Yonghong noticed that error messages for potential verifier bugs often
have a '(1)' at the end. This is happening because verifier_bug_if(cond,
env, fmt, args...) prints "(" #cond ")\n" as part of the message and
verifier_bug() is defined as:
#define verifier_bug(env, fmt, args...) verifier_bug_if(1, env, fmt, ##args)
Hence, verifier_bug() always ends up displaying '(1)'. This small patch
fixes it by having verifier_bug_if conditionally call verifier_bug
instead of the other way around.
Fixes: 1cb0f56d9618 ("bpf: WARN_ONCE on verifier bugs")
Reported-by: Yonghong Song <yonghong.song@xxxxxxxxx>
Signed-off-by: Paul Chaignon <paul.chaignon@xxxxxxxxx>
---
include/linux/bpf_verifier.h | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index c823f8efe3ed..d38b5ac6a191 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -876,12 +876,15 @@ __printf(3, 4) void verbose_linfo(struct bpf_verifier_env *env,
({ \
bool __cond = (cond); \
if (unlikely(__cond)) { \
- BPF_WARN_ONCE(1, "verifier bug: " fmt "(" #cond ")\n", ##args); \
- bpf_log(&env->log, "verifier bug: " fmt "(" #cond ")\n", ##args); \
+ verifier_bug(env, fmt " (" #cond ")", ##args); \
} \
(__cond); \
})
-#define verifier_bug(env, fmt, args...) verifier_bug_if(1, env, fmt, ##args)
+#define verifier_bug(env, fmt, args...) \
+ ({ \
+ BPF_WARN_ONCE(1, "verifier bug: " fmt "\n", ##args); \
+ bpf_log(&env->log, "verifier bug: " fmt "\n", ##args); \
+ })
static inline struct bpf_func_state *cur_func(struct bpf_verifier_env *env)
{
--
2.43.0
