From: Benjamin Berg <benjamin.berg@intel.com>
Date: Wed, 24 Sep 2025 14:20:52 +0000 (+0200)
Subject: tools/nolibc: implement %m if errno is not defined
X-Git-Tag: v6.19-rc1~194^2~19
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fbd1b7f6b322a63b21ebbf00c732a17bb8bdb5d4;p=thirdparty%2Flinux.git

tools/nolibc: implement %m if errno is not defined

For improved compatibility, print %m as "unknown error" when nolibc is
compiled using NOLIBC_IGNORE_ERRNO.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---

diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index 724d05ce69624..1f16dab2ac884 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -321,11 +321,13 @@ int __nolibc_printf(__nolibc_printf_cb cb, intptr_t state, size_t n, const char
 				if (!outstr)
 					outstr="(null)";
 			}
-#ifndef NOLIBC_IGNORE_ERRNO
 			else if (c == 'm') {
+#ifdef NOLIBC_IGNORE_ERRNO
+				outstr = "unknown error";
+#else
 				outstr = strerror(errno);
-			}
 #endif /* NOLIBC_IGNORE_ERRNO */
+			}
 			else if (c == '%') {
 				/* queue it verbatim */
 				continue;