| Message ID | 20210303190458.GA16321@embeddedor (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [next] drm/radeon/si_dpm: Replace one-element array with flexible-array in struct SISLANDS_SMC_SWSTATE | expand |
Applied. Thanks! Alex On Wed, Mar 3, 2021 at 2:05 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 by > fixing the following warnings: > > drivers/gpu/drm/radeon/si_dpm.c: In function ‘si_convert_power_state_to_smc’: > drivers/gpu/drm/radeon/si_dpm.c:2350:20: 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] > 2350 | smc_state->levels[i].dpm2.MaxPS = (u8)((SISLANDS_DPM2_MAX_PULSE_SKIP * (max_sclk - min_sclk)) / max_sclk); > | ~~~~~~~~~~~~~~~~~^~~ > drivers/gpu/drm/radeon/si_dpm.c:2351:20: 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] > 2351 | smc_state->levels[i].dpm2.NearTDPDec = SISLANDS_DPM2_NEAR_TDP_DEC; > | ~~~~~~~~~~~~~~~~~^~~ > drivers/gpu/drm/radeon/si_dpm.c:2352:20: 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] > 2352 | smc_state->levels[i].dpm2.AboveSafeInc = SISLANDS_DPM2_ABOVE_SAFE_INC; > | ~~~~~~~~~~~~~~~~~^~~ > drivers/gpu/drm/radeon/si_dpm.c:2353:20: 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] > 2353 | smc_state->levels[i].dpm2.BelowSafeInc = SISLANDS_DPM2_BELOW_SAFE_INC; > | ~~~~~~~~~~~~~~~~~^~~ > drivers/gpu/drm/radeon/si_dpm.c:2354:20: 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] > 2354 | smc_state->levels[i].dpm2.PwrEfficiencyRatio = cpu_to_be16(pwr_efficiency_ratio); > | ~~~~~~~~~~~~~~~~~^~~ > drivers/gpu/drm/radeon/si_dpm.c:5105:20: 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] > 5105 | 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/603f9a8f.aDLrpMFzzSApzVYQ%25lkp@intel.com/ > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> > --- > drivers/gpu/drm/radeon/si_dpm.c | 5 ++--- > drivers/gpu/drm/radeon/sislands_smc.h | 10 +++++----- > 2 files changed, 7 insertions(+), 8 deletions(-) > > diff --git a/drivers/gpu/drm/radeon/si_dpm.c b/drivers/gpu/drm/radeon/si_dpm.c > index 91bfc4762767..918609551804 100644 > --- a/drivers/gpu/drm/radeon/si_dpm.c > +++ b/drivers/gpu/drm/radeon/si_dpm.c > @@ -5250,10 +5250,9 @@ 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); > > diff --git a/drivers/gpu/drm/radeon/sislands_smc.h b/drivers/gpu/drm/radeon/sislands_smc.h > index 966e3a556011..fbd6589bdab9 100644 > --- a/drivers/gpu/drm/radeon/sislands_smc.h > +++ b/drivers/gpu/drm/radeon/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 > > _______________________________________________ > amd-gfx mailing list > amd-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
On Fri, Mar 05, 2021 at 02:10:44PM -0500, Alex Deucher wrote:
> Applied. Thanks!
Awesome. :)
Thanks, Alex.
--
Gustavo
diff --git a/drivers/gpu/drm/radeon/si_dpm.c b/drivers/gpu/drm/radeon/si_dpm.c index 91bfc4762767..918609551804 100644 --- a/drivers/gpu/drm/radeon/si_dpm.c +++ b/drivers/gpu/drm/radeon/si_dpm.c @@ -5250,10 +5250,9 @@ 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); diff --git a/drivers/gpu/drm/radeon/sislands_smc.h b/drivers/gpu/drm/radeon/sislands_smc.h index 966e3a556011..fbd6589bdab9 100644 --- a/drivers/gpu/drm/radeon/sislands_smc.h +++ b/drivers/gpu/drm/radeon/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 by fixing the following warnings: drivers/gpu/drm/radeon/si_dpm.c: In function ‘si_convert_power_state_to_smc’: drivers/gpu/drm/radeon/si_dpm.c:2350:20: 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] 2350 | smc_state->levels[i].dpm2.MaxPS = (u8)((SISLANDS_DPM2_MAX_PULSE_SKIP * (max_sclk - min_sclk)) / max_sclk); | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/si_dpm.c:2351:20: 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] 2351 | smc_state->levels[i].dpm2.NearTDPDec = SISLANDS_DPM2_NEAR_TDP_DEC; | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/si_dpm.c:2352:20: 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] 2352 | smc_state->levels[i].dpm2.AboveSafeInc = SISLANDS_DPM2_ABOVE_SAFE_INC; | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/si_dpm.c:2353:20: 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] 2353 | smc_state->levels[i].dpm2.BelowSafeInc = SISLANDS_DPM2_BELOW_SAFE_INC; | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/si_dpm.c:2354:20: 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] 2354 | smc_state->levels[i].dpm2.PwrEfficiencyRatio = cpu_to_be16(pwr_efficiency_ratio); | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/si_dpm.c:5105:20: 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] 5105 | 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/603f9a8f.aDLrpMFzzSApzVYQ%25lkp@intel.com/ Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- drivers/gpu/drm/radeon/si_dpm.c | 5 ++--- drivers/gpu/drm/radeon/sislands_smc.h | 10 +++++----- 2 files changed, 7 insertions(+), 8 deletions(-)