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* [PATCH] drm/amdgpu: use kmalloc_array() instead of kmalloc()
@ 2025-06-16  2:55 Yunshui Jiang
  2025-06-16  3:14 ` Matthew Wilcox
  2025-06-16  7:30 ` [PATCH] " kernel test robot
  0 siblings, 2 replies; 7+ messages in thread
From: Yunshui Jiang @ 2025-06-16  2:55 UTC (permalink / raw)
  To: alexander.deucher, chriistian.koenig
  Cc: linux-doc, linux-kernel, Yunshui Jiang

Use kmalloc_array() instead of kmalloc() with multiplication.
kmalloc_array() is a safer way because of its multiply overflow check.

Signed-off-by: Yunshui Jiang <jiangyunshui@kylinos.cn>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
index de0944947eaf..ab02011842e4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
@@ -2563,7 +2563,7 @@ static int amdgpu_ras_badpages_read(struct amdgpu_device *adev,
 		goto out;
 	}
 
-	*bps = kmalloc(sizeof(struct ras_badpage) * data->count, GFP_KERNEL);
+	*bps = kmalloc_array(data->count, sizeof(struct ras_badpage), GFP_KERNEL);
 	if (!*bps) {
 		ret = -ENOMEM;
 		goto out;
@@ -2719,7 +2719,7 @@ static int amdgpu_ras_realloc_eh_data_space(struct amdgpu_device *adev,
 	unsigned int old_space = data->count + data->space_left;
 	unsigned int new_space = old_space + pages;
 	unsigned int align_space = ALIGN(new_space, 512);
-	void *bps = kmalloc(align_space * sizeof(*data->bps), GFP_KERNEL);
+	void *bps = kmalloc(align_space, sizeof(*data->bps), GFP_KERNEL);
 
 	if (!bps) {
 		return -ENOMEM;
-- 
2.47.1


^ permalink raw reply	[flat|nested] 7+ messages in thread
* [PATCH] drm/amdgpu: Use kmalloc_array() instead of kmalloc()
@ 2025-09-16  9:29 Rahul Kumar
  2025-09-17 18:25 ` Kuehling, Felix
  0 siblings, 1 reply; 7+ messages in thread
From: Rahul Kumar @ 2025-09-16  9:29 UTC (permalink / raw)
  To: Felix.Kuehling, alexander.deucher, christian.koenig, airlied,
	simona, amd-gfx, dri-devel
  Cc: linux-kernel, linux-kernel-mentees, skhan, rk0006818

Documentation/process/deprecated.rst recommends against the use of
kmalloc with dynamic size calculations due to the risk of overflow and
smaller allocation being made than the caller was expecting.

Replace kmalloc() with kmalloc_array() in amdgpu_amdkfd_gfx_v10.c
to make the intended allocation size clearer and avoid potential
overflow issues.

Signed-off-by: Rahul Kumar <rk0006818@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
index 04ef0ca10541..0239114fb6c4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
@@ -352,7 +352,7 @@ static int kgd_hqd_dump(struct amdgpu_device *adev,
 		(*dump)[i++][1] = RREG32_SOC15_IP(GC, addr);		\
 	} while (0)
 
-	*dump = kmalloc(HQD_N_REGS*2*sizeof(uint32_t), GFP_KERNEL);
+	*dump = kmalloc_array(HQD_N_REGS, sizeof(**dump), GFP_KERNEL);
 	if (*dump == NULL)
 		return -ENOMEM;
 
@@ -449,7 +449,7 @@ static int kgd_hqd_sdma_dump(struct amdgpu_device *adev,
 #undef HQD_N_REGS
 #define HQD_N_REGS (19+6+7+10)
 
-	*dump = kmalloc(HQD_N_REGS*2*sizeof(uint32_t), GFP_KERNEL);
+	*dump = kmalloc_array(HQD_N_REGS, sizeof(**dump), GFP_KERNEL);
 	if (*dump == NULL)
 		return -ENOMEM;
 
-- 
2.43.0


^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2025-09-17 18:25 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2025-06-16  2:55 [PATCH] drm/amdgpu: use kmalloc_array() instead of kmalloc() Yunshui Jiang
2025-06-16  3:14 ` Matthew Wilcox
2025-07-24  1:37   ` [PATCH v2] " Yunshui Jiang
2025-07-24  1:48     ` Jeff Johnson
2025-06-16  7:30 ` [PATCH] " kernel test robot
2025-09-16  9:29 [PATCH] drm/amdgpu: Use " Rahul Kumar
2025-09-17 18:25 ` Kuehling, Felix

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