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| author | Andrii Nakryiko <andrii@kernel.org> | 2022-01-06 12:51:56 -0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-01-06 22:25:53 +0100 |
| commit | 70bc793382a0e37ba4e35e4d1a317b280b829a44 (patch) | |
| tree | 4268e76853208cdcc9d54122b80e7772497da51e /tools | |
| parent | 1372d34ccf6dd480332b2bcb2fd59a2b9a0df415 (diff) | |
| download | linux-70bc793382a0e37ba4e35e4d1a317b280b829a44.tar.gz linux-70bc793382a0e37ba4e35e4d1a317b280b829a44.tar.bz2 linux-70bc793382a0e37ba4e35e4d1a317b280b829a44.zip | |
selftests/bpf: Don't rely on preserving volatile in PT_REGS macros in loop3
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@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220106205156.955373-1-andrii@kernel.org
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/loop3.c | 4 |
1 files 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..717dab14322b 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); |