[PATCH 00/14] drm/amd/pm: Replace one-element arrays with flexible-array members

Gustavo A. R. Silva
2020-10-07T15:55:30Z

Hi all,

This series aims to replace one-element arrays with flexible-array
members.

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 flexible-array members, instead
of one-element arrays, and use the struct_size() helper to calculate the
size for the dynamic memory allocation.

Also, save some heap space in the process. More on this on each individual
patch.

This series also addresses multiple of the following sorts of warnings:

drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu8_hwmgr.c:1515:37:
warning: array subscript 1 is above array bounds of ‘const struct
phm_clock_voltage_dependency_record[1]’ [-Warray-bounds]

which, in this case, they are false positives, but nervertheless should be
fixed in order to enable -Warray-bounds[3][4].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays
[3] https://git.kernel.org/linus/44720996e2d79e47d508b0abe99b931a726a3197
[4] https://github.com/KSPP/linux/issues/109

Gustavo A. R. Silva (14):
drm/amd/pm: Replace one-element array with flexible-array member
drm/amd/pm: Replace one-element array with flexible-array member in
struct vi_dpm_table
drm/amd/pm: Replace one-element array with flexible-array in struct
phm_clock_array
drm/amd/pm: Replace one-element array with flexible-array in struct
phm_uvd_clock_voltage_dependency_table
drm/amd/pm: Replace one-element array with flexible-array in struct
phm_acp_clock_voltage_dependency_table
drm/amd/pm: Replace one-element array with flexible-array in struct
phm_phase_shedding_limits_table
drm/amd/pm: Replace one-element array with flexible-array in struct
phm_vce_clock_voltage_dependency_table
drm/amd/pm: Replace one-element array with flexible-array in struct
phm_cac_leakage_table
drm/amd/pm: Replace one-element array with flexible-array in struct
phm_samu_clock_voltage_dependency_table
drm/amd/pm: Replace one-element array with flexible-array in struct
phm_ppt_v1_clock_voltage_dependency_table
drm/amd/pm: Replace one-element array with flexible-array in struct
phm_ppt_v1_mm_clock_voltage_dependency_table
drm/amd/pm: Replace one-element array with flexible-array in struct
phm_ppt_v1_voltage_lookup_table
drm/amd/pm: Replace one-element array with flexible-array in struct
phm_ppt_v1_pcie_table
drm/amd/pm: Replace one-element array with flexible-array in struct
ATOM_Vega10_GFXCLK_Dependency_Table

drivers/gpu/drm/amd/pm/inc/hwmgr.h | 20 ++---
.../drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h | 8 +-
.../powerplay/hwmgr/process_pptables_v1_0.c | 85 +++++++-----------
.../amd/pm/powerplay/hwmgr/processpptables.c | 85 +++++++-----------
.../drm/amd/pm/powerplay/hwmgr/smu8_hwmgr.c | 2 +-
.../drm/amd/pm/powerplay/hwmgr/smu_helper.c | 5 +-
.../amd/pm/powerplay/hwmgr/vega10_pptable.h | 2 +-
.../powerplay/hwmgr/vega10_processpptables.c | 88 ++++++-------------
8 files changed, 107 insertions(+), 188 deletions(-)

--
2.27.0