kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-16 22:39:48 +00:00
Code Issues Releases Packages Activity
No description
1,157,183 commits 116 branches 5,798 tags 5.6 GiB
  • C 96.9%
  • Assembly 0.9%
  • Rust 0.6%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Janusz Krzysztofik 9159db27fb drm/i915/active: Fix misuse of non-idle barriers as fence trackers 
commit e0e6b416b2 upstream.

Users reported oopses on list corruptions when using i915 perf with a
number of concurrently running graphics applications.  Root cause analysis
pointed at an issue in barrier processing code -- a race among perf open /
close replacing active barriers with perf requests on kernel context and
concurrent barrier preallocate / acquire operations performed during user
context first pin / last unpin.

When adding a request to a composite tracker, we try to reuse an existing
fence tracker, already allocated and registered with that composite.  The
tracker we obtain may already track another fence, may be an idle barrier,
or an active barrier.

If the tracker we get occurs a non-idle barrier then we try to delete that
barrier from a list of barrier tasks it belongs to.  However, while doing
that we don't respect return value from a function that performs the
barrier deletion.  Should the deletion ever fail, we would end up reusing
the tracker still registered as a barrier task.  Since the same structure
field is reused with both fence callback lists and barrier tasks list,
list corruptions would likely occur.

Barriers are now deleted from a barrier tasks list by temporarily removing
the list content, traversing that content with skip over the node to be
deleted, then populating the list back with the modified content.  Should
that intentionally racy concurrent deletion attempts be not serialized,
one or more of those may fail because of the list being temporary empty.

Related code that ignores the results of barrier deletion was initially
introduced in v5.4 by commit d8af05ff38 ("drm/i915: Allow sharing the
idle-barrier from other kernel requests").  However, all users of the
barrier deletion routine were apparently serialized at that time, then the
issue didn't exhibit itself.  Results of git bisect with help of a newly
developed igt@gem_barrier_race@remote-request IGT test indicate that list
corruptions might start to appear after commit 311770173f ("drm/i915/gt:
Schedule request retirement when timeline idles"), introduced in v5.5.

Respect results of barrier deletion attempts -- mark the barrier as idle
only if successfully deleted from the list.  Then, before proceeding with
setting our fence as the one currently tracked, make sure that the tracker
we've got is not a non-idle barrier.  If that check fails then don't use
that tracker but go back and try to acquire a new, usable one.

v3: use unlikely() to document what outcome we expect (Andi),
  - fix bad grammar in commit description.
v2: no code changes,
  - blame commit 311770173f ("drm/i915/gt: Schedule request retirement
    when timeline idles"), v5.5, not commit d8af05ff38 ("drm/i915: Allow
    sharing the idle-barrier from other kernel requests"), v5.4,
  - reword commit description.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6333
Fixes: 311770173f ("drm/i915/gt: Schedule request retirement when timeline idles")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org # v5.5
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230302120820.48740-1-janusz.krzysztofik@linux.intel.com
(cherry picked from commit 5060060557)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2023-03-22 13:38:03 +01:00
arch riscv: asid: Fixup stale TLB entry cause application crash 2023-03-22 13:38:03 +01:00
block block: count 'ios' and 'sectors' when io is done for bio-based device 2023-03-22 13:37:50 +01:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-01-31 17:53:01 +09:00
crypto crypto: rsa-pkcs1pad - Use akcipher_request_complete 2023-03-10 09:28:18 +01:00
Documentation docs: Correct missing "d_" prefix for dentry_operations member d_weak_revalidate 2023-03-22 13:37:42 +01:00
drivers drm/i915/active: Fix misuse of non-idle barriers as fence trackers 2023-03-22 13:38:03 +01:00
fs cifs: use DFS root session instead of tcon ses 2023-03-22 13:38:02 +01:00
include tracing: Make tracepoint lockdep check actually test something 2023-03-22 13:38:01 +01:00
init Kbuild fixes for v6.2 (3rd) 2023-01-21 10:56:37 -08:00
io_uring io_uring/uring_cmd: ensure that device supports IOPOLL 2023-03-17 08:57:45 +01:00
ipc Non-MM patches for 6.2-rc1. 2022-12-12 17:28:58 -08:00
kernel tracing: Check field value in hist_field_name() 2023-03-22 13:38:01 +01:00
lib cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG 2023-03-10 09:29:06 +01:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm memory tier: release the new_memtier in find_create_memory_tier() 2023-03-10 09:29:50 +01:00
net net/9p: fix bug in client create for .L 2023-03-22 13:37:56 +01:00
rust rust: print: avoid evaluating arguments in pr_* macros in unsafe blocks 2023-01-16 00:54:35 +01:00
samples ftrace: Export ftrace_free_filter() to modules 2023-01-24 11:20:58 -05:00
scripts kconfig: Update config changed flag before calling callback 2023-03-22 13:37:55 +01:00
security ima: Align ima_file_mmap() parameters with mmap_file LSM hook 2023-03-10 09:29:36 +01:00
sound ALSA: hda/realtek: fix speaker, mute/micmute LEDs not work on a HP platform 2023-03-22 13:38:03 +01:00
tools selftests: net: devlink_port_split.py: skip test if no suitable device available 2023-03-22 13:37:53 +01:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM: Register /dev/kvm as the _very_ last thing during initialization 2023-03-10 09:29:33 +01:00
.clang-format iommufd for 6.2 2022-12-14 09:15:43 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore *.rpm 2022-12-30 17:22:14 +09:00
.mailmap 12 hotfixes, mostly against mm/. Five of these fixes are cc:stable. 2023-02-13 14:09:20 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: update SCTP maintainers 2023-02-02 11:35:33 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS audit: update the mailing list in MAINTAINERS 2023-02-25 11:13:29 +01:00
Makefile Linux 6.2.7 2023-03-17 08:58:04 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

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

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

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.