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Diffstat (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c')
-rw-r--r--drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c46
1 files changed, 29 insertions, 17 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
index 5505d646f43a..06f0a6534a94 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
@@ -524,46 +524,58 @@ static ssize_t amdgpu_debugfs_mqd_read(struct file *f, char __user *buf,
{
struct amdgpu_ring *ring = file_inode(f)->i_private;
volatile u32 *mqd;
- int r;
+ u32 *kbuf;
+ int r, i;
uint32_t value, result;
if (*pos & 3 || size & 3)
return -EINVAL;
- result = 0;
+ kbuf = kmalloc(ring->mqd_size, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
r = amdgpu_bo_reserve(ring->mqd_obj, false);
if (unlikely(r != 0))
- return r;
+ goto err_free;
r = amdgpu_bo_kmap(ring->mqd_obj, (void **)&mqd);
- if (r) {
- amdgpu_bo_unreserve(ring->mqd_obj);
- return r;
- }
+ if (r)
+ goto err_unreserve;
+ /*
+ * Copy to local buffer to avoid put_user(), which might fault
+ * and acquire mmap_sem, under reservation_ww_class_mutex.
+ */
+ for (i = 0; i < ring->mqd_size/sizeof(u32); i++)
+ kbuf[i] = mqd[i];
+
+ amdgpu_bo_kunmap(ring->mqd_obj);
+ amdgpu_bo_unreserve(ring->mqd_obj);
+
+ result = 0;
while (size) {
if (*pos >= ring->mqd_size)
- goto done;
+ break;
- value = mqd[*pos/4];
+ value = kbuf[*pos/4];
r = put_user(value, (uint32_t *)buf);
if (r)
- goto done;
+ goto err_free;
buf += 4;
result += 4;
size -= 4;
*pos += 4;
}
-done:
- amdgpu_bo_kunmap(ring->mqd_obj);
- mqd = NULL;
- amdgpu_bo_unreserve(ring->mqd_obj);
- if (r)
- return r;
-
+ kfree(kbuf);
return result;
+
+err_unreserve:
+ amdgpu_bo_unreserve(ring->mqd_obj);
+err_free:
+ kfree(kbuf);
+ return r;
}
static const struct file_operations amdgpu_debugfs_mqd_fops = {