linux/drivers/media/common/v4l2-tpg
Arnd Bergmann c49cdaafa4 media: v4l2-tpg: reduce stack usage for kasan builds
tpg_fill_plane_buffer() is a rather complex function. While there is
nothing wrong with it per se, I have run into corner cases with clang-22
on s390 using KASAN that makes it run out of registers and blow the
stack warning limit from excessive spills:

drivers/media/common/v4l2-tpg/v4l2-tpg-core.c:2629:6: error: stack frame size (1560) exceeds limit (1536)
      in 'tpg_fill_plane_buffer' [-Werror,-Wframe-larger-than]
 2629 | void tpg_fill_plane_buffer(struct tpg_data *tpg, v4l2_std_id std,

Forcing the two largest callees out of line completely avoids the problem
and prevents all the register spills, with the stack usage for each function
going down to a few bytes for the local variables.

Arguably this is a problem caused by clang rather than the code, but
a noinline_for_stack annotation is an easy workaround.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
2026-07-10 10:32:27 +02:00
..
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
v4l2-tpg-colors.c media: replace ADOBERGB by OPRGB 2018-09-24 09:21:47 -04:00
v4l2-tpg-core.c media: v4l2-tpg: reduce stack usage for kasan builds 2026-07-10 10:32:27 +02:00