From 737123d67e02fdd6597aaac168e0c17e984c4234 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Wed, 7 Oct 2020 11:04:49 -0500 Subject: [PATCH] drm/amd/pm: Replace one-element array with flexible-array in struct phm_uvd_clock_voltage_dependency_table MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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_uvd_clock_voltage_dependency_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->numEntries by sizeof(struct phm_uvd_clock_voltage_dependency_table) when it should have multiplied it by sizeof(phm_uvd_clock_voltage_dependency_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 Link: https://lore.kernel.org/lkml/5f7c433e.pXkC6KsN6HN%2FLdhj%25lkp@intel.com/ Acked-by: Christian König Signed-off-by: Gustavo A. R. Silva Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/pm/inc/hwmgr.h | 2 +- drivers/gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c | 11 ++++------- 2 files changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/amd/pm/inc/hwmgr.h b/drivers/gpu/drm/amd/pm/inc/hwmgr.h index e84cff0..2f1886b 100644 --- a/drivers/gpu/drm/amd/pm/inc/hwmgr.h +++ b/drivers/gpu/drm/amd/pm/inc/hwmgr.h @@ -140,7 +140,7 @@ struct phm_uvd_clock_voltage_dependency_record { struct phm_uvd_clock_voltage_dependency_table { uint8_t count; - struct phm_uvd_clock_voltage_dependency_record entries[1]; + struct phm_uvd_clock_voltage_dependency_record entries[]; }; struct phm_acp_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 d9bed4d..305d95c 100644 --- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c +++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c @@ -1105,15 +1105,12 @@ static int get_uvd_clock_voltage_limit_table(struct pp_hwmgr *hwmgr, const ATOM_PPLIB_UVD_Clock_Voltage_Limit_Table *table, const UVDClockInfoArray *array) { - unsigned long table_size, i; + unsigned long i; struct phm_uvd_clock_voltage_dependency_table *uvd_table; - table_size = sizeof(unsigned long) + - sizeof(struct phm_uvd_clock_voltage_dependency_table) * - table->numEntries; - - uvd_table = kzalloc(table_size, GFP_KERNEL); - if (NULL == uvd_table) + uvd_table = kzalloc(struct_size(uvd_table, entries, table->numEntries), + GFP_KERNEL); + if (!uvd_table) return -ENOMEM; uvd_table->count = table->numEntries; -- 2.7.4