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Mansur Alisha Shaik 9696960f13 media: venus: core: handle race condititon for core ops
For core ops we are having only write protect but there
is no read protect, because of this in multithreading
and concurrency, one CPU core is reading without wait
which is causing the NULL pointer dereferece crash.

one such scenario is as show below, where in one CPU
core, core->ops becoming NULL and in another CPU core
calling core->ops->session_init().

CPU: core-7:
Call trace:
 hfi_session_init+0x180/0x1dc [venus_core]
 vdec_queue_setup+0x9c/0x364 [venus_dec]
 vb2_core_reqbufs+0x1e4/0x368 [videobuf2_common]
 vb2_reqbufs+0x4c/0x64 [videobuf2_v4l2]
 v4l2_m2m_reqbufs+0x50/0x84 [v4l2_mem2mem]
 v4l2_m2m_ioctl_reqbufs+0x2c/0x38 [v4l2_mem2mem]
 v4l_reqbufs+0x4c/0x5c
__video_do_ioctl+0x2b0/0x39c

CPU: core-0:
Call trace:
 venus_shutdown+0x98/0xfc [venus_core]
 venus_sys_error_handler+0x64/0x148 [venus_core]
 process_one_work+0x210/0x3d0
 worker_thread+0x248/0x3f4
 kthread+0x11c/0x12c

Signed-off-by: Mansur Alisha Shaik <mansur@codeaurora.org>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-17 06:54:36 +01:00
Documentation media: dt-bindings: media: allwinner,sun4i-a10-video-engine: Add R40 compatible 2020-11-16 10:31:16 +01:00
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arch treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
block block-5.10-2020-10-24 2020-10-24 12:46:42 -07:00
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crypto drivers-5.10-2020-10-12 2020-10-13 13:04:41 -07:00
drivers media: venus: core: handle race condititon for core ops 2020-11-17 06:54:36 +01:00
fs treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
include media: fix kernel-doc markups 2020-11-16 10:31:16 +01:00
init linux-kselftest-kunit-5.10-rc1 2020-10-18 14:45:59 -07:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
lib random32: make prandom_u32() less predictable 2020-10-25 10:40:08 -07:00
mm Refactored code for 5.10: 2020-10-23 11:33:41 -07:00
net mm: remove kzfree() compatibility definition 2020-10-25 11:39:02 -07:00
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security SafeSetID changes for v5.10 2020-10-25 10:45:26 -07:00
sound ARM: SoC platform updates 2020-10-24 10:33:08 -07:00
tools treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt kvm: x86/mmu: Support dirty logging for the TDP MMU 2020-10-23 03:42:13 -04:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
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.mailmap MAINTAINERS: jarkko.sakkinen@linux.intel.com -> jarkko@kernel.org 2020-10-16 11:11:19 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS media: MAINTAINERS: Add ADV7604 bindings documentation 2020-11-16 10:31:14 +01:00
Makefile Linux 5.10-rc1 2020-10-25 15:14:11 -07:00
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.