: 140.37, cpu: 4380.61 / 2801.87 #10 : 511.139, ravg: 177.45, cpu: 3077.73 / 2829.45 As shown above, the -f option really works now. Besides for replay, -f option can also work for latency and map. Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427809596-29559-9-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

SMP blocks are configured for specific client IDs (ports). These client IDs can be different from one chip to another for a given pipe. e.g.: DMA0 pipe fetch Y component is connected to: - port #10 for MDP5 v1.3 - port #4 for MDP5 v1.6 In order to be compatible for upcoming versions of MDP5, the client ID list is passed through the MDP5 config module rather than using a list of hard-coded enum values. Signed-off-by: Stephane Viau <sviau@codeaurora.org> Signed-off-by: Rob Clark <robdclark@gmail.com>

Fix the following warning by initializing necessary fields in the dma_device structure. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at drivers/dma/dmaengine.c:863 dma_async_device_register+0x2b4/0x4f0() this driver doesn't support generic slave capabilities reporting Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 4.0.0-rc5+ #10 Hardware name: Sharp-Collie [<c0105cd8>] (unwind_backtrace) from [<c0103ef8>] (show_stack+0x10/0x14) [<c0103ef8>] (show_stack) from [<c010e9b8>] (warn_slowpath_common+0x74/0xac) [<c010e9b8>] (warn_slowpath_common) from [<c010ea20>] (warn_slowpath_fmt+0x30/0x40) [<c010ea20>] (warn_slowpath_fmt) from [<c02956fc>] (dma_async_device_register+0x2b4/0x4f0) [<c02956fc>] (dma_async_device_register) from [<c0296a9c>] (sa11x0_dma_probe+0x21c/0x358) [<c0296a9c>] (sa11x0_dma_probe) from [<c02c52c0>] (platform_drv_probe+0x30/0x94) [<c02c52c0>] (platform_drv_probe) from [<c02c39bc>] (driver_probe_device+0x84/0x234) [<c02c39bc>] (driver_probe_device) from [<c02c3c4c>] (__driver_attach+0x98/0x9c) [<c02c3c4c>] (__driver_attach) from [<c02c1f9c>] (bus_for_each_dev+0x74/0xa4) [<c02c1f9c>] (bus_for_each_dev) from [<c02c3230>] (bus_add_driver+0x13c/0x1e8) [<c02c3230>] (bus_add_driver) from [<c02c4260>] (driver_register+0x78/0xf8) [<c02c4260>] (driver_register) from [<c0100624>] (do_one_initcall+0x84/0x1f4) [<c0100624>] (do_one_initcall) from [<c0700e1c>] (kernel_init_freeable+0xf8/0x1b4) [<c0700e1c>] (kernel_init_freeable) from [<c040a920>] (kernel_init+0x8/0xf0) [<c040a920>] (kernel_init) from [<c01013a8>] (ret_from_fork+0x14/0x2c) ---[ end trace e188b8fe0e782e75 ]--- Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Vinod Koul <vinod.koul@intel.com>

…nterface When cpsw's number of slave is set to 1 in device tree and while accessing second slave ndev and priv in cpsw_tx_interrupt(), there is a kernel crash. This is due to cpsw_get_slave_priv() not verifying number of slaves while retriving netdev priv and returns a invalid memory region. Fixing the issue by introducing number of slave check in cpsw_get_slave_priv() and cpsw_get_slave_ndev(). [ 15.879589] Unable to handle kernel paging request at virtual address 0f0e142c [ 15.888540] pgd = ed374000 [ 15.891359] [0f0e142c] *pgd=00000000 [ 15.895105] Internal error: Oops: 5 [#1] SMP ARM [ 15.899936] Modules linked in: [ 15.903139] CPU: 0 PID: 593 Comm: udhcpc Tainted: G W 4.1.0-12205-gfda8b18-dirty #10 [ 15.912386] Hardware name: Generic AM43 (Flattened Device Tree) [ 15.918557] task: ed2a2e00 ti: ed3fe000 task.ti: ed3fe000 [ 15.924187] PC is at cpsw_tx_interrupt+0x30/0x44 [ 15.929008] LR is at _raw_spin_unlock_irqrestore+0x40/0x44 [ 15.934726] pc : [<c048b9cc>] lr : [<c05ef4f4>] psr: 20000193 [ 15.934726] sp : ed3ffc08 ip : ed2a2e40 fp : 00000000 [ 15.946685] r10: c0969ce8 r9 : c0969cfc r8 : 00000000 [ 15.952129] r7 : 000000c6 r6 : ee54ab00 r5 : ee169c64 r4 : ee534e00 [ 15.958932] r3 : 0f0e0d0c r2 : 00000000 r1 : ed3ffbc0 r0 : 00000001 [ 15.965735] Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user [ 15.973261] Control: 10c5387d Table: ad374059 DAC: 00000015 [ 15.979246] Process udhcpc (pid: 593, stack limit = 0xed3fe218) [ 15.985414] Stack: (0xed3ffc08 to 0xed400000) [ 15.989954] fc00: ee54ab00 c009928c c0a9e648 60000193 000032e4 ee169c00 [ 15.998478] fc20: ee169c64 ee169c00 ee169c64 ee54ab00 00000001 00000001 ee67e268 ee008800 [ 16.006995] fc40: ee534800 c009946c ee169c00 ee169c64 c08bd660 c009c370 c009c2a4 000000c6 [ 16.015513] fc60: c08b75c4 c08b0854 00000000 c0098b3c 000000c6 c0098c50 ed3ffcb0 0000003a [ 16.024033] fc80: ed3ffcb0 fa24010c c08b7800 fa240100 ee7e9880 c00094c4 c05ef4e8 60000013 [ 16.032556] fca0: ffffffff ed3ffce4 ee7e9880 c05ef964 00000001 ed2a33d8 00000000 ed2a2e00 [ 16.041080] fcc0: 60000013 ee536bf8 60000013 ee51b800 ee7e9880 ee67e268 ee7e9880 ee534800 [ 16.049603] fce0: c0ad0768 ed3ffcf8 c008e910 c05ef4e8 60000013 ffffffff 00000001 00000001 [ 16.058121] fd00: ee536bf8 c0487a04 00000000 00000000 ee534800 00000000 00000156 c048c990 [ 16.066645] fd20: 00000000 00000000 c0969f40 00000000 00000000 c05000e8 00000001 00000000 [ 16.075167] fd40: 00000000 c051eefc 00000000 ee67e268 00000000 00000000 ee51b800 ed3ffd9c [ 16.083690] fd60: 00000000 ee67e200 ee51b800 ee7e9880 ee67e268 00000000 00000000 ee67e200 [ 16.092211] fd80: ee51b800 ee7e9880 ee67e268 ee534800 ee67e200 c051eedc ee67e268 00000010 [ 16.100727] fda0: 00000000 00000000 ee7e9880 ee534800 00000000 ee67e268 ee51b800 c05006fc [ 16.109247] fdc0: ee67e268 00000001 c0500488 00000156 ee7e9880 00000000 ed3fe000 fffffff4 [ 16.117771] fde0: ed3fff1c ee7e9880 ee534800 00000148 00000000 ed1f8340 00000000 00000000 [ 16.126289] fe00: 00000000 c05a9054 00000000 00000000 00000156 c0ab62a8 00000010 ed3e7000 [ 16.134812] fe20: 00000000 00000008 edcfb700 ed3fff1c c0fb5f94 ed2a2e00 c0fb5f64 000005d8 [ 16.143336] fe40: c0a9b3b8 00000000 ed3e7070 00000000 00000000 00000000 00009f40 00000000 [ 16.151858] fe60: 00000000 00020022 00110008 00000000 00000000 43004400 00000000 ffffffff [ 16.160374] fe80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 16.168898] fea0: edcfb700 bee5f380 00000014 00000000 ed3fe000 00000000 00004400 c04e2b64 [ 16.177415] fec0: 00000002 c04e3b00 ed3ffeec 00000001 0000011a 00000000 00000000 bee5f394 [ 16.185937] fee0: 00000148 ed3fff10 00000014 00000001 00000000 00000000 ed3ffee4 00000000 [ 16.194459] ff00: 00000000 00000000 00000000 c04e3664 00080011 00000002 06000000 ffffffff [ 16.202980] ff20: 0000ffff ffffffff 0000ffff c008dd54 ee5a6f08 ee636e8 c096972d c0089c14 [ 16.211499] ff40: 00000000 60000013 ee5a6f40 60000013 00000000 ee5a6f40 00000002 00000006 [ 16.220023] ff60: 00000000 edcfb700 00000001 ed2a2e00 c000f60c 00000001 0000011a c008ea34 [ 16.228540] ff80: 00000006 00000000 bee5f380 00000014 bee5f380 00000014 bee5f380 00000122 [ 16.237059] ffa0: c000f7c4 c000f5e0 bee5f380 00000014 00000006 bee5f394 00000148 00000000 [ 16.245581] ffc0: bee5f380 00000014 bee5f380 00000122 fffffd6e 00004300 00004800 00004400 [ 16.254104] ffe0: bee5f378 bee5f36c 000307ec b6f39044 40000010 00000006 ed36fa40 00000000 [ 16.262642] [<c048b9cc>] (cpsw_tx_interrupt) from [<c009928c>] (handle_irq_event_percpu+0x64/0x204) [ 16.272076] [<c009928c>] (handle_irq_event_percpu) from [<c009946c>] (handle_irq_event+0x40/0x64) [ 16.281330] [<c009946c>] (handle_irq_event) from [<c009c370>] (handle_fasteoi_irq+0xcc/0x1a8) [ 16.290220] [<c009c370>] (handle_fasteoi_irq) from [<c0098b3c>] (generic_handle_irq+0x20/0x30) [ 16.299197] [<c0098b3c>] (generic_handle_irq) from [<c0098c50>] (__handle_domain_irq+0x64/0xdc) [ 16.308273] [<c0098c50>] (__handle_domain_irq) from [<c00094c4>] (gic_handle_irq+0x20/0x60) [ 16.316987] [<c00094c4>] (gic_handle_irq) from [<c05ef964>] (__irq_svc+0x44/0x5c) [ 16.324779] Exception stack(0xed3ffcb0 to 0xed3ffcf8) [ 16.330044] fca0: 00000001 ed2a33d8 00000000 ed2a2e00 [ 16.338567] fcc0: 60000013 ee536bf8 60000013 ee51b800 ee7e9880 ee67e268 ee7e9880 ee534800 [ 16.347090] fce0: c0ad0768 ed3ffcf8 c008e910 c05ef4e8 60000013 ffffffff [ 16.353987] [<c05ef964>] (__irq_svc) from [<c05ef4e8>] (_raw_spin_unlock_irqrestore+0x34/0x44) [ 16.362973] [<c05ef4e8>] (_raw_spin_unlock_irqrestore) from [<c0487a04>] (cpdma_check_free_tx_desc+0x60/0x6c) [ 16.373311] [<c0487a04>] (cpdma_check_free_tx_desc) from [<c048c990>] (cpsw_ndo_start_xmit+0xb4/0x1ac) [ 16.383017] [<c048c990>] (cpsw_ndo_start_xmit) from [<c05000e8>] (dev_hard_start_xmit+0x2a4/0x4c0) [ 16.392364] [<c05000e8>] (dev_hard_start_xmit) from [<c051eedc>] (sch_direct_xmit+0xf4/0x210) [ 16.401246] [<c051eedc>] (sch_direct_xmit) from [<c05006fc>] (__dev_queue_xmit+0x2ac/0x7bc) [ 16.409960] [<c05006fc>] (__dev_queue_xmit) from [<c05a9054>] (packet_sendmsg+0xc68/0xeb4) [ 16.418585] [<c05a9054>] (packet_sendmsg) from [<c04e2b64>] (sock_sendmsg+0x14/0x24) [ 16.426663] [<c04e2b64>] (sock_sendmsg) from [<c04e3b00>] (SyS_sendto+0xb4/0xe0) [ 16.434377] [<c04e3b00>] (SyS_sendto) from [<c000f5e0>] (ret_fast_syscall+0x0/0x54) [ 16.442360] Code: e5943118 e593303c e3530000 0a000002 (e5930720) [ 16.448716] ---[ end trace a68159f094d85ba6 ]--- [ 16.453526] Kernel panic - not syncing: Fatal exception in interrupt [ 16.460149] ---[ end Kernel panic - not syncing: Fatal exception in interrupt Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com> Cc: <stable@vger.kernel.org> # v3.8+ Signed-off-by: David S. Miller <davem@davemloft.net>

…7305/MC7355 Sierra Wireless MC7305/MC7355 with USB ID 1199:9041 also provide a second QMI/network interface like the MC73xx with USB ID 1199:68c0 on USB interface #10 when used in the appropriate USB configuration. Add the corresponding QMI_FIXED_INTF entry to the qmi_wwan driver. Please note that the second QMI/network interface is not working for early MC73xx firmware versions like 01.08.x as the device does not respond to QMI messages on the second /dev/cdc-wdm port. Signed-off-by: Reinhard Speyerer <rspmn@arcor.de> Signed-off-by: David S. Miller <davem@davemloft.net>

Nikolay has reported a hang when a memcg reclaim got stuck with the following backtrace: PID: 18308 TASK: ffff883d7c9b0a30 CPU: 1 COMMAND: "rsync" #0 __schedule at ffffffff815ab152 #1 schedule at ffffffff815ab76e #2 schedule_timeout at ffffffff815ae5e5 #3 io_schedule_timeout at ffffffff815aad6a #4 bit_wait_io at ffffffff815abfc6 #5 __wait_on_bit at ffffffff815abda5 #6 wait_on_page_bit at ffffffff8111fd4f #7 shrink_page_list at ffffffff81135445 #8 shrink_inactive_list at ffffffff81135845 #9 shrink_lruvec at ffffffff81135ead #10 shrink_zone at ffffffff811360c3 #11 shrink_zones at ffffffff81136eff #12 do_try_to_free_pages at ffffffff8113712f #13 try_to_free_mem_cgroup_pages at ffffffff811372be #14 try_charge at ffffffff81189423 #15 mem_cgroup_try_charge at ffffffff8118c6f5 #16 __add_to_page_cache_locked at ffffffff8112137d #17 add_to_page_cache_lru at ffffffff81121618 #18 pagecache_get_page at ffffffff8112170b #19 grow_dev_page at ffffffff811c8297 #20 __getblk_slow at ffffffff811c91d6 #21 __getblk_gfp at ffffffff811c92c1 #22 ext4_ext_grow_indepth at ffffffff8124565c #23 ext4_ext_create_new_leaf at ffffffff81246ca8 #24 ext4_ext_insert_extent at ffffffff81246f09 #25 ext4_ext_map_blocks at ffffffff8124a848 #26 ext4_map_blocks at ffffffff8121a5b7 #27 mpage_map_one_extent at ffffffff8121b1fa #28 mpage_map_and_submit_extent at ffffffff8121f07b #29 ext4_writepages at ffffffff8121f6d5 #30 do_writepages at ffffffff8112c490 #31 __filemap_fdatawrite_range at ffffffff81120199 #32 filemap_flush at ffffffff8112041c #33 ext4_alloc_da_blocks at ffffffff81219da1 #34 ext4_rename at ffffffff81229b91 #35 ext4_rename2 at ffffffff81229e32 #36 vfs_rename at ffffffff811a08a5 #37 SYSC_renameat2 at ffffffff811a3ffc #38 sys_renameat2 at ffffffff811a408e #39 sys_rename at ffffffff8119e51e #40 system_call_fastpath at ffffffff815afa89 Dave Chinner has properly pointed out that this is a deadlock in the reclaim code because ext4 doesn't submit pages which are marked by PG_writeback right away. The heuristic was introduced by commit e62e384 ("memcg: prevent OOM with too many dirty pages") and it was applied only when may_enter_fs was specified. The code has been changed by c3b94f4 ("memcg: further prevent OOM with too many dirty pages") which has removed the __GFP_FS restriction with a reasoning that we do not get into the fs code. But this is not sufficient apparently because the fs doesn't necessarily submit pages marked PG_writeback for IO right away. ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily submit the bio. Instead it tries to map more pages into the bio and mpage_map_one_extent might trigger memcg charge which might end up waiting on a page which is marked PG_writeback but hasn't been submitted yet so we would end up waiting for something that never finishes. Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2) before we go to wait on the writeback. The page fault path, which is the only path that triggers memcg oom killer since 3.12, shouldn't require GFP_NOFS and so we shouldn't reintroduce the premature OOM killer issue which was originally addressed by the heuristic. As per David Chinner the xfs is doing similar thing since 2.6.15 already so ext4 is not the only affected filesystem. Moreover he notes: : For example: IO completion might require unwritten extent conversion : which executes filesystem transactions and GFP_NOFS allocations. The : writeback flag on the pages can not be cleared until unwritten : extent conversion completes. Hence memory reclaim cannot wait on : page writeback to complete in GFP_NOFS context because it is not : safe to do so, memcg reclaim or otherwise. Cc: stable@vger.kernel.org # 3.9+ [tytso@mit.edu: corrected the control flow] Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages") Reported-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Alex reported the following crash when using fq_codel with htb: crash> bt PID: 630839 TASK: ffff8823c990d280 CPU: 14 COMMAND: "tc" [... snip ...] #8 [ffff8820ceec17a0] page_fault at ffffffff8160a8c2 [exception RIP: htb_qlen_notify+24] RIP: ffffffffa0841718 RSP: ffff8820ceec1858 RFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88241747b400 RDX: ffff88241747b408 RSI: 0000000000000000 RDI: ffff8811fb27d000 RBP: ffff8820ceec1868 R8: ffff88120cdeff24 R9: ffff88120cdeff30 R10: 0000000000000bd4 R11: ffffffffa0840919 R12: ffffffffa0843340 R13: 0000000000000000 R14: 0000000000000001 R15: ffff8808dae5c2e8 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #9 [...] qdisc_tree_decrease_qlen at ffffffff81565375 #10 [...] fq_codel_dequeue at ffffffffa084e0a0 [sch_fq_codel] #11 [...] fq_codel_reset at ffffffffa084e2f8 [sch_fq_codel] #12 [...] qdisc_destroy at ffffffff81560d2d #13 [...] htb_destroy_class at ffffffffa08408f8 [sch_htb] #14 [...] htb_put at ffffffffa084095c [sch_htb] #15 [...] tc_ctl_tclass at ffffffff815645a3 #16 [...] rtnetlink_rcv_msg at ffffffff81552cb0 [... snip ...] As Jamal pointed out, there is actually no need to call dequeue to purge the queued skb's in reset, data structures can be just reset explicitly. Therefore, we reset everything except config's and stats, so that we would have a fresh start after device flipping. Fixes: 4b549a2 ("fq_codel: Fair Queue Codel AQM") Reported-by: Alex Gartrell <agartrell@fb.com> Cc: Alex Gartrell <agartrell@fb.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> [xiyou.wangcong@gmail.com: added codel_vars_init() and qdisc_qstats_backlog_dec()] Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

PID: 614 TASK: ffff882a739da580 CPU: 3 COMMAND: "ocfs2dc" #0 [ffff882ecc3759b0] machine_kexec at ffffffff8103b35d #1 [ffff882ecc375a20] crash_kexec at ffffffff810b95b5 #2 [ffff882ecc375af0] oops_end at ffffffff815091d8 #3 [ffff882ecc375b20] die at ffffffff8101868b #4 [ffff882ecc375b50] do_trap at ffffffff81508bb0 #5 [ffff882ecc375ba0] do_invalid_op at ffffffff810165e5 #6 [ffff882ecc375c40] invalid_op at ffffffff815116fb [exception RIP: ocfs2_ci_checkpointed+208] RIP: ffffffffa0a7e940 RSP: ffff882ecc375cf0 RFLAGS: 00010002 RAX: 0000000000000001 RBX: 000000000000654b RCX: ffff8812dc83f1f8 RDX: 00000000000017d9 RSI: ffff8812dc83f1f8 RDI: ffffffffa0b2c318 RBP: ffff882ecc375d20 R8: ffff882ef6ecfa60 R9: ffff88301f272200 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffffffffff R13: ffff8812dc83f4f0 R14: 0000000000000000 R15: ffff8812dc83f1f8 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff882ecc375d28] ocfs2_check_meta_downconvert at ffffffffa0a7edbd [ocfs2] #8 [ffff882ecc375d38] ocfs2_unblock_lock at ffffffffa0a84af8 [ocfs2] #9 [ffff882ecc375dc8] ocfs2_process_blocked_lock at ffffffffa0a85285 [ocfs2] #10 [ffff882ecc375e18] ocfs2_downconvert_thread_do_work at ffffffffa0a85445 [ocfs2] #11 [ffff882ecc375e68] ocfs2_downconvert_thread at ffffffffa0a854de [ocfs2] #12 [ffff882ecc375ee8] kthread at ffffffff81090da7 #13 [ffff882ecc375f48] kernel_thread_helper at ffffffff81511884 assert is tripped because the tran is not checkpointed and the lock level is PR. Some time ago, chmod command had been executed. As result, the following call chain left the inode cluster lock in PR state, latter on causing the assert. system_call_fastpath -> my_chmod -> sys_chmod -> sys_fchmodat -> notify_change -> ocfs2_setattr -> posix_acl_chmod -> ocfs2_iop_set_acl -> ocfs2_set_acl -> ocfs2_acl_set_mode Here is how. 1119 int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) 1120 { 1247 ocfs2_inode_unlock(inode, 1); <<< WRONG thing to do. .. 1258 if (!status && attr->ia_valid & ATTR_MODE) { 1259 status = posix_acl_chmod(inode, inode->i_mode); 519 posix_acl_chmod(struct inode *inode, umode_t mode) 520 { .. 539 ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS); 287 int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, ... 288 { 289 return ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL); 224 int ocfs2_set_acl(handle_t *handle, 225 struct inode *inode, ... 231 { .. 252 ret = ocfs2_acl_set_mode(inode, di_bh, 253 handle, mode); 168 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head ... 170 { 183 if (handle == NULL) { >>> BUG: inode lock not held in ex at this point <<< 184 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb), 185 OCFS2_INODE_UPDATE_CREDITS); ocfs2_setattr.#1247 we unlock and at #1259 call posix_acl_chmod. When we reach ocfs2_acl_set_mode.torvalds#181 and do trans, the inode cluster lock is not held in EX mode (it should be). How this could have happended? We are the lock master, were holding lock EX and have released it in ocfs2_setattr.#1247. Note that there are no holders of this lock at this point. Another node needs the lock in PR, and we downconvert from EX to PR. So the inode lock is PR when do the trans in ocfs2_acl_set_mode.torvalds#184. The trans stays in core (not flushed to disc). Now another node want the lock in EX, downconvert thread gets kicked (the one that tripped assert abovt), finds an unflushed trans but the lock is not EX (it is PR). If the lock was at EX, it would have flushed the trans ocfs2_ci_checkpointed -> ocfs2_start_checkpoint before downconverting (to NULL) for the request. ocfs2_setattr must not drop inode lock ex in this code path. If it does, takes it again before the trans, say in ocfs2_set_acl, another cluster node can get in between, execute another setattr, overwriting the one in progress on this node, resulting in a mode acl size combo that is a mix of the two. Orabug: 20189959 Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Martin KaFai Lau says: ==================== ipv6: Initialize rt6_info properly in ip6_blackhole_route() This patchset ensures the rt6_info's fields are initialized properly in ip6_blackhole_route() where xfrm_policy is the primarily user. The first patch is a prep work. The second patch is the fix. It fixes d52d399 ("ipv6: Create percpu rt6_info"). Here is the oops reported by Phil Sutter <phil@nwl.cc>: BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0 IP: [<ffffffff8171a95e>] __ip6_datagram_connect+0x71e/0xa20 PGD c2cb1067 PUD c2d7a067 PMD 0 Oops: 0000 [#1] PREEMPT SMP Modules linked in: cmac nfs lockd grace sunrpc bridge stp llc nvidia(PO) snd_usb_audio snd_usbmidi_lib iTCO_wdt CPU: 1 PID: 2964 Comm: ping6 Tainted: P O 4.2.1-aufs #10 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./4Core1333-Viiv, BIOS P1.60 07/01/2008 task: ffff8800ca62bc00 ti: ffff880129a14000 task.ti: ffff880129a14000 RIP: 0010:[<ffffffff8171a95e>] [<ffffffff8171a95e>] __ip6_datagram_connect+0x71e/0xa20 RSP: 0018:ffff880129a17da8 EFLAGS: 00010296 RAX: 000000000000000b RBX: 0000000000000000 RCX: 0000000000000006 RDX: 0000000000000007 RSI: 0000000000000246 RDI: ffff88012fc8d5a0 RBP: ffff8800cb9a9048 R08: 756e207369207472 R09: 216c6c756e207369 R10: 0000000000000665 R11: 0000000000000006 R12: ffff8800cb9a8cf8 R13: ffff8800cb9a8cf8 R14: 0000000000000000 R15: ffff8800cb9a8cc0 FS: 00007fb76ad74700(0000) GS:ffff88012fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000a0 CR3: 00000000c2dba000 CR4: 00000000000406e0 Stack: ffff8800cb9a9048 ffff8800cb9a8de0 ffff8800cb9feb70 ffffffff816b2c41 00007fb70000000b ffffea0000df7200 ffff8800cb9f5cfc ffff8800cb9a8cc0 03fffffffe068a20 ffff8800cb9a8cc0 ffffffff817097c0 0000000100000000 Call Trace: [<ffffffff816b2c41>] ? udp_lib_get_port+0x1a1/0x380 [<ffffffff817097c0>] ? udpv6_rcv+0x20/0x20 [<ffffffff8171ac82>] ? ip6_datagram_connect+0x22/0x40 [<ffffffff8163ae9b>] ? SyS_connect+0x6b/0xb0 [<ffffffff810767ac>] ? __do_page_fault+0x15c/0x380 [<ffffffff8163a8d3>] ? SyS_socket+0x63/0xa0 [<ffffffff81741957>] ? entry_SYSCALL_64_fastpath+0x12/0x6a Code: ba ae 00 00 00 48 c7 c6 7b 71 94 81 48 c7 c7 63 71 94 81 e8 6c 0f 02 00 48 85 db 75 0e 48 c7 c7 9f 71 94 81 31 c0 e8 59 0f 02 00 <48> 83 bb a0 00 00 00 00 75 0e 48 c7 c7 ae 71 94 81 31 c0 e8 41 RIP [<ffffffff8171a95e>] __ip6_datagram_connect+0x71e/0xa20 RSP <ffff880129a17da8> CR2: 00000000000000a0 ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

We're consistently hitting deadlocks here with XFS on recent kernels. After some digging through the crash files, it looks like everyone in the system is waiting for XFS to reclaim memory. Something like this: PID: 2733434 TASK: ffff8808cd242800 CPU: 19 COMMAND: "java" #0 [ffff880019c53588] __schedule at ffffffff818c4df2 #1 [ffff880019c535d8] schedule at ffffffff818c5517 #2 [ffff880019c535f8] _xfs_log_force_lsn at ffffffff81316348 #3 [ffff880019c53688] xfs_log_force_lsn at ffffffff813164fb #4 [ffff880019c536b8] xfs_iunpin_wait at ffffffff8130835e #5 [ffff880019c53728] xfs_reclaim_inode at ffffffff812fd453 #6 [ffff880019c53778] xfs_reclaim_inodes_ag at ffffffff812fd8c7 #7 [ffff880019c53928] xfs_reclaim_inodes_nr at ffffffff812fe433 #8 [ffff880019c53958] xfs_fs_free_cached_objects at ffffffff8130d3b9 #9 [ffff880019c53968] super_cache_scan at ffffffff811a6f73 #10 [ffff880019c539c8] shrink_slab at ffffffff811460e6 #11 [ffff880019c53aa8] shrink_zone at ffffffff8114a53f #12 [ffff880019c53b48] do_try_to_free_pages at ffffffff8114a8ba #13 [ffff880019c53be8] try_to_free_pages at ffffffff8114ad5a #14 [ffff880019c53c78] __alloc_pages_nodemask at ffffffff8113e1b8 #15 [ffff880019c53d88] alloc_kmem_pages_node at ffffffff8113e671 #16 [ffff880019c53dd8] copy_process at ffffffff8104f781 #17 [ffff880019c53ec8] do_fork at ffffffff8105129c #18 [ffff880019c53f38] sys_clone at ffffffff810515b6 #19 [ffff880019c53f48] stub_clone at ffffffff818c8e4d xfs_log_force_lsn is waiting for logs to get cleaned, which is waiting for IO, which is waiting for workers to complete the IO which is waiting for worker threads that don't exist yet: PID: 2752451 TASK: ffff880bd6bdda00 CPU: 37 COMMAND: "kworker/37:1" #0 [ffff8808d20abbb0] __schedule at ffffffff818c4df2 #1 [ffff8808d20abc00] schedule at ffffffff818c5517 #2 [ffff8808d20abc20] schedule_timeout at ffffffff818c7c6c #3 [ffff8808d20abcc0] wait_for_completion_killable at ffffffff818c6495 #4 [ffff8808d20abd30] kthread_create_on_node at ffffffff8106ec82 #5 [ffff8808d20abdf0] create_worker at ffffffff8106752f #6 [ffff8808d20abe40] worker_thread at ffffffff810699be #7 [ffff8808d20abec0] kthread at ffffffff8106ef59 #8 [ffff8808d20abf50] ret_from_fork at ffffffff818c8ac8 I think we should be using WQ_MEM_RECLAIM to make sure this thread pool makes progress when we're not able to allocate new workers. [dchinner: make all workqueues WQ_MEM_RECLAIM] Signed-off-by: Chris Mason <clm@fb.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>

Fixes segmentation fault using, for instance: (gdb) run record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls Starting program: /home/acme/bin/perf record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls Missing separate debuginfos, use: dnf debuginfo-install glibc-2.22-7.fc23.x86_64 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". Program received signal SIGSEGV, Segmentation fault. 0 x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410 (gdb) bt #0 0x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410 #1 0x00000000004b9fc5 in add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:433 #2 0x00000000004ba334 in add_tracepoint_event (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:498 #3 0x00000000004bb699 in parse_events_add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys=0x19b1370 "sched", event=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:936 #4 0x00000000004f6eda in parse_events_parse (_data=0x7fffffffb8b0, scanner=0x19a49d0) at util/parse-events.y:391 #5 0x00000000004bc8e5 in parse_events__scanner (str=0x663ff2 "sched:sched_switch", data=0x7fffffffb8b0, start_token=258) at util/parse-events.c:1361 #6 0x00000000004bca57 in parse_events (evlist=0x19a5220, str=0x663ff2 "sched:sched_switch", err=0x0) at util/parse-events.c:1401 #7 0x0000000000518d5f in perf_evlist__can_select_event (evlist=0x19a3b90, str=0x663ff2 "sched:sched_switch") at util/record.c:253 #8 0x0000000000553c42 in intel_pt_track_switches (evlist=0x19a3b90) at arch/x86/util/intel-pt.c:364 #9 0x00000000005549d1 in intel_pt_recording_options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at arch/x86/util/intel-pt.c:664 #10 0x000000000051e076 in auxtrace_record__options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at util/auxtrace.c:539 #11 0x0000000000433368 in cmd_record (argc=1, argv=0x7fffffffde60, prefix=0x0) at builtin-record.c:1264 #12 0x000000000049bec2 in run_builtin (p=0x8fa2a8 <commands+168>, argc=5, argv=0x7fffffffde60) at perf.c:390 #13 0x000000000049c12a in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:451 #14 0x000000000049c278 in run_argv (argcp=0x7fffffffdcbc, argv=0x7fffffffdcb0) at perf.c:495 #15 0x000000000049c60a in main (argc=5, argv=0x7fffffffde60) at perf.c:618 (gdb) Intel PT attempts to find the sched:sched_switch tracepoint but that seg faults if tracefs is not readable, because the error reporting structure is null, as errors are not reported when automatically adding tracepoints. Fix by checking before using. Committer note: This doesn't take place in a kernel that supports perf_event_attr.context_switch, that is the default way that will be used for tracking context switches, only in older kernels, like 4.2, in a machine with Intel PT (e.g. Broadwell) for non-priviledged users. Further info from a similar patch by Wang: The error is in tracepoint_error: it assumes the 'e' parameter is valid. However, there are many situation a parse_event() can be called without parse_events_error. See result of $ grep 'parse_events(.*NULL)' ./tools/perf/ -r' Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Tong Zhang <ztong@vt.edu> Cc: Wang Nan <wangnan0@huawei.com> Cc: stable@vger.kernel.org # v4.4+ Fixes: 1965817 ("perf tools: Enhance parsing events tracepoint error output") Link: http://lkml.kernel.org/r/1453809921-24596-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

…antiated arm:pxa_defconfig can result in the following crash if the max1111 driver is not instantiated. Unhandled fault: page domain fault (0x01b) at 0x00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: : 1b [#1] PREEMPT ARM Modules linked in: CPU: 0 PID: 300 Comm: kworker/0:1 Not tainted 4.5.0-01301-g1701f680407c #10 Hardware name: SHARP Akita Workqueue: events sharpsl_charge_toggle task: c390a000 ti: c391e000 task.ti: c391e000 PC is at max1111_read_channel+0x20/0x30 LR is at sharpsl_pm_pxa_read_max1111+0x2c/0x3c pc : [<c03aaab0>] lr : [<c0024b50>] psr: 20000013 ... [<c03aaab0>] (max1111_read_channel) from [<c0024b50>] (sharpsl_pm_pxa_read_max1111+0x2c/0x3c) [<c0024b50>] (sharpsl_pm_pxa_read_max1111) from [<c00262e0>] (spitzpm_read_devdata+0x5c/0xc4) [<c00262e0>] (spitzpm_read_devdata) from [<c0024094>] (sharpsl_check_battery_temp+0x78/0x110) [<c0024094>] (sharpsl_check_battery_temp) from [<c0024f9c>] (sharpsl_charge_toggle+0x48/0x110) [<c0024f9c>] (sharpsl_charge_toggle) from [<c004429c>] (process_one_work+0x14c/0x48c) [<c004429c>] (process_one_work) from [<c0044618>] (worker_thread+0x3c/0x5d4) [<c0044618>] (worker_thread) from [<c004a238>] (kthread+0xd0/0xec) [<c004a238>] (kthread) from [<c000a670>] (ret_from_fork+0x14/0x24) This can occur because the SPI controller driver (SPI_PXA2XX) is built as module and thus not necessarily loaded. While building SPI_PXA2XX into the kernel would make the problem disappear, it appears prudent to ensure that the driver is instantiated before accessing its data structures. Cc: Arnd Bergmann <arnd@arndb.de> Cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck <linux@roeck-us.net>

…rive This patch fixes Machine Check "Data Write PLB Error" which happens when libata-sff's ata_sff_dev_select is trying to write into the device_addr in order to select a drive. However, SATA has no master or slave devices like the old ATA Bus, therefore selecting a different drive is kind of pointless. Data Write PLB Error Oops: Machine check, sig: 7 [#1] PowerPC 44x Platform Modules linked in: CPU: 0 PID: 508 Comm: scsi_eh_0 Not tainted 4.6.0-rc3-next-20160412+ #10 [...] NIP [c027e820] ata_sff_dev_select+0x3c/0x44 LR [c027e810] ata_sff_dev_select+0x2c/0x44 Call Trace: [cec31cd0] [c027da00] ata_sff_postreset+0x40/0xb4 (unreliable) [cec31ce0] [c027a03c] ata_eh_reset+0x5cc/0x928 [cec31d60] [c027a840] ata_eh_recover+0x330/0x10bc [cec31df0] [c027bae0] ata_do_eh+0x4c/0xa4 [...] Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Signed-off-by: Tejun Heo <tj@kernel.org>

Function ib_create_qp() was failing to return an error when rdma_rw_init_mrs() fails, causing a crash further down in ib_create_qp() when trying to dereferece the qp pointer which was actually a negative errno. The crash: crash> log|grep BUG [ 136.458121] BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 crash> bt PID: 3736 TASK: ffff8808543215c0 CPU: 2 COMMAND: "kworker/u64:2" #0 [ffff88084d323340] machine_kexec at ffffffff8105fbb0 #1 [ffff88084d3233b0] __crash_kexec at ffffffff81116758 #2 [ffff88084d323480] crash_kexec at ffffffff8111682d #3 [ffff88084d3234b0] oops_end at ffffffff81032bd6 #4 [ffff88084d3234e0] no_context at ffffffff8106e431 #5 [ffff88084d323530] __bad_area_nosemaphore at ffffffff8106e610 #6 [ffff88084d323590] bad_area_nosemaphore at ffffffff8106e6f4 #7 [ffff88084d3235a0] __do_page_fault at ffffffff8106ebdc #8 [ffff88084d323620] do_page_fault at ffffffff8106f057 #9 [ffff88084d323660] page_fault at ffffffff816e3148 [exception RIP: ib_create_qp+427] RIP: ffffffffa02554fb RSP: ffff88084d323718 RFLAGS: 00010246 RAX: 0000000000000004 RBX: fffffffffffffff4 RCX: 000000018020001f RDX: ffff880830997fc0 RSI: 0000000000000001 RDI: ffff88085f407200 RBP: ffff88084d323778 R8: 0000000000000001 R9: ffffea0020bae210 R10: ffffea0020bae218 R11: 0000000000000001 R12: ffff88084d3237c8 R13: 00000000fffffff4 R14: ffff880859fa5000 R15: ffff88082eb89800 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #10 [ffff88084d323780] rdma_create_qp at ffffffffa0782681 [rdma_cm] #11 [ffff88084d3237b0] nvmet_rdma_create_queue_ib at ffffffffa07c43f3 [nvmet_rdma] #12 [ffff88084d323860] nvmet_rdma_alloc_queue at ffffffffa07c5ba9 [nvmet_rdma] #13 [ffff88084d323900] nvmet_rdma_queue_connect at ffffffffa07c5c96 [nvmet_rdma] #14 [ffff88084d323980] nvmet_rdma_cm_handler at ffffffffa07c6450 [nvmet_rdma] #15 [ffff88084d3239b0] iw_conn_req_handler at ffffffffa0787480 [rdma_cm] #16 [ffff88084d323a60] cm_conn_req_handler at ffffffffa0775f06 [iw_cm] #17 [ffff88084d323ab0] process_event at ffffffffa0776019 [iw_cm] #18 [ffff88084d323af0] cm_work_handler at ffffffffa0776170 [iw_cm] #19 [ffff88084d323cb0] process_one_work at ffffffff810a1483 #20 [ffff88084d323d90] worker_thread at ffffffff810a211d #21 [ffff88084d323ec0] kthread at ffffffff810a6c5c #22 [ffff88084d323f50] ret_from_fork at ffffffff816e1ebf Fixes: 632bc3f ("IB/core, RDMA RW API: Do not exceed QP SGE send limit") Signed-off-by: Steve Wise <swise@opengridcomputing.com> Cc: stable@vger.kernel.org Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Doug Ledford <dledford@redhat.com>

Yuval Mintz says: ==================== qed*: Add XDP support This patch series is intended to add XDP to the qede driver, although it contains quite a bit of cleanups, refactorings and infrastructure changes as well. The content of this series can be roughly divided into: - Datapath improvements - mostly focused on having the datapath utilize parameters which can be more tightly contained in cachelines. Patches #1, #2, #8, #9 belong to this group. - Refactoring - done mostly in favour of XDP. Patches #3, #4, #5, #9. - Infrastructure changes - done in favour of XDP. Paches #6 and #7 belong to this category [#7 being by far the biggest patch in the series]. - Actual XDP support - last two patches [#10, #11]. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

@offset

The HID report buffers that are initially allocated on i2c_hid_probe() might not be big enough to hold the HID reports from a specific device, in which case they will be freed and new ones will be allocated in i2c_hid_start(), at point which the device's report size is known. But at this point ihid->irq is already running, and may call i2c_hid_get_input() which passes ihid->inbuf to i2c_master_recv(). Since this handler runs in a separate thread, ihid->inbuf may be freed at this very moment, and i2c_master_recv() will write on memory which may be already owned by a different part of the kernel, corrupting its data. This problem has been observed on an Asus UX360UA laptop which has an I2C touchpad, and results in a complete system freeze or an unusable slowness with a lof of "BUG: unable to handle kernel paging request at <address>" warnings. Enabling SLUB debugging shows a use-after-free warning on memory allocated in i2c_hid_alloc_buffers() and freed in i2c_hid_free_buffers(): ============================================================================= BUG kmalloc-64 (Not tainted): Poison overwritten ----------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: 0xffff880264083273-0xffff88026408329e. first byte 0x0 instead of 0x6b INFO: Allocated in i2c_hid_alloc_buffers+0x25/0xa0 [i2c_hid] age=35793 cpu=2 pid=430 ___slab_alloc+0x41e/0x460 __slab_alloc+0x20/0x40 __kmalloc+0x210/0x280 i2c_hid_alloc_buffers+0x25/0xa0 [i2c_hid] i2c_hid_probe+0x12f/0x5e0 [i2c_hid] i2c_device_probe+0x10a/0x1b0 driver_probe_device+0x220/0x4a0 __device_attach_driver+0x71/0xa0 bus_for_each_drv+0x67/0xb0 __device_attach+0xdc/0x170 device_initial_probe+0x13/0x20 bus_probe_device+0x92/0xa0 device_add+0x4aa/0x670 device_register+0x1a/0x20 i2c_new_device+0x18e/0x230 acpi_i2c_add_device+0x1a0/0x210 INFO: Freed in i2c_hid_free_buffers+0x16/0x60 [i2c_hid] age=7552 cpu=1 pid=1473 __slab_free+0x221/0x330 kfree+0x139/0x160 i2c_hid_free_buffers+0x16/0x60 [i2c_hid] i2c_hid_start+0x2a9/0x2df [i2c_hid] mt_probe+0x160/0x22e [hid_multitouch] hid_device_probe+0xd7/0x150 [hid] driver_probe_device+0x220/0x4a0 __driver_attach+0x84/0x90 bus_for_each_dev+0x6c/0xc0 driver_attach+0x1e/0x20 bus_add_driver+0x1c3/0x280 driver_register+0x60/0xe0 __hid_register_driver+0x53/0x90 [hid] 0xffffffffc004f01e do_one_initcall+0xb3/0x1f0 do_init_module+0x5f/0x1d0 INFO: Slab 0xffffea0009902080 objects=20 used=20 fp=0x (null) flags=0x17fff8000004080 INFO: Object 0xffff880264083260 @offset=4704 fp=0x (null) Bytes b4 ffff880264083250: 8d e6 fe ff 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a ........ZZZZZZZZ Object ffff880264083260: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object ffff880264083270: 6b 6b 6b 00 00 00 00 00 00 00 00 00 00 00 00 00 kkk............. Object ffff880264083280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffff880264083290: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Redzone ffff8802640832a0: bb bb bb bb bb bb bb bb ........ Padding ffff8802640833e0: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ CPU: 1 PID: 1503 Comm: python3 Tainted: G B 4.4.21+ #10 Hardware name: ASUSTeK COMPUTER INC. UX360UA/UX360UA, BIOS UX360UA.200 05/05/2016 0000000000000086 00000000622d48a2 ffff88026061ba38 ffffffff813f6044 ffff880264082010 ffff880264083260 ffff88026061ba78 ffffffff811e8eab 0000000000000008 ffff880200000001 ffff88026408329f ffff88026a007700 Call Trace: [<ffffffff813f6044>] dump_stack+0x63/0x8f [<ffffffff811e8eab>] print_trailer+0x14b/0x1f0 [<ffffffff811e94c1>] check_bytes_and_report+0xc1/0x100 [<ffffffff811e96c4>] check_object+0x1c4/0x240 [<ffffffff81293fde>] ? ext4_htree_store_dirent+0x3e/0x120 [<ffffffff811e9b44>] alloc_debug_processing+0x104/0x180 [<ffffffff811eb7be>] ___slab_alloc+0x41e/0x460 [<ffffffff81293fde>] ? ext4_htree_store_dirent+0x3e/0x120 [<ffffffff8124590b>] ? __getblk_gfp+0x2b/0x60 [<ffffffff8129b969>] ? ext4_getblk+0xa9/0x190 [<ffffffff811eb820>] __slab_alloc+0x20/0x40 [<ffffffff811ed320>] __kmalloc+0x210/0x280 [<ffffffff81293fde>] ? ext4_htree_store_dirent+0x3e/0x120 [<ffffffff812c1602>] ? ext4fs_dirhash+0xc2/0x2a0 [<ffffffff81293fde>] ext4_htree_store_dirent+0x3e/0x120 [<ffffffff812a4f47>] htree_dirblock_to_tree+0x187/0x1b0 [<ffffffff812a5fd2>] ext4_htree_fill_tree+0xb2/0x2e0 [<ffffffff811ebb7a>] ? kmem_cache_alloc_trace+0x1fa/0x220 [<ffffffff81293e45>] ? ext4_readdir+0x775/0x8b0 [<ffffffff81293cb1>] ext4_readdir+0x5e1/0x8b0 [<ffffffff81221c82>] iterate_dir+0x92/0x120 [<ffffffff81222118>] SyS_getdents+0x98/0x110 [<ffffffff81221d10>] ? iterate_dir+0x120/0x120 [<ffffffff818157f2>] entry_SYSCALL_64_fastpath+0x16/0x71 FIX kmalloc-64: Restoring 0xffff880264083273-0xffff88026408329e=0x6b FIX kmalloc-64: Marking all objects used Signed-off-by: João Paulo Rechi Vita <jprvita@endlessm.com> Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>

There have been several reports over the years of NULL pointer dereferences in xfs_trans_log_inode during xfs_fsr processes, when the process is doing an fput and tearing down extents on the temporary inode, something like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 PID: 29439 TASK: ffff880550584fa0 CPU: 6 COMMAND: "xfs_fsr" [exception RIP: xfs_trans_log_inode+0x10] #9 [ffff8800a57bbbe0] xfs_bunmapi at ffffffffa037398e [xfs] #10 [ffff8800a57bbce8] xfs_itruncate_extents at ffffffffa0391b29 [xfs] #11 [ffff8800a57bbd88] xfs_inactive_truncate at ffffffffa0391d0c [xfs] #12 [ffff8800a57bbdb8] xfs_inactive at ffffffffa0392508 [xfs] #13 [ffff8800a57bbdd8] xfs_fs_evict_inode at ffffffffa035907e [xfs] #14 [ffff8800a57bbe00] evict at ffffffff811e1b67 #15 [ffff8800a57bbe28] iput at ffffffff811e23a5 #16 [ffff8800a57bbe58] dentry_kill at ffffffff811dcfc8 #17 [ffff8800a57bbe88] dput at ffffffff811dd06c #18 [ffff8800a57bbea8] __fput at ffffffff811c823b #19 [ffff8800a57bbef0] ____fput at ffffffff811c846e #20 [ffff8800a57bbf00] task_work_run at ffffffff81093b27 #21 [ffff8800a57bbf30] do_notify_resume at ffffffff81013b0c #22 [ffff8800a57bbf50] int_signal at ffffffff8161405d As it turns out, this is because the i_itemp pointer, along with the d_ops pointer, has been overwritten with zeros when we tear down the extents during truncate. When the in-core inode fork on the temporary inode used by xfs_fsr was originally set up during the extent swap, we mistakenly looked at di_nextents to determine whether all extents fit inline, but this misses extents generated by speculative preallocation; we should be using if_bytes instead. This mistake corrupts the in-memory inode, and code in xfs_iext_remove_inline eventually gets bad inputs, causing it to memmove and memset incorrect ranges; this became apparent because the two values in ifp->if_u2.if_inline_ext[1] contained what should have been in d_ops and i_itemp; they were memmoved due to incorrect array indexing and then the original locations were zeroed with memset, again due to an array overrun. Fix this by properly using i_df.if_bytes to determine the number of extents, not di_nextents. Thanks to dchinner for looking at this with me and spotting the root cause. Cc: stable@vger.kernel.org Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>

As Eric Dumazet pointed out this also needs to be fixed in IPv6. v2: Contains the IPv6 tcp/Ipv6 dccp patches as well. We have seen a few incidents lately where a dst_enty has been freed with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that dst_entry. If the conditions/timings are right a crash then ensues when the freed dst_entry is referenced later on. A Common crashing back trace is: #8 [] page_fault at ffffffff8163e648 [exception RIP: __tcp_ack_snd_check+74] . . #9 [] tcp_rcv_established at ffffffff81580b64 #10 [] tcp_v4_do_rcv at ffffffff8158b54a #11 [] tcp_v4_rcv at ffffffff8158cd02 #12 [] ip_local_deliver_finish at ffffffff815668f4 #13 [] ip_local_deliver at ffffffff81566bd9 #14 [] ip_rcv_finish at ffffffff8156656d #15 [] ip_rcv at ffffffff81566f06 #16 [] __netif_receive_skb_core at ffffffff8152b3a2 #17 [] __netif_receive_skb at ffffffff8152b608 #18 [] netif_receive_skb at ffffffff8152b690 #19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3] #20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3] #21 [] net_rx_action at ffffffff8152bac2 #22 [] __do_softirq at ffffffff81084b4f #23 [] call_softirq at ffffffff8164845c #24 [] do_softirq at ffffffff81016fc5 #25 [] irq_exit at ffffffff81084ee5 #26 [] do_IRQ at ffffffff81648ff8 Of course it may happen with other NIC drivers as well. It's found the freed dst_entry here: 224 static bool tcp_in_quickack_mode(struct sock *sk)↩ 225 {↩ 226 ▹ const struct inet_connection_sock *icsk = inet_csk(sk);↩ 227 ▹ const struct dst_entry *dst = __sk_dst_get(sk);↩ 228 ↩ 229 ▹ return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩ 230 ▹ ▹ (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩ 231 }↩ But there are other backtraces attributed to the same freed dst_entry in netfilter code as well. All the vmcores showed 2 significant clues: - Remote hosts behind the default gateway had always been redirected to a different gateway. A rtable/dst_entry will be added for that host. Making more dst_entrys with lower reference counts. Making this more probable. - All vmcores showed a postitive LockDroppedIcmps value, e.g: LockDroppedIcmps 267 A closer look at the tcp_v4_err() handler revealed that do_redirect() will run regardless of whether user space has the socket locked. This can result in a race condition where the same dst_entry cached in sk->sk_dst_entry can be decremented twice for the same socket via: do_redirect()->__sk_dst_check()-> dst_release(). Which leads to the dst_entry being prematurely freed with another socket pointing to it via sk->sk_dst_cache and a subsequent crash. To fix this skip do_redirect() if usespace has the socket locked. Instead let the redirect take place later when user space does not have the socket locked. The dccp/IPv6 code is very similar in this respect, so fixing it there too. As Eric Garver pointed out the following commit now invalidates routes. Which can set the dst->obsolete flag so that ipv4_dst_check() returns null and triggers the dst_release(). Fixes: ceb3320 ("ipv4: Kill routes during PMTU/redirect updates.") Cc: Eric Garver <egarver@redhat.com> Cc: Hannes Sowa <hsowa@redhat.com> Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

If a given cpu is not in cpu_present and cpu hotplug is disabled, arch can skip setting up the cpu_dev. Arch cpuidle driver should pass correct cpu mask for registration, but failing to do so by the driver causes error to propagate and crash like this: [ 30.076045] Unable to handle kernel paging request for data at address 0x00000048 [ 30.076100] Faulting instruction address: 0xc0000000007b2f30 cpu 0x4d: Vector: 300 (Data Access) at [c000003feb18b670] pc: c0000000007b2f30: kobject_get+0x20/0x70 lr: c0000000007b3c94: kobject_add_internal+0x54/0x3f0 sp: c000003feb18b8f0 msr: 9000000000009033 dar: 48 dsisr: 40000000 current = 0xc000003fd2ed8300 paca = 0xc00000000fbab500 softe: 0 irq_happened: 0x01 pid = 1, comm = swapper/0 Linux version 4.11.0-rc2-svaidy+ (sv@sagarika) (gcc version 6.2.0 20161005 (Ubuntu 6.2.0-5ubuntu12) ) #10 SMP Sun Mar 19 00:08:09 IST 2017 enter ? for help [c000003feb18b960] c0000000007b3c94 kobject_add_internal+0x54/0x3f0 [c000003feb18b9f0] c0000000007b43a4 kobject_init_and_add+0x64/0xa0 [c000003feb18ba70] c000000000e284f4 cpuidle_add_sysfs+0xb4/0x130 [c000003feb18baf0] c000000000e26038 cpuidle_register_device+0x118/0x1c0 [c000003feb18bb30] c000000000e26c48 cpuidle_register+0x78/0x120 [c000003feb18bbc0] c00000000168fd9c powernv_processor_idle_init+0x110/0x1c4 [c000003feb18bc40] c00000000000cff8 do_one_initcall+0x68/0x1d0 [c000003feb18bd00] c0000000016242f4 kernel_init_freeable+0x280/0x360 [c000003feb18bdc0] c00000000000d864 kernel_init+0x24/0x160 [c000003feb18be30] c00000000000b4e8 ret_from_kernel_thread+0x5c/0x74 Validating cpu_dev fixes the crash and reports correct error message like: [ 30.163506] Failed to register cpuidle device for cpu136 [ 30.173329] Registration of powernv driver failed. Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> [ rjw: Comment massage ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

mipsxx_pmu_handle_shared_irq() calls irq_work_run() while holding the pmuint_rwlock for read. irq_work_run() can, via perf_pending_event(), call try_to_wake_up() which can try to take rq->lock. However, perf can also call perf_pmu_enable() (and thus take the pmuint_rwlock for write) while holding the rq->lock, from finish_task_switch() via perf_event_context_sched_in(). This leads to an ABBA deadlock: PID: 3855 TASK: 8f7ce288 CPU: 2 COMMAND: "process" #0 [89c39ac8] __delay at 803b5be4 #1 [89c39ac8] do_raw_spin_lock at 8008fdcc #2 [89c39af8] try_to_wake_up at 8006e47c #3 [89c39b38] pollwake at 8018eab0 #4 [89c39b68] __wake_up_common at 800879f4 #5 [89c39b98] __wake_up at 800880e4 #6 [89c39bc8] perf_event_wakeup at 8012109c #7 [89c39be8] perf_pending_event at 80121184 #8 [89c39c08] irq_work_run_list at 801151f0 #9 [89c39c38] irq_work_run at 80115274 #10 [89c39c50] mipsxx_pmu_handle_shared_irq at 8002cc7c PID: 1481 TASK: 8eaac6a8 CPU: 3 COMMAND: "process" #0 [8de7f900] do_raw_write_lock at 800900e0 #1 [8de7f918] perf_event_context_sched_in at 80122310 #2 [8de7f938] __perf_event_task_sched_in at 80122608 #3 [8de7f958] finish_task_switch at 8006b8a4 #4 [8de7f998] __schedule at 805e4dc4 #5 [8de7f9f8] schedule at 805e5558 #6 [8de7fa10] schedule_hrtimeout_range_clock at 805e9984 #7 [8de7fa70] poll_schedule_timeout at 8018e8f8 #8 [8de7fa88] do_select at 8018f338 #9 [8de7fd88] core_sys_select at 8018f5cc #10 [8de7fee0] sys_select at 8018f854 #11 [8de7ff28] syscall_common at 80028fc8 The lock seems to be there to protect the hardware counters so there is no need to hold it across irq_work_run(). Signed-off-by: Rabin Vincent <rabinv@axis.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Since v4.9 i2c-tiny-usb generates the below call trace and longer works, since it can't communicate with the USB device. The reason is, that since v4.9 the USB stack checks, that the buffer it should transfer is DMA capable. This was a requirement since v2.2 days, but it usually worked nevertheless. [ 17.504959] ------------[ cut here ]------------ [ 17.505488] WARNING: CPU: 0 PID: 93 at drivers/usb/core/hcd.c:1587 usb_hcd_map_urb_for_dma+0x37c/0x570 [ 17.506545] transfer buffer not dma capable [ 17.507022] Modules linked in: [ 17.507370] CPU: 0 PID: 93 Comm: i2cdetect Not tainted 4.11.0-rc8+ #10 [ 17.508103] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 17.509039] Call Trace: [ 17.509320] ? dump_stack+0x5c/0x78 [ 17.509714] ? __warn+0xbe/0xe0 [ 17.510073] ? warn_slowpath_fmt+0x5a/0x80 [ 17.510532] ? nommu_map_sg+0xb0/0xb0 [ 17.510949] ? usb_hcd_map_urb_for_dma+0x37c/0x570 [ 17.511482] ? usb_hcd_submit_urb+0x336/0xab0 [ 17.511976] ? wait_for_completion_timeout+0x12f/0x1a0 [ 17.512549] ? wait_for_completion_timeout+0x65/0x1a0 [ 17.513125] ? usb_start_wait_urb+0x65/0x160 [ 17.513604] ? usb_control_msg+0xdc/0x130 [ 17.514061] ? usb_xfer+0xa4/0x2a0 [ 17.514445] ? __i2c_transfer+0x108/0x3c0 [ 17.514899] ? i2c_transfer+0x57/0xb0 [ 17.515310] ? i2c_smbus_xfer_emulated+0x12f/0x590 [ 17.515851] ? _raw_spin_unlock_irqrestore+0x11/0x20 [ 17.516408] ? i2c_smbus_xfer+0x125/0x330 [ 17.516876] ? i2c_smbus_xfer+0x125/0x330 [ 17.517329] ? i2cdev_ioctl_smbus+0x1c1/0x2b0 [ 17.517824] ? i2cdev_ioctl+0x75/0x1c0 [ 17.518248] ? do_vfs_ioctl+0x9f/0x600 [ 17.518671] ? vfs_write+0x144/0x190 [ 17.519078] ? SyS_ioctl+0x74/0x80 [ 17.519463] ? entry_SYSCALL_64_fastpath+0x1e/0xad [ 17.519959] ---[ end trace d047c04982f5ac50 ]--- Cc: <stable@vger.kernel.org> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Till Harbaum <till@harbaum.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Andre Wild reported the following warning: WARNING: CPU: 2 PID: 1205 at kernel/cpu.c:240 lockdep_assert_cpus_held+0x4c/0x60 Modules linked in: CPU: 2 PID: 1205 Comm: bash Not tainted 4.13.0-rc2-00022-gfd2b2c57ec20 #10 Hardware name: IBM 2964 N96 702 (z/VM 6.4.0) task: 00000000701d8100 task.stack: 0000000073594000 Krnl PSW : 0704f00180000000 0000000000145e24 (lockdep_assert_cpus_held+0x4c/0x60) ... Call Trace: lockdep_assert_cpus_held+0x42/0x60) stop_machine_cpuslocked+0x62/0xf0 build_all_zonelists+0x92/0x150 numa_zonelist_order_handler+0x102/0x150 proc_sys_call_handler.isra.12+0xda/0x118 proc_sys_write+0x34/0x48 __vfs_write+0x3c/0x178 vfs_write+0xbc/0x1a0 SyS_write+0x66/0xc0 system_call+0xc4/0x2b0 locks held by bash/1205: #0: (sb_writers#4){.+.+.+}, at: vfs_write+0xa6/0x1a0 #1: (zl_order_mutex){+.+...}, at: numa_zonelist_order_handler+0x44/0x150 #2: (zonelists_mutex){+.+...}, at: numa_zonelist_order_handler+0xf4/0x150 Last Breaking-Event-Address: lockdep_assert_cpus_held+0x48/0x60 This can be easily triggered with e.g. echo n > /proc/sys/vm/numa_zonelist_order In commit 3f906ba ("mm/memory-hotplug: switch locking to a percpu rwsem") memory hotplug locking was changed to fix a potential deadlock. This also switched the stop_machine() invocation within build_all_zonelists() to stop_machine_cpuslocked() which now expects that online cpus are locked when being called. This assumption is not true if build_all_zonelists() is being called from numa_zonelist_order_handler(). In order to fix this simply add a mem_hotplug_begin()/mem_hotplug_done() pair to numa_zonelist_order_handler(). Link: http://lkml.kernel.org/r/20170726111738.38768-1-heiko.carstens@de.ibm.com Fixes: 3f906ba ("mm/memory-hotplug: switch locking to a percpu rwsem") Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reported-by: Andre Wild <wild@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Based on a syzkaller report [1], I found that a per cpu allocation failure in snmp6_alloc_dev() would then lead to NULL dereference in ip6_route_dev_notify(). It seems this is a very old bug, thus no Fixes tag in this submission. Let's add in6_dev_put_clear() helper, as we will probably use it elsewhere (once available/present in net-next) [1] kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 17294 Comm: syz-executor6 Not tainted 4.13.0-rc2+ #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88019f456680 task.stack: ffff8801c6e58000 RIP: 0010:__read_once_size include/linux/compiler.h:250 [inline] RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:26 [inline] RIP: 0010:refcount_sub_and_test+0x7d/0x1b0 lib/refcount.c:178 RSP: 0018:ffff8801c6e5f1b0 EFLAGS: 00010202 RAX: 0000000000000037 RBX: dffffc0000000000 RCX: ffffc90005d25000 RDX: ffff8801c6e5f218 RSI: ffffffff82342bbf RDI: 0000000000000001 RBP: ffff8801c6e5f240 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10038dcbe37 R13: 0000000000000006 R14: 0000000000000001 R15: 00000000000001b8 FS: 00007f21e0429700(0000) GS:ffff8801dc100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001ddbc22000 CR3: 00000001d632b000 CR4: 00000000001426e0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: refcount_dec_and_test+0x1a/0x20 lib/refcount.c:211 in6_dev_put include/net/addrconf.h:335 [inline] ip6_route_dev_notify+0x1c9/0x4a0 net/ipv6/route.c:3732 notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x51/0x90 net/core/dev.c:1678 call_netdevice_notifiers net/core/dev.c:1694 [inline] rollback_registered_many+0x91c/0xe80 net/core/dev.c:7107 rollback_registered+0x1be/0x3c0 net/core/dev.c:7149 register_netdevice+0xbcd/0xee0 net/core/dev.c:7587 register_netdev+0x1a/0x30 net/core/dev.c:7669 loopback_net_init+0x76/0x160 drivers/net/loopback.c:214 ops_init+0x10a/0x570 net/core/net_namespace.c:118 setup_net+0x313/0x710 net/core/net_namespace.c:294 copy_net_ns+0x27c/0x580 net/core/net_namespace.c:418 create_new_namespaces+0x425/0x880 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xae/0x1e0 kernel/nsproxy.c:206 SYSC_unshare kernel/fork.c:2347 [inline] SyS_unshare+0x653/0xfa0 kernel/fork.c:2297 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x4512c9 RSP: 002b:00007f21e0428c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000718150 RCX: 00000000004512c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062020200 RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004b973d R13: 00000000ffffffff R14: 000000002001d000 R15: 00000000000002dd Code: 50 2b 34 82 c7 00 f1 f1 f1 f1 c7 40 04 04 f2 f2 f2 c7 40 08 f3 f3 f3 f3 e8 a1 43 39 ff 4c 89 f8 48 8b 95 70 ff ff ff 48 c1 e8 03 <0f> b6 0c 18 4c 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 RIP: __read_once_size include/linux/compiler.h:250 [inline] RSP: ffff8801c6e5f1b0 RIP: atomic_read arch/x86/include/asm/atomic.h:26 [inline] RSP: ffff8801c6e5f1b0 RIP: refcount_sub_and_test+0x7d/0x1b0 lib/refcount.c:178 RSP: ffff8801c6e5f1b0 ---[ end trace e441d046c6410d31 ]--- Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>

There is a KASAN slab-out-of-bounds: BUG: KASAN: slab-out-of-bounds in _copy_from_iter_full+0x783/0xaa0 Read of size 80 at addr ffff88810c35e180 by task mount.cifs/539 CPU: 1 PID: 539 Comm: mount.cifs Not tainted 4.19 #10 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0xdd/0x12a print_address_description+0xa7/0x540 kasan_report+0x1ff/0x550 check_memory_region+0x2f1/0x310 memcpy+0x2f/0x80 _copy_from_iter_full+0x783/0xaa0 tcp_sendmsg_locked+0x1840/0x4140 tcp_sendmsg+0x37/0x60 inet_sendmsg+0x18c/0x490 sock_sendmsg+0xae/0x130 smb_send_kvec+0x29c/0x520 __smb_send_rqst+0x3ef/0xc60 smb_send_rqst+0x25a/0x2e0 compound_send_recv+0x9e8/0x2af0 cifs_send_recv+0x24/0x30 SMB2_open+0x35e/0x1620 open_shroot+0x27b/0x490 smb2_open_op_close+0x4e1/0x590 smb2_query_path_info+0x2ac/0x650 cifs_get_inode_info+0x1058/0x28f0 cifs_root_iget+0x3bb/0xf80 cifs_smb3_do_mount+0xe00/0x14c0 cifs_do_mount+0x15/0x20 mount_fs+0x5e/0x290 vfs_kern_mount+0x88/0x460 do_mount+0x398/0x31e0 ksys_mount+0xc6/0x150 __x64_sys_mount+0xea/0x190 do_syscall_64+0x122/0x590 entry_SYSCALL_64_after_hwframe+0x44/0xa9 It can be reproduced by the following step: 1. samba configured with: server max protocol = SMB2_10 2. mount -o vers=default When parse the mount version parameter, the 'ops' and 'vals' was setted to smb30, if negotiate result is smb21, just update the 'ops' to smb21, but the 'vals' is still smb30. When add lease context, the iov_base is allocated with smb21 ops, but the iov_len is initiallited with the smb30. Because the iov_len is longer than iov_base, when send the message, copy array out of bounds. we need to keep the 'ops' and 'vals' consistent. Fixes: 9764c02 ("SMB3: Add support for multidialect negotiate (SMB2.1 and later)") Fixes: d5c7076 ("smb3: add smb3.1.1 to default dialect list") Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

By calling maps__insert() we assume to get 2 references on the map, which we relese within maps__remove call. However if there's already same map name, we currently don't bump the reference and can crash, like: Program received signal SIGABRT, Aborted. 0x00007ffff75e60f5 in raise () from /lib64/libc.so.6 (gdb) bt #0 0x00007ffff75e60f5 in raise () from /lib64/libc.so.6 #1 0x00007ffff75d0895 in abort () from /lib64/libc.so.6 #2 0x00007ffff75d0769 in __assert_fail_base.cold () from /lib64/libc.so.6 #3 0x00007ffff75de596 in __assert_fail () from /lib64/libc.so.6 #4 0x00000000004fc006 in refcount_sub_and_test (i=1, r=0x1224e88) at tools/include/linux/refcount.h:131 #5 refcount_dec_and_test (r=0x1224e88) at tools/include/linux/refcount.h:148 #6 map__put (map=0x1224df0) at util/map.c:299 #7 0x00000000004fdb95 in __maps__remove (map=0x1224df0, maps=0xb17d80) at util/map.c:953 #8 maps__remove (maps=0xb17d80, map=0x1224df0) at util/map.c:959 #9 0x00000000004f7d8a in map_groups__remove (map=<optimized out>, mg=<optimized out>) at util/map_groups.h:65 #10 machine__process_ksymbol_unregister (sample=<optimized out>, event=0x7ffff7279670, machine=<optimized out>) at util/machine.c:728 #11 machine__process_ksymbol (machine=<optimized out>, event=0x7ffff7279670, sample=<optimized out>) at util/machine.c:741 #12 0x00000000004fffbb in perf_session__deliver_event (session=0xb11390, event=0x7ffff7279670, tool=0x7fffffffc7b0, file_offset=13936) at util/session.c:1362 #13 0x00000000005039bb in do_flush (show_progress=false, oe=0xb17e80) at util/ordered-events.c:243 #14 __ordered_events__flush (oe=0xb17e80, how=OE_FLUSH__ROUND, timestamp=<optimized out>) at util/ordered-events.c:322 #15 0x00000000005005e4 in perf_session__process_user_event (session=session@entry=0xb11390, event=event@entry=0x7ffff72a4af8, ... Add the map to the list and getting the reference event if we find the map with same name. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Fixes: 1e62856 ("perf symbols: Fix slowness due to -ffunction-section") Link: http://lkml.kernel.org/r/20190416160127.30203-10-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

bpf/btf write_* functions need ff->ph->env. With this missing, pipe-mode (perf record -o -) would crash like: Program terminated with signal SIGSEGV, Segmentation fault. This patch assign proper ph value to ff. Committer testing: (gdb) run record -o - Starting program: /root/bin/perf record -o - PERFILE2 <SNIP start of perf.data headers> Thread 1 "perf" received signal SIGSEGV, Segmentation fault. __do_write_buf (size=4, buf=0x160, ff=0x7fffffff8f80) at util/header.c:126 126 memcpy(ff->buf + ff->offset, buf, size); (gdb) bt #0 __do_write_buf (size=4, buf=0x160, ff=0x7fffffff8f80) at util/header.c:126 #1 do_write (ff=ff@entry=0x7fffffff8f80, buf=buf@entry=0x160, size=4) at util/header.c:137 #2 0x00000000004eddba in write_bpf_prog_info (ff=0x7fffffff8f80, evlist=<optimized out>) at util/header.c:912 #3 0x00000000004f69d7 in perf_event__synthesize_features (tool=tool@entry=0x97cc00 <record>, session=session@entry=0x7fffe9c6d010, evlist=0x7fffe9cae010, process=process@entry=0x4435d0 <process_synthesized_event>) at util/header.c:3695 #4 0x0000000000443c79 in record__synthesize (tail=tail@entry=false, rec=0x97cc00 <record>) at builtin-record.c:1214 #5 0x0000000000444ec9 in __cmd_record (rec=0x97cc00 <record>, argv=<optimized out>, argc=0) at builtin-record.c:1435 #6 cmd_record (argc=0, argv=<optimized out>) at builtin-record.c:2450 #7 0x00000000004ae3e9 in run_builtin (p=p@entry=0x98e058 <commands+216>, argc=argc@entry=3, argv=0x7fffffffd670) at perf.c:304 #8 0x000000000042eded in handle_internal_command (argv=<optimized out>, argc=<optimized out>) at perf.c:356 #9 run_argv (argcp=<optimized out>, argv=<optimized out>) at perf.c:400 #10 main (argc=3, argv=<optimized out>) at perf.c:522 (gdb) After the patch the SEGSEGV is gone. Reported-by: David Carrillo Cisneros <davidca@fb.com> Signed-off-by: Song Liu <songliubraving@fb.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: kernel-team@fb.com Cc: stable@vger.kernel.org # v5.1+ Fixes: 606f972 ("perf bpf: Save bpf_prog_info information as headers to perf.data") Link: http://lkml.kernel.org/r/20190620010453.4118689-1-songliubraving@fb.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

A deadlock with this stacktrace was observed. The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio shrinker and the shrinker depends on I/O completion in the dm-bufio subsystem. In order to fix the deadlock (and other similar ones), we set the flag PF_MEMALLOC_NOIO at loop thread entry. PID: 474 TASK: ffff8813e11f4600 CPU: 10 COMMAND: "kswapd0" #0 [ffff8813dedfb938] __schedule at ffffffff8173f405 #1 [ffff8813dedfb990] schedule at ffffffff8173fa27 #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186 #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8 #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81 #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio] #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio] #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio] #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778 #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f #13 [ffff8813dedfbec0] kthread at ffffffff810a8428 #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242 PID: 14127 TASK: ffff881455749c00 CPU: 11 COMMAND: "loop1" #0 [ffff88272f5af228] __schedule at ffffffff8173f405 #1 [ffff88272f5af280] schedule at ffffffff8173fa27 #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5 #4 [ffff88272f5af330] mutex_lock at ffffffff81742133 #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio] #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778 #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34 #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8 #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3 #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71 #12 [ffff88272f5af760] new_slab at ffffffff811f4523 #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5 #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3 #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3 #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs] #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994 #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs] #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop] #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop] #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c #23 [ffff88272f5afec0] kthread at ffffffff810a8428 #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>

Revert the commit bd293d0. The proper fix has been made available with commit d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread"). Note that the fix offered by commit bd293d0 doesn't really prevent the deadlock from occuring - if we look at the stacktrace reported by Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex - i.e. it has already successfully taken the mutex. Changing the mutex from mutex_lock to mutex_trylock won't help with deadlocks that happen afterwards. PID: 474 TASK: ffff8813e11f4600 CPU: 10 COMMAND: "kswapd0" #0 [ffff8813dedfb938] __schedule at ffffffff8173f405 #1 [ffff8813dedfb990] schedule at ffffffff8173fa27 #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186 #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8 #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81 #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio] #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio] #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio] #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778 #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f #13 [ffff8813dedfbec0] kthread at ffffffff810a8428 #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Fixes: bd293d0 ("dm bufio: fix deadlock with loop device") Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread") Signed-off-by: Mike Snitzer <snitzer@redhat.com>

There has oops as below happen on i.MX8MP EVK platform that has 6G bytes DDR memory. when (xmit->tail < xmit->head) && (xmit->head == 0), it setups one sg entry with sg->length is zero: sg_set_buf(sgl + 1, xmit->buf, xmit->head); if xmit->buf is allocated from >4G address space, and SDMA only support <4G address space, then dma_map_sg() will call swiotlb_map() to do bounce buffer copying and mapping. But swiotlb_map() don't allow sg entry's length is zero, otherwise report BUG_ON(). So the patch is to correct the tx DMA scatter list. Oops: [ 287.675715] kernel BUG at kernel/dma/swiotlb.c:497! [ 287.680592] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 287.686075] Modules linked in: [ 287.689133] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.3-00016-g3fdc4e0-dirty #10 [ 287.696872] Hardware name: FSL i.MX8MP EVK (DT) [ 287.701402] pstate: 80000085 (Nzcv daIf -PAN -UAO) [ 287.706199] pc : swiotlb_tbl_map_single+0x1fc/0x310 [ 287.711076] lr : swiotlb_map+0x60/0x148 [ 287.714909] sp : ffff800010003c00 [ 287.718221] x29: ffff800010003c00 x28: 0000000000000000 [ 287.723533] x27: 0000000000000040 x26: ffff800011ae0000 [ 287.728844] x25: ffff800011ae09f8 x24: 0000000000000000 [ 287.734155] x23: 00000001b7af9000 x22: 0000000000000000 [ 287.739465] x21: ffff000176409c10 x20: 00000000001f7ffe [ 287.744776] x19: ffff000176409c10 x18: 000000000000002e [ 287.750087] x17: 0000000000000000 x16: 0000000000000000 [ 287.755397] x15: 0000000000000000 x14: 0000000000000000 [ 287.760707] x13: ffff00017f334000 x12: 0000000000000001 [ 287.766018] x11: 00000000001fffff x10: 0000000000000000 [ 287.771328] x9 : 0000000000000003 x8 : 0000000000000000 [ 287.776638] x7 : 0000000000000000 x6 : 0000000000000000 [ 287.781949] x5 : 0000000000200000 x4 : 0000000000000000 [ 287.787259] x3 : 0000000000000001 x2 : 00000001b7af9000 [ 287.792570] x1 : 00000000fbfff000 x0 : 0000000000000000 [ 287.797881] Call trace: [ 287.800328] swiotlb_tbl_map_single+0x1fc/0x310 [ 287.804859] swiotlb_map+0x60/0x148 [ 287.808347] dma_direct_map_page+0xf0/0x130 [ 287.812530] dma_direct_map_sg+0x78/0xe0 [ 287.816453] imx_uart_dma_tx+0x134/0x2f8 [ 287.820374] imx_uart_dma_tx_callback+0xd8/0x168 [ 287.824992] vchan_complete+0x194/0x200 [ 287.828828] tasklet_action_common.isra.0+0x154/0x1a0 [ 287.833879] tasklet_action+0x24/0x30 [ 287.837540] __do_softirq+0x120/0x23c [ 287.841202] irq_exit+0xb8/0xd8 [ 287.844343] __handle_domain_irq+0x64/0xb8 [ 287.848438] gic_handle_irq+0x5c/0x148 [ 287.852185] el1_irq+0xb8/0x180 [ 287.855327] cpuidle_enter_state+0x84/0x360 [ 287.859508] cpuidle_enter+0x34/0x48 [ 287.863083] call_cpuidle+0x18/0x38 [ 287.866571] do_idle+0x1e0/0x280 [ 287.869798] cpu_startup_entry+0x20/0x40 [ 287.873721] rest_init+0xd4/0xe0 [ 287.876949] arch_call_rest_init+0xc/0x14 [ 287.880958] start_kernel+0x420/0x44c [ 287.884622] Code: 9124c021 9417aff8 a94363f7 17ffffd5 (d4210000) [ 287.890718] ---[ end trace 5bc44c4ab6b009ce ]--- [ 287.895334] Kernel panic - not syncing: Fatal exception in interrupt [ 287.901686] SMP: stopping secondary CPUs [ 288.905607] SMP: failed to stop secondary CPUs 0-1 [ 288.910395] Kernel Offset: disabled [ 288.913882] CPU features: 0x0002,2000200c [ 288.917888] Memory Limit: none [ 288.920944] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- Reported-by: Eagle Zhou <eagle.zhou@nxp.com> Tested-by: Eagle Zhou <eagle.zhou@nxp.com> Signed-off-by: Fugang Duan <fugang.duan@nxp.com> Cc: stable <stable@vger.kernel.org> Fixes: 7942f85 ("serial: imx: TX DMA: clean up sg initialization") Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/1581401761-6378-1-git-send-email-fugang.duan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch is to fix a crash: #3 [ffffb6580689f898] oops_end at ffffffffa2835bc2 #4 [ffffb6580689f8b8] no_context at ffffffffa28766e7 #5 [ffffb6580689f920] async_page_fault at ffffffffa320135e [exception RIP: f2fs_is_compressed_page+34] RIP: ffffffffa2ba83a2 RSP: ffffb6580689f9d8 RFLAGS: 00010213 RAX: 0000000000000001 RBX: fffffc0f50b34bc0 RCX: 0000000000002122 RDX: 0000000000002123 RSI: 0000000000000c00 RDI: fffffc0f50b34bc0 RBP: ffff97e815a40178 R8: 0000000000000000 R9: ffff97e83ffc9000 R10: 0000000000032300 R11: 0000000000032380 R12: ffffb6580689fa38 R13: fffffc0f50b34bc0 R14: ffff97e825cbd000 R15: 0000000000000c00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #6 [ffffb6580689f9d8] __is_cp_guaranteed at ffffffffa2b7ea98 #7 [ffffb6580689f9f0] f2fs_submit_page_write at ffffffffa2b81a69 #8 [ffffb6580689fa30] f2fs_do_write_meta_page at ffffffffa2b99777 #9 [ffffb6580689fae0] __f2fs_write_meta_page at ffffffffa2b75f1a #10 [ffffb6580689fb18] f2fs_sync_meta_pages at ffffffffa2b77466 #11 [ffffb6580689fc98] do_checkpoint at ffffffffa2b78e46 #12 [ffffb6580689fd88] f2fs_write_checkpoint at ffffffffa2b79c29 #13 [ffffb6580689fdd0] f2fs_sync_fs at ffffffffa2b69d95 #14 [ffffb6580689fe20] sync_filesystem at ffffffffa2ad2574 #15 [ffffb6580689fe30] generic_shutdown_super at ffffffffa2a9b582 #16 [ffffb6580689fe48] kill_block_super at ffffffffa2a9b6d1 #17 [ffffb6580689fe60] kill_f2fs_super at ffffffffa2b6abe1 #18 [ffffb6580689fea0] deactivate_locked_super at ffffffffa2a9afb6 #19 [ffffb6580689feb8] cleanup_mnt at ffffffffa2abcad4 #20 [ffffb6580689fee0] task_work_run at ffffffffa28bca28 #21 [ffffb6580689ff00] exit_to_usermode_loop at ffffffffa28050b7 #22 [ffffb6580689ff38] do_syscall_64 at ffffffffa280560e #23 [ffffb6580689ff50] entry_SYSCALL_64_after_hwframe at ffffffffa320008c This occurred when umount f2fs if enable F2FS_FS_COMPRESSION with F2FS_IO_TRACE. Fixes it by adding IS_IO_TRACED_PAGE to check validity of pid for page_private. Signed-off-by: Yu Changchun <yuchangchun1@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

https://bugzilla.kernel.org/show_bug.cgi?id=208565 PID: 257 TASK: ecdd0000 CPU: 0 COMMAND: "init" #0 [<c0b420ec>] (__schedule) from [<c0b423c8>] #1 [<c0b423c8>] (schedule) from [<c0b459d4>] #2 [<c0b459d4>] (rwsem_down_read_failed) from [<c0b44fa0>] #3 [<c0b44fa0>] (down_read) from [<c044233c>] #4 [<c044233c>] (f2fs_truncate_blocks) from [<c0442890>] #5 [<c0442890>] (f2fs_truncate) from [<c044d408>] #6 [<c044d408>] (f2fs_evict_inode) from [<c030be18>] #7 [<c030be18>] (evict) from [<c030a558>] #8 [<c030a558>] (iput) from [<c047c600>] #9 [<c047c600>] (f2fs_sync_node_pages) from [<c0465414>] #10 [<c0465414>] (f2fs_write_checkpoint) from [<c04575f4>] #11 [<c04575f4>] (f2fs_sync_fs) from [<c0441918>] #12 [<c0441918>] (f2fs_do_sync_file) from [<c0441098>] #13 [<c0441098>] (f2fs_sync_file) from [<c0323fa0>] #14 [<c0323fa0>] (vfs_fsync_range) from [<c0324294>] #15 [<c0324294>] (do_fsync) from [<c0324014>] #16 [<c0324014>] (sys_fsync) from [<c0108bc0>] This can be caused by flush_dirty_inode() in f2fs_sync_node_pages() where iput() requires f2fs_lock_op() again resulting in livelock. Reported-by: Zhiguo Niu <Zhiguo.Niu@unisoc.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

…s metrics" test Linux 5.9 introduced perf test case "Parse and process metrics" and on s390 this test case always dumps core: [root@t35lp67 perf]# ./perf test -vvvv -F 67 67: Parse and process metrics : --- start --- metric expr inst_retired.any / cpu_clk_unhalted.thread for IPC parsing metric: inst_retired.any / cpu_clk_unhalted.thread Segmentation fault (core dumped) [root@t35lp67 perf]# I debugged this core dump and gdb shows this call chain: (gdb) where #0 0x000003ffabc3192a in __strnlen_c_1 () from /lib64/libc.so.6 #1 0x000003ffabc293de in strcasestr () from /lib64/libc.so.6 #2 0x0000000001102ba2 in match_metric(list=0x1e6ea20 "inst_retired.any", n=<optimized out>) at util/metricgroup.c:368 #3 find_metric (map=<optimized out>, map=<optimized out>, metric=0x1e6ea20 "inst_retired.any") at util/metricgroup.c:765 #4 __resolve_metric (ids=0x0, map=<optimized out>, metric_list=0x0, metric_no_group=<optimized out>, m=<optimized out>) at util/metricgroup.c:844 #5 resolve_metric (ids=0x0, map=0x0, metric_list=0x0, metric_no_group=<optimized out>) at util/metricgroup.c:881 #6 metricgroup__add_metric (metric=<optimized out>, metric_no_group=metric_no_group@entry=false, events=<optimized out>, events@entry=0x3ffd84fb878, metric_list=0x0, metric_list@entry=0x3ffd84fb868, map=0x0) at util/metricgroup.c:943 #7 0x00000000011034ae in metricgroup__add_metric_list (map=0x13f9828 <map>, metric_list=0x3ffd84fb868, events=0x3ffd84fb878, metric_no_group=<optimized out>, list=<optimized out>) at util/metricgroup.c:988 #8 parse_groups (perf_evlist=perf_evlist@entry=0x1e70260, str=str@entry=0x12f34b2 "IPC", metric_no_group=<optimized out>, metric_no_merge=<optimized out>, fake_pmu=fake_pmu@entry=0x1462f18 <perf_pmu.fake>, metric_events=0x3ffd84fba58, map=0x1) at util/metricgroup.c:1040 #9 0x0000000001103eb2 in metricgroup__parse_groups_test( evlist=evlist@entry=0x1e70260, map=map@entry=0x13f9828 <map>, str=str@entry=0x12f34b2 "IPC", metric_no_group=metric_no_group@entry=false, metric_no_merge=metric_no_merge@entry=false, metric_events=0x3ffd84fba58) at util/metricgroup.c:1082 #10 0x00000000010c84d8 in __compute_metric (ratio2=0x0, name2=0x0, ratio1=<synthetic pointer>, name1=0x12f34b2 "IPC", vals=0x3ffd84fbad8, name=0x12f34b2 "IPC") at tests/parse-metric.c:159 #11 compute_metric (ratio=<synthetic pointer>, vals=0x3ffd84fbad8, name=0x12f34b2 "IPC") at tests/parse-metric.c:189 #12 test_ipc () at tests/parse-metric.c:208 ..... ..... omitted many more lines This test case was added with commit 218ca91 ("perf tests: Add parse metric test for frontend metric"). When I compile with make DEBUG=y it works fine and I do not get a core dump. It turned out that the above listed function call chain worked on a struct pmu_event array which requires a trailing element with zeroes which was missing. The marco map_for_each_event() loops over that array tests for members metric_expr/metric_name/metric_group being non-NULL. Adding this element fixes the issue. Output after: [root@t35lp46 perf]# ./perf test 67 67: Parse and process metrics : Ok [root@t35lp46 perf]# Committer notes: As Ian remarks, this is not s390 specific: <quote Ian> This also shows up with address sanitizer on all architectures (perhaps change the patch title) and perhaps add a "Fixes: <commit>" tag. ================================================================= ==4718==ERROR: AddressSanitizer: global-buffer-overflow on address 0x55c93b4d59e8 at pc 0x55c93a1541e2 bp 0x7ffd24327c60 sp 0x7ffd24327c58 READ of size 8 at 0x55c93b4d59e8 thread T0 #0 0x55c93a1541e1 in find_metric tools/perf/util/metricgroup.c:764:2 #1 0x55c93a153e6c in __resolve_metric tools/perf/util/metricgroup.c:844:9 #2 0x55c93a152f18 in resolve_metric tools/perf/util/metricgroup.c:881:9 #3 0x55c93a1528db in metricgroup__add_metric tools/perf/util/metricgroup.c:943:9 #4 0x55c93a151996 in metricgroup__add_metric_list tools/perf/util/metricgroup.c:988:9 #5 0x55c93a1511b9 in parse_groups tools/perf/util/metricgroup.c:1040:8 #6 0x55c93a1513e1 in metricgroup__parse_groups_test tools/perf/util/metricgroup.c:1082:9 #7 0x55c93a0108ae in __compute_metric tools/perf/tests/parse-metric.c:159:8 #8 0x55c93a010744 in compute_metric tools/perf/tests/parse-metric.c:189:9 #9 0x55c93a00f5ee in test_ipc tools/perf/tests/parse-metric.c:208:2 #10 0x55c93a00f1e8 in test__parse_metric tools/perf/tests/parse-metric.c:345:2 #11 0x55c939fd7202 in run_test tools/perf/tests/builtin-test.c:410:9 #12 0x55c939fd6736 in test_and_print tools/perf/tests/builtin-test.c:440:9 #13 0x55c939fd58c3 in __cmd_test tools/perf/tests/builtin-test.c:661:4 #14 0x55c939fd4e02 in cmd_test tools/perf/tests/builtin-test.c:807:9 #15 0x55c939e4763d in run_builtin tools/perf/perf.c:313:11 #16 0x55c939e46475 in handle_internal_command tools/perf/perf.c:365:8 #17 0x55c939e4737e in run_argv tools/perf/perf.c:409:2 #18 0x55c939e45f7e in main tools/perf/perf.c:539:3 0x55c93b4d59e8 is located 0 bytes to the right of global variable 'pme_test' defined in 'tools/perf/tests/parse-metric.c:17:25' (0x55c93b4d54a0) of size 1352 SUMMARY: AddressSanitizer: global-buffer-overflow tools/perf/util/metricgroup.c:764:2 in find_metric Shadow bytes around the buggy address: 0x0ab9a7692ae0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0ab9a7692af0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0ab9a7692b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0ab9a7692b10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0ab9a7692b20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>0x0ab9a7692b30: 00 00 00 00 00 00 00 00 00 00 00 00 00[f9]f9 f9 0x0ab9a7692b40: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 0x0ab9a7692b50: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 0x0ab9a7692b60: f9 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 00 00 0x0ab9a7692b70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0ab9a7692b80: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb Shadow gap: cc </quote> I'm also adding the missing "Fixes" tag and setting just .name to NULL, as doing it that way is more compact (the compiler will zero out everything else) and the table iterators look for .name being NULL as the sentinel marking the end of the table. Fixes: 0a507af ("perf tests: Add parse metric test for ipc metric") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Link: http://lore.kernel.org/lkml/20200825071211.16959-1-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The aliases were never released causing the following leaks: Indirect leak of 1224 byte(s) in 9 object(s) allocated from: #0 0x7feefb830628 in malloc (/lib/x86_64-linux-gnu/libasan.so.5+0x107628) #1 0x56332c8f1b62 in __perf_pmu__new_alias util/pmu.c:322 #2 0x56332c8f401f in pmu_add_cpu_aliases_map util/pmu.c:778 #3 0x56332c792ce9 in __test__pmu_event_aliases tests/pmu-events.c:295 #4 0x56332c792ce9 in test_aliases tests/pmu-events.c:367 #5 0x56332c76a09b in run_test tests/builtin-test.c:410 #6 0x56332c76a09b in test_and_print tests/builtin-test.c:440 #7 0x56332c76ce69 in __cmd_test tests/builtin-test.c:695 #8 0x56332c76ce69 in cmd_test tests/builtin-test.c:807 #9 0x56332c7d2214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312 #10 0x56332c6701a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364 #11 0x56332c6701a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408 #12 0x56332c6701a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538 #13 0x7feefb359cc9 in __libc_start_main ../csu/libc-start.c:308 Fixes: 956a783 ("perf test: Test pmu-events aliases") Signed-off-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: John Garry <john.garry@huawei.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20200915031819.386559-11-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The evsel->unit borrows a pointer of pmu event or alias instead of owns a string. But tool event (duration_time) passes a result of strdup() caused a leak. It was found by ASAN during metric test: Direct leak of 210 byte(s) in 70 object(s) allocated from: #0 0x7fe366fca0b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5) #1 0x559fbbcc6ea3 in add_event_tool util/parse-events.c:414 #2 0x559fbbcc6ea3 in parse_events_add_tool util/parse-events.c:1414 #3 0x559fbbd8474d in parse_events_parse util/parse-events.y:439 #4 0x559fbbcc95da in parse_events__scanner util/parse-events.c:2096 #5 0x559fbbcc95da in __parse_events util/parse-events.c:2141 #6 0x559fbbc28555 in check_parse_id tests/pmu-events.c:406 #7 0x559fbbc28555 in check_parse_id tests/pmu-events.c:393 #8 0x559fbbc28555 in check_parse_cpu tests/pmu-events.c:415 #9 0x559fbbc28555 in test_parsing tests/pmu-events.c:498 #10 0x559fbbc0109b in run_test tests/builtin-test.c:410 #11 0x559fbbc0109b in test_and_print tests/builtin-test.c:440 #12 0x559fbbc03e69 in __cmd_test tests/builtin-test.c:695 #13 0x559fbbc03e69 in cmd_test tests/builtin-test.c:807 #14 0x559fbbc691f4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312 #15 0x559fbbb071a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364 #16 0x559fbbb071a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408 #17 0x559fbbb071a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538 #18 0x7fe366b68cc9 in __libc_start_main ../csu/libc-start.c:308 Fixes: f0fbb11 ("perf stat: Implement duration_time as a proper event") Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20200915031819.386559-6-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The test_generic_metric() missed to release entries in the pctx. Asan reported following leak (and more): Direct leak of 128 byte(s) in 1 object(s) allocated from: #0 0x7f4c9396980e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e) #1 0x55f7e748cc14 in hashmap_grow (/home/namhyung/project/linux/tools/perf/perf+0x90cc14) #2 0x55f7e748d497 in hashmap__insert (/home/namhyung/project/linux/tools/perf/perf+0x90d497) #3 0x55f7e7341667 in hashmap__set /home/namhyung/project/linux/tools/perf/util/hashmap.h:111 #4 0x55f7e7341667 in expr__add_ref util/expr.c:120 #5 0x55f7e7292436 in prepare_metric util/stat-shadow.c:783 #6 0x55f7e729556d in test_generic_metric util/stat-shadow.c:858 #7 0x55f7e712390b in compute_single tests/parse-metric.c:128 #8 0x55f7e712390b in __compute_metric tests/parse-metric.c:180 #9 0x55f7e712446d in compute_metric tests/parse-metric.c:196 #10 0x55f7e712446d in test_dcache_l2 tests/parse-metric.c:295 #11 0x55f7e712446d in test__parse_metric tests/parse-metric.c:355 #12 0x55f7e70be09b in run_test tests/builtin-test.c:410 #13 0x55f7e70be09b in test_and_print tests/builtin-test.c:440 #14 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661 #15 0x55f7e70c101a in cmd_test tests/builtin-test.c:807 #16 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312 #17 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364 #18 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408 #19 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538 #20 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308 Fixes: 6d432c4 ("perf tools: Add test_generic_metric function") Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20200915031819.386559-8-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The metricgroup__add_metric() can find multiple match for a metric group and it's possible to fail. Also it can fail in the middle like in resolve_metric() even for single metric. In those cases, the intermediate list and ids will be leaked like: Direct leak of 3 byte(s) in 1 object(s) allocated from: #0 0x7f4c938f40b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5) #1 0x55f7e71c1bef in __add_metric util/metricgroup.c:683 #2 0x55f7e71c31d0 in add_metric util/metricgroup.c:906 #3 0x55f7e71c3844 in metricgroup__add_metric util/metricgroup.c:940 #4 0x55f7e71c488d in metricgroup__add_metric_list util/metricgroup.c:993 #5 0x55f7e71c488d in parse_groups util/metricgroup.c:1045 #6 0x55f7e71c60a4 in metricgroup__parse_groups_test util/metricgroup.c:1087 #7 0x55f7e71235ae in __compute_metric tests/parse-metric.c:164 #8 0x55f7e7124650 in compute_metric tests/parse-metric.c:196 #9 0x55f7e7124650 in test_recursion_fail tests/parse-metric.c:318 #10 0x55f7e7124650 in test__parse_metric tests/parse-metric.c:356 #11 0x55f7e70be09b in run_test tests/builtin-test.c:410 #12 0x55f7e70be09b in test_and_print tests/builtin-test.c:440 #13 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661 #14 0x55f7e70c101a in cmd_test tests/builtin-test.c:807 #15 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312 #16 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364 #17 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408 #18 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538 #19 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308 Fixes: 83de0b7 ("perf metric: Collect referenced metrics in struct metric_ref_node") Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20200915031819.386559-9-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The following leaks were detected by ASAN: Indirect leak of 360 byte(s) in 9 object(s) allocated from: #0 0x7fecc305180e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e) #1 0x560578f6dce5 in perf_pmu__new_format util/pmu.c:1333 #2 0x560578f752fc in perf_pmu_parse util/pmu.y:59 #3 0x560578f6a8b7 in perf_pmu__format_parse util/pmu.c:73 #4 0x560578e07045 in test__pmu tests/pmu.c:155 #5 0x560578de109b in run_test tests/builtin-test.c:410 #6 0x560578de109b in test_and_print tests/builtin-test.c:440 #7 0x560578de401a in __cmd_test tests/builtin-test.c:661 #8 0x560578de401a in cmd_test tests/builtin-test.c:807 #9 0x560578e49354 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312 #10 0x560578ce71a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364 #11 0x560578ce71a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408 #12 0x560578ce71a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538 #13 0x7fecc2b7acc9 in __libc_start_main ../csu/libc-start.c:308 Fixes: cff7f95 ("perf tests: Move pmu tests into separate object") Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20200915031819.386559-12-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Very sporadically I had test case btrfs/069 from fstests hanging (for years, it is not a recent regression), with the following traces in dmesg/syslog: [162301.160628] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg started [162301.181196] BTRFS info (device sdc): scrub: finished on devid 4 with status: 0 [162301.287162] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg finished [162513.513792] INFO: task btrfs-transacti:1356167 blocked for more than 120 seconds. [162513.514318] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.514522] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.514747] task:btrfs-transacti state:D stack: 0 pid:1356167 ppid: 2 flags:0x00004000 [162513.514751] Call Trace: [162513.514761] __schedule+0x5ce/0xd00 [162513.514765] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.514771] schedule+0x46/0xf0 [162513.514844] wait_current_trans+0xde/0x140 [btrfs] [162513.514850] ? finish_wait+0x90/0x90 [162513.514864] start_transaction+0x37c/0x5f0 [btrfs] [162513.514879] transaction_kthread+0xa4/0x170 [btrfs] [162513.514891] ? btrfs_cleanup_transaction+0x660/0x660 [btrfs] [162513.514894] kthread+0x153/0x170 [162513.514897] ? kthread_stop+0x2c0/0x2c0 [162513.514902] ret_from_fork+0x22/0x30 [162513.514916] INFO: task fsstress:1356184 blocked for more than 120 seconds. [162513.515192] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.515431] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.515680] task:fsstress state:D stack: 0 pid:1356184 ppid:1356177 flags:0x00004000 [162513.515682] Call Trace: [162513.515688] __schedule+0x5ce/0xd00 [162513.515691] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.515697] schedule+0x46/0xf0 [162513.515712] wait_current_trans+0xde/0x140 [btrfs] [162513.515716] ? finish_wait+0x90/0x90 [162513.515729] start_transaction+0x37c/0x5f0 [btrfs] [162513.515743] btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs] [162513.515753] btrfs_sync_fs+0x61/0x1c0 [btrfs] [162513.515758] ? __ia32_sys_fdatasync+0x20/0x20 [162513.515761] iterate_supers+0x87/0xf0 [162513.515765] ksys_sync+0x60/0xb0 [162513.515768] __do_sys_sync+0xa/0x10 [162513.515771] do_syscall_64+0x33/0x80 [162513.515774] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.515781] RIP: 0033:0x7f5238f50bd7 [162513.515782] Code: Bad RIP value. [162513.515784] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2 [162513.515786] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7 [162513.515788] RDX: 00000000ffffffff RSI: 000000000daf0e74 RDI: 000000000000003a [162513.515789] RBP: 0000000000000032 R08: 000000000000000a R09: 00007f5239019be0 [162513.515791] R10: fffffffffffff24f R11: 0000000000000206 R12: 000000000000003a [162513.515792] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340 [162513.515804] INFO: task fsstress:1356185 blocked for more than 120 seconds. [162513.516064] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.516329] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.516617] task:fsstress state:D stack: 0 pid:1356185 ppid:1356177 flags:0x00000000 [162513.516620] Call Trace: [162513.516625] __schedule+0x5ce/0xd00 [162513.516628] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.516634] schedule+0x46/0xf0 [162513.516647] wait_current_trans+0xde/0x140 [btrfs] [162513.516650] ? finish_wait+0x90/0x90 [162513.516662] start_transaction+0x4d7/0x5f0 [btrfs] [162513.516679] btrfs_setxattr_trans+0x3c/0x100 [btrfs] [162513.516686] __vfs_setxattr+0x66/0x80 [162513.516691] __vfs_setxattr_noperm+0x70/0x200 [162513.516697] vfs_setxattr+0x6b/0x120 [162513.516703] setxattr+0x125/0x240 [162513.516709] ? lock_acquire+0xb1/0x480 [162513.516712] ? mnt_want_write+0x20/0x50 [162513.516721] ? rcu_read_lock_any_held+0x8e/0xb0 [162513.516723] ? preempt_count_add+0x49/0xa0 [162513.516725] ? __sb_start_write+0x19b/0x290 [162513.516727] ? preempt_count_add+0x49/0xa0 [162513.516732] path_setxattr+0xba/0xd0 [162513.516739] __x64_sys_setxattr+0x27/0x30 [162513.516741] do_syscall_64+0x33/0x80 [162513.516743] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.516745] RIP: 0033:0x7f5238f56d5a [162513.516746] Code: Bad RIP value. [162513.516748] RSP: 002b:00007fff67b97868 EFLAGS: 00000202 ORIG_RAX: 00000000000000bc [162513.516750] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f5238f56d5a [162513.516751] RDX: 000055b1fbb0d5a0 RSI: 00007fff67b978a0 RDI: 000055b1fbb0d470 [162513.516753] RBP: 000055b1fbb0d5a0 R08: 0000000000000001 R09: 00007fff67b97700 [162513.516754] R10: 0000000000000004 R11: 0000000000000202 R12: 0000000000000004 [162513.516756] R13: 0000000000000024 R14: 0000000000000001 R15: 00007fff67b978a0 [162513.516767] INFO: task fsstress:1356196 blocked for more than 120 seconds. [162513.517064] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.517365] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.517763] task:fsstress state:D stack: 0 pid:1356196 ppid:1356177 flags:0x00004000 [162513.517780] Call Trace: [162513.517786] __schedule+0x5ce/0xd00 [162513.517789] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.517796] schedule+0x46/0xf0 [162513.517810] wait_current_trans+0xde/0x140 [btrfs] [162513.517814] ? finish_wait+0x90/0x90 [162513.517829] start_transaction+0x37c/0x5f0 [btrfs] [162513.517845] btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs] [162513.517857] btrfs_sync_fs+0x61/0x1c0 [btrfs] [162513.517862] ? __ia32_sys_fdatasync+0x20/0x20 [162513.517865] iterate_supers+0x87/0xf0 [162513.517869] ksys_sync+0x60/0xb0 [162513.517872] __do_sys_sync+0xa/0x10 [162513.517875] do_syscall_64+0x33/0x80 [162513.517878] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.517881] RIP: 0033:0x7f5238f50bd7 [162513.517883] Code: Bad RIP value. [162513.517885] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2 [162513.517887] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7 [162513.517889] RDX: 0000000000000000 RSI: 000000007660add2 RDI: 0000000000000053 [162513.517891] RBP: 0000000000000032 R08: 0000000000000067 R09: 00007f5239019be0 [162513.517893] R10: fffffffffffff24f R11: 0000000000000206 R12: 0000000000000053 [162513.517895] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340 [162513.517908] INFO: task fsstress:1356197 blocked for more than 120 seconds. [162513.518298] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.518672] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.519157] task:fsstress state:D stack: 0 pid:1356197 ppid:1356177 flags:0x00000000 [162513.519160] Call Trace: [162513.519165] __schedule+0x5ce/0xd00 [162513.519168] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.519174] schedule+0x46/0xf0 [162513.519190] wait_current_trans+0xde/0x140 [btrfs] [162513.519193] ? finish_wait+0x90/0x90 [162513.519206] start_transaction+0x4d7/0x5f0 [btrfs] [162513.519222] btrfs_create+0x57/0x200 [btrfs] [162513.519230] lookup_open+0x522/0x650 [162513.519246] path_openat+0x2b8/0xa50 [162513.519270] do_filp_open+0x91/0x100 [162513.519275] ? find_held_lock+0x32/0x90 [162513.519280] ? lock_acquired+0x33b/0x470 [162513.519285] ? do_raw_spin_unlock+0x4b/0xc0 [162513.519287] ? _raw_spin_unlock+0x29/0x40 [162513.519295] do_sys_openat2+0x20d/0x2d0 [162513.519300] do_sys_open+0x44/0x80 [162513.519304] do_syscall_64+0x33/0x80 [162513.519307] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.519309] RIP: 0033:0x7f5238f4a903 [162513.519310] Code: Bad RIP value. [162513.519312] RSP: 002b:00007fff67b97758 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 [162513.519314] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f5238f4a903 [162513.519316] RDX: 0000000000000000 RSI: 00000000000001b6 RDI: 000055b1fbb0d470 [162513.519317] RBP: 00007fff67b978c0 R08: 0000000000000001 R09: 0000000000000002 [162513.519319] R10: 00007fff67b974f7 R11: 0000000000000246 R12: 0000000000000013 [162513.519320] R13: 00000000000001b6 R14: 00007fff67b97906 R15: 000055b1fad1c620 [162513.519332] INFO: task btrfs:1356211 blocked for more than 120 seconds. [162513.519727] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.520115] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.520508] task:btrfs state:D stack: 0 pid:1356211 ppid:1356178 flags:0x00004002 [162513.520511] Call Trace: [162513.520516] __schedule+0x5ce/0xd00 [162513.520519] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.520525] schedule+0x46/0xf0 [162513.520544] btrfs_scrub_pause+0x11f/0x180 [btrfs] [162513.520548] ? finish_wait+0x90/0x90 [162513.520562] btrfs_commit_transaction+0x45a/0xc30 [btrfs] [162513.520574] ? start_transaction+0xe0/0x5f0 [btrfs] [162513.520596] btrfs_dev_replace_finishing+0x6d8/0x711 [btrfs] [162513.520619] btrfs_dev_replace_by_ioctl.cold+0x1cc/0x1fd [btrfs] [162513.520639] btrfs_ioctl+0x2a25/0x36f0 [btrfs] [162513.520643] ? do_sigaction+0xf3/0x240 [162513.520645] ? find_held_lock+0x32/0x90 [162513.520648] ? do_sigaction+0xf3/0x240 [162513.520651] ? lock_acquired+0x33b/0x470 [162513.520655] ? _raw_spin_unlock_irq+0x24/0x50 [162513.520657] ? lockdep_hardirqs_on+0x7d/0x100 [162513.520660] ? _raw_spin_unlock_irq+0x35/0x50 [162513.520662] ? do_sigaction+0xf3/0x240 [162513.520671] ? __x64_sys_ioctl+0x83/0xb0 [162513.520672] __x64_sys_ioctl+0x83/0xb0 [162513.520677] do_syscall_64+0x33/0x80 [162513.520679] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.520681] RIP: 0033:0x7fc3cd307d87 [162513.520682] Code: Bad RIP value. [162513.520684] RSP: 002b:00007ffe30a56bb8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [162513.520686] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fc3cd307d87 [162513.520687] RDX: 00007ffe30a57a30 RSI: 00000000ca289435 RDI: 0000000000000003 [162513.520689] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [162513.520690] R10: 0000000000000008 R11: 0000000000000202 R12: 0000000000000003 [162513.520692] R13: 0000557323a212e0 R14: 00007ffe30a5a520 R15: 0000000000000001 [162513.520703] Showing all locks held in the system: [162513.520712] 1 lock held by khungtaskd/54: [162513.520713] #0: ffffffffb40a91a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x15/0x197 [162513.520728] 1 lock held by in:imklog/596: [162513.520729] #0: ffff8f3f0d781400 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x4d/0x60 [162513.520782] 1 lock held by btrfs-transacti/1356167: [162513.520784] #0: ffff8f3d810cc848 (&fs_info->transaction_kthread_mutex){+.+.}-{3:3}, at: transaction_kthread+0x4a/0x170 [btrfs] [162513.520798] 1 lock held by btrfs/1356190: [162513.520800] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write_file+0x22/0x60 [162513.520805] 1 lock held by fsstress/1356184: [162513.520806] #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0 [162513.520811] 3 locks held by fsstress/1356185: [162513.520812] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50 [162513.520815] #1: ffff8f3d80a650b8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: vfs_setxattr+0x50/0x120 [162513.520820] #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] [162513.520833] 1 lock held by fsstress/1356196: [162513.520834] #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0 [162513.520838] 3 locks held by fsstress/1356197: [162513.520839] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50 [162513.520843] #1: ffff8f3d506465e8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: path_openat+0x2a7/0xa50 [162513.520846] #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] [162513.520858] 2 locks held by btrfs/1356211: [162513.520859] #0: ffff8f3d810cde30 (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+.}-{3:3}, at: btrfs_dev_replace_finishing+0x52/0x711 [btrfs] [162513.520877] #1: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] This was weird because the stack traces show that a transaction commit, triggered by a device replace operation, is blocking trying to pause any running scrubs but there are no stack traces of blocked tasks doing a scrub. After poking around with drgn, I noticed there was a scrub task that was constantly running and blocking for shorts periods of time: >>> t = find_task(prog, 1356190) >>> prog.stack_trace(t) #0 __schedule+0x5ce/0xcfc #1 schedule+0x46/0xe4 #2 schedule_timeout+0x1df/0x475 #3 btrfs_reada_wait+0xda/0x132 #4 scrub_stripe+0x2a8/0x112f #5 scrub_chunk+0xcd/0x134 #6 scrub_enumerate_chunks+0x29e/0x5ee #7 btrfs_scrub_dev+0x2d5/0x91b #8 btrfs_ioctl+0x7f5/0x36e7 #9 __x64_sys_ioctl+0x83/0xb0 #10 do_syscall_64+0x33/0x77 #11 entry_SYSCALL_64+0x7c/0x156 Which corresponds to: int btrfs_reada_wait(void *handle) { struct reada_control *rc = handle; struct btrfs_fs_info *fs_info = rc->fs_info; while (atomic_read(&rc->elems)) { if (!atomic_read(&fs_info->reada_works_cnt)) reada_start_machine(fs_info); wait_event_timeout(rc->wait, atomic_read(&rc->elems) == 0, (HZ + 9) / 10); } (...) So the counter "rc->elems" was set to 1 and never decreased to 0, causing the scrub task to loop forever in that function. Then I used the following script for drgn to check the readahead requests: $ cat dump_reada.py import sys import drgn from drgn import NULL, Object, cast, container_of, execscript, \ reinterpret, sizeof from drgn.helpers.linux import * mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1" mnt = None for mnt in for_each_mount(prog, dst = mnt_path): pass if mnt is None: sys.stderr.write(f'Error: mount point {mnt_path} not found\n') sys.exit(1) fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info) def dump_re(re): nzones = re.nzones.value_() print(f're at {hex(re.value_())}') print(f'\t logical {re.logical.value_()}') print(f'\t refcnt {re.refcnt.value_()}') print(f'\t nzones {nzones}') for i in range(nzones): dev = re.zones[i].device name = dev.name.str.string_() print(f'\t\t dev id {dev.devid.value_()} name {name}') print() for _, e in radix_tree_for_each(fs_info.reada_tree): re = cast('struct reada_extent *', e) dump_re(re) $ drgn dump_reada.py re at 0xffff8f3da9d25ad8 logical 38928384 refcnt 1 nzones 1 dev id 0 name b'/dev/sdd' $ So there was one readahead extent with a single zone corresponding to the source device of that last device replace operation logged in dmesg/syslog. Also the ID of that zone's device was 0 which is a special value set in the source device of a device replace operation when the operation finishes (constant BTRFS_DEV_REPLACE_DEVID set at btrfs_dev_replace_finishing()), confirming again that device /dev/sdd was the source of a device replace operation. Normally there should be as many zones in the readahead extent as there are devices, and I wasn't expecting the extent to be in a block group with a 'single' profile, so I went and confirmed with the following drgn script that there weren't any single profile block groups: $ cat dump_block_groups.py import sys import drgn from drgn import NULL, Object, cast, container_of, execscript, \ reinterpret, sizeof from drgn.helpers.linux import * mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1" mnt = None for mnt in for_each_mount(prog, dst = mnt_path): pass if mnt is None: sys.stderr.write(f'Error: mount point {mnt_path} not found\n') sys.exit(1) fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info) BTRFS_BLOCK_GROUP_DATA = (1 << 0) BTRFS_BLOCK_GROUP_SYSTEM = (1 << 1) BTRFS_BLOCK_GROUP_METADATA = (1 << 2) BTRFS_BLOCK_GROUP_RAID0 = (1 << 3) BTRFS_BLOCK_GROUP_RAID1 = (1 << 4) BTRFS_BLOCK_GROUP_DUP = (1 << 5) BTRFS_BLOCK_GROUP_RAID10 = (1 << 6) BTRFS_BLOCK_GROUP_RAID5 = (1 << 7) BTRFS_BLOCK_GROUP_RAID6 = (1 << 8) BTRFS_BLOCK_GROUP_RAID1C3 = (1 << 9) BTRFS_BLOCK_GROUP_RAID1C4 = (1 << 10) def bg_flags_string(bg): flags = bg.flags.value_() ret = '' if flags & BTRFS_BLOCK_GROUP_DATA: ret = 'data' if flags & BTRFS_BLOCK_GROUP_METADATA: if len(ret) > 0: ret += '|' ret += 'meta' if flags & BTRFS_BLOCK_GROUP_SYSTEM: if len(ret) > 0: ret += '|' ret += 'system' if flags & BTRFS_BLOCK_GROUP_RAID0: ret += ' raid0' elif flags & BTRFS_BLOCK_GROUP_RAID1: ret += ' raid1' elif flags & BTRFS_BLOCK_GROUP_DUP: ret += ' dup' elif flags & BTRFS_BLOCK_GROUP_RAID10: ret += ' raid10' elif flags & BTRFS_BLOCK_GROUP_RAID5: ret += ' raid5' elif flags & BTRFS_BLOCK_GROUP_RAID6: ret += ' raid6' elif flags & BTRFS_BLOCK_GROUP_RAID1C3: ret += ' raid1c3' elif flags & BTRFS_BLOCK_GROUP_RAID1C4: ret += ' raid1c4' else: ret += ' single' return ret def dump_bg(bg): print() print(f'block group at {hex(bg.value_())}') print(f'\t start {bg.start.value_()} length {bg.length.value_()}') print(f'\t flags {bg.flags.value_()} - {bg_flags_string(bg)}') bg_root = fs_info.block_group_cache_tree.address_of_() for bg in rbtree_inorder_for_each_entry('struct btrfs_block_group', bg_root, 'cache_node'): dump_bg(bg) $ drgn dump_block_groups.py block group at 0xffff8f3d673b0400 start 22020096 length 16777216 flags 258 - system raid6 block group at 0xffff8f3d53ddb400 start 38797312 length 536870912 flags 260 - meta raid6 block group at 0xffff8f3d5f4d9c00 start 575668224 length 2147483648 flags 257 - data raid6 block group at 0xffff8f3d08189000 start 2723151872 length 67108864 flags 258 - system raid6 block group at 0xffff8f3db70ff000 start 2790260736 length 1073741824 flags 260 - meta raid6 block group at 0xffff8f3d5f4dd800 start 3864002560 length 67108864 flags 258 - system raid6 block group at 0xffff8f3d67037000 start 3931111424 length 2147483648 flags 257 - data raid6 $ So there were only 2 reasons left for having a readahead extent with a single zone: reada_find_zone(), called when creating a readahead extent, returned NULL either because we failed to find the corresponding block group or because a memory allocation failed. With some additional and custom tracing I figured out that on every further ocurrence of the problem the block group had just been deleted when we were looping to create the zones for the readahead extent (at reada_find_extent()), so we ended up with only one zone in the readahead extent, corresponding to a device that ends up getting replaced. So after figuring that out it became obvious why the hang happens: 1) Task A starts a scrub on any device of the filesystem, except for device /dev/sdd; 2) Task B starts a device replace with /dev/sdd as the source device; 3) Task A calls btrfs_reada_add() from scrub_stripe() and it is currently starting to scrub a stripe from block group X. This call to btrfs_reada_add() is the one for the extent tree. When btrfs_reada_add() calls reada_add_block(), it passes the logical address of the extent tree's root node as its 'logical' argument - a value of 38928384; 4) Task A then enters reada_find_extent(), called from reada_add_block(). It finds there isn't any existing readahead extent for the logical address 38928384, so it proceeds to the path of creating a new one. It calls btrfs_map_block() to find out which stripes exist for the block group X. On the first iteration of the for loop that iterates over the stripes, it finds the stripe for device /dev/sdd, so it creates one zone for that device and adds it to the readahead extent. Before getting into the second iteration of the loop, the cleanup kthread deletes block group X because it was empty. So in the iterations for the remaining stripes it does not add more zones to the readahead extent, because the calls to reada_find_zone() returned NULL because they couldn't find block group X anymore. As a result the new readahead extent has a single zone, corresponding to the device /dev/sdd; 4) Before task A returns to btrfs_reada_add() and queues the readahead job for the readahead work queue, task B finishes the device replace and at btrfs_dev_replace_finishing() swaps the device /dev/sdd with the new device /dev/sdg; 5) Task A returns to reada_add_block(), which increments the counter "->elems" of the reada_control structure allocated at btrfs_reada_add(). Then it returns back to btrfs_reada_add() and calls reada_start_machine(). This queues a job in the readahead work queue to run the function reada_start_machine_worker(), which calls __reada_start_machine(). At __reada_start_machine() we take the device list mutex and for each device found in the current device list, we call reada_start_machine_dev() to start the readahead work. However at this point the device /dev/sdd was already freed and is not in the device list anymore. This means the corresponding readahead for the extent at 38928384 is never started, and therefore the "->elems" counter of the reada_control structure allocated at btrfs_reada_add() never goes down to 0, causing the call to btrfs_reada_wait(), done by the scrub task, to wait forever. Note that the readahead request can be made either after the device replace started or before it started, however in pratice it is very unlikely that a device replace is able to start after a readahead request is made and is able to complete before the readahead request completes - maybe only on a very small and nearly empty filesystem. This hang however is not the only problem we can have with readahead and device removals. When the readahead extent has other zones other than the one corresponding to the device that is being removed (either by a device replace or a device remove operation), we risk having a use-after-free on the device when dropping the last reference of the readahead extent. For example if we create a readahead extent with two zones, one for the device /dev/sdd and one for the device /dev/sde: 1) Before the readahead worker starts, the device /dev/sdd is removed, and the corresponding btrfs_device structure is freed. However the readahead extent still has the zone pointing to the device structure; 2) When the readahead worker starts, it only finds device /dev/sde in the current device list of the filesystem; 3) It starts the readahead work, at reada_start_machine_dev(), using the device /dev/sde; 4) Then when it finishes reading the extent from device /dev/sde, it calls __readahead_hook() which ends up dropping the last reference on the readahead extent through the last call to reada_extent_put(); 5) At reada_extent_put() it iterates over each zone of the readahead extent and attempts to delete an element from the device's 'reada_extents' radix tree, resulting in a use-after-free, as the device pointer of the zone for /dev/sdd is now stale. We can also access the device after dropping the last reference of a zone, through reada_zone_release(), also called by reada_extent_put(). And a device remove suffers the same problem, however since it shrinks the device size down to zero before removing the device, it is very unlikely to still have readahead requests not completed by the time we free the device, the only possibility is if the device has a very little space allocated. While the hang problem is exclusive to scrub, since it is currently the only user of btrfs_reada_add() and btrfs_reada_wait(), the use-after-free problem affects any path that triggers readhead, which includes btree_readahead_hook() and __readahead_hook() (a readahead worker can trigger readahed for the children of a node) for example - any path that ends up calling reada_add_block() can trigger the use-after-free after a device is removed. So fix this by waiting for any readahead requests for a device to complete before removing a device, ensuring that while waiting for existing ones no new ones can be made. This problem has been around for a very long time - the readahead code was added in 2011, device remove exists since 2008 and device replace was introduced in 2013, hard to pick a specific commit for a git Fixes tag. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>

This fix is for a failure that occurred in the DWARF unwind perf test. Stack unwinders may probe memory when looking for frames. Memory sanitizer will poison and track uninitialized memory on the stack, and on the heap if the value is copied to the heap. This can lead to false memory sanitizer failures for the use of an uninitialized value. Avoid this problem by removing the poison on the copied stack. The full msan failure with track origins looks like: ==2168==WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x559ceb10755b in handle_cfi elfutils/libdwfl/frame_unwind.c:648:8 #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4 #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7 #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10 #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17 #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17 #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14 #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10 #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8 #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8 #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26 #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0) #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2 #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9 #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9 #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8 #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9 #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9 #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4 #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9 #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11 #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8 #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2 #23 0x559cea95fbce in main tools/perf/perf.c:539:3 Uninitialized value was stored to memory at #0 0x559ceb106acf in __libdwfl_frame_reg_set elfutils/libdwfl/frame_unwind.c:77:22 #1 0x559ceb106acf in handle_cfi elfutils/libdwfl/frame_unwind.c:627:13 #2 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4 #3 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7 #4 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10 #5 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17 #6 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17 #7 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14 #8 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10 #9 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8 #10 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8 #11 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26 #12 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0) #13 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2 #14 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9 #15 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9 #16 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8 #17 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9 #18 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9 #19 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4 #20 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9 #21 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11 #22 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8 #23 0x559cea95fbce in run_argv tools/perf/perf.c:409:2 #24 0x559cea95fbce in main tools/perf/perf.c:539:3 Uninitialized value was stored to memory at #0 0x559ceb106a54 in handle_cfi elfutils/libdwfl/frame_unwind.c:613:9 #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4 #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7 #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10 #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17 #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17 #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14 #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10 #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8 #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8 #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26 #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0) #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2 #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9 #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9 #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8 #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9 #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9 #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4 #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9 #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11 #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8 #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2 #23 0x559cea95fbce in main tools/perf/perf.c:539:3 Uninitialized value was stored to memory at #0 0x559ceaff8800 in memory_read tools/perf/util/unwind-libdw.c:156:10 #1 0x559ceb10f053 in expr_eval elfutils/libdwfl/frame_unwind.c:501:13 #2 0x559ceb1060cc in handle_cfi elfutils/libdwfl/frame_unwind.c:603:18 #3 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4 #4 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7 #5 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10 #6 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17 #7 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17 #8 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14 #9 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10 #10 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8 #11 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8 #12 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26 #13 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0) #14 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2 #15 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9 #16 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9 #17 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8 #18 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9 #19 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9 #20 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4 #21 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9 #22 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11 #23 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8 #24 0x559cea95fbce in run_argv tools/perf/perf.c:409:2 #25 0x559cea95fbce in main tools/perf/perf.c:539:3 Uninitialized value was stored to memory at #0 0x559cea9027d9 in __msan_memcpy llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1558:3 #1 0x559cea9d2185 in sample_ustack tools/perf/arch/x86/tests/dwarf-unwind.c:41:2 #2 0x559cea9d202c in test__arch_unwind_sample tools/perf/arch/x86/tests/dwarf-unwind.c:72:9 #3 0x559ceabc9cbd in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:106:6 #4 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26 #5 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0) #6 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2 #7 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9 #8 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9 #9 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8 #10 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9 #11 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9 #12 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4 #13 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9 #14 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11 #15 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8 #16 0x559cea95fbce in run_argv tools/perf/perf.c:409:2 #17 0x559cea95fbce in main tools/perf/perf.c:539:3 Uninitialized value was created by an allocation of 'bf' in the stack frame of function 'perf_event__synthesize_mmap_events' #0 0x559ceafc5f60 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:445 SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi Signed-off-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: clang-built-linux@googlegroups.com Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sandeep Dasgupta <sdasgup@google.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20201113182053.754625-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The evlist has the maps with its own refcounts so we don't need to set the pointers to NULL. Otherwise following error was reported by Asan. # perf test -v 4 4: Read samples using the mmap interface : --- start --- test child forked, pid 139782 mmap size 528384B ================================================================= ==139782==ERROR: LeakSanitizer: detected memory leaks Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7f1f76daee8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x564ba21a0fea in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x564ba21a1a0f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149 #3 0x564ba21a21cf in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166 #4 0x564ba21a21cf in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181 #5 0x564ba1e48298 in test__basic_mmap tests/mmap-basic.c:55 #6 0x564ba1e278fb in run_test tests/builtin-test.c:428 #7 0x564ba1e278fb in test_and_print tests/builtin-test.c:458 #8 0x564ba1e29a53 in __cmd_test tests/builtin-test.c:679 #9 0x564ba1e29a53 in cmd_test tests/builtin-test.c:825 #10 0x564ba1e95cb4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #11 0x564ba1d1fa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #12 0x564ba1d1fa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #13 0x564ba1d1fa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #14 0x7f1f768e4d09 in __libc_start_main ../csu/libc-start.c:308 ... test child finished with 1 ---- end ---- Read samples using the mmap interface: FAILED! failed to open shell test directory: /home/namhyung/libexec/perf-core/tests/shell Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Stephane Eranian <eranian@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Link: https://lore.kernel.org/r/20210301140409.184570-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The evlist has the maps with its own refcounts so we don't need to set the pointers to NULL. Otherwise following error was reported by Asan. Also change the goto label since it doesn't need to have two. # perf test -v 24 24: Number of exit events of a simple workload : --- start --- test child forked, pid 145915 mmap size 528384B ================================================================= ==145915==ERROR: LeakSanitizer: detected memory leaks Direct leak of 32 byte(s) in 1 object(s) allocated from: #0 0x7fc44e50d1f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164 #1 0x561cf50f4d2e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23 #2 0x561cf4eeb949 in thread_map__new_by_tid util/thread_map.c:63 #3 0x561cf4db7fd2 in test__task_exit tests/task-exit.c:74 #4 0x561cf4d798fb in run_test tests/builtin-test.c:428 #5 0x561cf4d798fb in test_and_print tests/builtin-test.c:458 #6 0x561cf4d7ba53 in __cmd_test tests/builtin-test.c:679 #7 0x561cf4d7ba53 in cmd_test tests/builtin-test.c:825 #8 0x561cf4de7d04 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #9 0x561cf4c71a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #10 0x561cf4c71a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #11 0x561cf4c71a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #12 0x7fc44e042d09 in __libc_start_main ../csu/libc-start.c:308 ... test child finished with 1 ---- end ---- Number of exit events of a simple workload: FAILED! Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/r/20210301140409.184570-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The evlist has the maps with its own refcounts so we don't need to set the pointers to NULL. Otherwise following error was reported by Asan. Also change the goto label since it doesn't need to have two. # perf test -v 25 25: Software clock events period values : --- start --- test child forked, pid 149154 mmap size 528384B mmap size 528384B ================================================================= ==149154==ERROR: LeakSanitizer: detected memory leaks Direct leak of 32 byte(s) in 1 object(s) allocated from: #0 0x7fef5cd071f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164 #1 0x56260d5e8b8e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23 #2 0x56260d3df7a9 in thread_map__new_by_tid util/thread_map.c:63 #3 0x56260d2ac6b2 in __test__sw_clock_freq tests/sw-clock.c:65 #4 0x56260d26d8fb in run_test tests/builtin-test.c:428 #5 0x56260d26d8fb in test_and_print tests/builtin-test.c:458 #6 0x56260d26fa53 in __cmd_test tests/builtin-test.c:679 #7 0x56260d26fa53 in cmd_test tests/builtin-test.c:825 #8 0x56260d2dbb64 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #9 0x56260d165a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #10 0x56260d165a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #11 0x56260d165a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #12 0x7fef5c83cd09 in __libc_start_main ../csu/libc-start.c:308 ... test child finished with 1 ---- end ---- Software clock events period values : FAILED! Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/r/20210301140409.184570-5-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The evlist and the cpu/thread maps should be released together. Otherwise following error was reported by Asan. Note that this test still has memory leaks in DSOs so it still fails even after this change. I'll take a look at that too. # perf test -v 26 26: Object code reading : --- start --- test child forked, pid 154184 Looking at the vmlinux_path (8 entries long) symsrc__init: build id mismatch for vmlinux. symsrc__init: cannot get elf header. Using /proc/kcore for kernel data Using /proc/kallsyms for symbols Parsing event 'cycles' mmap size 528384B ... ================================================================= ==154184==ERROR: LeakSanitizer: detected memory leaks Direct leak of 439 byte(s) in 1 object(s) allocated from: #0 0x7fcb66e77037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x55ad9b7e821e in dso__new_id util/dso.c:1256 #2 0x55ad9b8cfd4a in __machine__addnew_vdso util/vdso.c:132 #3 0x55ad9b8cfd4a in machine__findnew_vdso util/vdso.c:347 #4 0x55ad9b845b7e in map__new util/map.c:176 #5 0x55ad9b8415a2 in machine__process_mmap2_event util/machine.c:1787 #6 0x55ad9b8fab16 in perf_tool__process_synth_event util/synthetic-events.c:64 #7 0x55ad9b8fab16 in perf_event__synthesize_mmap_events util/synthetic-events.c:499 #8 0x55ad9b8fbfdf in __event__synthesize_thread util/synthetic-events.c:741 #9 0x55ad9b8ff3e3 in perf_event__synthesize_thread_map util/synthetic-events.c:833 #10 0x55ad9b738585 in do_test_code_reading tests/code-reading.c:608 #11 0x55ad9b73b25d in test__code_reading tests/code-reading.c:722 #12 0x55ad9b6f28fb in run_test tests/builtin-test.c:428 #13 0x55ad9b6f28fb in test_and_print tests/builtin-test.c:458 #14 0x55ad9b6f4a53 in __cmd_test tests/builtin-test.c:679 #15 0x55ad9b6f4a53 in cmd_test tests/builtin-test.c:825 #16 0x55ad9b760cc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #17 0x55ad9b5eaa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #18 0x55ad9b5eaa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #19 0x55ad9b5eaa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #20 0x7fcb669acd09 in __libc_start_main ../csu/libc-start.c:308 ... SUMMARY: AddressSanitizer: 471 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Object code reading: FAILED! Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/r/20210301140409.184570-6-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The evlist and the cpu/thread maps should be released together. Otherwise following error was reported by Asan. $ perf test -v 28 28: Use a dummy software event to keep tracking: --- start --- test child forked, pid 156810 mmap size 528384B ================================================================= ==156810==ERROR: LeakSanitizer: detected memory leaks Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7f637d2bce8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x55cc6295cffa in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x55cc6295da1f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149 #3 0x55cc6295e1df in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166 #4 0x55cc6295e1df in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181 #5 0x55cc626287cf in test__keep_tracking tests/keep-tracking.c:84 #6 0x55cc625e38fb in run_test tests/builtin-test.c:428 #7 0x55cc625e38fb in test_and_print tests/builtin-test.c:458 #8 0x55cc625e5a53 in __cmd_test tests/builtin-test.c:679 #9 0x55cc625e5a53 in cmd_test tests/builtin-test.c:825 #10 0x55cc62651cc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #11 0x55cc624dba88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #12 0x55cc624dba88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #13 0x55cc624dba88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #14 0x7f637cdf2d09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Use a dummy software event to keep tracking: FAILED! Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/r/20210301140409.184570-7-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The evlist and cpu/thread maps should be released together. Otherwise the following error was reported by Asan. $ perf test -v 35 35: Track with sched_switch : --- start --- test child forked, pid 159287 Using CPUID GenuineIntel-6-8E-C mmap size 528384B 1295 events recorded ================================================================= ==159287==ERROR: LeakSanitizer: detected memory leaks Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7fa28d9a2e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x5652f5a5affa in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x5652f5a5ba1f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149 #3 0x5652f5a5c1df in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166 #4 0x5652f5a5c1df in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181 #5 0x5652f5723bbf in test__switch_tracking tests/switch-tracking.c:350 #6 0x5652f56e18fb in run_test tests/builtin-test.c:428 #7 0x5652f56e18fb in test_and_print tests/builtin-test.c:458 #8 0x5652f56e3a53 in __cmd_test tests/builtin-test.c:679 #9 0x5652f56e3a53 in cmd_test tests/builtin-test.c:825 #10 0x5652f574fcc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #11 0x5652f55d9a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #12 0x5652f55d9a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #13 0x5652f55d9a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #14 0x7fa28d4d8d09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Track with sched_switch: FAILED! Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/r/20210301140409.184570-8-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

It missed to call perf_thread_map__put() after using the map. $ perf test -v 43 43: Synthesize thread map : --- start --- test child forked, pid 162640 ================================================================= ==162640==ERROR: LeakSanitizer: detected memory leaks Direct leak of 32 byte(s) in 1 object(s) allocated from: #0 0x7fd48cdaa1f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164 #1 0x563e6d5f8d0e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23 #2 0x563e6d3ef69a in thread_map__new_by_pid util/thread_map.c:46 #3 0x563e6d2cec90 in test__thread_map_synthesize tests/thread-map.c:97 #4 0x563e6d27d8fb in run_test tests/builtin-test.c:428 #5 0x563e6d27d8fb in test_and_print tests/builtin-test.c:458 #6 0x563e6d27fa53 in __cmd_test tests/builtin-test.c:679 #7 0x563e6d27fa53 in cmd_test tests/builtin-test.c:825 #8 0x563e6d2ebce4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #9 0x563e6d175a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #10 0x563e6d175a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #11 0x563e6d175a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #12 0x7fd48c8dfd09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: 8224 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Synthesize thread map: FAILED! Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/r/20210301140409.184570-9-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

It should be released after printing the map. $ perf test -v 52 52: Print cpu map : --- start --- test child forked, pid 172233 ================================================================= ==172233==ERROR: LeakSanitizer: detected memory leaks Direct leak of 156 byte(s) in 1 object(s) allocated from: #0 0x7fc472518e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x55e63b378f7a in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x55e63b37a05c in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:237 #3 0x55e63b056d16 in cpu_map_print tests/cpumap.c:102 #4 0x55e63b056d16 in test__cpu_map_print tests/cpumap.c:120 #5 0x55e63afff8fb in run_test tests/builtin-test.c:428 #6 0x55e63afff8fb in test_and_print tests/builtin-test.c:458 #7 0x55e63b001a53 in __cmd_test tests/builtin-test.c:679 #8 0x55e63b001a53 in cmd_test tests/builtin-test.c:825 #9 0x55e63b06dc44 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #10 0x55e63aef7a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #11 0x55e63aef7a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #12 0x55e63aef7a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #13 0x7fc47204ed09 in __libc_start_main ../csu/libc-start.c:308 ... SUMMARY: AddressSanitizer: 448 byte(s) leaked in 7 allocation(s). test child finished with 1 ---- end ---- Print cpu map: FAILED! Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/r/20210301140409.184570-11-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

It should release the maps at the end. $ perf test -v 71 71: Convert perf time to TSC : --- start --- test child forked, pid 178744 mmap size 528384B 1st event perf time 59207256505278 tsc 13187166645142 rdtsc time 59207256542151 tsc 13187166723020 2nd event perf time 59207256543749 tsc 13187166726393 ================================================================= ==178744==ERROR: LeakSanitizer: detected memory leaks Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7faf601f9e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x55b620cfc00a in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x55b620cfca2f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149 #3 0x55b620cfd1ef in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166 #4 0x55b620cfd1ef in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181 #5 0x55b6209ef1b2 in test__perf_time_to_tsc tests/perf-time-to-tsc.c:73 #6 0x55b6209828fb in run_test tests/builtin-test.c:428 #7 0x55b6209828fb in test_and_print tests/builtin-test.c:458 #8 0x55b620984a53 in __cmd_test tests/builtin-test.c:679 #9 0x55b620984a53 in cmd_test tests/builtin-test.c:825 #10 0x55b6209f0cd4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #11 0x55b62087aa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #12 0x55b62087aa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #13 0x55b62087aa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #14 0x7faf5fd2fd09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Convert perf time to TSC: FAILED! Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/r/20210301140409.184570-12-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

I got a segfault when using -r option with event groups. The option makes it run the workload multiple times and it will reuse the evlist and evsel for each run. While most of resources are allocated and freed properly, the id hash in the evlist was not and it resulted in the bug. You can see it with the address sanitizer like below: $ perf stat -r 100 -e '{cycles,instructions}' true ================================================================= ==693052==ERROR: AddressSanitizer: heap-use-after-free on address 0x6080000003d0 at pc 0x558c57732835 bp 0x7fff1526adb0 sp 0x7fff1526ada8 WRITE of size 8 at 0x6080000003d0 thread T0 #0 0x558c57732834 in hlist_add_head /home/namhyung/project/linux/tools/include/linux/list.h:644 #1 0x558c57732834 in perf_evlist__id_hash /home/namhyung/project/linux/tools/lib/perf/evlist.c:237 #2 0x558c57732834 in perf_evlist__id_add /home/namhyung/project/linux/tools/lib/perf/evlist.c:244 #3 0x558c57732834 in perf_evlist__id_add_fd /home/namhyung/project/linux/tools/lib/perf/evlist.c:285 #4 0x558c5747733e in store_evsel_ids util/evsel.c:2765 #5 0x558c5747733e in evsel__store_ids util/evsel.c:2782 #6 0x558c5730b717 in __run_perf_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:895 #7 0x558c5730b717 in run_perf_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:1014 #8 0x558c5730b717 in cmd_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:2446 #9 0x558c57427c24 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #10 0x558c572b1a48 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #11 0x558c572b1a48 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #12 0x558c572b1a48 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #13 0x7fcadb9f7d09 in __libc_start_main ../csu/libc-start.c:308 #14 0x558c572b60f9 in _start (/home/namhyung/project/linux/tools/perf/perf+0x45d0f9) Actually the nodes in the hash table are struct perf_stream_id and they were freed in the previous run. Fix it by resetting the hash. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/r/20210225035148.778569-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

[ 6684.493350] Unable to handle kernel paging request at virtual address ffff800011c5b0f0 [ 6684.498531] mmc0: card 0001 removed [ 6684.501556] Mem abort info: [ 6684.509681] ESR = 0x96000047 [ 6684.512786] EC = 0x25: DABT (current EL), IL = 32 bits [ 6684.518394] SET = 0, FnV = 0 [ 6684.521707] EA = 0, S1PTW = 0 [ 6684.524998] Data abort info: [ 6684.528236] ISV = 0, ISS = 0x00000047 [ 6684.532986] CM = 0, WnR = 1 [ 6684.536129] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000081b22000 [ 6684.543923] [ffff800011c5b0f0] pgd=00000000bffff003, p4d=00000000bffff003, pud=00000000bfffe003, pmd=00000000900e1003, pte=0000000000000000 [ 6684.557915] Internal error: Oops: 96000047 [#1] PREEMPT SMP [ 6684.564240] Modules linked in: sdhci_esdhc_imx(-) sdhci_pltfm sdhci cqhci mmc_block mmc_core fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine rng_core authenc libdes crct10dif_ce flexcan can_dev caam error [last unloaded: mmc_core] [ 6684.587281] CPU: 0 PID: 79138 Comm: kworker/0:3H Not tainted 5.10.9-01410-g3ba33182767b-dirty #10 [ 6684.596160] Hardware name: Freescale i.MX8DXL EVK (DT) [ 6684.601320] Workqueue: kblockd blk_mq_run_work_fn [ 6684.606094] pstate: 40000005 (nZcv daif -PAN -UAO -TCO BTYPE=--) [ 6684.612286] pc : cqhci_request+0x148/0x4e8 [cqhci] ^GMessage from syslogd@ at Thu Jan 1 01:51:24 1970 ...[ 6684.617085] lr : cqhci_request+0x314/0x4e8 [cqhci] [ 6684.626734] sp : ffff80001243b9f0 [ 6684.630049] x29: ffff80001243b9f0 x28: ffff00002c3dd000 [ 6684.635367] x27: 0000000000000001 x26: 0000000000000001 [ 6684.640690] x25: ffff00002c451000 x24: 000000000000000f [ 6684.646007] x23: ffff000017e71c80 x22: ffff00002c451000 [ 6684.651326] x21: ffff00002c0f3550 x20: ffff00002c0f3550 [ 6684.656651] x19: ffff000017d46880 x18: ffff00002cea1500 [ 6684.661977] x17: 0000000000000000 x16: 0000000000000000 [ 6684.667294] x15: 000001ee628e3ed1 x14: 0000000000000278 [ 6684.672610] x13: 0000000000000001 x12: 0000000000000001 [ 6684.677927] x11: 0000000000000000 x10: 0000000000000000 [ 6684.683243] x9 : 000000000000002b x8 : 0000000000001000 [ 6684.688560] x7 : 0000000000000010 x6 : ffff00002c0f3678 [ 6684.693886] x5 : 000000000000000f x4 : ffff800011c5b000 [ 6684.699211] x3 : 000000000002d988 x2 : 0000000000000008 [ 6684.704537] x1 : 00000000000000f0 x0 : 0002d9880008102f [ 6684.709854] Call trace: [ 6684.712313] cqhci_request+0x148/0x4e8 [cqhci] [ 6684.716803] mmc_cqe_start_req+0x58/0x68 [mmc_core] [ 6684.721698] mmc_blk_mq_issue_rq+0x460/0x810 [mmc_block] [ 6684.727018] mmc_mq_queue_rq+0x118/0x2b0 [mmc_block] The problem occurs when cqhci_request() get called after cqhci_disable() as it leads to access of allocated memory that has already been freed. Let's fix the problem by calling cqhci_disable() a bit later in the remove path. Signed-off-by: Frank Li <Frank.Li@nxp.com> Diagnosed-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Link: https://lore.kernel.org/r/20210303174248.542175-1-Frank.Li@nxp.com Fixes: f690f44 ("mmc: mmc: Enable CQE's") Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

I got several memory leak reports from Asan with a simple command. It was because VDSO is not released due to the refcount. Like in __dsos_addnew_id(), it should put the refcount after adding to the list. $ perf record true [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.030 MB perf.data (10 samples) ] ================================================================= ==692599==ERROR: LeakSanitizer: detected memory leaks Direct leak of 439 byte(s) in 1 object(s) allocated from: #0 0x7fea52341037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x559bce4aa8ee in dso__new_id util/dso.c:1256 #2 0x559bce59245a in __machine__addnew_vdso util/vdso.c:132 #3 0x559bce59245a in machine__findnew_vdso util/vdso.c:347 #4 0x559bce50826c in map__new util/map.c:175 #5 0x559bce503c92 in machine__process_mmap2_event util/machine.c:1787 #6 0x559bce512f6b in machines__deliver_event util/session.c:1481 #7 0x559bce515107 in perf_session__deliver_event util/session.c:1551 #8 0x559bce51d4d2 in do_flush util/ordered-events.c:244 #9 0x559bce51d4d2 in __ordered_events__flush util/ordered-events.c:323 #10 0x559bce519bea in __perf_session__process_events util/session.c:2268 #11 0x559bce519bea in perf_session__process_events util/session.c:2297 #12 0x559bce2e7a52 in process_buildids /home/namhyung/project/linux/tools/perf/builtin-record.c:1017 #13 0x559bce2e7a52 in record__finish_output /home/namhyung/project/linux/tools/perf/builtin-record.c:1234 #14 0x559bce2ed4f6 in __cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2026 #15 0x559bce2ed4f6 in cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2858 #16 0x559bce422db4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #17 0x559bce2acac8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #18 0x559bce2acac8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #19 0x559bce2acac8 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #20 0x7fea51e76d09 in __libc_start_main ../csu/libc-start.c:308 Indirect leak of 32 byte(s) in 1 object(s) allocated from: #0 0x7fea52341037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x559bce520907 in nsinfo__copy util/namespaces.c:169 #2 0x559bce50821b in map__new util/map.c:168 #3 0x559bce503c92 in machine__process_mmap2_event util/machine.c:1787 #4 0x559bce512f6b in machines__deliver_event util/session.c:1481 #5 0x559bce515107 in perf_session__deliver_event util/session.c:1551 #6 0x559bce51d4d2 in do_flush util/ordered-events.c:244 #7 0x559bce51d4d2 in __ordered_events__flush util/ordered-events.c:323 #8 0x559bce519bea in __perf_session__process_events util/session.c:2268 #9 0x559bce519bea in perf_session__process_events util/session.c:2297 #10 0x559bce2e7a52 in process_buildids /home/namhyung/project/linux/tools/perf/builtin-record.c:1017 #11 0x559bce2e7a52 in record__finish_output /home/namhyung/project/linux/tools/perf/builtin-record.c:1234 #12 0x559bce2ed4f6 in __cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2026 #13 0x559bce2ed4f6 in cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2858 #14 0x559bce422db4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #15 0x559bce2acac8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #16 0x559bce2acac8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #17 0x559bce2acac8 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #18 0x7fea51e76d09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: 471 byte(s) leaked in 2 allocation(s). Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lore.kernel.org/lkml/20210315045641.700430-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The following deadlock is detected: truncate -> setattr path is waiting for pending direct IO to be done (inode->i_dio_count become zero) with inode->i_rwsem held (down_write). PID: 14827 TASK: ffff881686a9af80 CPU: 20 COMMAND: "ora_p005_hrltd9" #0 __schedule at ffffffff818667cc #1 schedule at ffffffff81866de6 #2 inode_dio_wait at ffffffff812a2d04 #3 ocfs2_setattr at ffffffffc05f322e [ocfs2] #4 notify_change at ffffffff812a5a09 #5 do_truncate at ffffffff812808f5 #6 do_sys_ftruncate.constprop.18 at ffffffff81280cf2 #7 sys_ftruncate at ffffffff81280d8e #8 do_syscall_64 at ffffffff81003949 #9 entry_SYSCALL_64_after_hwframe at ffffffff81a001ad dio completion path is going to complete one direct IO (decrement inode->i_dio_count), but before that it hung at locking inode->i_rwsem: #0 __schedule+700 at ffffffff818667cc #1 schedule+54 at ffffffff81866de6 #2 rwsem_down_write_failed+536 at ffffffff8186aa28 #3 call_rwsem_down_write_failed+23 at ffffffff8185a1b7 #4 down_write+45 at ffffffff81869c9d #5 ocfs2_dio_end_io_write+180 at ffffffffc05d5444 [ocfs2] #6 ocfs2_dio_end_io+85 at ffffffffc05d5a85 [ocfs2] #7 dio_complete+140 at ffffffff812c873c #8 dio_aio_complete_work+25 at ffffffff812c89f9 #9 process_one_work+361 at ffffffff810b1889 #10 worker_thread+77 at ffffffff810b233d #11 kthread+261 at ffffffff810b7fd5 #12 ret_from_fork+62 at ffffffff81a0035e Thus above forms ABBA deadlock. The same deadlock was mentioned in upstream commit 28f5a8a ("ocfs2: should wait dio before inode lock in ocfs2_setattr()"). It seems that that commit only removed the cluster lock (the victim of above dead lock) from the ABBA deadlock party. End-user visible effects: Process hang in truncate -> ocfs2_setattr path and other processes hang at ocfs2_dio_end_io_write path. This is to fix the deadlock itself. It removes inode_lock() call from dio completion path to remove the deadlock and add ip_alloc_sem lock in setattr path to synchronize the inode modifications. [wen.gang.wang@oracle.com: remove the "had_alloc_lock" as suggested] Link: https://lkml.kernel.org/r/20210402171344.1605-1-wen.gang.wang@oracle.com Link: https://lkml.kernel.org/r/20210331203654.3911-1-wen.gang.wang@oracle.com Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When bringing down the netdevice or system shutdown, a panic can be triggered while accessing the sysfs path because the device is already removed. [ 755.549084] mlx5_core 0000:12:00.1: Shutdown was called [ 756.404455] mlx5_core 0000:12:00.0: Shutdown was called ... [ 757.937260] BUG: unable to handle kernel NULL pointer dereference at (null) [ 758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280 crash> bt ... PID: 12649 TASK: ffff8924108f2100 CPU: 1 COMMAND: "amsd" ... #9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778 [exception RIP: dma_pool_alloc+0x1ab] RIP: ffffffff8ee11acb RSP: ffff89240e1a3968 RFLAGS: 00010046 RAX: 0000000000000246 RBX: ffff89243d874100 RCX: 0000000000001000 RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffff89243d874090 RBP: ffff89240e1a39c0 R8: 000000000001f080 R9: ffff8905ffc03c00 R10: ffffffffc04680d4 R11: ffffffff8edde9fd R12: 00000000000080d0 R13: ffff89243d874090 R14: ffff89243d874080 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core] #11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core] #12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core] #13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core] #14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core] #15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core] #16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core] #17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46 #18 [ffff89240e1a3d48] speed_show at ffffffff8f277208 #19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3 #20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf #21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596 #22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10 #23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5 #24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff #25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f #26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92 crash> net_device.state ffff89443b0c0000 state = 0x5 (__LINK_STATE_START| __LINK_STATE_NOCARRIER) To prevent this scenario, we also make sure that the netdevice is present. Signed-off-by: suresh kumar <suresh2514@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

dabrace merged this pull request into dabrace:master Nov 24, 2014

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Sync up with Linus #10

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dabrace commented Nov 24, 2014

Sync up with Linus #10

Sync up with Linus #10

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dabrace commented Nov 24, 2014