powerpc/perf: Return accordingly on invalid chip-id in

[ Upstream commit a913e5e8b43be1d3897a141ce61c1ec071cad89c ]

Nest hardware counter memory resides in a per-chip reserve-memory.
During nest_imc_event_init(), chip-id of the event-cpu is considered to
calculate the base memory addresss for that cpu. Return, proper error
condition if the chip_id calculated is invalid.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 885dcd709ba91 ("powerpc/perf: Add nest IMC PMU support")
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
index 1fafc32..3cebfdf 100644 (file)
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -496,6 +496,11 @@ static int nest_imc_event_init(struct perf_event *event)
         * Get the base memory addresss for this cpu.
         */
        chip_id = cpu_to_chip_id(event->cpu);
+
+       /* Return, if chip_id is not valid */
+       if (chip_id < 0)
+               return -ENODEV;
+
        pcni = pmu->mem_info;
        do {
                if (pcni->id == chip_id) {