Trigger __rust_probestack in example 3 #2

adamrk · 2021-01-20T07:53:20Z

No description provided.

This is a big PR, but most of it is interdependent to the rest. - Shared Rust infrastructure: `libkernel`, `libmodule`, `libcore`, `liballoc`, `libcompiler_builtins`. + The Rust modules are now much smaller since they do not contain several copies of those libraries. Our example `.ko` on release is just 12 KiB, down from 1.3 MiB. For reference: `vmlinux` on release w/ Rust is 23 MiB (compressed: 2.1 MiB) `vmlinux` on release w/o Rust is 22 MiB (compressed: 1.9 MiB) i.e. the bulk is now shared. + Multiple builtin modules are now supported since their symbols do not collide against each other (fixes #9). + Faster compilation (less crates to compile & less repetition). + We achieve this by compiling all the shared code to `.rlib`s (and the `.so` for the proc macro). For loadable modules, we need to rely on the upcoming v0 Rust mangling scheme, plus we need to export the Rust symbols needed by the `.ko`s. - Simpler, flat file structure: now a small driver may only need a single file like `drivers/char/rust_example.rs`, like in C. + All the `rust/*` and `driver/char/rust_example/*` files moved to fit in the new structure: less files around. - Only `rust-lang/{rust,rust-bindgen,compiler-builtins}` as dependencies. + Also helps with the faster compilation. - Dependency handling integration with `Kbuild`/`fixdep`. + Changes to the Rust standard library, kernel headers (bindings), `rust/` source files, `.rs` changes, command-line changes, flag changes, etc. all trigger recompilation as needed. + Works as expected with parallel support (`-j`). - Automatic generation of the `exports.c` list: + Instead of manually handling the list, all non-local functions available in `core`, `alloc` and `kernel` are exported, so all modules should work, regardless of what they need, and without failing linking due to symbols in the manual list not existing (e.g. due to differences in config options). + They are a lot, though: * ~6k Rust symbols vs. ~4k C symbols in release. * However, 4k of those are `bindings_raw` (i.e. duplicated C ones), which shouldn't be exported. Thus we should look into making `bindings_raw` private to the crate (at the moment, the (first) Rust example requires `<kernel::bindings...::miscdevice as Default>::default`). + Licensing: * `kernel`'s symbols are exported as GPL. * `core`'s and `alloc`'s symbols are exported as non-GPL so that third-parties can build Rust modules as long as they write their own kernel support infrastructure, i.e. without taking advantage of `kernel`. This seemed to make the most sense compared to other exports from the kernel, plus it follows more closely the original licence of the crates. - Support for GCC-compiled kernels: + The generated bindings do not have meaningful differences in our release config, between GCC 10.1 and Clang 11. + Other configs (e.g. our debug one) may add/remove types and functions. That is fine unless we use them form our bindings. + However, there are config options that may not work (e.g. the randstruct GCC plugin if we use one of those structs). - Support for `arm64` architecture: + Added to the CI: BusyBox is cross-compiled on the fly (increased timeout a bit to match). + Requires weakening of a few compiler builtins and adding `copy_{from,to}_user` helpers. - Proper `make clean` support. - Offline builds by default (there is no "online compilation" anymore; fixes #17). - No interleaved Cargo output (fixes Rust-for-Linux#29). - No nightly dependency on Cargo's `build-std`; since now we manage the cross-compilation ourselves (should fix Rust-for-Linux#27). - "Big" kallsyms symbol support: + I already raised ksym names from 128 to 256 back when I wrote the first integration. However, Rust symbols can be huge in debug/non-optimized, so I increased it again to 512; plus the module name from 56 to 248. + In turn, this required tuning the table format to support 2-byte lengths for ksyms. Compression at generation and kernel decompression is covered, although it may be the case that some script/tool also requires changes to understand the new table format. - Since now a kernel can be "Rust-enabled", a new `CONFIG_RUST` option is added to enable/disable it manually, regardless of whether one has `rustc` available or not (`CONFIG_HAS_RUST`). - Improved handling of `rustc` flags (`opt-level`, `debuginfo`, etc.), by default following what the user selected for C, but customizable through a Kconfig menu. As well as options for tweaking overflow checks and debug assertions. - This rewrite of the Kbuild support is cleaner, i.e. less hacks in general handling paths (e.g. no more `shell readlink` for `O=`). - Duplicated the example driver 3 times so that we can test in the CI that 2 builtins and 2 loadables work, all at the same time. - Do not export any helpers' symbols. - Updated the quick start guide. - Updated CI: + Now we always test with 2 builtins and 2 loadables Rust example drivers, removing the matrix test for builtin/loadable. + Added `toolchain` to matrix: now we test building with GCC, Clang or a full LLVM toolchain. + Added `arch` to matrix: now we test both arm64 and x86_64. + Added `rustc` to matrix: now we test with a very recent nightly as well. + Only build `output == build` once to reduce the number of combinations. + Debug x86_64 config: more things enabled (debuginfo, kgdb, unit testing, etc.) that mimic more what a developer would have. Running the CI will be slightly slower, but should be OK. Also enable `-C opt-level=0` to test that such an extreme works and also to see how much bloated everything becomes. + Release x86_64 config: disabled `EXPERT` and changed a few things to make it look more like a normal desktop configuration, although it is still pretty minimal. + The configs for arm64 are `EXPERT` and `EMBEDDED` ones, very minimal, for the particular CPU we are simulating. + Update configs to v5.10. + Use `$GITHUB_ENV` to simplify. - Less `extern crate`s needed since we pass it via `rustc` (closer to idiomatic 2018 edition Rust code). Things to note: - There is two more nightly features used: + The new Rust mangling scheme: we know it will be stable (and the default on, later on). + The binary dep-info output: if we remove all other nightly features, this one can easily go too. - The hack at `exports.c` to export symbols to loadable modules. - The hack at `allocator.rs` to get the `__rust_*()` functions. - The hack to get the proper flags for bindgen on GCC builds. Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Ido Schimmel says: ==================== mlxsw: Various fixes This patchset contains various fixes for mlxsw. Patch #1 fixes a race condition in a selftest. The race and fix are explained in detail in the changelog. Patch #2 re-adds a link mode that was wrongly removed, resulting in a regression in some setups. Patch #3 fixes a race condition in route installation with nexthop objects. Please consider patches #2 and #3 for stable. ==================== Link: https://lore.kernel.org/r/20210225165721.1322424-1-idosch@idosch.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Michael Chan says: ==================== bnxt_en: Error recovery bug fixes. Two error recovery related bug fixes for 2 corner cases. Please queue patch #2 for -stable. Thanks. ==================== Link: https://lore.kernel.org/r/1614332590-17865-1-git-send-email-michael.chan@broadcom.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

label err_eni_release is reachable when eni_start() fail. In eni_start() it calls dev->phy->start() in the last step, if start() fail we don't need to call phy->stop(), if start() is never called, we neither need to call phy->stop(), otherwise null-ptr-deref will happen. In order to fix this issue, don't call phy->stop() in label err_eni_release [ 4.875714] ================================================================== [ 4.876091] BUG: KASAN: null-ptr-deref in suni_stop+0x47/0x100 [suni] [ 4.876433] Read of size 8 at addr 0000000000000030 by task modprobe/95 [ 4.876778] [ 4.876862] CPU: 0 PID: 95 Comm: modprobe Not tainted 5.11.0-rc7-00090-gdcc0b49040c7 #2 [ 4.877290] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-48-gd94 [ 4.877876] Call Trace: [ 4.878009] dump_stack+0x7d/0xa3 [ 4.878191] kasan_report.cold+0x10c/0x10e [ 4.878410] ? __slab_free+0x2f0/0x340 [ 4.878612] ? suni_stop+0x47/0x100 [suni] [ 4.878832] suni_stop+0x47/0x100 [suni] [ 4.879043] eni_do_release+0x3b/0x70 [eni] [ 4.879269] eni_init_one.cold+0x1152/0x1747 [eni] [ 4.879528] ? _raw_spin_lock_irqsave+0x7b/0xd0 [ 4.879768] ? eni_ioctl+0x270/0x270 [eni] [ 4.879990] ? __mutex_lock_slowpath+0x10/0x10 [ 4.880226] ? eni_ioctl+0x270/0x270 [eni] [ 4.880448] local_pci_probe+0x6f/0xb0 [ 4.880650] pci_device_probe+0x171/0x240 [ 4.880864] ? pci_device_remove+0xe0/0xe0 [ 4.881086] ? kernfs_create_link+0xb6/0x110 [ 4.881315] ? sysfs_do_create_link_sd.isra.0+0x76/0xe0 [ 4.881594] really_probe+0x161/0x420 [ 4.881791] driver_probe_device+0x6d/0xd0 [ 4.882010] device_driver_attach+0x82/0x90 [ 4.882233] ? device_driver_attach+0x90/0x90 [ 4.882465] __driver_attach+0x60/0x100 [ 4.882671] ? device_driver_attach+0x90/0x90 [ 4.882903] bus_for_each_dev+0xe1/0x140 [ 4.883114] ? subsys_dev_iter_exit+0x10/0x10 [ 4.883346] ? klist_node_init+0x61/0x80 [ 4.883557] bus_add_driver+0x254/0x2a0 [ 4.883764] driver_register+0xd3/0x150 [ 4.883971] ? 0xffffffffc0038000 [ 4.884149] do_one_initcall+0x84/0x250 [ 4.884355] ? trace_event_raw_event_initcall_finish+0x150/0x150 [ 4.884674] ? unpoison_range+0xf/0x30 [ 4.884875] ? ____kasan_kmalloc.constprop.0+0x84/0xa0 [ 4.885150] ? unpoison_range+0xf/0x30 [ 4.885352] ? unpoison_range+0xf/0x30 [ 4.885557] do_init_module+0xf8/0x350 [ 4.885760] load_module+0x3fe6/0x4340 [ 4.885960] ? vm_unmap_ram+0x1d0/0x1d0 [ 4.886166] ? ____kasan_kmalloc.constprop.0+0x84/0xa0 [ 4.886441] ? module_frob_arch_sections+0x20/0x20 [ 4.886697] ? __do_sys_finit_module+0x108/0x170 [ 4.886941] __do_sys_finit_module+0x108/0x170 [ 4.887178] ? __ia32_sys_init_module+0x40/0x40 [ 4.887419] ? file_open_root+0x200/0x200 [ 4.887634] ? do_sys_open+0x85/0xe0 [ 4.887826] ? filp_open+0x50/0x50 [ 4.888009] ? fpregs_assert_state_consistent+0x4d/0x60 [ 4.888287] ? exit_to_user_mode_prepare+0x2f/0x130 [ 4.888547] do_syscall_64+0x33/0x40 [ 4.888739] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 4.889010] RIP: 0033:0x7ff62fcf1cf7 [ 4.889202] Code: 48 89 57 30 48 8b 04 24 48 89 47 38 e9 1d a0 02 00 48 89 f8 48 89 f71 [ 4.890172] RSP: 002b:00007ffe6644ade8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 4.890570] RAX: ffffffffffffffda RBX: 0000000000f2ca70 RCX: 00007ff62fcf1cf7 [ 4.890944] RDX: 0000000000000000 RSI: 0000000000f2b9e0 RDI: 0000000000000003 [ 4.891318] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 [ 4.891691] R10: 00007ff62fd55300 R11: 0000000000000246 R12: 0000000000f2b9e0 [ 4.892064] R13: 0000000000000000 R14: 0000000000f2bdd0 R15: 0000000000000001 [ 4.892439] ================================================================== Signed-off-by: Tong Zhang <ztong0001@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

…t context Running "perf mem record" in powerpc platforms with selinux enabled resulted in soft lockup's. Below call-trace was seen in the logs: CPU: 58 PID: 3751 Comm: sssd_nss Not tainted 5.11.0-rc7+ #2 NIP: c000000000dff3d4 LR: c000000000dff3d0 CTR: 0000000000000000 REGS: c000007fffab7d60 TRAP: 0100 Not tainted (5.11.0-rc7+) ... NIP _raw_spin_lock_irqsave+0x94/0x120 LR _raw_spin_lock_irqsave+0x90/0x120 Call Trace: 0xc00000000fd47260 (unreliable) skb_queue_tail+0x3c/0x90 audit_log_end+0x6c/0x180 common_lsm_audit+0xb0/0xe0 slow_avc_audit+0xa4/0x110 avc_has_perm+0x1c4/0x260 selinux_perf_event_open+0x74/0xd0 security_perf_event_open+0x68/0xc0 record_and_restart+0x6e8/0x7f0 perf_event_interrupt+0x22c/0x560 performance_monitor_exception0x4c/0x60 performance_monitor_common_virt+0x1c8/0x1d0 interrupt: f00 at _raw_spin_lock_irqsave+0x38/0x120 NIP: c000000000dff378 LR: c000000000b5fbbc CTR: c0000000007d47f0 REGS: c00000000fd47860 TRAP: 0f00 Not tainted (5.11.0-rc7+) ... NIP _raw_spin_lock_irqsave+0x38/0x120 LR skb_queue_tail+0x3c/0x90 interrupt: f00 0x38 (unreliable) 0xc00000000aae6200 audit_log_end+0x6c/0x180 audit_log_exit+0x344/0xf80 __audit_syscall_exit+0x2c0/0x320 do_syscall_trace_leave+0x148/0x200 syscall_exit_prepare+0x324/0x390 system_call_common+0xfc/0x27c The above trace shows that while the CPU was handling a performance monitor exception, there was a call to security_perf_event_open() function. In powerpc core-book3s, this function is called from perf_allow_kernel() check during recording of data address in the sample via perf_get_data_addr(). Commit da97e18 ("perf_event: Add support for LSM and SELinux checks") introduced security enhancements to perf. As part of this commit, the new security hook for perf_event_open() was added in all places where perf paranoid check was previously used. In powerpc core-book3s code, originally had paranoid checks in perf_get_data_addr() and power_pmu_bhrb_read(). So perf_paranoid_kernel() checks were replaced with perf_allow_kernel() in these PMU helper functions as well. The intention of paranoid checks in core-book3s was to verify privilege access before capturing some of the sample data. Along with paranoid checks, perf_allow_kernel() also does a security_perf_event_open(). Since these functions are accessed while recording a sample, we end up calling selinux_perf_event_open() in PMI context. Some of the security functions use spinlock like sidtab_sid2str_put(). If a perf interrupt hits under a spin lock and if we end up in calling selinux hook functions in PMI handler, this could cause a dead lock. Since the purpose of this security hook is to control access to perf_event_open(), it is not right to call this in interrupt context. The paranoid checks in powerpc core-book3s were done at interrupt time which is also not correct. Reference commits: Commit cd1231d ("powerpc/perf: Prevent kernel address leak via perf_get_data_addr()") Commit bb19af8 ("powerpc/perf: Prevent kernel address leak to userspace via BHRB buffer") We only allow creation of events that have already passed the privilege checks in perf_event_open(). So these paranoid checks are not needed at event time. As a fix, patch uses 'event->attr.exclude_kernel' check to prevent exposing kernel address for userspace only sampling. Fixes: cd1231d ("powerpc/perf: Prevent kernel address leak via perf_get_data_addr()") Cc: stable@vger.kernel.org # v4.17+ Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1614247839-1428-1-git-send-email-atrajeev@linux.vnet.ibm.com

Ido Schimmel says: ==================== nexthop: Do not flush blackhole nexthops when loopback goes down Patch #1 prevents blackhole nexthops from being flushed when the loopback device goes down given that as far as user space is concerned, these nexthops do not have a nexthop device. Patch #2 adds a test case. There are no regressions in fib_nexthops.sh with this change: # ./fib_nexthops.sh ... Tests passed: 165 Tests failed: 0 ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

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>

[ This problem is in mainline, but only rt has the chops to be able to detect it. ] Lockdep reports a circular lock dependency between serv->sv_lock and softirq_ctl.lock on system shutdown, when using a kernel built with CONFIG_PREEMPT_RT=y, and a nfs mount exists. This is due to the definition of spin_lock_bh on rt: local_bh_disable(); rt_spin_lock(lock); which forces a softirq_ctl.lock -> serv->sv_lock dependency. This is not a problem as long as _every_ lock of serv->sv_lock is a: spin_lock_bh(&serv->sv_lock); but there is one of the form: spin_lock(&serv->sv_lock); This is what is causing the circular dependency splat. The spin_lock() grabs the lock without first grabbing softirq_ctl.lock via local_bh_disable. If later on in the critical region, someone does a local_bh_disable, we get a serv->sv_lock -> softirq_ctrl.lock dependency established. Deadlock. Fix is to make serv->sv_lock be locked with spin_lock_bh everywhere, no exceptions. [ OK ] Stopped target NFS client services. Stopping Logout off all iSCSI sessions on shutdown... Stopping NFS server and services... [ 109.442380] [ 109.442385] ====================================================== [ 109.442386] WARNING: possible circular locking dependency detected [ 109.442387] 5.10.16-rt30 #1 Not tainted [ 109.442389] ------------------------------------------------------ [ 109.442390] nfsd/1032 is trying to acquire lock: [ 109.442392] ffff994237617f60 ((softirq_ctrl.lock).lock){+.+.}-{2:2}, at: __local_bh_disable_ip+0xd9/0x270 [ 109.442405] [ 109.442405] but task is already holding lock: [ 109.442406] ffff994245cb00b0 (&serv->sv_lock){+.+.}-{0:0}, at: svc_close_list+0x1f/0x90 [ 109.442415] [ 109.442415] which lock already depends on the new lock. [ 109.442415] [ 109.442416] [ 109.442416] the existing dependency chain (in reverse order) is: [ 109.442417] [ 109.442417] -> #1 (&serv->sv_lock){+.+.}-{0:0}: [ 109.442421] rt_spin_lock+0x2b/0xc0 [ 109.442428] svc_add_new_perm_xprt+0x42/0xa0 [ 109.442430] svc_addsock+0x135/0x220 [ 109.442434] write_ports+0x4b3/0x620 [ 109.442438] nfsctl_transaction_write+0x45/0x80 [ 109.442440] vfs_write+0xff/0x420 [ 109.442444] ksys_write+0x4f/0xc0 [ 109.442446] do_syscall_64+0x33/0x40 [ 109.442450] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 109.442454] [ 109.442454] -> #0 ((softirq_ctrl.lock).lock){+.+.}-{2:2}: [ 109.442457] __lock_acquire+0x1264/0x20b0 [ 109.442463] lock_acquire+0xc2/0x400 [ 109.442466] rt_spin_lock+0x2b/0xc0 [ 109.442469] __local_bh_disable_ip+0xd9/0x270 [ 109.442471] svc_xprt_do_enqueue+0xc0/0x4d0 [ 109.442474] svc_close_list+0x60/0x90 [ 109.442476] svc_close_net+0x49/0x1a0 [ 109.442478] svc_shutdown_net+0x12/0x40 [ 109.442480] nfsd_destroy+0xc5/0x180 [ 109.442482] nfsd+0x1bc/0x270 [ 109.442483] kthread+0x194/0x1b0 [ 109.442487] ret_from_fork+0x22/0x30 [ 109.442492] [ 109.442492] other info that might help us debug this: [ 109.442492] [ 109.442493] Possible unsafe locking scenario: [ 109.442493] [ 109.442493] CPU0 CPU1 [ 109.442494] ---- ---- [ 109.442495] lock(&serv->sv_lock); [ 109.442496] lock((softirq_ctrl.lock).lock); [ 109.442498] lock(&serv->sv_lock); [ 109.442499] lock((softirq_ctrl.lock).lock); [ 109.442501] [ 109.442501] *** DEADLOCK *** [ 109.442501] [ 109.442501] 3 locks held by nfsd/1032: [ 109.442503] #0: ffffffff93b49258 (nfsd_mutex){+.+.}-{3:3}, at: nfsd+0x19a/0x270 [ 109.442508] #1: ffff994245cb00b0 (&serv->sv_lock){+.+.}-{0:0}, at: svc_close_list+0x1f/0x90 [ 109.442512] #2: ffffffff93a81b20 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0x5/0xc0 [ 109.442518] [ 109.442518] stack backtrace: [ 109.442519] CPU: 0 PID: 1032 Comm: nfsd Not tainted 5.10.16-rt30 #1 [ 109.442522] Hardware name: Supermicro X9DRL-3F/iF/X9DRL-3F/iF, BIOS 3.2 09/22/2015 [ 109.442524] Call Trace: [ 109.442527] dump_stack+0x77/0x97 [ 109.442533] check_noncircular+0xdc/0xf0 [ 109.442546] __lock_acquire+0x1264/0x20b0 [ 109.442553] lock_acquire+0xc2/0x400 [ 109.442564] rt_spin_lock+0x2b/0xc0 [ 109.442570] __local_bh_disable_ip+0xd9/0x270 [ 109.442573] svc_xprt_do_enqueue+0xc0/0x4d0 [ 109.442577] svc_close_list+0x60/0x90 [ 109.442581] svc_close_net+0x49/0x1a0 [ 109.442585] svc_shutdown_net+0x12/0x40 [ 109.442588] nfsd_destroy+0xc5/0x180 [ 109.442590] nfsd+0x1bc/0x270 [ 109.442595] kthread+0x194/0x1b0 [ 109.442600] ret_from_fork+0x22/0x30 [ 109.518225] nfsd: last server has exited, flushing export cache [ OK ] Stopped NFSv4 ID-name mapping service. [ OK ] Stopped GSSAPI Proxy Daemon. [ OK ] Stopped NFS Mount Daemon. [ OK ] Stopped NFS status monitor for NFSv2/3 locking.. Fixes: 719f8bc ("svcrpc: fix xpt_list traversal locking on shutdown") Signed-off-by: Joe Korty <joe.korty@concurrent-rt.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

afs_listxattr() lists all the available special afs xattrs (i.e. those in the "afs.*" space), no matter what type of server we're dealing with. But OpenAFS servers, for example, cannot deal with some of the extra-capable attributes that AuriStor (YFS) servers provide. Unfortunately, the presence of the afs.yfs.* attributes causes errors[1] for anything that tries to read them if the server is of the wrong type. Fix the problem by removing afs_listxattr() so that none of the special xattrs are listed (AFS doesn't support xattrs). It does mean, however, that getfattr won't list them, though they can still be accessed with getxattr() and setxattr(). This can be tested with something like: getfattr -d -m ".*" /afs/example.com/path/to/file With this change, none of the afs.* attributes should be visible. Changes: ver #2: - Hide all of the afs.* xattrs, not just the ACL ones. Fixes: ae46578 ("afs: Get YFS ACLs and information through xattrs") Reported-by: Gaja Sophie Peters <gaja.peters@math.uni-hamburg.de> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Gaja Sophie Peters <gaja.peters@math.uni-hamburg.de> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003502.html [1] Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003567.html # v1 Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003573.html # v2

Recent changes changed the completion of SCSI commands from Soft-IRQ context to IRQ context. This triggers the following warning, when we're completing writes to zoned block devices that go through the zone append emulation: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc2+ #2 Hardware name: Supermicro Super Server/X10SRL-F, BIOS 2.0 12/17/2015 RIP: 0010:__local_bh_disable_ip+0x3f/0x50 RSP: 0018:ffff8883e1409ba8 EFLAGS: 00010006 RAX: 0000000080010001 RBX: 0000000000000001 RCX: 0000000000000013 RDX: ffff888129e4d200 RSI: 0000000000000201 RDI: ffffffff915b9dbd RBP: ffff888113e9a540 R08: ffff888113e9a540 R09: 00000000000077f0 R10: 0000000000080000 R11: 0000000000000001 R12: ffff888129e4d200 R13: 0000000000001000 R14: 00000000000077f0 R15: ffff888129e4d218 FS: 0000000000000000(0000) GS:ffff8883e1400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2f8418ebc0 CR3: 000000021202a006 CR4: 00000000001706f0 Call Trace: <IRQ> _raw_spin_lock_bh+0x18/0x40 sd_zbc_complete+0x43d/0x1150 sd_done+0x631/0x1040 ? mark_lock+0xe4/0x2fd0 ? provisioning_mode_store+0x3f0/0x3f0 scsi_finish_command+0x31b/0x5c0 _scsih_io_done+0x960/0x29e0 [mpt3sas] ? mpt3sas_scsih_scsi_lookup_get+0x1c7/0x340 [mpt3sas] ? __lock_acquire+0x166b/0x58b0 ? _get_st_from_smid+0x4a/0x80 [mpt3sas] _base_process_reply_queue+0x23f/0x26e0 [mpt3sas] ? lock_is_held_type+0x98/0x110 ? find_held_lock+0x2c/0x110 ? mpt3sas_base_sync_reply_irqs+0x360/0x360 [mpt3sas] _base_interrupt+0x8d/0xd0 [mpt3sas] ? rcu_read_lock_sched_held+0x3f/0x70 __handle_irq_event_percpu+0x24d/0x600 handle_irq_event+0xef/0x240 ? handle_irq_event_percpu+0x110/0x110 handle_edge_irq+0x1f6/0xb60 __common_interrupt+0x75/0x160 common_interrupt+0x7b/0xa0 </IRQ> asm_common_interrupt+0x1e/0x40 Don't use spin_lock_bh() to protect the update of the write pointer offset cache, but use spin_lock_irqsave() for it. Link: https://lore.kernel.org/r/3cfebe48d09db73041b7849be71ffbcec7ee40b3.1615369586.git.johannes.thumshirn@wdc.com Fixes: 664f0dc ("scsi: mpt3sas: Add support for shared host tagset for CPU hotplug") Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Starting with commit f295c8c ("drm/nouveau: fix dma syncing warning with debugging on.") the following oops occures: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 6 PID: 1013 Comm: Xorg.bin Tainted: G E 5.11.0-desktop-rc0+ #2 Hardware name: Acer Aspire VN7-593G/Pluto_KLS, BIOS V1.11 08/01/2018 RIP: 0010:nouveau_bo_sync_for_device+0x40/0xb0 [nouveau] Call Trace: nouveau_bo_validate+0x5d/0x80 [nouveau] nouveau_gem_ioctl_pushbuf+0x662/0x1120 [nouveau] ? nouveau_gem_ioctl_new+0xf0/0xf0 [nouveau] drm_ioctl_kernel+0xa6/0xf0 [drm] drm_ioctl+0x1f4/0x3a0 [drm] ? nouveau_gem_ioctl_new+0xf0/0xf0 [nouveau] nouveau_drm_ioctl+0x50/0xa0 [nouveau] __x64_sys_ioctl+0x7e/0xb0 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae ---[ end trace ccfb1e7f4064374f ]--- RIP: 0010:nouveau_bo_sync_for_device+0x40/0xb0 [nouveau] The underlying problem is not introduced by the commit, yet it uncovered the underlying issue. The cited commit relies on valid pages. This is not given for due to some bugs. For now, just warn and work around the issue by just ignoring the bad ttm objects. Below is some debug info gathered while debugging this issue: nouveau 0000:01:00.0: DRM: ttm_dma->num_pages: 2048 nouveau 0000:01:00.0: DRM: ttm_dma->pages is NULL nouveau 0000:01:00.0: DRM: ttm_dma: 00000000e96058e7 nouveau 0000:01:00.0: DRM: ttm_dma->page_flags: nouveau 0000:01:00.0: DRM: ttm_dma: Populated: 1 nouveau 0000:01:00.0: DRM: ttm_dma: No Retry: 0 nouveau 0000:01:00.0: DRM: ttm_dma: SG: 256 nouveau 0000:01:00.0: DRM: ttm_dma: Zero Alloc: 0 nouveau 0000:01:00.0: DRM: ttm_dma: Swapped: 0 Signed-off-by: Tobias Klausmann <tobias.klausmann@freenet.de> Signed-off-by: Dave Airlie <airlied@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210313222159.3346-1-tobias.klausmann@freenet.de

…egulator The interrupt pin of the external ethernet phy is used, instead of the enable-gpio pin of the tf-io regulator. The GPIOE_2 pin is located in the gpio_ao bank. This causes phy interrupt problems at system startup. [ 76.645190] irq 36: nobody cared (try booting with the "irqpoll" option) [ 76.649617] CPU: 0 PID: 1416 Comm: irq/36-0.0:00 Not tainted 5.16.0 #2 [ 76.649629] Hardware name: Hardkernel ODROID-HC4 (DT) [ 76.649635] Call trace: [ 76.649638] dump_backtrace+0x0/0x1c8 [ 76.649658] show_stack+0x14/0x60 [ 76.649667] dump_stack_lvl+0x64/0x7c [ 76.649676] dump_stack+0x14/0x2c [ 76.649683] __report_bad_irq+0x38/0xe8 [ 76.649695] note_interrupt+0x220/0x3a0 [ 76.649704] handle_irq_event_percpu+0x58/0x88 [ 76.649713] handle_irq_event+0x44/0xd8 [ 76.649721] handle_fasteoi_irq+0xa8/0x130 [ 76.649730] generic_handle_domain_irq+0x38/0x58 [ 76.649738] gic_handle_irq+0x9c/0xb8 [ 76.649747] call_on_irq_stack+0x28/0x38 [ 76.649755] do_interrupt_handler+0x7c/0x80 [ 76.649763] el1_interrupt+0x34/0x80 [ 76.649772] el1h_64_irq_handler+0x14/0x20 [ 76.649781] el1h_64_irq+0x74/0x78 [ 76.649788] irq_finalize_oneshot.part.56+0x68/0xf8 [ 76.649796] irq_thread_fn+0x5c/0x98 [ 76.649804] irq_thread+0x13c/0x260 [ 76.649812] kthread+0x144/0x178 [ 76.649822] ret_from_fork+0x10/0x20 [ 76.649830] handlers: [ 76.653170] [<0000000025a6cd31>] irq_default_primary_handler threaded [<0000000093580eb7>] phy_interrupt [ 76.661256] Disabling IRQ Rust-for-Linux#36 Fixes: 1f80a5c ("arm64: dts: meson-sm1-odroid: add missing enable gpio and supply for tf_io regulator") Signed-off-by: Lutz Koschorreck <theleks@ko-hh.de> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> [narmstrong: removed spurious invalid & blank lines from commit message] Link: https://lore.kernel.org/r/20220127130537.GA187347@odroid-VirtualBox

When using the flushoncommit mount option, during almost every transaction commit we trigger a warning from __writeback_inodes_sb_nr(): $ cat fs/fs-writeback.c: (...) static void __writeback_inodes_sb_nr(struct super_block *sb, ... { (...) WARN_ON(!rwsem_is_locked(&sb->s_umount)); (...) } (...) The trace produced in dmesg looks like the following: [947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3 [947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif [947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 Rust-for-Linux#186 [947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3 [947.502097] Code: 24 10 4c 89 44 24 18 c6 (...) [947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246 [947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000 [947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50 [947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000 [947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488 [947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460 [947.553621] FS: 0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000 [947.560537] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0 [947.571072] Call Trace: [947.572354] <TASK> [947.573266] btrfs_commit_transaction+0x1f1/0x998 [947.576785] ? start_transaction+0x3ab/0x44e [947.579867] ? schedule_timeout+0x8a/0xdd [947.582716] transaction_kthread+0xe9/0x156 [947.585721] ? btrfs_cleanup_transaction.isra.0+0x407/0x407 [947.590104] kthread+0x131/0x139 [947.592168] ? set_kthread_struct+0x32/0x32 [947.595174] ret_from_fork+0x22/0x30 [947.597561] </TASK> [947.598553] ---[ end trace 644721052755541c ]--- This is because we started using writeback_inodes_sb() to flush delalloc when committing a transaction (when using -o flushoncommit), in order to avoid deadlocks with filesystem freeze operations. This change was made by commit ce8ea7c ("btrfs: don't call btrfs_start_delalloc_roots in flushoncommit"). After that change we started producing that warning, and every now and then a user reports this since the warning happens too often, it spams dmesg/syslog, and a user is unsure if this reflects any problem that might compromise the filesystem's reliability. We can not just lock the sb->s_umount semaphore before calling writeback_inodes_sb(), because that would at least deadlock with filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem() is called while we are holding that semaphore in write mode, and that can trigger a transaction commit, resulting in a deadlock. It would also trigger the same type of deadlock in the unmount path. Possibly, it could also introduce some other locking dependencies that lockdep would report. To fix this call try_to_writeback_inodes_sb() instead of writeback_inodes_sb(), because that will try to read lock sb->s_umount and then will only call writeback_inodes_sb() if it was able to lock it. This is fine because the cases where it can't read lock sb->s_umount are during a filesystem unmount or during a filesystem freeze - in those cases sb->s_umount is write locked and sync_filesystem() is called, which calls writeback_inodes_sb(). In other words, in all cases where we can't take a read lock on sb->s_umount, writeback is already being triggered elsewhere. An alternative would be to call btrfs_start_delalloc_roots() with a number of pages different from LONG_MAX, for example matching the number of delalloc bytes we currently have, in which case we would end up starting all delalloc with filemap_fdatawrite_wbc() and not with an async flush via filemap_flush() - that is only possible after the rather recent commit e076ab2 ("btrfs: shrink delalloc pages instead of full inodes"). However that creates a whole new can of worms due to new lock dependencies, which lockdep complains, like for example: [ 8948.247280] ====================================================== [ 8948.247823] WARNING: possible circular locking dependency detected [ 8948.248353] 5.17.0-rc1-btrfs-next-111 #1 Not tainted [ 8948.248786] ------------------------------------------------------ [ 8948.249320] kworker/u16:18/933570 is trying to acquire lock: [ 8948.249812] ffff9b3de1591690 (sb_internal#2){.+.+}-{0:0}, at: find_free_extent+0x141e/0x1590 [btrfs] [ 8948.250638] but task is already holding lock: [ 8948.251140] ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.252018] which lock already depends on the new lock. [ 8948.252710] the existing dependency chain (in reverse order) is: [ 8948.253343] -> #2 (&root->delalloc_mutex){+.+.}-{3:3}: [ 8948.253950] __mutex_lock+0x90/0x900 [ 8948.254354] start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.254859] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.255408] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.255942] btrfs_mksubvol+0x380/0x570 [btrfs] [ 8948.256406] btrfs_mksnapshot+0x81/0xb0 [btrfs] [ 8948.256870] __btrfs_ioctl_snap_create+0x17f/0x190 [btrfs] [ 8948.257413] btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs] [ 8948.257961] btrfs_ioctl+0x1196/0x3630 [btrfs] [ 8948.258418] __x64_sys_ioctl+0x83/0xb0 [ 8948.258793] do_syscall_64+0x3b/0xc0 [ 8948.259146] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.259709] -> #1 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}: [ 8948.260330] __mutex_lock+0x90/0x900 [ 8948.260692] btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.261234] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.261766] btrfs_set_free_space_cache_v1_active+0x38/0x60 [btrfs] [ 8948.262379] btrfs_start_pre_rw_mount+0x119/0x180 [btrfs] [ 8948.262909] open_ctree+0x1511/0x171e [btrfs] [ 8948.263359] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 8948.263863] legacy_get_tree+0x30/0x50 [ 8948.264242] vfs_get_tree+0x28/0xc0 [ 8948.264594] vfs_kern_mount.part.0+0x71/0xb0 [ 8948.265017] btrfs_mount+0x11d/0x3a0 [btrfs] [ 8948.265462] legacy_get_tree+0x30/0x50 [ 8948.265851] vfs_get_tree+0x28/0xc0 [ 8948.266203] path_mount+0x2d4/0xbe0 [ 8948.266554] __x64_sys_mount+0x103/0x140 [ 8948.266940] do_syscall_64+0x3b/0xc0 [ 8948.267300] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.267790] -> #0 (sb_internal#2){.+.+}-{0:0}: [ 8948.268322] __lock_acquire+0x12e8/0x2260 [ 8948.268733] lock_acquire+0xd7/0x310 [ 8948.269092] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.269591] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.270087] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.270588] cow_file_range+0x17e/0x490 [btrfs] [ 8948.271051] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.271586] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.272071] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.272579] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.273113] extent_writepages+0x76/0x130 [btrfs] [ 8948.273573] do_writepages+0xd2/0x1c0 [ 8948.273942] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.274371] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.274876] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.275417] flush_space+0x1f2/0x630 [btrfs] [ 8948.275863] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.276438] process_one_work+0x252/0x5a0 [ 8948.276829] worker_thread+0x55/0x3b0 [ 8948.277189] kthread+0xf2/0x120 [ 8948.277506] ret_from_fork+0x22/0x30 [ 8948.277868] other info that might help us debug this: [ 8948.278548] Chain exists of: sb_internal#2 --> &fs_info->delalloc_root_mutex --> &root->delalloc_mutex [ 8948.279601] Possible unsafe locking scenario: [ 8948.280102] CPU0 CPU1 [ 8948.280508] ---- ---- [ 8948.280915] lock(&root->delalloc_mutex); [ 8948.281271] lock(&fs_info->delalloc_root_mutex); [ 8948.281915] lock(&root->delalloc_mutex); [ 8948.282487] lock(sb_internal#2); [ 8948.282800] *** DEADLOCK *** [ 8948.283333] 4 locks held by kworker/u16:18/933570: [ 8948.283750] #0: ffff9b3dc00a9d48 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.284609] #1: ffffa90349dafe70 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.285637] #2: ffff9b3e14db5040 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}, at: btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.286674] #3: ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.287596] stack backtrace: [ 8948.287975] CPU: 3 PID: 933570 Comm: kworker/u16:18 Not tainted 5.17.0-rc1-btrfs-next-111 #1 [ 8948.288677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 8948.289649] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] [ 8948.290298] Call Trace: [ 8948.290517] <TASK> [ 8948.290700] dump_stack_lvl+0x59/0x73 [ 8948.291026] check_noncircular+0xf3/0x110 [ 8948.291375] ? start_transaction+0x228/0x6e0 [btrfs] [ 8948.291826] __lock_acquire+0x12e8/0x2260 [ 8948.292241] lock_acquire+0xd7/0x310 [ 8948.292714] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.293241] ? lock_is_held_type+0xea/0x140 [ 8948.293601] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.294055] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294518] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294957] ? _raw_spin_unlock+0x29/0x40 [ 8948.295312] ? btrfs_get_alloc_profile+0x124/0x290 [btrfs] [ 8948.295813] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.296270] cow_file_range+0x17e/0x490 [btrfs] [ 8948.296691] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.297175] ? find_lock_delalloc_range+0x247/0x270 [btrfs] [ 8948.297678] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.298123] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.298570] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.299061] extent_writepages+0x76/0x130 [btrfs] [ 8948.299495] do_writepages+0xd2/0x1c0 [ 8948.299817] ? sched_clock_cpu+0xd/0x110 [ 8948.300160] ? lock_release+0x155/0x4a0 [ 8948.300494] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.300874] ? do_raw_spin_unlock+0x4b/0xa0 [ 8948.301243] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.301706] ? lock_release+0x155/0x4a0 [ 8948.302055] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.302564] flush_space+0x1f2/0x630 [btrfs] [ 8948.302970] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.303510] process_one_work+0x252/0x5a0 [ 8948.303860] ? process_one_work+0x5a0/0x5a0 [ 8948.304221] worker_thread+0x55/0x3b0 [ 8948.304543] ? process_one_work+0x5a0/0x5a0 [ 8948.304904] kthread+0xf2/0x120 [ 8948.305184] ? kthread_complete_and_exit+0x20/0x20 [ 8948.305598] ret_from_fork+0x22/0x30 [ 8948.305921] </TASK> It all comes from the fact that btrfs_start_delalloc_roots() takes the delalloc_root_mutex, in the transaction commit path we are holding a read lock on one of the superblock's freeze semaphores (via sb_start_intwrite()), the async reclaim task can also do a call to btrfs_start_delalloc_roots(), which ends up triggering writeback with calls to filemap_fdatawrite_wbc(), resulting in extent allocation which in turn can call btrfs_start_transaction(), which will result in taking the freeze semaphore via sb_start_intwrite(), forming a nasty dependency on all those locks which can be taken in different orders by different code paths. So just adopt the simple approach of calling try_to_writeback_inodes_sb() at btrfs_start_delalloc_flush(). Link: https://lore.kernel.org/linux-btrfs/20220130005258.GA7465@cuci.nl/ Link: https://lore.kernel.org/linux-btrfs/43acc426-d683-d1b6-729d-c6bc4a2fff4d@gmail.com/ Link: https://lore.kernel.org/linux-btrfs/6833930a-08d7-6fbc-0141-eb9cdfd6bb4d@gmail.com/ Link: https://lore.kernel.org/linux-btrfs/20190322041731.GF16651@hungrycats.org/ Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> [ add more link reports ] Signed-off-by: David Sterba <dsterba@suse.com>

Yonghong Song says: ==================== The patch [1] exposed a bpf_timer initialization bug in function check_and_init_map_value(). With bug fix here, the patch [1] can be applied with all selftests passed. Please see individual patches for fix details. [1] https://lore.kernel.org/bpf/20220209070324.1093182-2-memxor@gmail.com/ Changelog: v3 -> v4: . move header file in patch #1 to avoid bpf-next merge conflict v2 -> v3: . switch patch #1 and patch #2 for better bisecting v1 -> v2: . add Fixes tag for patch #1 . rebase against bpf tree ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>

ojeda and others added 2 commits January 10, 2021 16:25

trigger __rust_probestack in example 3

6414d13

adamrk force-pushed the rust-rustc-kbuild branch from 9ea67cb to 7c6155b Compare January 20, 2021 08:22

adamrk closed this Jan 21, 2021

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Trigger __rust_probestack in example 3 #2

Trigger __rust_probestack in example 3 #2

adamrk commented Jan 20, 2021

Trigger __rust_probestack in example 3 #2

Trigger __rust_probestack in example 3 #2

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adamrk commented Jan 20, 2021