iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
1,215,134 Commits 104 Branches 1,843 Tags 5.7 GiB
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%
6bd01c4299
Go to file
Luca Ceresoli 6bd01c4299 staging: media: tegra-video: fix infinite recursion regression 
Since commit 9bf19fbf0c ("media: v4l: async: Rework internal lists"), aka
v6.6-rc1~97^2~198, probing the tegra-video VI driver causes infinite
recursion due tegra_vi_graph_parse_one() calling itself until:

[    1.571168] Insufficient stack space to handle exception!
...
[    1.591416] Internal error: kernel stack overflow: 0 [#1] PREEMPT SMP ARM
...
[    3.861013]  of_phandle_iterator_init from __of_parse_phandle_with_args+0x40/0xf0
[    3.868497]  __of_parse_phandle_with_args from of_fwnode_graph_get_remote_endpoint+0x68/0xa8
[    3.876938]  of_fwnode_graph_get_remote_endpoint from fwnode_graph_get_remote_port_parent+0x30/0x7c
[    3.885984]  fwnode_graph_get_remote_port_parent from tegra_vi_graph_parse_one+0x7c/0x224
[    3.894158]  tegra_vi_graph_parse_one from tegra_vi_graph_parse_one+0x144/0x224
[    3.901459]  tegra_vi_graph_parse_one from tegra_vi_graph_parse_one+0x144/0x224
[    3.908760]  tegra_vi_graph_parse_one from tegra_vi_graph_parse_one+0x144/0x224
[    3.916061]  tegra_vi_graph_parse_one from tegra_vi_graph_parse_one+0x144/0x224
...
[    4.857892]  tegra_vi_graph_parse_one from tegra_vi_graph_parse_one+0x144/0x224
[    4.865193]  tegra_vi_graph_parse_one from tegra_vi_graph_parse_one+0x144/0x224
[    4.872494]  tegra_vi_graph_parse_one from tegra_vi_init+0x574/0x6d4
[    4.878842]  tegra_vi_init from host1x_device_init+0x84/0x15c
[    4.884594]  host1x_device_init from host1x_video_probe+0xa0/0x114
[    4.890770]  host1x_video_probe from really_probe+0xe0/0x400

The reason is the mentioned commit changed tegra_vi_graph_find_entity() to
search for an entity in the done notifier list:

> @@ -1464,7 +1464,7 @@ tegra_vi_graph_find_entity(struct tegra_vi_channel *chan,
>  	struct tegra_vi_graph_entity *entity;
>  	struct v4l2_async_connection *asd;
>
> -	list_for_each_entry(asd, &chan->notifier.asc_list, asc_entry) {
> +	list_for_each_entry(asd, &chan->notifier.done_list, asc_entry) {
>  		entity = to_tegra_vi_graph_entity(asd);
>  		if (entity->asd.match.fwnode == fwnode)
>  			return entity;

This is not always correct, being tegra_vi_graph_find_entity() called in
three locations, in this order:

 1. tegra_vi_graph_parse_one()    -- called while probing
 2. tegra_vi_graph_notify_bound() -- the .bound notifier op
 3. tegra_vi_graph_build()        -- called in the .complete notifier op

Locations 1 and 2 are called before moving the entity from waiting_list to
done_list, thus they won't find what they are looking for in
done_list. Location 3 happens afterwards and thus it is not broken, however
it means tegra_vi_graph_find_entity() should not search in the same list
every time.

The error appears at step 1: tegra_vi_graph_parse_one() iterates
recursively until it finds the entity already notified, which now never
happens.

Fix by passing the specific notifier list pointer to
tegra_vi_graph_find_entity() instead of the channel, so each caller can
search in whatever list is correct.

Also improve the tegra_vi_graph_find_entity() comment.

Fixes: 9bf19fbf0c ("media: v4l: async: Rework internal lists")
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
[Sakari Ailus: Wrapped some long lines.]
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
2023-10-02 10:02:53 +02:00
arch Fix preemption delays in the SGX code, remove unnecessarily UAPI-exported code, 2023-09-10 10:39:31 -07:00
block block: fix pin count management when merging same-page segments 2023-09-06 07:32:27 -06:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto This update includes the following changes: 2023-08-29 11:23:29 -07:00
Documentation drm ci for 6.6-rc1 2023-09-10 11:55:26 -07:00
drivers staging: media: tegra-video: fix infinite recursion regression 2023-10-02 10:02:53 +02:00
fs six smb3 client fixes, one fix for nls Kconfig, one minor spnego registry update 2023-09-09 19:56:23 -07:00
include six smb3 client fixes, one fix for nls Kconfig, one minor spnego registry update 2023-09-09 19:56:23 -07:00
init workqueue: Changes for v6.6 2023-09-01 16:06:32 -07:00
io_uring Revert "io_uring: fix IO hang in io_wq_put_and_exit from do_exit()" 2023-09-07 09:41:49 -06:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel RISC-V Patches for the 6.6 Merge Window, Part 2 (try 2) 2023-09-09 14:25:11 -07:00
lib iov_iter: Kunit tests for page extraction 2023-09-09 15:11:49 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm LoongArch changes for v6.6 2023-09-08 12:16:52 -07:00
net Including fixes from netfilter and bpf. 2023-09-07 18:33:07 -07:00
rust Documentation work keeps chugging along; stuff for 6.6 includes: 2023-08-30 20:05:42 -07:00
samples VFIO updates for v6.6-rc1 2023-08-30 20:36:01 -07:00
scripts Fix preemption delays in the SGX code, remove unnecessarily UAPI-exported code, 2023-09-10 10:39:31 -07:00
security Landlock updates for v6.6-rc1 2023-09-08 12:06:51 -07:00
sound sound fixes for 6.6-rc1 2023-09-08 13:07:50 -07:00
tools perf tools changes for v6.6: 2023-09-09 20:06:17 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap for-linus-2023083101 2023-09-01 12:31:44 -07:00
.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 USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
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 drm ci for 6.6-rc1 2023-09-10 11:55:26 -07:00
Makefile Linux 6.6-rc1 2023-09-10 16:28:41 -07:00
README

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.