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Chris Wilson c218ee03b9 drm/i915: Don't adjust priority on an already signaled fence
When we retire a signaled fence, we free the dependency tree. However,
we skip clearing the list so that if we then try to adjust the priority
of the signaled fence, we may walk the list of freed dependencies.

[ 3083.156757] ==================================================================
[ 3083.156806] BUG: KASAN: use-after-free in execlists_schedule+0x199/0x660 [i915]
[ 3083.156810] Read of size 8 at addr ffff8806bf20f400 by task Xorg/831

[ 3083.156815] CPU: 0 PID: 831 Comm: Xorg Not tainted 4.15.0-rc6-no-psn+ #1
[ 3083.156817] Hardware name: Notebook                         N24_25BU/N24_25BU, BIOS 5.12 02/17/2017
[ 3083.156818] Call Trace:
[ 3083.156823]  dump_stack+0x5c/0x7a
[ 3083.156827]  print_address_description+0x6b/0x290
[ 3083.156830]  kasan_report+0x28f/0x380
[ 3083.156872]  ? execlists_schedule+0x199/0x660 [i915]
[ 3083.156914]  execlists_schedule+0x199/0x660 [i915]
[ 3083.156956]  ? intel_crtc_atomic_check+0x146/0x4e0 [i915]
[ 3083.156997]  ? execlists_submit_request+0xe0/0xe0 [i915]
[ 3083.157038]  ? i915_vma_misplaced.part.4+0x25/0xb0 [i915]
[ 3083.157079]  ? __i915_vma_do_pin+0x7c8/0xc80 [i915]
[ 3083.157121]  ? intel_atomic_state_alloc+0x44/0x60 [i915]
[ 3083.157130]  ? drm_atomic_helper_page_flip+0x3e/0xb0 [drm_kms_helper]
[ 3083.157145]  ? drm_mode_page_flip_ioctl+0x7d2/0x850 [drm]
[ 3083.157159]  ? drm_ioctl_kernel+0xa7/0xf0 [drm]
[ 3083.157172]  ? drm_ioctl+0x45b/0x560 [drm]
[ 3083.157211]  i915_gem_object_wait_priority+0x14c/0x2c0 [i915]
[ 3083.157251]  ? i915_gem_get_aperture_ioctl+0x150/0x150 [i915]
[ 3083.157290]  ? i915_vma_pin_fence+0x1d8/0x320 [i915]
[ 3083.157331]  ? intel_pin_and_fence_fb_obj+0x175/0x250 [i915]
[ 3083.157372]  ? intel_rotation_info_size+0x60/0x60 [i915]
[ 3083.157413]  ? intel_link_compute_m_n+0x80/0x80 [i915]
[ 3083.157428]  ? drm_dev_printk+0x1b0/0x1b0 [drm]
[ 3083.157443]  ? drm_dev_printk+0x1b0/0x1b0 [drm]
[ 3083.157485]  intel_prepare_plane_fb+0x2f8/0x5a0 [i915]
[ 3083.157527]  ? intel_crtc_get_vblank_counter+0x80/0x80 [i915]
[ 3083.157536]  drm_atomic_helper_prepare_planes+0xa0/0x1c0 [drm_kms_helper]
[ 3083.157587]  intel_atomic_commit+0x12e/0x4e0 [i915]
[ 3083.157605]  drm_atomic_helper_page_flip+0xa2/0xb0 [drm_kms_helper]
[ 3083.157621]  drm_mode_page_flip_ioctl+0x7d2/0x850 [drm]
[ 3083.157638]  ? drm_mode_cursor2_ioctl+0x10/0x10 [drm]
[ 3083.157652]  ? drm_lease_owner+0x1a/0x30 [drm]
[ 3083.157668]  ? drm_mode_cursor2_ioctl+0x10/0x10 [drm]
[ 3083.157681]  drm_ioctl_kernel+0xa7/0xf0 [drm]
[ 3083.157696]  drm_ioctl+0x45b/0x560 [drm]
[ 3083.157711]  ? drm_mode_cursor2_ioctl+0x10/0x10 [drm]
[ 3083.157725]  ? drm_getstats+0x20/0x20 [drm]
[ 3083.157729]  ? timerqueue_del+0x49/0x80
[ 3083.157732]  ? __remove_hrtimer+0x62/0xb0
[ 3083.157735]  ? hrtimer_try_to_cancel+0x173/0x210
[ 3083.157738]  do_vfs_ioctl+0x13b/0x880
[ 3083.157741]  ? ioctl_preallocate+0x140/0x140
[ 3083.157744]  ? _raw_spin_unlock_irq+0xe/0x30
[ 3083.157746]  ? do_setitimer+0x234/0x370
[ 3083.157750]  ? SyS_setitimer+0x19e/0x1b0
[ 3083.157752]  ? SyS_alarm+0x140/0x140
[ 3083.157755]  ? __rcu_read_unlock+0x66/0x80
[ 3083.157757]  ? __fget+0xc4/0x100
[ 3083.157760]  SyS_ioctl+0x74/0x80
[ 3083.157763]  entry_SYSCALL_64_fastpath+0x1a/0x7d
[ 3083.157765] RIP: 0033:0x7f6135d0c6a7
[ 3083.157767] RSP: 002b:00007fff01451888 EFLAGS: 00003246 ORIG_RAX: 0000000000000010
[ 3083.157769] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f6135d0c6a7
[ 3083.157771] RDX: 00007fff01451950 RSI: 00000000c01864b0 RDI: 000000000000000c
[ 3083.157772] RBP: 00007f613076f600 R08: 0000000000000001 R09: 0000000000000000
[ 3083.157773] R10: 0000000000000060 R11: 0000000000003246 R12: 0000000000000000
[ 3083.157774] R13: 0000000000000060 R14: 000000000000001b R15: 0000000000000060

[ 3083.157779] Allocated by task 831:
[ 3083.157783]  kmem_cache_alloc+0xc0/0x200
[ 3083.157822]  i915_gem_request_await_dma_fence+0x2c4/0x5d0 [i915]
[ 3083.157861]  i915_gem_request_await_object+0x321/0x370 [i915]
[ 3083.157900]  i915_gem_do_execbuffer+0x1165/0x19c0 [i915]
[ 3083.157937]  i915_gem_execbuffer2+0x1ad/0x550 [i915]
[ 3083.157950]  drm_ioctl_kernel+0xa7/0xf0 [drm]
[ 3083.157962]  drm_ioctl+0x45b/0x560 [drm]
[ 3083.157964]  do_vfs_ioctl+0x13b/0x880
[ 3083.157966]  SyS_ioctl+0x74/0x80
[ 3083.157968]  entry_SYSCALL_64_fastpath+0x1a/0x7d

[ 3083.157971] Freed by task 831:
[ 3083.157973]  kmem_cache_free+0x77/0x220
[ 3083.158012]  i915_gem_request_retire+0x72c/0xa70 [i915]
[ 3083.158051]  i915_gem_request_alloc+0x1e9/0x8b0 [i915]
[ 3083.158089]  i915_gem_do_execbuffer+0xa96/0x19c0 [i915]
[ 3083.158127]  i915_gem_execbuffer2+0x1ad/0x550 [i915]
[ 3083.158140]  drm_ioctl_kernel+0xa7/0xf0 [drm]
[ 3083.158153]  drm_ioctl+0x45b/0x560 [drm]
[ 3083.158155]  do_vfs_ioctl+0x13b/0x880
[ 3083.158156]  SyS_ioctl+0x74/0x80
[ 3083.158158]  entry_SYSCALL_64_fastpath+0x1a/0x7d

[ 3083.158162] The buggy address belongs to the object at ffff8806bf20f400
                which belongs to the cache i915_dependency of size 64
[ 3083.158166] The buggy address is located 0 bytes inside of
                64-byte region [ffff8806bf20f400, ffff8806bf20f440)
[ 3083.158168] The buggy address belongs to the page:
[ 3083.158171] page:00000000d43decc4 count:1 mapcount:0 mapping:          (null) index:0x0
[ 3083.158174] flags: 0x17ffe0000000100(slab)
[ 3083.158179] raw: 017ffe0000000100 0000000000000000 0000000000000000 0000000180200020
[ 3083.158182] raw: ffffea001afc16c0 0000000500000005 ffff880731b881c0 0000000000000000
[ 3083.158184] page dumped because: kasan: bad access detected

[ 3083.158187] Memory state around the buggy address:
[ 3083.158190]  ffff8806bf20f300: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[ 3083.158192]  ffff8806bf20f380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[ 3083.158195] >ffff8806bf20f400: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[ 3083.158196]                    ^
[ 3083.158199]  ffff8806bf20f480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[ 3083.158201]  ffff8806bf20f500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[ 3083.158203] ==================================================================

Reported-by: Alexandru Chirvasitu <achirvasub@gmail.com>
Reported-by: Mike Keehan <mike@keehan.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104436
Fixes: 1f181225f8 ("drm/i915/execlists: Keep request->priority for its lifetime")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Alexandru Chirvasitu <achirvasub@gmail.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Tested-by: Alexandru Chirvasitu <achirvasub@gmail.com>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180106105618.13532-1-chris@chris-wilson.co.uk
2018-01-08 09:16:02 +00:00
Documentation docs: fix, intel_guc_loader.c has been moved to intel_guc_fw.c 2017-12-12 16:24:05 +01:00
arch x86/gpu: add CFL to early quirks 2017-12-15 13:18:00 -08:00
block Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-12-01 08:05:45 -05:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-11-28 16:22:10 -08:00
drivers drm/i915: Don't adjust priority on an already signaled fence 2018-01-08 09:16:02 +00:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs NFS client fixes for Linux 4.15-rc2 2017-12-01 20:04:20 -05:00
include drm/i915/cfl: Adding more Coffee Lake PCI IDs. 2017-12-20 11:24:25 -08:00
init EXPERT Kconfig menu: fix broken EXPERT menu 2017-11-17 16:10:05 -08:00
ipc Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
kernel Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-12-01 08:05:45 -05:00
lib RISC-V Cleanups and ABI Fixes for 4.15-rc2 2017-12-01 19:39:12 -05:00
mm Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-12-01 08:05:45 -05:00
net NFS client fixes for Linux 4.15-rc2 2017-12-01 20:04:20 -05:00
samples kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
scripts Merge branch 'akpm' (patches from Andrew) 2017-11-29 19:12:44 -08:00
security bug fixes: 2017-11-30 18:56:41 -05:00
sound Revert "ALSA: usb-audio: Fix potential zero-division at parsing FU" 2017-11-28 09:34:36 -08:00
tools Power management fixes for v4.15-rc2 2017-11-30 18:45:55 -05:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt * x86 bugfixes: APIC, nested virtualization, IOAPIC 2017-11-30 08:15:19 -08:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild misc updates for v4.15 2017-11-17 17:51:33 -08:00
.mailmap Add Jason Gunthorpe as co-maintainer of the RDMA stack 2017-11-17 09:36:18 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge arlied/drm-next into drm-misc-next 2017-12-04 16:04:45 -02:00
Makefile Linux 4.15-rc2 2017-12-03 11:01:47 -05:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.