| Message ID | 20210210224031.GA8795@embeddedor (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [next] drm/amd/pm: Replace one-element array with flexible-array in struct SISLANDS_SMC_SWSTATE | expand |
On Wed, Feb 10, 2021 at 5:40 PM Gustavo A. R. Silva <gustavoars@kernel.org> wrote: > > There is a regular need in the kernel to provide a way to declare having > a dynamically sized set of trailing elements in a structure. Kernel code > should always use “flexible array members”[1] for these cases. The older > style of one-element or zero-length arrays should no longer be used[2]. > > Refactor the code according to the use of a flexible-array member in > struct SISLANDS_SMC_SWSTATE, instead of a one-element array, and use > the struct_size() helper to calculate the size for the allocation. > > Also, this helps with the ongoing efforts to enable -Warray-bounds and > fix the following warnings: > > drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:2448:20: warning: array > subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ > {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:2449:20: warning: array > subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ > {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:2450:20: warning: array > subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ > {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:2451:20: warning: array > subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ > {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:2452:20: warning: array > subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ > {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:5570:20: warning: array > subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ > {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > > [1] https://en.wikipedia.org/wiki/Flexible_array_member > [2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays > > Link: https://github.com/KSPP/linux/issues/79 > Link: https://github.com/KSPP/linux/issues/109 > Build-tested-by: kernel test robot <lkp@intel.com> > Link: https://lore.kernel.org/lkml/6023be58.sk66L%2FV4vuSJI5mI%25lkp@intel.com/ > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Applied. Thanks! Alex > --- > drivers/gpu/drm/amd/pm/powerplay/si_dpm.c | 6 ++---- > drivers/gpu/drm/amd/pm/powerplay/sislands_smc.h | 10 +++++----- > 2 files changed, 7 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/amd/pm/powerplay/si_dpm.c b/drivers/gpu/drm/amd/pm/powerplay/si_dpm.c > index afa1711c9620..62291358fb1c 100644 > --- a/drivers/gpu/drm/amd/pm/powerplay/si_dpm.c > +++ b/drivers/gpu/drm/amd/pm/powerplay/si_dpm.c > @@ -5715,11 +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); > > ret = si_convert_power_state_to_smc(adev, amdgpu_new_state, smc_state); > diff --git a/drivers/gpu/drm/amd/pm/powerplay/sislands_smc.h b/drivers/gpu/drm/amd/pm/powerplay/sislands_smc.h > index d2930eceaf3c..0f7554052c90 100644 > --- a/drivers/gpu/drm/amd/pm/powerplay/sislands_smc.h > +++ b/drivers/gpu/drm/amd/pm/powerplay/sislands_smc.h > @@ -182,11 +182,11 @@ typedef struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL SISLANDS_SMC_HW_PERFORMANCE_LEV > > struct SISLANDS_SMC_SWSTATE > { > - uint8_t flags; > - uint8_t levelCount; > - uint8_t padding2; > - uint8_t padding3; > - SISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[1]; > + uint8_t flags; > + uint8_t levelCount; > + uint8_t padding2; > + uint8_t padding3; > + SISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[]; > }; > > typedef struct SISLANDS_SMC_SWSTATE SISLANDS_SMC_SWSTATE; > -- > 2.27.0 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff --git a/drivers/gpu/drm/amd/pm/powerplay/si_dpm.c b/drivers/gpu/drm/amd/pm/powerplay/si_dpm.c index afa1711c9620..62291358fb1c 100644 --- a/drivers/gpu/drm/amd/pm/powerplay/si_dpm.c +++ b/drivers/gpu/drm/amd/pm/powerplay/si_dpm.c @@ -5715,11 +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); ret = si_convert_power_state_to_smc(adev, amdgpu_new_state, smc_state); diff --git a/drivers/gpu/drm/amd/pm/powerplay/sislands_smc.h b/drivers/gpu/drm/amd/pm/powerplay/sislands_smc.h index d2930eceaf3c..0f7554052c90 100644 --- a/drivers/gpu/drm/amd/pm/powerplay/sislands_smc.h +++ b/drivers/gpu/drm/amd/pm/powerplay/sislands_smc.h @@ -182,11 +182,11 @@ typedef struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL SISLANDS_SMC_HW_PERFORMANCE_LEV struct SISLANDS_SMC_SWSTATE { - uint8_t flags; - uint8_t levelCount; - uint8_t padding2; - uint8_t padding3; - SISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[1]; + uint8_t flags; + uint8_t levelCount; + uint8_t padding2; + uint8_t padding3; + SISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[]; }; typedef struct SISLANDS_SMC_SWSTATE SISLANDS_SMC_SWSTATE;
There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Refactor the code according to the use of a flexible-array member in struct SISLANDS_SMC_SWSTATE, instead of a one-element array, and use the struct_size() helper to calculate the size for the allocation. Also, this helps with the ongoing efforts to enable -Warray-bounds and fix the following warnings: drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:2448:20: warning: array subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:2449:20: warning: array subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:2450:20: warning: array subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:2451:20: warning: array subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:2452:20: warning: array subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] drivers/gpu/drm/amd/amdgpu/../pm/powerplay/si_dpm.c:5570:20: warning: array subscript 1 is above array bounds of ‘SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/109 Build-tested-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/lkml/6023be58.sk66L%2FV4vuSJI5mI%25lkp@intel.com/ Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- drivers/gpu/drm/amd/pm/powerplay/si_dpm.c | 6 ++---- drivers/gpu/drm/amd/pm/powerplay/sislands_smc.h | 10 +++++----- 2 files changed, 7 insertions(+), 9 deletions(-)