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authorThiago Jung Bauermann <bauerman@linux.vnet.ibm.com>2017-06-30 00:55:32 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2017-07-02 13:40:30 +0300
commit36c8fb2c616d9373758b155d9723774353067a87 (patch)
tree7d53b180cb46c8b571e4ae2440fae7c960e40e27 /arch
parent12bf85a71000af7419b19b5e90910919f36f336c (diff)
downloadlinux-36c8fb2c616d9373758b155d9723774353067a87.tar.xz
powerpc/perf/hv-24x7: Fix off-by-one error in request_buffer check
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@linux.vnet.ibm.com> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/perf/hv-24x7.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
index 1354cde7095c..141de0f708f7 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;