diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2019-07-18 17:16:43 +0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-07-23 18:42:20 +0300 |
| commit | 1a03f91c2c2419c3709c4554952c66695575e91c (patch) | |
| tree | d9016401feacfd10eb6004d55220d7bfeff059de /drivers/media | |
| parent | 6732ecb335f5c8957ae319f50949b15f78d54621 (diff) | |
| download | linux-1a03f91c2c2419c3709c4554952c66695575e91c.tar.xz | |
media: vivid: work around high stack usage with clang
Building a KASAN-enabled kernel with clang ends up in a case where too
much is inlined into vivid_thread_vid_cap() and the stack usage grows
a lot, possibly when the register allocation fails to produce efficient
code and spills a lot of temporaries to the stack. This uses more
than twice the amount of stack than the sum of the individual functions
when they are not inlined:
drivers/media/platform/vivid/vivid-kthread-cap.c:766:12: error: stack frame size of 2208 bytes in function 'vivid_thread_vid_cap' [-Werror,-Wframe-larger-than=]
Marking two of the key functions in here as 'noinline_for_stack' avoids
the pathological case in clang without any apparent downside for gcc.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/platform/vivid/vivid-kthread-cap.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/media/platform/vivid/vivid-kthread-cap.c b/drivers/media/platform/vivid/vivid-kthread-cap.c index ed466d737a90..003319d7816d 100644 --- a/drivers/media/platform/vivid/vivid-kthread-cap.c +++ b/drivers/media/platform/vivid/vivid-kthread-cap.c @@ -232,8 +232,8 @@ static void *plane_vaddr(struct tpg_data *tpg, struct vivid_buffer *buf, return vbuf; } -static int vivid_copy_buffer(struct vivid_dev *dev, unsigned p, u8 *vcapbuf, - struct vivid_buffer *vid_cap_buf) +static noinline_for_stack int vivid_copy_buffer(struct vivid_dev *dev, unsigned p, + u8 *vcapbuf, struct vivid_buffer *vid_cap_buf) { bool blank = dev->must_blank[vid_cap_buf->vb.vb2_buf.index]; struct tpg_data *tpg = &dev->tpg; @@ -672,7 +672,8 @@ static void vivid_cap_update_frame_period(struct vivid_dev *dev) dev->cap_frame_period = f_period; } -static void vivid_thread_vid_cap_tick(struct vivid_dev *dev, int dropped_bufs) +static noinline_for_stack void vivid_thread_vid_cap_tick(struct vivid_dev *dev, + int dropped_bufs) { struct vivid_buffer *vid_cap_buf = NULL; struct vivid_buffer *vbi_cap_buf = NULL; |