From: Khem Raj <raj.khem@gmail.com>
Date: Fri, 13 Jan 2023 19:44:07 +0000 (-0700)
Subject: api: Use GNU strerror_r when available
X-Git-Tag: v3.1.0~244
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=942ef655237b90909edf53eafd121842cdc07ce1;p=thirdparty%2Flibcgroup.git

api: Use GNU strerror_r when available

GNU strerror_r is only available in glibc, musl impelents the XSI
version which is slightly different, therefore check if GNU version is
available before using it, otherwise use the XSI compliant version.

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
TJH: Minor formatting change so that the line doesn't exceed 100 chars
---

diff --git a/configure.ac b/configure.ac
index 2856a174..42d77e7b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -207,6 +207,11 @@ AC_FUNC_REALLOC
 AC_FUNC_STAT
 AC_CHECK_FUNCS([getmntent hasmntopt memset mkdir rmdir strdup])
 
+orig_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -D_GNU_SOURCE"
+AC_FUNC_STRERROR_R
+CFLAGS="$orig_CFLAGS"
+
 AC_SEARCH_LIBS(
 	[fts_open],
 	[fts],
diff --git a/src/api.c b/src/api.c
index 484b46ab..cea3efe1 100644
--- a/src/api.c
+++ b/src/api.c
@@ -4672,9 +4672,14 @@ const char *cgroup_strerror(int code)
 {
 	int idx = code % ECGROUPNOTCOMPILED;
 
-	if (code == ECGOTHER)
+	if (code == ECGOTHER) {
+#ifdef STRERROR_R_CHAR_P
 		return strerror_r(cgroup_get_last_errno(), errtext, MAXLEN);
-
+#else
+		return strerror_r(cgroup_get_last_errno(), errtext, sizeof (errtext)) ?
+			"unknown error" : errtext;
+#endif
+	}
 	if (idx >= sizeof(cgroup_strerror_codes)/sizeof(cgroup_strerror_codes[0]))
 		return "Invalid error code";