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[ Upstream commit f45140d ] If the loop times out then we want to exit with "to" set to zero, but in the current code it's set to -1. Fixes: c575b7e ("drm/xen-front: Add support for Xen PV display frontend") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180508092829.GC661@mwanda
[ Upstream commit 069035c ] When unplugging a hotpluggable DRM device we first unregister it with drm_dev_unregister and then set drm_device.unplugged flag which is used to mark device critical sections with drm_dev_enter()/ drm_dev_exit() preventing access to device resources that are not available after the device is gone. But drm_dev_unregister may lead to hotplug uevent(s) fired to user-space on card and/or connector removal, thus making it possible for user-space to try accessing a disconnected device. Fix this by first making sure device is properly marked as disconnected and only then unregister it. Fixes: bee330f ("drm: Use srcu to protect drm_device.unplugged") Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reported-by: Andrii Chepurnyi <andrii_chepurnyi@epam.com> Cc: "Noralf Trønnes" <noralf@tronnes.org> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20180522141304.18646-1-andr2000@gmail.com
[ Upstream commit 6e3cc2a ] Only gnttab_{alloc|free}_pages are exported as EXPORT_SYMBOL while all the rest are exported as EXPORT_SYMBOL_GPL, thus effectively making it not possible for non-GPL driver modules to use grant table module. Export gnttab_{alloc|free}_pages as EXPORT_SYMBOL_GPL so all the exports are aligned. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
[ Upstream commit 8c3799e ] Make set/clear page private code shared and accessible to other kernel modules which can re-use these instead of open-coding. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
[ Upstream commit ae4c51a with 4.14 fixes ] Memory {increase|decrease}_reservation and VA mappings update/reset code used in balloon driver can be made common, so other drivers can also re-use the same functionality without open-coding. Create a dedicated file for the shared code and export corresponding symbols for other kernel modules. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
[ Upstream commit 9bdc730 ] Extend grant table module API to allow allocating buffers that can be used for DMA operations and mapping foreign grant references on top of those. The resulting buffer is similar to the one allocated by the balloon driver in that proper memory reservation is made by ({increase|decrease}_reservation and VA mappings are updated if needed). This is useful for sharing foreign buffers with HW drivers which cannot work with scattered buffers provided by the balloon driver, but require DMAable memory instead. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
[ Upstream commit 975ef7f with 4.14 fixes ] Fixes for 4.14: - provide a fake bus to miscdevice, so of_dma_configure can complete Allow mappings for DMA backed buffers if grant table module supports such: this extends grant device to not only map buffers made of balloon pages, but also from buffers allocated with dma_alloc_xxx. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
[ Upstream commit 1d31456 ] This is in preparation for adding support of DMA buffer functionality: make map/unmap related code and structures, used privately by gntdev, ready for dma-buf extension, which will re-use these. Rename corresponding structures as those become non-private to gntdev now. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
[ Upstream commit 932d656 ] Add UAPI and IOCTLs for dma-buf grant device driver extension: the extension allows userspace processes and kernel modules to use Xen backed dma-buf implementation. With this extension grant references to the pages of an imported dma-buf can be exported for other domain use and grant references coming from a foreign domain can be converted into a local dma-buf for local export. Implement basic initialization and stubs for Xen DMA buffers' support. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
[ Upstream commit a240d6e with fixes for 4.14 ] Fixes for 4.14: - implement struct dma_buf_ops.map_atomic/unmap_atomic 1. Create a dma-buf from grant references provided by the foreign domain. By default dma-buf is backed by system memory pages, but by providing GNTDEV_DMA_FLAG_XXX flags it can also be created as a DMA write-combine/coherent buffer, e.g. allocated with corresponding dma_alloc_xxx API. Export the resulting buffer as a new dma-buf. 2. Implement waiting for the dma-buf to be released: block until the dma-buf with the file descriptor provided is released. If within the time-out provided the buffer is not released then -ETIMEDOUT error is returned. If the buffer with the file descriptor does not exist or has already been released, then -ENOENT is returned. For valid file descriptors this must not be treated as error. 3. Make gntdev's common code and structures available to dma-buf. [boris: added 'args.fd = -1' to dmabuf_exp_from_refs() to avoid an unnecessary warning about it not being initialized on i386 with gcc 8.1.1] Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
[ Upstream commit bf8dc55 ] 1. Import a dma-buf with the file descriptor provided and export granted references to the pages of that dma-buf into the array of grant references. 2. Add API to close all references to an imported buffer, so it can be released by the owner. This is only valid for buffers created with IOCTL_GNTDEV_DMABUF_IMP_TO_REFS. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
[ Upstream commit 2789e83 ] Currently when the allocation of gntdev_dmabuf fails, the error exit path will call dmabuf_imp_free_storage and causes a null pointer dereference on gntdev_dmabuf. Fix this by adding an error exit path that won't free gntdev_dmabuf. Detected by CoverityScan, CID#1472124 ("Dereference after null check") Fixes: bf8dc55 ("xen/gntdev: Implement dma-buf import functionality") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
added 2 commits
December 19, 2018 15:10
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
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andr2000
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Jan 29, 2019
Since commit b89d82e ("arm64: kpti: Avoid rewriting early page tables when KASLR is enabled"), a kernel built with CONFIG_RANDOMIZE_BASE can decide early whether to use non-global mappings by checking the kaslr_offset(). A kernel built without CONFIG_RANDOMIZE_BASE, instead checks the cpufeature static-key. This leaves a gap where CONFIG_RANDOMIZE_BASE was enabled, no kaslr seed was provided, but kpti was forced on using the cmdline option. When the decision is made late, kpti_install_ng_mappings() will re-write the page tables, but arm64_kernel_use_ng_mappings()'s value does not change as it only tests the cpufeature static-key if CONFIG_RANDOMIZE_BASE is disabled. This function influences PROT_DEFAULT via PTE_MAYBE_NG, and causes pgattr_change_is_safe() to catch nG->G transitions when the unchanged PROT_DEFAULT is used as part of PAGE_KERNEL_RO: [ 1.942255] alternatives: patching kernel code [ 1.998288] ------------[ cut here ]------------ [ 2.000693] kernel BUG at arch/arm64/mm/mmu.c:165! [ 2.019215] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 2.020257] Modules linked in: [ 2.020807] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2 xen-troops#51 [ 2.021917] Hardware name: linux,dummy-virt (DT) [ 2.022790] pstate: 40000005 (nZcv daif -PAN -UAO) [ 2.023742] pc : __create_pgd_mapping+0x508/0x6d0 [ 2.024671] lr : __create_pgd_mapping+0x500/0x6d0 [ 2.058059] Process swapper/0 (pid: 1, stack limit = 0x(____ptrval____)) [ 2.059369] Call trace: [ 2.059845] __create_pgd_mapping+0x508/0x6d0 [ 2.060684] update_mapping_prot+0x48/0xd0 [ 2.061477] mark_linear_text_alias_ro+0xdc/0xe4 [ 2.070502] smp_cpus_done+0x90/0x98 [ 2.071216] smp_init+0x100/0x114 [ 2.071878] kernel_init_freeable+0xd4/0x220 [ 2.072750] kernel_init+0x10/0x100 [ 2.073455] ret_from_fork+0x10/0x18 [ 2.075414] ---[ end trace 3572f3a7782292de ]--- [ 2.076389] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b If arm64_kernel_unmapped_at_el0() is true, arm64_kernel_use_ng_mappings() should also be true. Signed-off-by: James Morse <james.morse@arm.com> CC: Ard Biesheuvel <ard.biesheuvel@linaro.org> CC: John Garry <john.garry@huawei.com> CC: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
andr2000
pushed a commit
to andr2000/linux
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Mar 14, 2019
Due to quadratic behavior of x25_new_lci(), syzbot was able to trigger an rcu stall. Fix this by not blocking BH for the whole duration of the function, and inserting a reschedule point when possible. If we care enough, using a bitmap could get rid of the quadratic behavior. syzbot report : rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=4fa/1/0x4000000000000002 softirq=283376/283376 fqs=0 rcu: (t=10501 jiffies g=383105 q=136) rcu: rcu_preempt kthread starved for 10502 jiffies! g383105 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt I28928 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2844 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3485 schedule+0x92/0x180 kernel/sched/core.c:3529 schedule_timeout+0x4db/0xfd0 kernel/time/timer.c:1803 rcu_gp_fqs_loop kernel/rcu/tree.c:1948 [inline] rcu_gp_kthread+0x956/0x17a0 kernel/rcu/tree.c:2105 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 0 CPU: 0 PID: 8759 Comm: syz-executor2 Not tainted 5.0.0-rc4+ xen-troops#51 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree.c:1211 print_cpu_stall kernel/rcu/tree.c:1348 [inline] check_cpu_stall kernel/rcu/tree.c:1422 [inline] rcu_pending kernel/rcu/tree.c:3018 [inline] rcu_check_callbacks.cold+0x500/0xa4a kernel/rcu/tree.c:2521 update_process_times+0x32/0x80 kernel/time/timer.c:1635 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline] smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 </IRQ> RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline] RIP: 0010:queued_write_lock_slowpath+0x13e/0x290 kernel/locking/qrwlock.c:86 Code: 00 00 fc ff df 4c 8d 2c 01 41 83 c7 03 41 0f b6 45 00 41 38 c7 7c 08 84 c0 0f 85 0c 01 00 00 8b 03 3d 00 01 00 00 74 1a f3 90 <41> 0f b6 55 00 41 38 d7 7c eb 84 d2 74 e7 48 89 df e8 6c 0f 4f 00 RSP: 0018:ffff88805f117bd8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000300 RBX: ffffffff89413ba0 RCX: 1ffffffff1282774 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff89413ba0 RBP: ffff88805f117c70 R08: 1ffffffff1282774 R09: fffffbfff1282775 R10: fffffbfff1282774 R11: ffffffff89413ba3 R12: 00000000000000ff R13: fffffbfff1282774 R14: 1ffff1100be22f7d R15: 0000000000000003 queued_write_lock include/asm-generic/qrwlock.h:104 [inline] do_raw_write_lock+0x1d6/0x290 kernel/locking/spinlock_debug.c:203 __raw_write_lock_bh include/linux/rwlock_api_smp.h:204 [inline] _raw_write_lock_bh+0x3b/0x50 kernel/locking/spinlock.c:312 x25_insert_socket+0x21/0xe0 net/x25/af_x25.c:267 x25_bind+0x273/0x340 net/x25/af_x25.c:705 __sys_bind+0x23f/0x290 net/socket.c:1505 __do_sys_bind net/socket.c:1516 [inline] __se_sys_bind net/socket.c:1514 [inline] __x64_sys_bind+0x73/0xb0 net/socket.c:1514 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e39 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fafccd0dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39 RDX: 0000000000000012 RSI: 0000000020000240 RDI: 0000000000000004 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fafccd0e6d4 R13: 00000000004bdf8b R14: 00000000004ce4b8 R15: 00000000ffffffff Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8752 Comm: syz-executor4 Not tainted 5.0.0-rc4+ xen-troops#51 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__x25_find_socket+0x78/0x120 net/x25/af_x25.c:328 Code: 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 a6 00 00 00 4d 8b 64 24 68 4d 85 e4 74 7f e8 03 97 3d fb 49 83 ec 68 74 74 e8 f8 96 3d fb <49> 8d bc 24 88 04 00 00 48 89 f8 48 c1 e8 03 0f b6 04 18 84 c0 74 RSP: 0018:ffff8880639efc58 EFLAGS: 00000246 RAX: 0000000000040000 RBX: dffffc0000000000 RCX: ffffc9000e677000 RDX: 0000000000040000 RSI: ffffffff863244b8 RDI: ffff88806a764628 RBP: ffff8880639efc80 R08: ffff8880a80d05c0 R09: fffffbfff1282775 R10: fffffbfff1282774 R11: ffffffff89413ba3 R12: ffff88806a7645c0 R13: 0000000000000001 R14: ffff88809f29ac00 R15: 0000000000000000 FS: 00007fe8d0c58700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32823000 CR3: 00000000672eb000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: x25_new_lci net/x25/af_x25.c:357 [inline] x25_connect+0x374/0xdf0 net/x25/af_x25.c:786 __sys_connect+0x266/0x330 net/socket.c:1686 __do_sys_connect net/socket.c:1697 [inline] __se_sys_connect net/socket.c:1694 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1694 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e39 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe8d0c57c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39 RDX: 0000000000000012 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe8d0c586d4 R13: 00000000004be378 R14: 00000000004ceb00 R15: 00000000ffffffff Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Andrew Hendry <andrew.hendry@gmail.com> Cc: linux-x25@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
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Please note this PR also aligns target branch with branch being used for DomD in the context of DRM/grant-table stuff.