From: Thomas Richter <tmricht@linux.ibm.com>
Date: Mon, 30 Jul 2018 10:53:23 +0200
Subject: bpf: fix build error in libbpf with EXTRA_CFLAGS="-Wp,
-D_FORTIFY_SOURCE=2 -O2"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Patch-mainline: v4.19-rc1
Git-commit: 1ce6a9fc154935d9db771173ecde03fa9b42df4a
References: bsc#1109837
Commit 531b014e7a2f ("tools: bpf: make use of reallocarray") causes
a compiler error when building the perf tool in the linux-next tree.
Compile file tools/lib/bpf/libbpf.c on a FEDORA 28 installation with
gcc compiler version: gcc (GCC) 8.0.1 20180324 (Red Hat 8.0.1-0.20)
shows this error message:
[root@p23lp27] # make V=1 EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2"
[...]
make -f /home6/tmricht/linux-next/tools/build/Makefile.build
dir=./util/scripting-engines obj=libperf
libbpf.c: In function ‘bpf_object__elf_collect’:
libbpf.c:811:15: error: ignoring return value of ‘strerror_r’,
declared with attribute warn_unused_result [-Werror=unused-result]
strerror_r(-err, errmsg, sizeof(errmsg));
^
cc1: all warnings being treated as errors
mv: cannot stat './.libbpf.o.tmp': No such file or directory
/home6/tmricht/linux-next/tools/build/Makefile.build:96: recipe for target 'libbpf.o' failed
Replace all occurrences of strerror() by calls to strerror_r(). To
keep the compiler quiet also use the return value from strerror_r()
otherwise a 'variable set but not use' warning which is treated as
error terminates the compile.
Fixes: 531b014e7a2f ("tools: bpf: make use of reallocarray")
Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
tools/lib/bpf/libbpf.c | 42 +++++++++++++++++++++++++++++-------------
1 file changed, 29 insertions(+), 13 deletions(-)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -468,8 +468,10 @@ static int bpf_object__elf_init(struct b
} else {
obj->efile.fd = open(obj->path, O_RDONLY);
if (obj->efile.fd < 0) {
- pr_warning("failed to open %s: %s\n", obj->path,
- strerror(errno));
+ char errmsg[STRERR_BUFSIZE];
+ char *cp = strerror_r(errno, errmsg, sizeof(errmsg));
+
+ pr_warning("failed to open %s: %s\n", obj->path, cp);
return -errno;
}
@@ -808,10 +810,11 @@ static int bpf_object__elf_collect(struc
data->d_size, name, idx);
if (err) {
char errmsg[STRERR_BUFSIZE];
+ char *cp = strerror_r(-err, errmsg,
+ sizeof(errmsg));
- strerror_r(-err, errmsg, sizeof(errmsg));
pr_warning("failed to alloc program %s (%s): %s",
- name, obj->path, errmsg);
+ name, obj->path, cp);
}
} else if (sh.sh_type == SHT_REL) {
void *reloc = obj->efile.reloc;
@@ -1109,6 +1112,7 @@ bpf_object__create_maps(struct bpf_objec
for (i = 0; i < obj->nr_maps; i++) {
struct bpf_map *map = &obj->maps[i];
struct bpf_map_def *def = &map->def;
+ char *cp, errmsg[STRERR_BUFSIZE];
int *pfd = &map->fd;
if (map->fd >= 0) {
@@ -1136,8 +1140,9 @@ bpf_object__create_maps(struct bpf_objec
*pfd = bpf_create_map_xattr(&create_attr);
if (*pfd < 0 && create_attr.btf_key_type_id) {
+ cp = strerror_r(errno, errmsg, sizeof(errmsg));
pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n",
- map->name, strerror(errno), errno);
+ map->name, cp, errno);
create_attr.btf_fd = 0;
create_attr.btf_key_type_id = 0;
create_attr.btf_value_type_id = 0;
@@ -1150,9 +1155,9 @@ bpf_object__create_maps(struct bpf_objec
size_t j;
err = *pfd;
+ cp = strerror_r(errno, errmsg, sizeof(errmsg));
pr_warning("failed to create map (name: '%s'): %s\n",
- map->name,
- strerror(errno));
+ map->name, cp);
for (j = 0; j < i; j++)
zclose(obj->maps[j].fd);
return err;
@@ -1304,6 +1309,7 @@ load_program(enum bpf_prog_type type, en
char *license, u32 kern_version, int *pfd, int prog_ifindex)
{
struct bpf_load_program_attr load_attr;
+ char *cp, errmsg[STRERR_BUFSIZE];
char *log_buf;
int ret;
@@ -1333,7 +1339,8 @@ load_program(enum bpf_prog_type type, en
}
ret = -LIBBPF_ERRNO__LOAD;
- pr_warning("load bpf program failed: %s\n", strerror(errno));
+ cp = strerror_r(errno, errmsg, sizeof(errmsg));
+ pr_warning("load bpf program failed: %s\n", cp);
if (log_buf && log_buf[0] != '\0') {
ret = -LIBBPF_ERRNO__VERIFY;
@@ -1630,6 +1637,7 @@ out:
static int check_path(const char *path)
{
+ char *cp, errmsg[STRERR_BUFSIZE];
struct statfs st_fs;
char *dname, *dir;
int err = 0;
@@ -1643,7 +1651,8 @@ static int check_path(const char *path)
dir = dirname(dname);
if (statfs(dir, &st_fs)) {
- pr_warning("failed to statfs %s: %s\n", dir, strerror(errno));
+ cp = strerror_r(errno, errmsg, sizeof(errmsg));
+ pr_warning("failed to statfs %s: %s\n", dir, cp);
err = -errno;
}
free(dname);
@@ -1659,6 +1668,7 @@ static int check_path(const char *path)
int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
int instance)
{
+ char *cp, errmsg[STRERR_BUFSIZE];
int err;
err = check_path(path);
@@ -1677,7 +1687,8 @@ int bpf_program__pin_instance(struct bpf
}
if (bpf_obj_pin(prog->instances.fds[instance], path)) {
- pr_warning("failed to pin program: %s\n", strerror(errno));
+ cp = strerror_r(errno, errmsg, sizeof(errmsg));
+ pr_warning("failed to pin program: %s\n", cp);
return -errno;
}
pr_debug("pinned program '%s'\n", path);
@@ -1687,13 +1698,16 @@ int bpf_program__pin_instance(struct bpf
static int make_dir(const char *path)
{
+ char *cp, errmsg[STRERR_BUFSIZE];
int err = 0;
if (mkdir(path, 0700) && errno != EEXIST)
err = -errno;
- if (err)
- pr_warning("failed to mkdir %s: %s\n", path, strerror(-err));
+ if (err) {
+ cp = strerror_r(-err, errmsg, sizeof(errmsg));
+ pr_warning("failed to mkdir %s: %s\n", path, cp);
+ }
return err;
}
@@ -1740,6 +1754,7 @@ int bpf_program__pin(struct bpf_program
int bpf_map__pin(struct bpf_map *map, const char *path)
{
+ char *cp, errmsg[STRERR_BUFSIZE];
int err;
err = check_path(path);
@@ -1752,7 +1767,8 @@ int bpf_map__pin(struct bpf_map *map, co
}
if (bpf_obj_pin(map->fd, path)) {
- pr_warning("failed to pin map: %s\n", strerror(errno));
+ cp = strerror_r(errno, errmsg, sizeof(errmsg));
+ pr_warning("failed to pin map: %s\n", cp);
return -errno;
}