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author | Martin KaFai Lau <kafai@fb.com> | 2018-03-24 11:44:23 -0700 |
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committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-03-26 09:58:17 +0200 |
commit | 77d2e05abd45886dcad2b632c738cf46b9f7c19e (patch) | |
tree | dab2d5beef6275329e8ed3dbaff7f720d6f05f6c /kernel/bpf | |
parent | b9193c1b61ddb97da4713155b0d580e41fb544ac (diff) | |
download | op-kernel-dev-77d2e05abd45886dcad2b632c738cf46b9f7c19e.zip op-kernel-dev-77d2e05abd45886dcad2b632c738cf46b9f7c19e.tar.gz |
bpf: Add bpf_verifier_vlog() and bpf_verifier_log_needed()
The BTF (BPF Type Format) verifier needs to reuse the current
BPF verifier log. Hence, it requires the following changes:
(1) Expose log_write() in verifier.c for other users.
Its name is renamed to bpf_verifier_vlog().
(2) The BTF verifier also needs to check
'log->level && log->ubuf && !bpf_verifier_log_full(log);'
independently outside of the current log_write(). It is
because the BTF verifier will do one-check before
making multiple calls to btf_verifier_vlog to log
the details of a type.
Hence, this check is also re-factored to a new function
bpf_verifier_log_needed(). Since it is re-factored,
we can check it before va_start() in the current
bpf_verifier_log_write() and verbose().
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf')
-rw-r--r-- | kernel/bpf/verifier.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 1e84e02..8acd220 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -168,15 +168,11 @@ struct bpf_call_arg_meta { static DEFINE_MUTEX(bpf_verifier_lock); -static void log_write(struct bpf_verifier_env *env, const char *fmt, - va_list args) +void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt, + va_list args) { - struct bpf_verifier_log *log = &env->log; unsigned int n; - if (!log->level || !log->ubuf || bpf_verifier_log_full(log)) - return; - n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args); WARN_ONCE(n >= BPF_VERIFIER_TMP_LOG_SIZE - 1, @@ -200,18 +196,25 @@ __printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env, { va_list args; + if (!bpf_verifier_log_needed(&env->log)) + return; + va_start(args, fmt); - log_write(env, fmt, args); + bpf_verifier_vlog(&env->log, fmt, args); va_end(args); } EXPORT_SYMBOL_GPL(bpf_verifier_log_write); __printf(2, 3) static void verbose(void *private_data, const char *fmt, ...) { + struct bpf_verifier_env *env = private_data; va_list args; + if (!bpf_verifier_log_needed(&env->log)) + return; + va_start(args, fmt); - log_write(private_data, fmt, args); + bpf_verifier_vlog(&env->log, fmt, args); va_end(args); } |