From: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxxxxxxx>
[ Upstream commit 36c8fb2c616d9373758b155d9723774353067a87 ]
request_buffer can hold 254 requests, so if it already has that number of
entries we can't add a new one.
Also, define constant to show where the number comes from.
Fixes: e3ee15dc5d19 ("powerpc/perf/hv-24x7: Define add_event_to_24x7_request()")
Reviewed-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
arch/powerpc/perf/hv-24x7.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
index 13cea4e8c56d..9fc2be138e32 100644
--- a/arch/powerpc/perf/hv-24x7.c
+++ b/arch/powerpc/perf/hv-24x7.c
@@ -166,6 +166,10 @@ DEFINE_PER_CPU(struct hv_24x7_hw, hv_24x7_hw);
DEFINE_PER_CPU(char, hv_24x7_reqb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
DEFINE_PER_CPU(char, hv_24x7_resb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
+#define MAX_NUM_REQUESTS ((H24x7_DATA_BUFFER_SIZE - \
+ sizeof(struct hv_24x7_request_buffer)) \
+ / sizeof(struct hv_24x7_request))
+
static char *event_name(struct hv_24x7_event_data *ev, int *len)
{
*len = be16_to_cpu(ev->event_name_len) - 2;
@@ -1107,7 +1111,7 @@ static int add_event_to_24x7_request(struct perf_event *event,
int i;
struct hv_24x7_request *req;
- if (request_buffer->num_requests > 254) {
+ if (request_buffer->num_requests >= MAX_NUM_REQUESTS) {
pr_devel("Too many requests for 24x7 HCALL %d\n",
request_buffer->num_requests);
return -EINVAL;
--
2.15.1