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 phm_cac_leakage_table, instead of a one-element array, and use the struct_size() helper to calculate the size for the allocation.
Also, save some heap space as the original code is multiplying table->ucNumEntries by sizeof(struct phm_cac_leakage_table) when it should have been multiplied it by sizeof(struct phm_cac_leakage_record) instead.
[1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length...
Build-tested-by: kernel test robot lkp@intel.com Link: https://lore.kernel.org/lkml/5f7c5d38.iT%2FQTjN+659XUDo5%25lkp@intel.com/ Signed-off-by: Gustavo A. R. Silva gustavoars@kernel.org --- drivers/gpu/drm/amd/pm/inc/hwmgr.h | 2 +- .../drm/amd/pm/powerplay/hwmgr/processpptables.c | 13 +++++-------- 2 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/amd/pm/inc/hwmgr.h b/drivers/gpu/drm/amd/pm/inc/hwmgr.h index b8e33325fac6..7e0c948a7097 100644 --- a/drivers/gpu/drm/amd/pm/inc/hwmgr.h +++ b/drivers/gpu/drm/amd/pm/inc/hwmgr.h @@ -393,7 +393,7 @@ union phm_cac_leakage_record {
struct phm_cac_leakage_table { uint32_t count; - union phm_cac_leakage_record entries[1]; + union phm_cac_leakage_record entries[]; };
struct phm_samu_clock_voltage_dependency_record { diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c index 7719f52e6d52..e059802d1e25 100644 --- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c +++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c @@ -1384,17 +1384,14 @@ static int get_cac_leakage_table(struct pp_hwmgr *hwmgr, const ATOM_PPLIB_CAC_Leakage_Table *table) { struct phm_cac_leakage_table *cac_leakage_table; - unsigned long table_size, i; + unsigned long i;
- if (hwmgr == NULL || table == NULL || ptable == NULL) + if (!hwmgr || !table || !ptable) return -EINVAL;
- table_size = sizeof(ULONG) + - (sizeof(struct phm_cac_leakage_table) * table->ucNumEntries); - - cac_leakage_table = kzalloc(table_size, GFP_KERNEL); - - if (cac_leakage_table == NULL) + cac_leakage_table = kzalloc(struct_size(cac_leakage_table, entries, table->ucNumEntries), + GFP_KERNEL); + if (!cac_leakage_table) return -ENOMEM;
cac_leakage_table->count = (ULONG)table->ucNumEntries;