3.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alex Ivanov <gnidorah@xxxxxxxxx>
commit 0eb3448aa6b31fbf24c31756aba7940cac5ad6b8 upstream.
Prevent NULL pointer dereference in case when radeon_ring_fini() did it's job.
Reading of r100_cp_ring_info and radeon_ring_gfx debugfs entries will lead to a KP if ring buffer was deallocated, e.g. on failed ring test.
Seen on PA-RISC machine having "radeon: ring test failed (scratch(0x8504)=0xCAFEDEAD)" issue.
v2: agd5f: add some parens around ring->ready check
Signed-off-by: Alex Ivanov <gnidorah@xxxxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/radeon/r100.c | 8 +++++---
drivers/gpu/drm/radeon/radeon_ring.c | 8 +++++---
2 files changed, 10 insertions(+), 6 deletions(-)
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -2935,9 +2935,11 @@ static int r100_debugfs_cp_ring_info(str
seq_printf(m, "CP_RB_RPTR 0x%08x\n", rdp);
seq_printf(m, "%u free dwords in ring\n", ring->ring_free_dw);
seq_printf(m, "%u dwords in ring\n", count);
- for (j = 0; j <= count; j++) {
- i = (rdp + j) & ring->ptr_mask;
- seq_printf(m, "r[%04d]=0x%08x\n", i, ring->ring[i]);
+ if (ring->ready) {
+ for (j = 0; j <= count; j++) {
+ i = (rdp + j) & ring->ptr_mask;
+ seq_printf(m, "r[%04d]=0x%08x\n", i, ring->ring[i]);
+ }
}
return 0;
}
--- a/drivers/gpu/drm/radeon/radeon_ring.c
+++ b/drivers/gpu/drm/radeon/radeon_ring.c
@@ -823,9 +823,11 @@ static int radeon_debugfs_ring_info(stru
* packet that is the root issue
*/
i = (ring->rptr + ring->ptr_mask + 1 - 32) & ring->ptr_mask;
- for (j = 0; j <= (count + 32); j++) {
- seq_printf(m, "r[%5d]=0x%08x\n", i, ring->ring[i]);
- i = (i + 1) & ring->ptr_mask;
+ if (ring->ready) {
+ for (j = 0; j <= (count + 32); j++) {
+ seq_printf(m, "r[%5d]=0x%08x\n", i, ring->ring[i]);
+ i = (i + 1) & ring->ptr_mask;
+ }
}
return 0;
}
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