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-and-one-element-arrays
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/5f7c5d38.iT%2FQTjN+659XUDo5%25lkp@intel.com/
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
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 {
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;