| Message ID | 20220407153814.104914-1-ytcoode@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 658d87687cd5a6c8762d1de8abee1e6792d8d71e |
| Headers | show |
| Series | [bpf-next] selftests/bpf: Fix return value checks in perf_event_stackmap.c | expand |
On 4/7/22 9:38 AM, Yuntao Wang wrote: > The bpf_get_stackid() function may also return 0 on success. Can you add couple of sentences to describe what this patch does? bpf_get_stackid() may also return doesn't really say anything about why this patch is needed. > > Signed-off-by: Yuntao Wang <ytcoode@gmail.com> > --- > tools/testing/selftests/bpf/progs/perf_event_stackmap.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/bpf/progs/perf_event_stackmap.c b/tools/testing/selftests/bpf/progs/perf_event_stackmap.c > index b3fcb5274ee0..f793280a3238 100644 > --- a/tools/testing/selftests/bpf/progs/perf_event_stackmap.c > +++ b/tools/testing/selftests/bpf/progs/perf_event_stackmap.c > @@ -35,10 +35,10 @@ int oncpu(void *ctx) > long val; > > val = bpf_get_stackid(ctx, &stackmap, 0); > - if (val > 0) > + if (val >= 0) > stackid_kernel = 2; > val = bpf_get_stackid(ctx, &stackmap, BPF_F_USER_STACK); > - if (val > 0) > + if (val >= 0) > stackid_user = 2; > > trace = bpf_map_lookup_elem(&stackdata_map, &key); > Linux 5.18-rc1 shows a couple of more bpf_get_stackid() in this function. Removed in bpf-next - I assume. The change is good. I would like to see it explained better in the commit log. With the commit log fixed to explain why this change is needed and what happens if val equals to 0 condition isn't checked: Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> thanks, -- Shuah
diff --git a/tools/testing/selftests/bpf/progs/perf_event_stackmap.c b/tools/testing/selftests/bpf/progs/perf_event_stackmap.c index b3fcb5274ee0..f793280a3238 100644 --- a/tools/testing/selftests/bpf/progs/perf_event_stackmap.c +++ b/tools/testing/selftests/bpf/progs/perf_event_stackmap.c @@ -35,10 +35,10 @@ int oncpu(void *ctx) long val; val = bpf_get_stackid(ctx, &stackmap, 0); - if (val > 0) + if (val >= 0) stackid_kernel = 2; val = bpf_get_stackid(ctx, &stackmap, BPF_F_USER_STACK); - if (val > 0) + if (val >= 0) stackid_user = 2; trace = bpf_map_lookup_elem(&stackdata_map, &key);
The bpf_get_stackid() function may also return 0 on success. Signed-off-by: Yuntao Wang <ytcoode@gmail.com> --- tools/testing/selftests/bpf/progs/perf_event_stackmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)