6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Robin Murphy <robin.murphy@xxxxxxx>
commit 1892fe103c3a20fced306c8dafa74f7f6d4ea0a3 upstream.
Calling arm_cmn_event_clear() before all DTC indices are allocated is
wrong, and can lead to arm_cmn_event_add() erroneously clearing live
counters from full DTCs where allocation fails. Since the DTC counters
are only updated by arm_cmn_init_counter() after all DTC and DTM
allocations succeed, nothing actually needs cleaning up in this case
anyway, and it should just return directly as it did before.
Fixes: 7633ec2c262f ("perf/arm-cmn: Rework DTC counters (again)")
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
Reviewed-by: Ilkka Koskinen <ilkka@xxxxxxxxxxxxxxxxxxxxxx>
Acked-by: Will Deacon <will@xxxxxxxxxx>
Link: https://lore.kernel.org/r/ed589c0d8e4130dc68b8ad1625226d28bdc185d4.1702322847.git.robin.murphy@xxxxxxx
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/perf/arm-cmn.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/perf/arm-cmn.c
+++ b/drivers/perf/arm-cmn.c
@@ -1794,7 +1794,7 @@ static int arm_cmn_event_add(struct perf
idx = 0;
while (cmn->dtc[j].counters[idx])
if (++idx == CMN_DT_NUM_COUNTERS)
- goto free_dtms;
+ return -ENOSPC;
}
hw->dtc_idx[j] = idx;
}
