bpf: Split off basic BPF verifier log into separate file

kernel/bpf/verifier.c file is large and growing larger all the time. So
it's good to start splitting off more or less self-contained parts into
separate files to keep source code size (somewhat) somewhat under
control.

This patch is a one step in this direction, moving some of BPF verifier log
routines into a separate kernel/bpf/log.c. Right now it's most low-level
and isolated routines to append data to log, reset log to previous
position, etc. Eventually we could probably move verifier state
printing logic here as well, but this patch doesn't attempt to do that
yet.

Subsequent patches will add more logic to verifier log management, so
having basics in a separate file will make sure verifier.c doesn't grow
more with new changes.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-2-andrii@kernel.org

1 files changed, 0 insertions, 69 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 3660b573048a..745ae0cd01d4 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -335,61 +335,6 @@ find_linfo(const struct bpf_verifier_env *env, u32 insn_off)
 	return &linfo[i - 1];
 }
 
-void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt,
-		       va_list args)
-{
-	unsigned int n;
-
-	n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args);
-
-	WARN_ONCE(n >= BPF_VERIFIER_TMP_LOG_SIZE - 1,
-		  "verifier log line truncated - local buffer too short\n");
-
-	if (log->level == BPF_LOG_KERNEL) {
-		bool newline = n > 0 && log->kbuf[n - 1] == '\n';
-
-		pr_err("BPF: %s%s", log->kbuf, newline ? "" : "\n");
-		return;
-	}
-
-	n = min(log->len_total - log->len_used - 1, n);
-	log->kbuf[n] = '\0';
-	if (!copy_to_user(log->ubuf + log->len_used, log->kbuf, n + 1))
-		log->len_used += n;
-	else
-		log->ubuf = NULL;
-}
-
-static void bpf_vlog_reset(struct bpf_verifier_log *log, u32 new_pos)
-{
-	char zero = 0;
-
-	if (!bpf_verifier_log_needed(log))
-		return;
-
-	log->len_used = new_pos;
-	if (put_user(zero, log->ubuf + new_pos))
-		log->ubuf = NULL;
-}
-
-/* log_level controls verbosity level of eBPF verifier.
- * bpf_verifier_log_write() is used to dump the verification trace to the log,
- * so the user can figure out what's wrong with the program
- */
-__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
-					   const char *fmt, ...)
-{
-	va_list args;
-
-	if (!bpf_verifier_log_needed(&env->log))
-		return;
-
-	va_start(args, fmt);
-	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;
@@ -403,20 +348,6 @@ __printf(2, 3) static void verbose(void *private_data, const char *fmt, ...)
 	va_end(args);
 }
 
-__printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
-			    const char *fmt, ...)
-{
-	va_list args;
-
-	if (!bpf_verifier_log_needed(log))
-		return;
-
-	va_start(args, fmt);
-	bpf_verifier_vlog(log, fmt, args);
-	va_end(args);
-}
-EXPORT_SYMBOL_GPL(bpf_log);
-
 static const char *ltrim(const char *s)
 {
 	while (isspace(*s))