PT_REGS*() macro on some architectures force-cast struct pt_regs to
other types (user_pt_regs, etc) and might drop volatile modifiers, if any.
Volatile isn't really required as pt_regs value isn't supposed to change
during the BPF program run, so this is correct behavior.
But progs/loop3.c relies on that volatile modifier to ensure that loop
is preserved. Fix loop3.c by declaring i and sum variables as volatile
instead. It preserves the loop and makes the test pass on all
architectures (including s390x which is currently broken).
Fixes: 3cc31d794097 ("libbpf: Normalize PT_REGS_xxx() macro definitions")
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
tools/testing/selftests/bpf/progs/loop3.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/loop3.c b/tools/testing/selftests/bpf/progs/loop3.c
index 76e93b31c14b..24ff85295830 100644
--- a/tools/testing/selftests/bpf/progs/loop3.c
+++ b/tools/testing/selftests/bpf/progs/loop3.c
@@ -12,9 +12,9 @@
char _license[] SEC("license") = "GPL";
SEC("raw_tracepoint/consume_skb")
-int while_true(volatile struct pt_regs* ctx)
+int while_true(struct pt_regs* ctx)
{
- __u64 i = 0, sum = 0;
+ volatile __u64 i = 0, sum = 0;
do {
i++;
sum += PT_REGS_RC(ctx);
--
2.30.2
