[PATCH 13/14] drm/amd/pm: Replace one-element array with flexible-array in struct phm_ppt_v1_pcie_table

Gustavo A. R. Silva
2020-10-07T16:04:47Z

struct phm_ppt_v1_pcie_table, instead of a one-element array, and use
the struct_size() helper to calculate the size for the allocation.

[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/5f7db0bc.7Xivn4K83f7XW0ug%25lkp@intel.com/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
.../drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h | 2 +-
.../powerplay/hwmgr/process_pptables_v1_0.c | 22 ++++++++-----------
.../powerplay/hwmgr/vega10_processpptables.c | 10 +++------
3 files changed, 13 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h
index e11298cdeb30..729615aff126 100644
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h
@@ -103,7 +103,7 @@ typedef struct phm_ppt_v1_pcie_record phm_ppt_v1_pcie_record;

struct phm_ppt_v1_pcie_table {
uint32_t count; /* Number of entries. */
- phm_ppt_v1_pcie_record entries[1]; /* Dynamically allocate count entries. */
+ phm_ppt_v1_pcie_record entries[]; /* Dynamically allocate count entries. */
};
typedef struct phm_ppt_v1_pcie_table phm_ppt_v1_pcie_table;

diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c
index 426655b9c678..4fa58614e26a 100644
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c
@@ -478,7 +478,7 @@ static int get_pcie_table(
PPTable_Generic_SubTable_Header const *ptable
)
{
- uint32_t table_size, i, pcie_count;
+ uint32_t i, pcie_count;
phm_ppt_v1_pcie_table *pcie_table;
struct phm_ppt_v1_information *pp_table_information =
(struct phm_ppt_v1_information *)(hwmgr->pptable);
@@ -491,12 +491,10 @@ static int get_pcie_table(
PP_ASSERT_WITH_CODE((atom_pcie_table->ucNumEntries != 0),
"Invalid PowerPlay Table!", return -1);

- table_size = sizeof(uint32_t) +
- sizeof(phm_ppt_v1_pcie_record) * atom_pcie_table->ucNumEntries;
-
- pcie_table = kzalloc(table_size, GFP_KERNEL);
-
- if (pcie_table == NULL)
+ pcie_table = kzalloc(struct_size(pcie_table, entries,
+ atom_pcie_table->ucNumEntries),
+ GFP_KERNEL);
+ if (!pcie_table)
return -ENOMEM;

/*
@@ -530,12 +528,10 @@ static int get_pcie_table(
PP_ASSERT_WITH_CODE((atom_pcie_table->ucNumEntries != 0),
"Invalid PowerPlay Table!", return -1);

- table_size = sizeof(uint32_t) +
- sizeof(phm_ppt_v1_pcie_record) * atom_pcie_table->ucNumEntries;
-
- pcie_table = kzalloc(table_size, GFP_KERNEL);
-
- if (pcie_table == NULL)
+ pcie_table = kzalloc(struct_size(pcie_table, entries,
+ atom_pcie_table->ucNumEntries),
+ GFP_KERNEL);
+ if (!pcie_table)
return -ENOMEM;

/*
diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_processpptables.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_processpptables.c
index 3d7f915381c8..535404de78a2 100644
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_processpptables.c
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_processpptables.c
@@ -784,7 +784,7 @@ static int get_pcie_table(struct pp_hwmgr *hwmgr,
struct phm_ppt_v1_pcie_table **vega10_pcie_table,
const Vega10_PPTable_Generic_SubTable_Header *table)
{
- uint32_t table_size, i, pcie_count;
+ uint32_t i, pcie_count;
struct phm_ppt_v1_pcie_table *pcie_table;
struct phm_ppt_v2_information *table_info =
(struct phm_ppt_v2_information *)(hwmgr->pptable);
@@ -795,12 +795,8 @@ static int get_pcie_table(struct pp_hwmgr *hwmgr,
"Invalid PowerPlay Table!",
return 0);

- table_size = sizeof(uint32_t) +
- sizeof(struct phm_ppt_v1_pcie_record) *
- atom_pcie_table->ucNumEntries;
-
- pcie_table = kzalloc(table_size, GFP_KERNEL);
-
+ pcie_table = kzalloc(struct_size(pcie_table, entries, atom_pcie_table->ucNumEntries),
+ GFP_KERNEL);
if (!pcie_table)