- 15 Jun, 2016 1 commit
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Robin Murphy authored
This reverts commit 1733a2ad. There is apparently something amiss with the way the TTM code handles DMA buffers, which the above commit was attempting to work around for arm64 systems with non-coherent PCI. Unfortunately, this completely breaks systems *with* coherent PCI (which appear to be the majority). Booting a plain arm64 defconfig + CONFIG_DRM + CONFIG_DRM_NOUVEAU on a machine with a PCI GPU having coherent dma_map_ops (in this case a 7600GT card plugged into an ARM Juno board) results in a fatal crash: [ 2.803438] nouveau 0000:06:00.0: DRM: allocated 1024x768 fb: 0x9000, bo ffffffc976141c00 [ 2.897662] Unable to handle kernel NULL pointer dereference at virtual address 000001ac [ 2.897666] pgd = ffffff8008e00000 [ 2.897675] [000001ac] *pgd=00000009ffffe003, *pud=00000009ffffe003, *pmd=0000000000000000 [ 2.897680] Internal error: Oops: 96000045 [#1] PREEMPT SMP [ 2.897685] Modules linked in: [ 2.897692] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.6.0-rc5+ #543 [ 2.897694] Hardware name: ARM Juno development board (r1) (DT) [ 2.897699] task: ffffffc9768a0000 ti: ffffffc9768a8000 task.ti: ffffffc9768a8000 [ 2.897711] PC is at __memcpy+0x7c/0x180 [ 2.897719] LR is at OUT_RINGp+0x34/0x70 [ 2.897724] pc : [<ffffff80083465fc>] lr : [<ffffff800854248c>] pstate: 80000045 [ 2.897726] sp : ffffffc9768ab360 [ 2.897732] x29: ffffffc9768ab360 x28: 0000000000000001 [ 2.897738] x27: ffffffc97624c000 x26: 0000000000000000 [ 2.897744] x25: 0000000000000080 x24: 0000000000006c00 [ 2.897749] x23: 0000000000000005 x22: ffffffc97624c010 [ 2.897755] x21: 0000000000000004 x20: 0000000000000004 [ 2.897761] x19: ffffffc9763da000 x18: ffffffc976b2491c [ 2.897766] x17: 0000000000000007 x16: 0000000000000006 [ 2.897771] x15: 0000000000000001 x14: 0000000000000001 [ 2.897777] x13: 0000000000e31b70 x12: ffffffc9768a0080 [ 2.897783] x11: 0000000000000000 x10: fffffffffffffb00 [ 2.897788] x9 : 0000000000000000 x8 : 0000000000000000 [ 2.897793] x7 : 0000000000000000 x6 : 00000000000001ac [ 2.897799] x5 : 00000000ffffffff x4 : 0000000000000000 [ 2.897804] x3 : 0000000000000010 x2 : 0000000000000010 [ 2.897810] x1 : ffffffc97624c010 x0 : 00000000000001ac ... [ 2.898494] Call trace: [ 2.898499] Exception stack(0xffffffc9768ab1a0 to 0xffffffc9768ab2c0) [ 2.898506] b1a0: ffffffc9763da000 0000000000000004 ffffffc9768ab360 ffffff80083465fc [ 2.898513] b1c0: ffffffc976801e00 ffffffc9762b8000 ffffffc9768ab1f0 ffffff80080ec158 [ 2.898520] b1e0: ffffffc9768ab230 ffffff8008496d04 ffffffc975ce6d80 ffffffc9768ab36e [ 2.898527] b200: ffffffc9768ab36f ffffffc9768ab29d ffffffc9768ab29e ffffffc9768a0000 [ 2.898533] b220: ffffffc9768ab250 ffffff80080e70c0 ffffffc9768ab270 ffffff8008496e44 [ 2.898540] b240: 00000000000001ac ffffffc97624c010 0000000000000010 0000000000000010 [ 2.898546] b260: 0000000000000000 00000000ffffffff 00000000000001ac 0000000000000000 [ 2.898552] b280: 0000000000000000 0000000000000000 fffffffffffffb00 0000000000000000 [ 2.898558] b2a0: ffffffc9768a0080 0000000000e31b70 0000000000000001 0000000000000001 [ 2.898566] [<ffffff80083465fc>] __memcpy+0x7c/0x180 [ 2.898574] [<ffffff800853e164>] nv04_fbcon_imageblit+0x1d4/0x2e8 [ 2.898582] [<ffffff800853d6d0>] nouveau_fbcon_imageblit+0xd8/0xe0 [ 2.898591] [<ffffff80083c4db4>] soft_cursor+0x154/0x1d8 [ 2.898598] [<ffffff80083c47b4>] bit_cursor+0x4fc/0x538 [ 2.898605] [<ffffff80083c0cfc>] fbcon_cursor+0x134/0x1a8 [ 2.898613] [<ffffff800841c280>] hide_cursor+0x38/0xa0 [ 2.898620] [<ffffff800841d420>] redraw_screen+0x120/0x228 [ 2.898628] [<ffffff80083bf268>] fbcon_prepare_logo+0x370/0x3f8 [ 2.898635] [<ffffff80083bf640>] fbcon_init+0x350/0x560 [ 2.898641] [<ffffff800841c634>] visual_init+0xac/0x108 [ 2.898648] [<ffffff800841df14>] do_bind_con_driver+0x1c4/0x3a8 [ 2.898655] [<ffffff800841e4f4>] do_take_over_console+0x174/0x1e8 [ 2.898662] [<ffffff80083bf8c4>] do_fbcon_takeover+0x74/0x100 [ 2.898669] [<ffffff80083c3e44>] fbcon_event_notify+0x8cc/0x920 [ 2.898680] [<ffffff80080d7e38>] notifier_call_chain+0x50/0x90 [ 2.898685] [<ffffff80080d8214>] __blocking_notifier_call_chain+0x4c/0x90 [ 2.898691] [<ffffff80080d826c>] blocking_notifier_call_chain+0x14/0x20 [ 2.898696] [<ffffff80083c5e1c>] fb_notifier_call_chain+0x1c/0x28 [ 2.898703] [<ffffff80083c81ac>] register_framebuffer+0x1cc/0x2e0 [ 2.898712] [<ffffff800845da80>] drm_fb_helper_initial_config+0x288/0x3e8 [ 2.898719] [<ffffff800853da20>] nouveau_fbcon_init+0xe0/0x118 [ 2.898727] [<ffffff800852d2f8>] nouveau_drm_load+0x268/0x890 [ 2.898734] [<ffffff8008466e24>] drm_dev_register+0xbc/0xc8 [ 2.898740] [<ffffff8008468a88>] drm_get_pci_dev+0xa0/0x180 [ 2.898747] [<ffffff800852cb28>] nouveau_drm_probe+0x1a0/0x1e0 [ 2.898755] [<ffffff80083a32e0>] pci_device_probe+0x98/0x110 [ 2.898763] [<ffffff800858e434>] driver_probe_device+0x204/0x2b0 [ 2.898770] [<ffffff800858e58c>] __driver_attach+0xac/0xb0 [ 2.898777] [<ffffff800858c3e0>] bus_for_each_dev+0x60/0xa0 [ 2.898783] [<ffffff800858dbc0>] driver_attach+0x20/0x28 [ 2.898789] [<ffffff800858d7b0>] bus_add_driver+0x1d0/0x238 [ 2.898796] [<ffffff800858ed50>] driver_register+0x60/0xf8 [ 2.898802] [<ffffff80083a20dc>] __pci_register_driver+0x3c/0x48 [ 2.898809] [<ffffff8008468eb4>] drm_pci_init+0xf4/0x120 [ 2.898818] [<ffffff8008c56fc0>] nouveau_drm_init+0x21c/0x230 [ 2.898825] [<ffffff80080829d4>] do_one_initcall+0x8c/0x190 [ 2.898832] [<ffffff8008c31af4>] kernel_init_freeable+0x14c/0x1f0 [ 2.898839] [<ffffff80088a0c20>] kernel_init+0x10/0x100 [ 2.898845] [<ffffff8008085e10>] ret_from_fork+0x10/0x40 [ 2.898853] Code: a88120c7 a8c12027 a88120c7 a8c12027 (a88120c7) [ 2.898871] ---[ end trace d5713dcad023ee04 ]--- [ 2.898888] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b In a toss-up between the GPU seeing stale data artefacts on some systems vs. catastrophic kernel crashes on other systems, the latter would seem to take precedence, so revert this change until the real underlying problem can be fixed. Signed-off-by:
Robin Murphy <robin.murphy@arm.com> Acked-by:
Alexandre Courbot <acourbot@nvidia.com> [acourbot@nvidia.com: port to Nouveau tree, remove bits in lib/] Signed-off-by:
Ben Skeggs <bskeggs@redhat.com> Cc: stable@vger.kernel.org
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- 06 Jun, 2016 2 commits
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Ben Skeggs authored
Signed-off-by: -
Ben Skeggs authored
It appears that, for whatever reason, both link A and B use the same register to control the training pattern. It's a little odd, as the GPUs before this (Tesla/Fermi1) have per-link registers, as do newer GPUs (Maxwell). Fixes the third DP output on NVS 510 (GK107). Signed-off-by:
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- 02 Jun, 2016 5 commits
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Ben Skeggs authored
Fixes a use-after-free reported by valgrind and KASAN. Signed-off-by: -
Ben Skeggs authored
Reported by KASAN. Signed-off-by: -
Ben Skeggs authored
Signed-off-by: -
Ben Skeggs authored
Signed-off-by: -
Ben Skeggs authored
As it turns out, a value of 0xff means "any protocol" and not "VGA". Signed-off-by:
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- 24 May, 2016 32 commits
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Arnd Bergmann authored
A recent addition to the DRM tree for 4.7 added 'extern "C"' guards for c++ to all the DRM headers, and that now causes warnings in 'make headers_check': usr/include/drm/amdgpu_drm.h:38: userspace cannot reference function or variable defined in the kernel usr/include/drm/drm.h:63: userspace cannot reference function or variable defined in the kernel usr/include/drm/drm.h:699: userspace cannot reference function or variable defined in the kernel usr/include/drm/drm_fourcc.h:30: userspace cannot reference function or variable defined in the kernel usr/include/drm/drm_mode.h:33: userspace cannot reference function or variable defined in the kernel usr/include/drm/drm_sarea.h:38: userspace cannot reference function or variable defined in the kernel usr/include/drm/exynos_drm.h:21: userspace cannot reference function or variable defined in the kernel usr/include/drm/i810_drm.h:7: userspace cannot reference function or variable defined in the kernel This changes the headers_check.pl script to not warn about this. I'm listing the merge commit as introducing the problem, because there are several patches in this branch that each do this for one file. Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Fixes: 7c10ddf8 ("Merge branch 'drm-uapi-extern-c-fixes' of https://github.com/evelikov/linux into drm-next") Reviewed-by:
Emil Velikov <emil.l.velikov@gmail.com> Signed-off-by:
Dave Airlie <airlied@redhat.com>
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Linus Torvalds authored
Merge yet more updates from Andrew Morton: - Oleg's "wait/ptrace: assume __WALL if the child is traced". It's a kernel-based workaround for existing userspace issues. - A few hotfixes - befs cleanups - nilfs2 updates - sys_wait() changes - kexec updates - kdump - scripts/gdb updates - the last of the MM queue - a few other misc things * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (84 commits) kgdb: depends on VT drm/amdgpu: make amdgpu_mn_get wait for mmap_sem killable drm/radeon: make radeon_mn_get wait for mmap_sem killable drm/i915: make i915_gem_mmap_ioctl wait for mmap_sem killable uprobes: wait for mmap_sem for write killable prctl: make PR_SET_THP_DISABLE wait for mmap_sem killable exec: make exec path waiting for mmap_sem killable aio: make aio_setup_ring killable coredump: make coredump_wait wait for mmap_sem for write killable vdso: make arch_setup_additional_pages wait for mmap_sem for write killable ipc, shm: make shmem attach/detach wait for mmap_sem killable mm, fork: make dup_mmap wait for mmap_sem for write killable mm, proc: make clear_refs killable mm: make vm_brk killable mm, elf: handle vm_brk error mm, aout: handle vm_brk failures mm: make vm_munmap killable mm: make vm_mmap killable mm: make mmap_sem for write waits killable for mm syscalls MAINTAINERS: add co-maintainer for scripts/gdb ...
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Linus Torvalds authored
Merge tag 'linux-kselftest-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pull kselftest updates from Shuah Khan: "This update for Kselftest adds: - a new ftrace testcase - fixes for ftrace and intel_pstate tests" * tag 'linux-kselftest-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: tools: testing: define the _GNU_SOURCE macro kselftests/ftrace: Add a test case for event pid filtering kselftests/ftrace: Detect tracefs mount point
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-traceLinus Torvalds authored
Pull tracing fix from Steven Rostedt: "Reviewing the selftest I recently submitted, I realize that the second part of it uses my old hack to get the PID of the spawned background tasks, which doesn't work for all shells, instead of the common use of $!" * tag 'trace-v4.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftracetest: Use proper logic to find process PID
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git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds authored
Pull arch/tile updates from Chris Metcalf: "This is an even quieter cycle than usual" * git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: Fix typo Fix typo Fix typo tile: sort the "select" lines in the TILE/TILEGX configs tile: clarify barrier semantics of atomic_add_return tile/defconfigs: Remove CONFIG_IPV6_PRIVACY
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/libataLinus Torvalds authored
Pull libata sata_dwc_460ex updates from Tejun Heo: "Patches to bring sata_dwc_460ex up to snuff. It was a separate pull request because it depends on dmaengine dw platform changes which are now in mainline" * 'for-4.7-dw' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata: (24 commits) ata: dwc: add DMADEVICES dependency powerpc/4xx: Device tree update for the 460ex DWC SATA ata: sata_dwc_460ex: make debug messages neat ata: sata_dwc_460ex: supply physical address of FIFO to DMA ata: sata_dwc_460ex: use devm_ioremap ata: sata_dwc_460ex: tidy up sata_dwc_clear_dmacr() ata: sata_dwc_460ex: use readl/writel_relaxed() ata: sata_dwc_460ex: switch to new dmaengine_terminate_* API ata: sata_dwc_460ex: add __iomem to register base pointer ata: sata_dwc_460ex: get rid of incorrect cast ata: sata_dwc_460ex: get rid of some pointless casts ata: sata_dwc_460ex: remove empty libata callback ata: sata_dwc_460ex: correct HOSTDEV{P}_FROM_*() macros ata: sata_dwc_460ex: get rid of global data ata: sata_dwc_460ex: add phy support ata: sata_dwc_460ex: use "dmas" DT property to find dma channel ata: sata_dwc_460ex: don't call ata_sff_qc_issue() on DMA commands ata: sata_dwc_460ex: skip dma setup for non-dma commands ata: sata_dwc_460ex: select only core part of DMA driver ata: sata_dwc_460ex: DMA is always a flow controller ...
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/libataLinus Torvalds authored
Pull libata ZAC support from Tejun Heo: "This contains Zone ATA Command support for Shingled Magnetic Recording devices. In addition to sending the new commands down to the device, as ZAC commands depend on getting a lot of responses from the device, piping up responses is beefed up too. However, it doesn't involve changes to libata core mechanism or its interaction with upper layers, so I'm not expecting too many fallouts. Kudos to Hannes for driving SMR support" * 'for-4.7-zac' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata: (28 commits) libata: support host-aware and host-managed ZAC devices libata: support device-managed ZAC devices libata: NCQ encapsulation for ZAC MANAGEMENT OUT libata: Implement ZBC OUT translation libata: implement ZBC IN translation libata: fixup ZAC device disabling libata-scsi: Generate sense code for disabled devices libata-trace: decode subcommands libata: Check log page directory before accessing pages libata: Add command definitions for NCQ Encapsulation for READ LOG DMA EXT libata: Separate out ata_dev_config_ncq_send_recv() libata/libsas: Define ATA_CMD_NCQ_NON_DATA libsas: enable FPDMA SEND/RECEIVE libata: do not attempt to retrieve sense code twice libata-scsi: Set information sense field for invalid parameter libata-scsi: set bit pointer for sense code information libata-scsi: Set field pointer in sense code scsi: add scsi_set_sense_field_pointer() libata: Implement control mode page to select sense format libata-scsi: generate correct ATA pass-through sense ...
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git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-securityLinus Torvalds authored
Pull more security subsystem updates from James Morris: "Minor updates for the keys code" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: MAINTAINERS: Update keyrings record and add asymmetric keys record lib: asn1_decoder - add MODULE_LICENSE("GPL") KEYS: The PKCS#7 test key type should use the secondary keyring
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Jiri Slaby authored
With VT=n, the kernel build fails with: drivers/built-in.o: In function `kgdboc_pre_exp_handler': kgdboc.c:(.text+0x7b5aa): undefined reference to `fg_console' kgdboc.c:(.text+0x7b5ce): undefined reference to `vc_cons' kgdboc.c:(.text+0x7b5d5): undefined reference to `vc_cons' kgdboc.o is built when KGDB_SERIAL_CONSOLE is set. So make KGDB_SERIAL_CONSOLE depend on HW_CONSOLE which includes those symbols. Link: http://lkml.kernel.org/r/1459412955-4696-1-git-send-email-jslaby@suse.czSigned-off-by:
Jiri Slaby <jslaby@suse.cz> Reported-by:
"Jim Davis" <jim.epost@gmail.com> Acked-by:
Jason Wessel <jason.wessel@windriver.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Michal Hocko authored
amdgpu_mn_get which is called during ioct path relies on mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. [arnd@arndb.de: use ERR_PTR() to return from amdgpu_mn_get] Signed-off-by:
Michal Hocko <mhocko@suse.com> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Reviewed-by:
Christian König <christian.koenig@amd.com> Cc: David Airlie <airlied@linux.ie> Cc: Alex Deucher <alexander.deucher@amd.com> Signed-off-by:
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Michal Hocko authored
radeon_mn_get which is called during ioct path relies on mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by:
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Michal Hocko authored
i915_gem_mmap_ioctl relies on mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by:
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Michal Hocko authored
xol_add_vma needs mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Do not warn in dup_xol_work if __create_xol_area failed due to fatal signal pending because this is usually considered a kernel issue. Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Acked-by:
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Michal Hocko authored
PR_SET_THP_DISABLE requires mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by:
Alex Thorlton <athorlton@sgi.com> Signed-off-by:
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Michal Hocko authored
setup_arg_pages requires mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. All the callers are already handling error path and the fatal signal doesn't need any additional treatment. The same applies to __bprm_mm_init. Signed-off-by:
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Michal Hocko authored
aio_setup_ring waits for mmap_sem in writable mode. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. This will also expedite the return to the userspace and do_exit. Signed-off-by:
Jeff Moyer <jmoyer@redhat.com> Acked-by:
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Michal Hocko authored
coredump_wait waits for mmap_sem for write currently which can prevent oom_reaper to reclaim the oom victims address space asynchronously because that requires mmap_sem for read. This might happen if the oom victim is multi threaded and some thread(s) is holding mmap_sem for read (e.g. page fault) and it is stuck in the page allocator while other thread(s) reached coredump_wait already. This patch simply uses down_write_killable and bails out with EINTR if the lock got interrupted by the fatal signal. do_coredump will return right away and do_group_exit will take care to zap the whole thread group. Signed-off-by:
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Michal Hocko authored
most architectures are relying on mmap_sem for write in their arch_setup_additional_pages. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by:
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Michal Hocko authored
shmat and shmdt rely on mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by:
Davidlohr Bueso <dave@stgolabs.net> Acked-by:
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Michal Hocko authored
dup_mmap needs to lock current's mm mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by:
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Michal Hocko authored
CLEAR_REFS_MM_HIWATER_RSS and CLEAR_REFS_SOFT_DIRTY are relying on mmap_sem for write. If the waiting task gets killed by the oom killer and it would operate on the current's mm it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. This will also expedite the return to the userspace and do_exit even if the mm is remote. Signed-off-by:
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Michal Hocko authored
Now that all the callers handle vm_brk failure we can change it wait for mmap_sem killable to help oom_reaper to not get blocked just because vm_brk gets blocked behind mmap_sem readers. Signed-off-by:
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Michal Hocko authored
load_elf_library doesn't handle vm_brk failure although nothing really indicates it cannot do that because the function is allowed to fail due to vm_mmap failures already. This might be not a problem now but later patch will make vm_brk killable (resp. mmap_sem for write waiting will become killable) and so the failure will be more probable. Signed-off-by:
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Michal Hocko authored
vm_brk is allowed to fail but load_aout_binary simply ignores the error and happily continues. I haven't noticed any problem from that in real life but later patches will make the failure more likely because vm_brk will become killable (resp. mmap_sem for write waiting will become killable) so we should be more careful now. The error handling should be quite straightforward because there are calls to vm_mmap which check the error properly already. The only notable exception is set_brk which is called after beyond_if label. But nothing indicates that we cannot move it above set_binfmt as the two do not depend on each other and fail before we do set_binfmt and alter reference counting. Signed-off-by:
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Michal Hocko authored
Almost all current users of vm_munmap are ignoring the return value and so they do not handle potential error. This means that some VMAs might stay behind. This patch doesn't try to solve those potential problems. Quite contrary it adds a new failure mode by using down_write_killable in vm_munmap. This should be safer than other failure modes, though, because the process is guaranteed to die as soon as it leaves the kernel and exit_mmap will clean the whole address space. This will help in the OOM conditions when the oom victim might be stuck waiting for the mmap_sem for write which in turn can block oom_reaper which relies on the mmap_sem for read to make a forward progress and reclaim the address space of the victim. Signed-off-by:
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Michal Hocko authored
All the callers of vm_mmap seem to check for the failure already and bail out in one way or another on the error which means that we can change it to use killable version of vm_mmap_pgoff and return -EINTR if the current task gets killed while waiting for mmap_sem. This also means that vm_mmap_pgoff can be killable by default and drop the additional parameter. This will help in the OOM conditions when the oom victim might be stuck waiting for the mmap_sem for write which in turn can block oom_reaper which relies on the mmap_sem for read to make a forward progress and reclaim the address space of the victim. Please note that load_elf_binary is ignoring vm_mmap error for current->personality & MMAP_PAGE_ZERO case but that shouldn't be a problem because the address is not used anywhere and we never return to the userspace if we got killed. Signed-off-by:
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Michal Hocko authored
This is a follow up work for oom_reaper [1]. As the async OOM killing depends on oom_sem for read we would really appreciate if a holder for write didn't stood in the way. This patchset is changing many of down_write calls to be killable to help those cases when the writer is blocked and waiting for readers to release the lock and so help __oom_reap_task to process the oom victim. Most of the patches are really trivial because the lock is help from a shallow syscall paths where we can return EINTR trivially and allow the current task to die (note that EINTR will never get to the userspace as the task has fatal signal pending). Others seem to be easy as well as the callers are already handling fatal errors and bail and return to userspace which should be sufficient to handle the failure gracefully. I am not familiar with all those code paths so a deeper review is really appreciated. As this work is touching more areas which are not directly connected I have tried to keep the CC list as small as possible and people who I believed would be familiar are CCed only to the specific patches (all should have received the cover though). This patchset is based on linux-next and it depends on down_write_killable for rw_semaphores which got merged into tip locking/rwsem branch and it is merged into this next tree. I guess it would be easiest to route these patches via mmotm because of the dependency on the tip tree but if respective maintainers prefer other way I have no objections. I haven't covered all the mmap_write(mm->mmap_sem) instances here $ git grep "down_write(.*\<mmap_sem\>)" next/master | wc -l 98 $ git grep "down_write(.*\<mmap_sem\>)" | wc -l 62 I have tried to cover those which should be relatively easy to review in this series because this alone should be a nice improvement. Other places can be changed on top. [0] http://lkml.kernel.org/r/1456752417-9626-1-git-send-email-mhocko@kernel.org [1] http://lkml.kernel.org/r/1452094975-551-1-git-send-email-mhocko@kernel.org [2] http://lkml.kernel.org/r/1456750705-7141-1-git-send-email-mhocko@kernel.org This patch (of 18): This is the first step in making mmap_sem write waiters killable. It focuses on the trivial ones which are taking the lock early after entering the syscall and they are not changing state before. Therefore it is very easy to change them to use down_write_killable and immediately return with -EINTR. This will allow the waiter to pass away without blocking the mmap_sem which might be required to make a forward progress. E.g. the oom reaper will need the lock for reading to dismantle the OOM victim address space. The only tricky function in this patch is vm_mmap_pgoff which has many call sites via vm_mmap. To reduce the risk keep vm_mmap with the original non-killable semantic for now. vm_munmap callers do not bother checking the return value so open code it into the munmap syscall path for now for simplicity. Signed-off-by:
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Kieran Bingham authored
Add myself as a co-maintainer for scripts/gdb supporting Jan Kizka Link: http://lkml.kernel.org/r/fb5d34ce563f33d2f324f26f592b24ded30032ee.1462865983.git.jan.kiszka@siemens.comSigned-off-by:
Kieran Bingham <kieran@bingham.xyz> Signed-off-by:
Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by:
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Kieran Bingham authored
The recent fixes to lx-dmesg, now allow the command to print successfully on Python3, however the python interpreter wraps the bytes for each line with a b'<text>' marker. To remove this, we need to decode the line, where .decode() will default to 'UTF-8' Link: http://lkml.kernel.org/r/d67ccf93f2479c94cb3399262b9b796e0dbefcf2.1462865983.git.jan.kiszka@siemens.comSigned-off-by:
Dom Cote <buzdelabuz2@gmail.com> Tested-by:
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Dom Cote authored
When built against Python 3, GDB differs in the return type for its read_memory function, causing the lx-dmesg command to fail. Now that we have an improved read_16() we can use the new read_memoryview() abstraction to make lx-dmesg return valid data on both current Python APIs Tested with python 3.4 and 2.7 Tested with gdb 7.7 Link: http://lkml.kernel.org/r/28477b727ff7fe3101fd4e426060e8a68317a639.1462865983.git.jan.kiszka@siemens.comSigned-off-by:
Dom Cote <buzdelabuz2+git@gmail.com> [kieran@bingham.xyz: Adjusted commit log to better reflect code changes] Tested-by: Kieran Bingham <kieran@bingham.xyz> (Py2.7,Py3.4,GDB10) Signed-off-by:
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Dom Cote authored
Change the read_u16 function so it accepts both 'str' and 'byte' as type for the arguments. When calling read_memory() from gdb API, depending on if it was built with 2.7 or 3.X, the format used to return the data will differ ( 'str' for 2.7, and 'byte' for 3.X ). Add a function read_memoryview() to be able to get a 'memoryview' object back from read_memory() both with python 2.7 and 3.X . Tested with python 3.4 and 2.7 Tested with gdb 7.7 Link: http://lkml.kernel.org/r/73621f564503137a002a639d174e4fb35f73f462.1462865983.git.jan.kiszka@siemens.comSigned-off-by:
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Kieran Bingham authored
The tasks module already provides helpers to find the task struct by pid, and the thread_info by task struct; however this is cumbersome to utilise on the gdb commandline. Wrap these two functionalities together in an extra single helper to allow exploring the thread info, from a PID value Link: http://lkml.kernel.org/r/dadc5667f053ec811eb3e3033d99d937fedbc93b.1462865983.git.jan.kiszka@siemens.comSigned-off-by:
Kieran Bingham <kieran.bingham@linaro.org> Signed-off-by:
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