| From ef6f80ee2d898a86da4220bed6461c9c44ceb1f4 Mon Sep 17 00:00:00 2001 |
| From: Arnd Bergmann <arnd@arndb.de> |
| Date: Fri, 22 Feb 2019 09:50:03 -0500 |
| Subject: media: vicodec: avoid clang frame size warning |
| |
| [ Upstream commit e855165f3dae6f71da859a5f00b85d5368641d61 ] |
| |
| Clang-9 makes some different inlining decisions compared to gcc, which |
| leads to a warning about a possible stack overflow problem when building |
| with CONFIG_KASAN, including when setting asan-stack=0, which avoids |
| most other frame overflow warnings: |
| |
| drivers/media/platform/vicodec/codec-fwht.c:673:12: error: stack frame size of 2224 bytes in function 'encode_plane' |
| |
| Manually adding noinline_for_stack annotations in those functions |
| called by encode_plane() or decode_plane() that require a significant |
| amount of kernel stack makes this impossible to happen with any |
| compiler. |
| |
| Signed-off-by: Arnd Bergmann <arnd@arndb.de> |
| 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> |
| --- |
| drivers/media/platform/vicodec/codec-fwht.c | 29 +++++++++++++-------- |
| 1 file changed, 18 insertions(+), 11 deletions(-) |
| |
| diff --git a/drivers/media/platform/vicodec/codec-fwht.c b/drivers/media/platform/vicodec/codec-fwht.c |
| index d1d6085da9f1d..cf469a1191aa7 100644 |
| --- a/drivers/media/platform/vicodec/codec-fwht.c |
| +++ b/drivers/media/platform/vicodec/codec-fwht.c |
| @@ -46,8 +46,12 @@ static const uint8_t zigzag[64] = { |
| 63, |
| }; |
| |
| - |
| -static int rlc(const s16 *in, __be16 *output, int blocktype) |
| +/* |
| + * noinline_for_stack to work around |
| + * https://bugs.llvm.org/show_bug.cgi?id=38809 |
| + */ |
| +static int noinline_for_stack |
| +rlc(const s16 *in, __be16 *output, int blocktype) |
| { |
| s16 block[8 * 8]; |
| s16 *wp = block; |
| @@ -106,8 +110,8 @@ static int rlc(const s16 *in, __be16 *output, int blocktype) |
| * This function will worst-case increase rlc_in by 65*2 bytes: |
| * one s16 value for the header and 8 * 8 coefficients of type s16. |
| */ |
| -static u16 derlc(const __be16 **rlc_in, s16 *dwht_out, |
| - const __be16 *end_of_input) |
| +static noinline_for_stack u16 |
| +derlc(const __be16 **rlc_in, s16 *dwht_out, const __be16 *end_of_input) |
| { |
| /* header */ |
| const __be16 *input = *rlc_in; |
| @@ -240,8 +244,9 @@ static void dequantize_inter(s16 *coeff) |
| *coeff <<= *quant; |
| } |
| |
| -static void fwht(const u8 *block, s16 *output_block, unsigned int stride, |
| - unsigned int input_step, bool intra) |
| +static void noinline_for_stack fwht(const u8 *block, s16 *output_block, |
| + unsigned int stride, |
| + unsigned int input_step, bool intra) |
| { |
| /* we'll need more than 8 bits for the transformed coefficients */ |
| s32 workspace1[8], workspace2[8]; |
| @@ -373,7 +378,8 @@ static void fwht(const u8 *block, s16 *output_block, unsigned int stride, |
| * Furthermore values can be negative... This is just a version that |
| * works with 16 signed data |
| */ |
| -static void fwht16(const s16 *block, s16 *output_block, int stride, int intra) |
| +static void noinline_for_stack |
| +fwht16(const s16 *block, s16 *output_block, int stride, int intra) |
| { |
| /* we'll need more than 8 bits for the transformed coefficients */ |
| s32 workspace1[8], workspace2[8]; |
| @@ -456,7 +462,8 @@ static void fwht16(const s16 *block, s16 *output_block, int stride, int intra) |
| } |
| } |
| |
| -static void ifwht(const s16 *block, s16 *output_block, int intra) |
| +static noinline_for_stack void |
| +ifwht(const s16 *block, s16 *output_block, int intra) |
| { |
| /* |
| * we'll need more than 8 bits for the transformed coefficients |
| @@ -604,9 +611,9 @@ static int var_inter(const s16 *old, const s16 *new) |
| return ret; |
| } |
| |
| -static int decide_blocktype(const u8 *cur, const u8 *reference, |
| - s16 *deltablock, unsigned int stride, |
| - unsigned int input_step) |
| +static noinline_for_stack int |
| +decide_blocktype(const u8 *cur, const u8 *reference, s16 *deltablock, |
| + unsigned int stride, unsigned int input_step) |
| { |
| s16 tmp[64]; |
| s16 old[64]; |
| -- |
| 2.20.1 |
| |