Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0eb3448a authored by Alex Ivanov's avatar Alex Ivanov Committed by Alex Deucher
Browse files

drm/radeon: Make r100_cp_ring_info() and radeon_ring_gfx() safe (v2) 



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: default avatarAlex Ivanov <gnidorah@p0n4ik.tk>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
parent 42baf21d

drivers/gpu/drm/radeon/r100.c

+5 −3
Original line number Diff line number Diff line
@@ -2933,10 +2933,12 @@ static int r100_debugfs_cp_ring_info(struct seq_file *m, void *data) 
	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);

	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;

}

drivers/gpu/drm/radeon/radeon_ring.c

+5 −3
Original line number Diff line number Diff line
@@ -839,10 +839,12 @@ static int radeon_debugfs_ring_info(struct seq_file *m, void *data) 
	 * packet that is the root issue

	 */

	i = (ring->rptr + ring->ptr_mask + 1 - 32) & 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;

}