tools: Introduce str_error_r()

The tools so far have been using the strerror_r() GNU variant, that
returns a string, be it the buffer passed or something else.

But that, besides being tricky in cases where we expect that the
function using strerror_r() returns the error formatted in a provided
buffer (we have to check if it returned something else and copy that
instead), breaks the build on systems not using glibc, like Alpine
Linux, where musl libc is used.

So, introduce yet another wrapper, str_error_r(), that has the GNU
interface, but uses the portable XSI variant of strerror_r(), so that
users rest asured that the provided buffer is used and it is what is
returned.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

15 files changed, 34 insertions, 27 deletions

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index fced8336e5fd..a6a805302312 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -70,6 +70,7 @@ libperf-y += stat.o
 libperf-y += stat-shadow.o
 libperf-y += record.o
 libperf-y += srcline.o
+libperf-y += str_error_r.o
 libperf-y += data.o
 libperf-y += tsc.o
 libperf-y += cloexec.o
@@ -173,6 +174,10 @@ $(OUTPUT)util/libstring.o: ../lib/string.c FORCE
 	$(call rule_mkdir)
 	$(call if_changed_dep,cc_o_c)
 
+$(OUTPUT)util/str_error_r.o: ../lib/str_error_r.c FORCE
+	$(call rule_mkdir)
+	$(call if_changed_dep,cc_o_c)
+
 $(OUTPUT)util/hweight.o: ../lib/hweight.c FORCE
 	$(call rule_mkdir)
 	$(call if_changed_dep,cc_o_c)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index dcc8845881ae..8445e89621fe 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -1589,7 +1589,7 @@ bpf_loader_strerror(int err, char *buf, size_t size)
 		snprintf(buf, size, "Unknown bpf loader error %d", err);
 	else
 		snprintf(buf, size, "%s",
-			 strerror_r(err, sbuf, sizeof(sbuf)));
+			 str_error_r(err, sbuf, sizeof(sbuf)));
 
 	buf[size - 1] = '\0';
 	return -1;
diff --git a/tools/perf/util/cloexec.c b/tools/perf/util/cloexec.c
index 2babddaa2481..fde772db1d5c 100644
--- a/tools/perf/util/cloexec.c
+++ b/tools/perf/util/cloexec.c
@@ -58,7 +58,7 @@ static int perf_flag_probe(void)
 
 	WARN_ONCE(err != EINVAL && err != EBUSY,
 		  "perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error %d (%s)\n",
-		  err, strerror_r(err, sbuf, sizeof(sbuf)));
+		  err, str_error_r(err, sbuf, sizeof(sbuf)));
 
 	/* not supported, confirm error related to PERF_FLAG_FD_CLOEXEC */
 	while (1) {
@@ -76,7 +76,7 @@ static int perf_flag_probe(void)
 
 	if (WARN_ONCE(fd < 0 && err != EBUSY,
 		      "perf_event_open(..., 0) failed unexpectedly with error %d (%s)\n",
-		      err, strerror_r(err, sbuf, sizeof(sbuf))))
+		      err, str_error_r(err, sbuf, sizeof(sbuf))))
 		return -1;
 
 	return 0;
diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c
index be83516155ee..60bfc9ca1e22 100644
--- a/tools/perf/util/data.c
+++ b/tools/perf/util/data.c
@@ -57,7 +57,7 @@ static int open_file_read(struct perf_data_file *file)
 		int err = errno;
 
 		pr_err("failed to open %s: %s", file->path,
-			strerror_r(err, sbuf, sizeof(sbuf)));
+			str_error_r(err, sbuf, sizeof(sbuf)));
 		if (err == ENOENT && !strcmp(file->path, "perf.data"))
 			pr_err("  (try 'perf record' first)");
 		pr_err("\n");
@@ -99,7 +99,7 @@ static int open_file_write(struct perf_data_file *file)
 
 	if (fd < 0)
 		pr_err("failed to open %s : %s\n", file->path,
-			strerror_r(errno, sbuf, sizeof(sbuf)));
+			str_error_r(errno, sbuf, sizeof(sbuf)));
 
 	return fd;
 }
diff --git a/tools/perf/util/debug.h b/tools/perf/util/debug.h
index 14bafda79eda..d242adc3d5a2 100644
--- a/tools/perf/util/debug.h
+++ b/tools/perf/util/debug.h
@@ -38,7 +38,7 @@ extern int debug_data_convert;
 #define pr_oe_time(t, fmt, ...)  pr_time_N(1, debug_ordered_events, t, pr_fmt(fmt), ##__VA_ARGS__)
 #define pr_oe_time2(t, fmt, ...) pr_time_N(2, debug_ordered_events, t, pr_fmt(fmt), ##__VA_ARGS__)
 
-#define STRERR_BUFSIZE	128	/* For the buffer size of strerror_r */
+#define STRERR_BUFSIZE	128	/* For the buffer size of str_error_r */
 
 int dump_printf(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
 void trace_event(union perf_event *event);
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index e1de6cc4863e..774f6ec884d5 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -335,7 +335,7 @@ static int do_open(char *name)
 			return fd;
 
 		pr_debug("dso open failed: %s\n",
-			 strerror_r(errno, sbuf, sizeof(sbuf)));
+			 str_error_r(errno, sbuf, sizeof(sbuf)));
 		if (!dso__data_open_cnt || errno != EMFILE)
 			break;
 
@@ -786,7 +786,7 @@ static int data_file_size(struct dso *dso, struct machine *machine)
 	if (fstat(dso->data.fd, &st) < 0) {
 		ret = -errno;
 		pr_err("dso cache fstat failed: %s\n",
-		       strerror_r(errno, sbuf, sizeof(sbuf)));
+		       str_error_r(errno, sbuf, sizeof(sbuf)));
 		dso->data.status = DSO_DATA_STATUS_ERROR;
 		goto out;
 	}
@@ -1366,7 +1366,7 @@ int dso__strerror_load(struct dso *dso, char *buf, size_t buflen)
 	BUG_ON(buflen == 0);
 
 	if (errnum >= 0) {
-		const char *err = strerror_r(errnum, buf, buflen);
+		const char *err = str_error_r(errnum, buf, buflen);
 
 		if (err != buf)
 			scnprintf(buf, buflen, "%s", err);
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 113507716044..f2d478df8c3e 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1790,7 +1790,7 @@ int perf_evlist__strerror_open(struct perf_evlist *evlist,
 			       int err, char *buf, size_t size)
 {
 	int printed, value;
-	char sbuf[STRERR_BUFSIZE], *emsg = strerror_r(err, sbuf, sizeof(sbuf));
+	char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
 
 	switch (err) {
 	case EACCES:
@@ -1842,7 +1842,7 @@ out_default:
 
 int perf_evlist__strerror_mmap(struct perf_evlist *evlist, int err, char *buf, size_t size)
 {
-	char sbuf[STRERR_BUFSIZE], *emsg = strerror_r(err, sbuf, sizeof(sbuf));
+	char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
 	int pages_attempted = evlist->mmap_len / 1024, pages_max_per_user, printed = 0;
 
 	switch (err) {
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 0fea724e735c..d8c2298cd32a 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2419,7 +2419,7 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
 	"The sys_perf_event_open() syscall returned with %d (%s) for event (%s).\n"
 	"/bin/dmesg may provide additional information.\n"
 	"No CONFIG_PERF_EVENTS=y kernel support configured?",
-			 err, strerror_r(err, sbuf, sizeof(sbuf)),
+			 err, str_error_r(err, sbuf, sizeof(sbuf)),
 			 perf_evsel__name(evsel));
 }
 
diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c
index 40b6f7269cb4..282c30f6a51d 100644
--- a/tools/perf/util/llvm-utils.c
+++ b/tools/perf/util/llvm-utils.c
@@ -106,7 +106,7 @@ read_from_pipe(const char *cmd, void **p_buf, size_t *p_read_sz)
 	file = popen(cmd, "r");
 	if (!file) {
 		pr_err("ERROR: unable to popen cmd: %s\n",
-		       strerror_r(errno, serr, sizeof(serr)));
+		       str_error_r(errno, serr, sizeof(serr)));
 		return -EINVAL;
 	}
 
@@ -140,7 +140,7 @@ read_from_pipe(const char *cmd, void **p_buf, size_t *p_read_sz)
 
 	if (ferror(file)) {
 		pr_err("ERROR: error occurred when reading from pipe: %s\n",
-		       strerror_r(errno, serr, sizeof(serr)));
+		       str_error_r(errno, serr, sizeof(serr)));
 		err = -EIO;
 		goto errout;
 	}
@@ -382,7 +382,7 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
 	if (path[0] != '-' && realpath(path, abspath) == NULL) {
 		err = errno;
 		pr_err("ERROR: problems with path %s: %s\n",
-		       path, strerror_r(err, serr, sizeof(serr)));
+		       path, str_error_r(err, serr, sizeof(serr)));
 		return -err;
 	}
 
@@ -410,7 +410,7 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
 	if (nr_cpus_avail <= 0) {
 		pr_err(
 "WARNING:\tunable to get available CPUs in this system: %s\n"
-"        \tUse 128 instead.\n", strerror_r(errno, serr, sizeof(serr)));
+"        \tUse 128 instead.\n", str_error_r(errno, serr, sizeof(serr)));
 		nr_cpus_avail = 128;
 	}
 	snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d",
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 0201f661ccb8..2b222a7955c9 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -468,7 +468,7 @@ static struct debuginfo *open_debuginfo(const char *module, bool silent)
 		err = kernel_get_module_dso(module, &dso);
 		if (err < 0) {
 			if (!dso || dso->load_errno == 0) {
-				if (!strerror_r(-err, reason, STRERR_BUFSIZE))
+				if (!str_error_r(-err, reason, STRERR_BUFSIZE))
 					strcpy(reason, "(unknown)");
 			} else
 				dso__strerror_load(dso, reason, STRERR_BUFSIZE);
@@ -806,7 +806,7 @@ static int __show_one_line(FILE *fp, int l, bool skip, bool show_num)
 error:
 	if (ferror(fp)) {
 		pr_warning("File read error: %s\n",
-			   strerror_r(errno, sbuf, sizeof(sbuf)));
+			   str_error_r(errno, sbuf, sizeof(sbuf)));
 		return -1;
 	}
 	return 0;
@@ -886,7 +886,7 @@ static int __show_line_range(struct line_range *lr, const char *module,
 	fp = fopen(lr->path, "r");
 	if (fp == NULL) {
 		pr_warning("Failed to open %s: %s\n", lr->path,
-			   strerror_r(errno, sbuf, sizeof(sbuf)));
+			   str_error_r(errno, sbuf, sizeof(sbuf)));
 		return -errno;
 	}
 	/* Skip to starting line number */
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 5b563b2e8b1d..98398b55a03f 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -50,7 +50,7 @@ static void print_open_warning(int err, bool uprobe)
 	else
 		pr_warning("Failed to open %cprobe_events: %s\n",
 			   uprobe ? 'u' : 'k',
-			   strerror_r(-err, sbuf, sizeof(sbuf)));
+			   str_error_r(-err, sbuf, sizeof(sbuf)));
 }
 
 static void print_both_open_warning(int kerr, int uerr)
@@ -64,9 +64,9 @@ static void print_both_open_warning(int kerr, int uerr)
 	else {
 		char sbuf[STRERR_BUFSIZE];
 		pr_warning("Failed to open kprobe events: %s.\n",
-			   strerror_r(-kerr, sbuf, sizeof(sbuf)));
+			   str_error_r(-kerr, sbuf, sizeof(sbuf)));
 		pr_warning("Failed to open uprobe events: %s.\n",
-			   strerror_r(-uerr, sbuf, sizeof(sbuf)));
+			   str_error_r(-uerr, sbuf, sizeof(sbuf)));
 	}
 }
 
@@ -224,7 +224,7 @@ int probe_file__add_event(int fd, struct probe_trace_event *tev)
 		if (write(fd, buf, strlen(buf)) < (int)strlen(buf)) {
 			ret = -errno;
 			pr_warning("Failed to write event: %s\n",
-				   strerror_r(errno, sbuf, sizeof(sbuf)));
+				   str_error_r(errno, sbuf, sizeof(sbuf)));
 		}
 	}
 	free(buf);
@@ -262,7 +262,7 @@ static int __del_trace_probe_event(int fd, struct str_node *ent)
 	return 0;
 error:
 	pr_warning("Failed to delete event: %s\n",
-		   strerror_r(-ret, buf, sizeof(buf)));
+		   str_error_r(-ret, buf, sizeof(buf)));
 	return ret;
 }
 
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 1259839dbf6d..f2d9ff064e2d 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -381,7 +381,7 @@ formatted:
 		if (ret >= 16)
 			ret = -E2BIG;
 		pr_warning("Failed to convert variable type: %s\n",
-			   strerror_r(-ret, sbuf, sizeof(sbuf)));
+			   str_error_r(-ret, sbuf, sizeof(sbuf)));
 		return ret;
 	}
 	tvar->type = strdup(buf);
@@ -809,7 +809,7 @@ static int find_lazy_match_lines(struct intlist *list,
 	fp = fopen(fname, "r");
 	if (!fp) {
 		pr_warning("Failed to open %s: %s\n", fname,
-			   strerror_r(errno, sbuf, sizeof(sbuf)));
+			   str_error_r(errno, sbuf, sizeof(sbuf)));
 		return -errno;
 	}
 
diff --git a/tools/perf/util/python-ext-sources b/tools/perf/util/python-ext-sources
index 36c6862119e3..49210b7a7925 100644
--- a/tools/perf/util/python-ext-sources
+++ b/tools/perf/util/python-ext-sources
@@ -13,6 +13,7 @@ util/cpumap.c
 ../lib/bitmap.c
 ../lib/find_bit.c
 ../lib/hweight.c
+../lib/str_error_r.c
 util/thread_map.c
 util/util.c
 util/xyarray.c
diff --git a/tools/perf/util/target.c b/tools/perf/util/target.c
index a53603b27e52..5898af4510cc 100644
--- a/tools/perf/util/target.c
+++ b/tools/perf/util/target.c
@@ -121,7 +121,7 @@ int target__strerror(struct target *target, int errnum,
 	BUG_ON(buflen == 0);
 
 	if (errnum >= 0) {
-		const char *err = strerror_r(errnum, buf, buflen);
+		const char *err = str_error_r(errnum, buf, buflen);
 
 		if (err != buf)
 			scnprintf(buf, buflen, "%s", err);
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 1e8c3167b9fb..2370cfb902b2 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -360,4 +360,5 @@ typedef void (*print_binary_t)(enum binary_printer_ops,
 void print_binary(unsigned char *data, size_t len,
 		  size_t bytes_per_line, print_binary_t printer,
 		  void *extra);
+
 #endif /* GIT_COMPAT_UTIL_H */