Commit f5cbd513 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Greg Kroah-Hartman

media: vicodec: avoid clang frame size warning

[ Upstream commit e855165f ]

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: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 6fb2ea55
......@@ -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];
......
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