diff options
| author | Gustavo A. R. Silva <gustavoars@kernel.org> | 2020-05-22 12:43:55 -0500 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2020-05-28 14:00:50 -0400 |
| commit | 4541ea81edde6ce9a1d9be082489aca7e8e7e1dc (patch) | |
| tree | cb1eaa4700c524584b2bd4dfae021679c823db4d /drivers | |
| parent | 6e20010a3acc41817daf69f801d8e9c34975223e (diff) | |
| download | linux-4541ea81edde6ce9a1d9be082489aca7e8e7e1dc.tar.bz2 | |
drm/[radeon|amdgpu]: Replace one-element array and use struct_size() helper
The current codebase makes use of one-element arrays in the following
form:
struct something {
int length;
u8 data[1];
};
struct something *instance;
instance = kmalloc(sizeof(*instance) + size, GFP_KERNEL);
instance->length = size;
memcpy(instance->data, source, size);
but the preferred mechanism to declare variable-length types such as
these ones is a flexible array member[1][2], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on. So, replace
the one-element array with a flexible-array member.
Also, make use of the new struct_size() helper to properly calculate the
size of struct SISLANDS_SMC_SWSTATE.
This issue was found with the help of Coccinelle and, audited and fixed
_manually_.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/si_dpm.c | 5 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/sislands_smc.h | 2 | ||||
| -rw-r--r-- | drivers/gpu/drm/radeon/si_dpm.c | 5 |
3 files changed, 5 insertions, 7 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/si_dpm.c b/drivers/gpu/drm/amd/amdgpu/si_dpm.c index c00ba4b23c9a..0fc56c5bac08 100644 --- a/drivers/gpu/drm/amd/amdgpu/si_dpm.c +++ b/drivers/gpu/drm/amd/amdgpu/si_dpm.c @@ -5715,10 +5715,9 @@ static int si_upload_sw_state(struct amdgpu_device *adev, int ret; u32 address = si_pi->state_table_start + offsetof(SISLANDS_SMC_STATETABLE, driverState); - u32 state_size = sizeof(SISLANDS_SMC_SWSTATE) + - ((new_state->performance_level_count - 1) * - sizeof(SISLANDS_SMC_HW_PERFORMANCE_LEVEL)); SISLANDS_SMC_SWSTATE *smc_state = &si_pi->smc_statetable.driverState; + size_t state_size = struct_size(smc_state, levels, + new_state->performance_level_count); memset(smc_state, 0, state_size); diff --git a/drivers/gpu/drm/amd/amdgpu/sislands_smc.h b/drivers/gpu/drm/amd/amdgpu/sislands_smc.h index d2930eceaf3c..a089dbf8f7a9 100644 --- a/drivers/gpu/drm/amd/amdgpu/sislands_smc.h +++ b/drivers/gpu/drm/amd/amdgpu/sislands_smc.h @@ -186,7 +186,7 @@ struct SISLANDS_SMC_SWSTATE uint8_t levelCount; uint8_t padding2; uint8_t padding3; - SISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[1]; + SISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[]; }; typedef struct SISLANDS_SMC_SWSTATE SISLANDS_SMC_SWSTATE; diff --git a/drivers/gpu/drm/radeon/si_dpm.c b/drivers/gpu/drm/radeon/si_dpm.c index a167e1c36d24..bab01ca864c6 100644 --- a/drivers/gpu/drm/radeon/si_dpm.c +++ b/drivers/gpu/drm/radeon/si_dpm.c @@ -5253,10 +5253,9 @@ static int si_upload_sw_state(struct radeon_device *rdev, int ret; u32 address = si_pi->state_table_start + offsetof(SISLANDS_SMC_STATETABLE, driverState); - u32 state_size = sizeof(SISLANDS_SMC_SWSTATE) + - ((new_state->performance_level_count - 1) * - sizeof(SISLANDS_SMC_HW_PERFORMANCE_LEVEL)); SISLANDS_SMC_SWSTATE *smc_state = &si_pi->smc_statetable.driverState; + size_t state_size = struct_size(smc_state, levels, + new_state->performance_level_count); memset(smc_state, 0, state_size); |