diff options
| author | Gustavo A. R. Silva <gustavoars@kernel.org> | 2020-05-19 17:55:45 -0500 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2020-05-21 12:48:43 -0400 |
| commit | 94f2026bd82ed00b86b0423ec40d9e8b95052121 (patch) | |
| tree | edc9aeaaf3a42fa6033425e4280e21a8b35f2aae | |
| parent | 4cf7c42739ccafca753ed942ed1c96cc445c728b (diff) | |
drm/amdgpu/smu10: Replace one-element array and use struct_size() helper
The current codebase makes use of one-element arrays in the following
form:
struct something {
int length;
u8 data[1];
};
struct something *instance;
instance = kmalloc(sizeof(*instance) + size, GFP_KERNEL);
instance->length = size;
memcpy(instance->data, source, size);
but the preferred mechanism to declare variable-length types such as
these ones is a flexible array member[1][2], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on. So, replace
the one-element array with a flexible-array member.
Also, make use of the new struct_size() helper to properly calculate the
size of struct smu10_voltage_dependency_table.
This issue was found with the help of Coccinelle and, audited and fixed
_manually_.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
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>
| -rw-r--r-- | drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.c | 6 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.h | 2 |
2 files changed, 3 insertions, 5 deletions
diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.c index 4f8c1b85e688..d1f0cc77d460 100644 --- a/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.c +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.c @@ -410,12 +410,10 @@ static int smu10_get_clock_voltage_dependency_table(struct pp_hwmgr *hwmgr, struct smu10_voltage_dependency_table **pptable, uint32_t num_entry, const DpmClock_t *pclk_dependency_table) { - uint32_t table_size, i; + uint32_t i; struct smu10_voltage_dependency_table *ptable; - table_size = sizeof(uint32_t) + sizeof(struct smu10_voltage_dependency_table) * num_entry; - ptable = kzalloc(table_size, GFP_KERNEL); - + ptable = kzalloc(struct_size(ptable, entries, num_entry), GFP_KERNEL); if (NULL == ptable) return -ENOMEM; diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.h b/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.h index 1fb296a996f3..0f969de10fab 100644 --- a/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.h +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.h @@ -192,7 +192,7 @@ struct smu10_clock_voltage_dependency_record { struct smu10_voltage_dependency_table { uint32_t count; - struct smu10_clock_voltage_dependency_record entries[1]; + struct smu10_clock_voltage_dependency_record entries[]; }; struct smu10_clock_voltage_information { |