Commit 9d100a19 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
Browse files

tools/bpf: print out btf log at LIBBPF_WARN level 



Currently, the btf log is allocated and printed out in case
of error at LIBBPF_DEBUG level.
Such logs from kernel are very important for debugging.
For example, bpf syscall BPF_PROG_LOAD command can get
verifier logs back to user space. In function load_program()
of libbpf.c, the log buffer is allocated unconditionally
and printed out at pr_warning() level.

Let us do the similar thing here for btf. Allocate buffer
unconditionally and print out error logs at pr_warning() level.
This can reduce one global function and
optimize for common situations where pr_warning()
is activated either by default or by user supplied
debug output function.

Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 8461ef8b

tools/lib/bpf/btf.c

+9 −10
Original line number Original line Diff line number Diff line
@@ -377,15 +377,14 @@ struct btf *btf__new(__u8 *data, __u32 size) 




	btf->fd = -1;

	btf->fd = -1;





	if (libbpf_print_level_available(LIBBPF_DEBUG)) {

	log_buf = malloc(BPF_LOG_BUF_SIZE);

	log_buf = malloc(BPF_LOG_BUF_SIZE);

	if (!log_buf) {

	if (!log_buf) {

		err = -ENOMEM;

		err = -ENOMEM;

		goto done;

		goto done;

	}

	}



	*log_buf = 0;

	*log_buf = 0;

	log_buf_size = BPF_LOG_BUF_SIZE;

	log_buf_size = BPF_LOG_BUF_SIZE;

	}





	btf->data = malloc(size);

	btf->data = malloc(size);

	if (!btf->data) {

	if (!btf->data) {
@@ -401,9 +400,9 @@ struct btf *btf__new(__u8 *data, __u32 size) 




	if (btf->fd == -1) {

	if (btf->fd == -1) {

		err = -errno;

		err = -errno;

		pr_debug("Error loading BTF: %s(%d)\n", strerror(errno), errno);

		pr_warning("Error loading BTF: %s(%d)\n", strerror(errno), errno);

		if (log_buf && *log_buf)

		if (log_buf && *log_buf)

			pr_debug("%s\n", log_buf);

			pr_warning("%s\n", log_buf);

		goto done;

		goto done;

	}

	}

tools/lib/bpf/libbpf.c

+0 −10
Original line number Original line Diff line number Diff line
@@ -98,16 +98,6 @@ void libbpf_print(enum libbpf_print_level level, const char *format, ...) 
	va_end(args);

	va_end(args);

}

}





bool libbpf_print_level_available(enum libbpf_print_level level)

{

	if (level == LIBBPF_WARN)

		return !!__pr_warning;

	else if (level == LIBBPF_INFO)

		return !!__pr_info;

	else

		return !!__pr_debug;

}



#define STRERR_BUFSIZE  128

#define STRERR_BUFSIZE  128





#define CHECK_ERR(action, err, out) do {	\

#define CHECK_ERR(action, err, out) do {	\

tools/lib/bpf/libbpf_util.h

+0 −2
Original line number Original line Diff line number Diff line
@@ -14,8 +14,6 @@ extern void libbpf_print(enum libbpf_print_level level, 
			 const char *format, ...)

			 const char *format, ...)

	__attribute__((format(printf, 2, 3)));

	__attribute__((format(printf, 2, 3)));





extern bool libbpf_print_level_available(enum libbpf_print_level level);



#define __pr(level, fmt, ...)	\

#define __pr(level, fmt, ...)	\

do {				\

do {				\

	libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__);	\

	libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__);	\

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