[PATCH 1/5] drm/amdgpu: Move a variable assignment behind a null pointer check in amdgpu_ras_interrupt_dispatch()

[Markus Elfring]

Date: Tue, 11 Apr 2023 10:52:48 +0200

The address of a data structure member was determined before
a corresponding null pointer check in the implementation of
the function “amdgpu_ras_interrupt_dispatch”.

Thus avoid the risk for undefined behaviour by moving the assignment
for the variable “data” behind the null pointer check.

This issue was detected by using the Coccinelle software.

Fixes: c030f2e4166c3f5597c7e7a70bcd9ab383695de4 ("drm/amdgpu: add amdgpu_ras.c 
to support ras (v2)")
Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
index 4069bce9479f..a920c7888d07 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
@@ -1730,11 +1730,12 @@ int amdgpu_ras_interrupt_dispatch(struct amdgpu_device 
*adev,
                struct ras_dispatch_if *info)
 {
        struct ras_manager *obj = amdgpu_ras_find_obj(adev, &info->head);
-       struct ras_ih_data *data = &obj->ih_data;
+       struct ras_ih_data *data;

        if (!obj)
                return -EINVAL;

+       data = &obj->ih_data;
        if (data->inuse == 0)
                return 0;

--
2.40.0