| Message ID | 20210210234927.GA68137@embeddedor (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [next] drm/radeon/nislands_smc.h: Replace one-element array with flexible-array member in struct NISLANDS_SMC_SWSTATE | expand |
On Wed, Feb 10, 2021 at 6:49 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]. > > Use flexible-array member in struct NISLANDS_SMC_SWSTATE, instead of > one-element array. > > Also, this helps with the ongoing efforts to enable -Warray-bounds by > fixing the following warnings: > > drivers/gpu/drm/radeon/ni_dpm.c: In function ‘ni_convert_power_state_to_smc’: > drivers/gpu/drm/radeon/ni_dpm.c:2521:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > 2521 | smc_state->levels[i].dpm2.MaxPS = > | ~~~~~~~~~~~~~~~~~^~~ > drivers/gpu/drm/radeon/ni_dpm.c:2523:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > 2523 | smc_state->levels[i].dpm2.NearTDPDec = NISLANDS_DPM2_NEAR_TDP_DEC; > | ~~~~~~~~~~~~~~~~~^~~ > drivers/gpu/drm/radeon/ni_dpm.c:2524:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > 2524 | smc_state->levels[i].dpm2.AboveSafeInc = NISLANDS_DPM2_ABOVE_SAFE_INC; > | ~~~~~~~~~~~~~~~~~^~~ > drivers/gpu/drm/radeon/ni_dpm.c:2525:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > 2525 | smc_state->levels[i].dpm2.BelowSafeInc = NISLANDS_DPM2_BELOW_SAFE_INC; > | ~~~~~~~~~~~~~~~~~^~~ > drivers/gpu/drm/radeon/ni_dpm.c:2526:35: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > 2526 | smc_state->levels[i].stateFlags |= > | ^~ > drivers/gpu/drm/radeon/ni_dpm.c:2526:35: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > 2526 | smc_state->levels[i].stateFlags |= > | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~ > 2527 | ((i != (state->performance_level_count - 1)) && power_boost_limit) ? > | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 2528 | PPSMC_STATEFLAG_POWERBOOST : 0; > | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/gpu/drm/radeon/ni_dpm.c:2442:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] > 2442 | smc_state->levels[i + 1].aT = cpu_to_be32(a_t); > > [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/6023ed54.BfIY+9Uz81I6nq19%25lkp@intel.com/ > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Applied. Thanks! Alex > --- > drivers/gpu/drm/radeon/nislands_smc.h | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/radeon/nislands_smc.h b/drivers/gpu/drm/radeon/nislands_smc.h > index 3cf8fc0d83f4..7395cb6b3cac 100644 > --- a/drivers/gpu/drm/radeon/nislands_smc.h > +++ b/drivers/gpu/drm/radeon/nislands_smc.h > @@ -134,11 +134,11 @@ typedef struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL NISLANDS_SMC_HW_PERFORMANCE_LEV > > struct NISLANDS_SMC_SWSTATE > { > - uint8_t flags; > - uint8_t levelCount; > - uint8_t padding2; > - uint8_t padding3; > - NISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[1]; > + uint8_t flags; > + uint8_t levelCount; > + uint8_t padding2; > + uint8_t padding3; > + NISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[]; > }; > > typedef struct NISLANDS_SMC_SWSTATE NISLANDS_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/radeon/nislands_smc.h b/drivers/gpu/drm/radeon/nislands_smc.h index 3cf8fc0d83f4..7395cb6b3cac 100644 --- a/drivers/gpu/drm/radeon/nislands_smc.h +++ b/drivers/gpu/drm/radeon/nislands_smc.h @@ -134,11 +134,11 @@ typedef struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL NISLANDS_SMC_HW_PERFORMANCE_LEV struct NISLANDS_SMC_SWSTATE { - uint8_t flags; - uint8_t levelCount; - uint8_t padding2; - uint8_t padding3; - NISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[1]; + uint8_t flags; + uint8_t levelCount; + uint8_t padding2; + uint8_t padding3; + NISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[]; }; typedef struct NISLANDS_SMC_SWSTATE NISLANDS_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]. Use flexible-array member in struct NISLANDS_SMC_SWSTATE, instead of one-element array. Also, this helps with the ongoing efforts to enable -Warray-bounds by fixing the following warnings: drivers/gpu/drm/radeon/ni_dpm.c: In function ‘ni_convert_power_state_to_smc’: drivers/gpu/drm/radeon/ni_dpm.c:2521:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2521 | smc_state->levels[i].dpm2.MaxPS = | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/ni_dpm.c:2523:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2523 | smc_state->levels[i].dpm2.NearTDPDec = NISLANDS_DPM2_NEAR_TDP_DEC; | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/ni_dpm.c:2524:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2524 | smc_state->levels[i].dpm2.AboveSafeInc = NISLANDS_DPM2_ABOVE_SAFE_INC; | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/ni_dpm.c:2525:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2525 | smc_state->levels[i].dpm2.BelowSafeInc = NISLANDS_DPM2_BELOW_SAFE_INC; | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/ni_dpm.c:2526:35: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2526 | smc_state->levels[i].stateFlags |= | ^~ drivers/gpu/drm/radeon/ni_dpm.c:2526:35: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2526 | smc_state->levels[i].stateFlags |= | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~ 2527 | ((i != (state->performance_level_count - 1)) && power_boost_limit) ? | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2528 | PPSMC_STATEFLAG_POWERBOOST : 0; | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/radeon/ni_dpm.c:2442:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2442 | smc_state->levels[i + 1].aT = cpu_to_be32(a_t); [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/6023ed54.BfIY+9Uz81I6nq19%25lkp@intel.com/ Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- drivers/gpu/drm/radeon/nislands_smc.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)