6 files changed, 120 insertions, 70 deletions

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index d682d3b8f7b9..93e792b82242 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -9,8 +9,9 @@
 #include <linux/btf.h>
 #include "btf.h"
 #include "bpf.h"
+#include "libbpf.h"
+#include "libbpf_util.h"
 
-#define elog(fmt, ...) { if (err_log) err_log(fmt, ##__VA_ARGS__); }
 #define max(a, b) ((a) > (b) ? (a) : (b))
 #define min(a, b) ((a) < (b) ? (a) : (b))
 
@@ -107,54 +108,54 @@ static int btf_add_type(struct btf *btf, struct btf_type *t)
 	return 0;
 }
 
-static int btf_parse_hdr(struct btf *btf, btf_print_fn_t err_log)
+static int btf_parse_hdr(struct btf *btf)
 {
 	const struct btf_header *hdr = btf->hdr;
 	__u32 meta_left;
 
 	if (btf->data_size < sizeof(struct btf_header)) {
-		elog("BTF header not found\n");
+		pr_debug("BTF header not found\n");
 		return -EINVAL;
 	}
 
 	if (hdr->magic != BTF_MAGIC) {
-		elog("Invalid BTF magic:%x\n", hdr->magic);
+		pr_debug("Invalid BTF magic:%x\n", hdr->magic);
 		return -EINVAL;
 	}
 
 	if (hdr->version != BTF_VERSION) {
-		elog("Unsupported BTF version:%u\n", hdr->version);
+		pr_debug("Unsupported BTF version:%u\n", hdr->version);
 		return -ENOTSUP;
 	}
 
 	if (hdr->flags) {
-		elog("Unsupported BTF flags:%x\n", hdr->flags);
+		pr_debug("Unsupported BTF flags:%x\n", hdr->flags);
 		return -ENOTSUP;
 	}
 
 	meta_left = btf->data_size - sizeof(*hdr);
 	if (!meta_left) {
-		elog("BTF has no data\n");
+		pr_debug("BTF has no data\n");
 		return -EINVAL;
 	}
 
 	if (meta_left < hdr->type_off) {
-		elog("Invalid BTF type section offset:%u\n", hdr->type_off);
+		pr_debug("Invalid BTF type section offset:%u\n", hdr->type_off);
 		return -EINVAL;
 	}
 
 	if (meta_left < hdr->str_off) {
-		elog("Invalid BTF string section offset:%u\n", hdr->str_off);
+		pr_debug("Invalid BTF string section offset:%u\n", hdr->str_off);
 		return -EINVAL;
 	}
 
 	if (hdr->type_off >= hdr->str_off) {
-		elog("BTF type section offset >= string section offset. No type?\n");
+		pr_debug("BTF type section offset >= string section offset. No type?\n");
 		return -EINVAL;
 	}
 
 	if (hdr->type_off & 0x02) {
-		elog("BTF type section is not aligned to 4 bytes\n");
+		pr_debug("BTF type section is not aligned to 4 bytes\n");
 		return -EINVAL;
 	}
 
@@ -163,7 +164,7 @@ static int btf_parse_hdr(struct btf *btf, btf_print_fn_t err_log)
 	return 0;
 }
 
-static int btf_parse_str_sec(struct btf *btf, btf_print_fn_t err_log)
+static int btf_parse_str_sec(struct btf *btf)
 {
 	const struct btf_header *hdr = btf->hdr;
 	const char *start = btf->nohdr_data + hdr->str_off;
@@ -171,7 +172,7 @@ static int btf_parse_str_sec(struct btf *btf, btf_print_fn_t err_log)
 
 	if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET ||
 	    start[0] || end[-1]) {
-		elog("Invalid BTF string section\n");
+		pr_debug("Invalid BTF string section\n");
 		return -EINVAL;
 	}
 
@@ -180,7 +181,7 @@ static int btf_parse_str_sec(struct btf *btf, btf_print_fn_t err_log)
 	return 0;
 }
 
-static int btf_parse_type_sec(struct btf *btf, btf_print_fn_t err_log)
+static int btf_parse_type_sec(struct btf *btf)
 {
 	struct btf_header *hdr = btf->hdr;
 	void *nohdr_data = btf->nohdr_data;
@@ -219,7 +220,7 @@ static int btf_parse_type_sec(struct btf *btf, btf_print_fn_t err_log)
 		case BTF_KIND_RESTRICT:
 			break;
 		default:
-			elog("Unsupported BTF_KIND:%u\n",
+			pr_debug("Unsupported BTF_KIND:%u\n",
 			     BTF_INFO_KIND(t->info));
 			return -EINVAL;
 		}
@@ -363,7 +364,7 @@ void btf__free(struct btf *btf)
 	free(btf);
 }
 
-struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log)
+struct btf *btf__new(__u8 *data, __u32 size)
 {
 	__u32 log_buf_size = 0;
 	char *log_buf = NULL;
@@ -376,7 +377,7 @@ struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log)
 
 	btf->fd = -1;
 
-	if (err_log) {
+	if (libbpf_print_level_available(LIBBPF_DEBUG)) {
 		log_buf = malloc(BPF_LOG_BUF_SIZE);
 		if (!log_buf) {
 			err = -ENOMEM;
@@ -400,21 +401,21 @@ struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log)
 
 	if (btf->fd == -1) {
 		err = -errno;
-		elog("Error loading BTF: %s(%d)\n", strerror(errno), errno);
+		pr_debug("Error loading BTF: %s(%d)\n", strerror(errno), errno);
 		if (log_buf && *log_buf)
-			elog("%s\n", log_buf);
+			pr_debug("%s\n", log_buf);
 		goto done;
 	}
 
-	err = btf_parse_hdr(btf, err_log);
+	err = btf_parse_hdr(btf);
 	if (err)
 		goto done;
 
-	err = btf_parse_str_sec(btf, err_log);
+	err = btf_parse_str_sec(btf);
 	if (err)
 		goto done;
 
-	err = btf_parse_type_sec(btf, err_log);
+	err = btf_parse_type_sec(btf);
 
 done:
 	free(log_buf);
@@ -491,7 +492,7 @@ int btf__get_from_id(__u32 id, struct btf **btf)
 		goto exit_free;
 	}
 
-	*btf = btf__new((__u8 *)(long)btf_info.btf, btf_info.btf_size, NULL);
+	*btf = btf__new((__u8 *)(long)btf_info.btf, btf_info.btf_size);
 	if (IS_ERR(*btf)) {
 		err = PTR_ERR(*btf);
 		*btf = NULL;
@@ -514,8 +515,7 @@ struct btf_ext_sec_copy_param {
 
 static int btf_ext_copy_info(struct btf_ext *btf_ext,
 			     __u8 *data, __u32 data_size,
-			     struct btf_ext_sec_copy_param *ext_sec,
-			     btf_print_fn_t err_log)
+			     struct btf_ext_sec_copy_param *ext_sec)
 {
 	const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
 	const struct btf_ext_info_sec *sinfo;
@@ -529,14 +529,14 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext,
 	data_size -= hdr->hdr_len;
 
 	if (ext_sec->off & 0x03) {
-		elog(".BTF.ext %s section is not aligned to 4 bytes\n",
+		pr_debug(".BTF.ext %s section is not aligned to 4 bytes\n",
 		     ext_sec->desc);
 		return -EINVAL;
 	}
 
 	if (data_size < ext_sec->off ||
 	    ext_sec->len > data_size - ext_sec->off) {
-		elog("%s section (off:%u len:%u) is beyond the end of the ELF section .BTF.ext\n",
+		pr_debug("%s section (off:%u len:%u) is beyond the end of the ELF section .BTF.ext\n",
 		     ext_sec->desc, ext_sec->off, ext_sec->len);
 		return -EINVAL;
 	}
@@ -546,7 +546,7 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext,
 
 	/* At least a record size */
 	if (info_left < sizeof(__u32)) {
-		elog(".BTF.ext %s record size not found\n", ext_sec->desc);
+		pr_debug(".BTF.ext %s record size not found\n", ext_sec->desc);
 		return -EINVAL;
 	}
 
@@ -554,7 +554,7 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext,
 	record_size = *(__u32 *)info;
 	if (record_size < ext_sec->min_rec_size ||
 	    record_size & 0x03) {
-		elog("%s section in .BTF.ext has invalid record size %u\n",
+		pr_debug("%s section in .BTF.ext has invalid record size %u\n",
 		     ext_sec->desc, record_size);
 		return -EINVAL;
 	}
@@ -564,7 +564,7 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext,
 
 	/* If no records, return failure now so .BTF.ext won't be used. */
 	if (!info_left) {
-		elog("%s section in .BTF.ext has no records", ext_sec->desc);
+		pr_debug("%s section in .BTF.ext has no records", ext_sec->desc);
 		return -EINVAL;
 	}
 
@@ -574,14 +574,14 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext,
 		__u32 num_records;
 
 		if (info_left < sec_hdrlen) {
-			elog("%s section header is not found in .BTF.ext\n",
+			pr_debug("%s section header is not found in .BTF.ext\n",
 			     ext_sec->desc);
 			return -EINVAL;
 		}
 
 		num_records = sinfo->num_info;
 		if (num_records == 0) {
-			elog("%s section has incorrect num_records in .BTF.ext\n",
+			pr_debug("%s section has incorrect num_records in .BTF.ext\n",
 			     ext_sec->desc);
 			return -EINVAL;
 		}
@@ -589,7 +589,7 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext,
 		total_record_size = sec_hdrlen +
 				    (__u64)num_records * record_size;
 		if (info_left < total_record_size) {
-			elog("%s section has incorrect num_records in .BTF.ext\n",
+			pr_debug("%s section has incorrect num_records in .BTF.ext\n",
 			     ext_sec->desc);
 			return -EINVAL;
 		}
@@ -610,8 +610,7 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext,
 }
 
 static int btf_ext_copy_func_info(struct btf_ext *btf_ext,
-				  __u8 *data, __u32 data_size,
-				  btf_print_fn_t err_log)
+				  __u8 *data, __u32 data_size)
 {
 	const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
 	struct btf_ext_sec_copy_param param = {
@@ -622,12 +621,11 @@ static int btf_ext_copy_func_info(struct btf_ext *btf_ext,
 		.desc = "func_info"
 	};
 
-	return btf_ext_copy_info(btf_ext, data, data_size, &param, err_log);
+	return btf_ext_copy_info(btf_ext, data, data_size, &param);
 }
 
 static int btf_ext_copy_line_info(struct btf_ext *btf_ext,
-				  __u8 *data, __u32 data_size,
-				  btf_print_fn_t err_log)
+				  __u8 *data, __u32 data_size)
 {
 	const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
 	struct btf_ext_sec_copy_param param = {
@@ -638,37 +636,36 @@ static int btf_ext_copy_line_info(struct btf_ext *btf_ext,
 		.desc = "line_info",
 	};
 
-	return btf_ext_copy_info(btf_ext, data, data_size, &param, err_log);
+	return btf_ext_copy_info(btf_ext, data, data_size, &param);
 }
 
-static int btf_ext_parse_hdr(__u8 *data, __u32 data_size,
-			     btf_print_fn_t err_log)
+static int btf_ext_parse_hdr(__u8 *data, __u32 data_size)
 {
 	const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
 
 	if (data_size < offsetof(struct btf_ext_header, func_info_off) ||
 	    data_size < hdr->hdr_len) {
-		elog("BTF.ext header not found");
+		pr_debug("BTF.ext header not found");
 		return -EINVAL;
 	}
 
 	if (hdr->magic != BTF_MAGIC) {
-		elog("Invalid BTF.ext magic:%x\n", hdr->magic);
+		pr_debug("Invalid BTF.ext magic:%x\n", hdr->magic);
 		return -EINVAL;
 	}
 
 	if (hdr->version != BTF_VERSION) {
-		elog("Unsupported BTF.ext version:%u\n", hdr->version);
+		pr_debug("Unsupported BTF.ext version:%u\n", hdr->version);
 		return -ENOTSUP;
 	}
 
 	if (hdr->flags) {
-		elog("Unsupported BTF.ext flags:%x\n", hdr->flags);
+		pr_debug("Unsupported BTF.ext flags:%x\n", hdr->flags);
 		return -ENOTSUP;
 	}
 
 	if (data_size == hdr->hdr_len) {
-		elog("BTF.ext has no data\n");
+		pr_debug("BTF.ext has no data\n");
 		return -EINVAL;
 	}
 
@@ -685,12 +682,12 @@ void btf_ext__free(struct btf_ext *btf_ext)
 	free(btf_ext);
 }
 
-struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log)
+struct btf_ext *btf_ext__new(__u8 *data, __u32 size)
 {
 	struct btf_ext *btf_ext;
 	int err;
 
-	err = btf_ext_parse_hdr(data, size, err_log);
+	err = btf_ext_parse_hdr(data, size);
 	if (err)
 		return ERR_PTR(err);
 
@@ -698,13 +695,13 @@ struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log)
 	if (!btf_ext)
 		return ERR_PTR(-ENOMEM);
 
-	err = btf_ext_copy_func_info(btf_ext, data, size, err_log);
+	err = btf_ext_copy_func_info(btf_ext, data, size);
 	if (err) {
 		btf_ext__free(btf_ext);
 		return ERR_PTR(err);
 	}
 
-	err = btf_ext_copy_line_info(btf_ext, data, size, err_log);
+	err = btf_ext_copy_line_info(btf_ext, data, size);
 	if (err) {
 		btf_ext__free(btf_ext);
 		return ERR_PTR(err);
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index b0610dcdae6b..b1e8e54cc21d 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -55,11 +55,8 @@ struct btf_ext_header {
 	__u32	line_info_len;
 };
 
-typedef int (*btf_print_fn_t)(const char *, ...)
-	__attribute__((format(printf, 1, 2)));
-
 LIBBPF_API void btf__free(struct btf *btf);
-LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log);
+LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size);
 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
 				   const char *type_name);
 LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
@@ -70,7 +67,7 @@ LIBBPF_API int btf__fd(const struct btf *btf);
 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
 
-struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log);
+struct btf_ext *btf_ext__new(__u8 *data, __u32 size);
 void btf_ext__free(struct btf_ext *btf_ext);
 int btf_ext__reloc_func_info(const struct btf *btf,
 			     const struct btf_ext *btf_ext,
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 03bc01ca2577..eeba77b695ad 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -42,6 +42,7 @@
 #include "bpf.h"
 #include "btf.h"
 #include "str_error.h"
+#include "libbpf_util.h"
 
 #ifndef EM_BPF
 #define EM_BPF 247
@@ -69,16 +70,6 @@ static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr;
 static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr;
 static __printf(1, 2) libbpf_print_fn_t __pr_debug;
 
-#define __pr(func, fmt, ...)	\
-do {				\
-	if ((func))		\
-		(func)("libbpf: " fmt, ##__VA_ARGS__); \
-} while (0)
-
-#define pr_warning(fmt, ...)	__pr(__pr_warning, fmt, ##__VA_ARGS__)
-#define pr_info(fmt, ...)	__pr(__pr_info, fmt, ##__VA_ARGS__)
-#define pr_debug(fmt, ...)	__pr(__pr_debug, fmt, ##__VA_ARGS__)
-
 void libbpf_set_print(libbpf_print_fn_t warn,
 		      libbpf_print_fn_t info,
 		      libbpf_print_fn_t debug)
@@ -88,6 +79,35 @@ void libbpf_set_print(libbpf_print_fn_t warn,
 	__pr_debug = debug;
 }
 
+__printf(2, 3)
+void libbpf_print(enum libbpf_print_level level, const char *format, ...)
+{
+	va_list args;
+
+	va_start(args, format);
+	if (level == LIBBPF_WARN) {
+		if (__pr_warning)
+			__pr_warning(format, args);
+	} else if (level == LIBBPF_INFO) {
+		if (__pr_info)
+			__pr_info(format, args);
+	} else {
+		if (__pr_debug)
+			__pr_debug(format, 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 CHECK_ERR(action, err, out) do {	\
@@ -839,8 +859,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 		else if (strcmp(name, "maps") == 0)
 			obj->efile.maps_shndx = idx;
 		else if (strcmp(name, BTF_ELF_SEC) == 0) {
-			obj->btf = btf__new(data->d_buf, data->d_size,
-					    __pr_debug);
+			obj->btf = btf__new(data->d_buf, data->d_size);
 			if (IS_ERR(obj->btf)) {
 				pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
 					   BTF_ELF_SEC, PTR_ERR(obj->btf));
@@ -915,8 +934,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 				 BTF_EXT_ELF_SEC, BTF_ELF_SEC);
 		} else {
 			obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,
-						    btf_ext_data->d_size,
-						    __pr_debug);
+						    btf_ext_data->d_size);
 			if (IS_ERR(obj->btf_ext)) {
 				pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
 					   BTF_EXT_ELF_SEC,
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 43c77e98df6f..0fb32cc04633 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -47,6 +47,12 @@ enum libbpf_errno {
 
 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);
 
+enum libbpf_print_level {
+        LIBBPF_WARN,
+        LIBBPF_INFO,
+        LIBBPF_DEBUG,
+};
+
 /*
  * __printf is defined in include/linux/compiler-gcc.h. However,
  * it would be better if libbpf.h didn't depend on Linux header files.
diff --git a/tools/lib/bpf/libbpf_util.h b/tools/lib/bpf/libbpf_util.h
new file mode 100644
index 000000000000..0fdc3b1d0e33
--- /dev/null
+++ b/tools/lib/bpf/libbpf_util.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/* Copyright (c) 2019 Facebook */
+
+#ifndef __LIBBPF_LIBBPF_UTIL_H
+#define __LIBBPF_LIBBPF_UTIL_H
+
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern void libbpf_print(enum libbpf_print_level level,
+			 const char *format, ...)
+	__attribute__((format(printf, 2, 3)));
+
+extern bool libbpf_print_level_available(enum libbpf_print_level level);
+
+#define __pr(level, fmt, ...)	\
+do {				\
+	libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__);	\
+} while (0)
+
+#define pr_warning(fmt, ...)	__pr(LIBBPF_WARN, fmt, ##__VA_ARGS__)
+#define pr_info(fmt, ...)	__pr(LIBBPF_INFO, fmt, ##__VA_ARGS__)
+#define pr_debug(fmt, ...)	__pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__)
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif
diff --git a/tools/lib/bpf/test_libbpf.cpp b/tools/lib/bpf/test_libbpf.cpp
index abf3fc25c9fa..be67f5ea2c19 100644
--- a/tools/lib/bpf/test_libbpf.cpp
+++ b/tools/lib/bpf/test_libbpf.cpp
@@ -14,5 +14,5 @@ int main(int argc, char *argv[])
     bpf_prog_get_fd_by_id(0);
 
     /* btf.h */
-    btf__new(NULL, 0, NULL);
+    btf__new(NULL, 0);
 }