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author | Arnd Bergmann <arnd@arndb.de> | 2019-07-18 10:16:43 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-05 13:13:26 +0200 |
commit | 988a38ff1cf0dbb4e65cadf7edee071fa419d57c (patch) | |
tree | eb376efd3998f3cf55de462d53b0d2c4febdba5a /drivers/media | |
parent | 615883ae490f4a3da9af878f389835d7a0ee8b11 (diff) | |
download | linux-stable-988a38ff1cf0dbb4e65cadf7edee071fa419d57c.tar.gz linux-stable-988a38ff1cf0dbb4e65cadf7edee071fa419d57c.tar.bz2 linux-stable-988a38ff1cf0dbb4e65cadf7edee071fa419d57c.zip |
media: vivid: work around high stack usage with clang
[ Upstream commit 1a03f91c2c2419c3709c4554952c66695575e91c ]
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>
Signed-off-by: Sasha Levin <sashal@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 cf6dfecf879f..96d85cd8839f 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; |