Commit 6d41907c authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

tools lib bpf: Provide wrapper for strerror_r to build in !_GNU_SOURCE systems 



Same problem that got fixed in a similar fashion in tools/perf/ in
c8b5f2c9 ("tools: Introduce str_error_r()"), fix it in the same
way, licensing needs to be sorted out to libbpf to use libapi, so,
for this simple case, just get the same wrapper in tools/lib/bpf.

This makes libbpf and its users (bpftool, selftests, perf) to build
again in Alpine Linux 3.[45678] and edge.

Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Yonghong Song <yhs@fb.com>
Fixes: 1ce6a9fc ("bpf: fix build error in libbpf with EXTRA_CFLAGS="-Wp, -D_FORTIFY_SOURCE=2 -O2"")
Link: https://lkml.kernel.org/r/20180917151636.GA21790@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent cb48b6a2

tools/lib/bpf/Build

+1 −1
Original line number Diff line number Diff line 
libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o
 
libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o

tools/lib/bpf/libbpf.c

+10 −10
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ 
#include "libbpf.h"

#include "bpf.h"

#include "btf.h"

#include "str_error.h"



#ifndef EM_BPF

#define EM_BPF 247
@@ -469,7 +470,7 @@ static int bpf_object__elf_init(struct bpf_object *obj) 
		obj->efile.fd = open(obj->path, O_RDONLY);

		if (obj->efile.fd < 0) {

			char errmsg[STRERR_BUFSIZE];

			char *cp = strerror_r(errno, errmsg, sizeof(errmsg));

			char *cp = str_error(errno, errmsg, sizeof(errmsg));



			pr_warning("failed to open %s: %s\n", obj->path, cp);

			return -errno;
@@ -810,8 +811,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj) 
						      data->d_size, name, idx);

			if (err) {

				char errmsg[STRERR_BUFSIZE];

				char *cp = strerror_r(-err, errmsg,

						      sizeof(errmsg));

				char *cp = str_error(-err, errmsg, sizeof(errmsg));



				pr_warning("failed to alloc program %s (%s): %s",

					   name, obj->path, cp);
@@ -1140,7 +1140,7 @@ bpf_object__create_maps(struct bpf_object *obj) 


		*pfd = bpf_create_map_xattr(&create_attr);

		if (*pfd < 0 && create_attr.btf_key_type_id) {

			cp = strerror_r(errno, errmsg, sizeof(errmsg));

			cp = str_error(errno, errmsg, sizeof(errmsg));

			pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n",

				   map->name, cp, errno);

			create_attr.btf_fd = 0;
@@ -1155,7 +1155,7 @@ bpf_object__create_maps(struct bpf_object *obj) 
			size_t j;



			err = *pfd;

			cp = strerror_r(errno, errmsg, sizeof(errmsg));

			cp = str_error(errno, errmsg, sizeof(errmsg));

			pr_warning("failed to create map (name: '%s'): %s\n",

				   map->name, cp);

			for (j = 0; j < i; j++)
@@ -1339,7 +1339,7 @@ load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, 
	}



	ret = -LIBBPF_ERRNO__LOAD;

	cp = strerror_r(errno, errmsg, sizeof(errmsg));

	cp = str_error(errno, errmsg, sizeof(errmsg));

	pr_warning("load bpf program failed: %s\n", cp);



	if (log_buf && log_buf[0] != '\0') {
@@ -1654,7 +1654,7 @@ static int check_path(const char *path) 


	dir = dirname(dname);

	if (statfs(dir, &st_fs)) {

		cp = strerror_r(errno, errmsg, sizeof(errmsg));

		cp = str_error(errno, errmsg, sizeof(errmsg));

		pr_warning("failed to statfs %s: %s\n", dir, cp);

		err = -errno;

	}
@@ -1690,7 +1690,7 @@ int bpf_program__pin_instance(struct bpf_program *prog, const char *path, 
	}



	if (bpf_obj_pin(prog->instances.fds[instance], path)) {

		cp = strerror_r(errno, errmsg, sizeof(errmsg));

		cp = str_error(errno, errmsg, sizeof(errmsg));

		pr_warning("failed to pin program: %s\n", cp);

		return -errno;

	}
@@ -1708,7 +1708,7 @@ static int make_dir(const char *path) 
		err = -errno;



	if (err) {

		cp = strerror_r(-err, errmsg, sizeof(errmsg));

		cp = str_error(-err, errmsg, sizeof(errmsg));

		pr_warning("failed to mkdir %s: %s\n", path, cp);

	}

	return err;
@@ -1770,7 +1770,7 @@ int bpf_map__pin(struct bpf_map *map, const char *path) 
	}



	if (bpf_obj_pin(map->fd, path)) {

		cp = strerror_r(errno, errmsg, sizeof(errmsg));

		cp = str_error(errno, errmsg, sizeof(errmsg));

		pr_warning("failed to pin map: %s\n", cp);

		return -errno;

	}

tools/lib/bpf/str_error.c

0 → 100644
+18 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: LGPL-2.1

#undef _GNU_SOURCE

#include <string.h>

#include <stdio.h>

#include "str_error.h"



/*

 * Wrapper to allow for building in non-GNU systems such as Alpine Linux's musl

 * libc, while checking strerror_r() return to avoid having to check this in

 * all places calling it.

 */

char *str_error(int err, char *dst, int len)

{

	int ret = strerror_r(err, dst, len);

	if (ret)

		snprintf(dst, len, "ERROR: strerror_r(%d)=%d", err, ret);

	return dst;

}

tools/lib/bpf/str_error.h

0 → 100644
+6 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: LGPL-2.1

#ifndef BPF_STR_ERROR

#define BPF_STR_ERROR



char *str_error(int err, char *dst, int len);

#endif // BPF_STR_ERROR

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