[src/trunk]: src/sys/external/bsd/drm2/include/linux Implement strscpy.

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/5bd5dbb62524
branches:  trunk
changeset: 1027813:5bd5dbb62524
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Dec 19 00:48:30 2021 +0000

description:
Implement strscpy.

diffstat:

 sys/external/bsd/drm2/include/linux/string.h |  24 +++++++++++++++++++++++-
 1 files changed, 23 insertions(+), 1 deletions(-)

diffs (43 lines):

diff -r c2512197522c -r 5bd5dbb62524 sys/external/bsd/drm2/include/linux/string.h
--- a/sys/external/bsd/drm2/include/linux/string.h      Sun Dec 19 00:48:23 2021 +0000
+++ b/sys/external/bsd/drm2/include/linux/string.h      Sun Dec 19 00:48:30 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: string.h,v 1.5 2018/08/27 06:49:23 riastradh Exp $     */
+/*     $NetBSD: string.h,v 1.6 2021/12/19 00:48:30 riastradh Exp $     */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -34,6 +34,7 @@
 
 #include <sys/types.h>
 #include <sys/cdefs.h>
+#include <sys/errno.h>
 #include <sys/null.h>
 
 #include <linux/slab.h>
@@ -93,4 +94,25 @@
        return kstrndup(src, strlen(src), gfp);
 }
 
+static inline ssize_t
+strscpy(char *dst, const char *src, size_t dstsize)
+{
+       size_t n = dstsize;
+
+       /* If no space for a NUL terminator, fail.  */
+       if (n == 0)
+               return -E2BIG;
+
+       /* Copy until we get a NUL terminator or the end of the buffer.  */
+       while ((*dst++ = *src++) != '\0') {
+               if (__predict_false(--n == 0)) {
+                       dst[-1] = '\0'; /* NUL-terminate */
+                       return -E2BIG;
+               }
+       }
+
+       /* Return the number of bytes copied, excluding NUL.  */
+       return dstsize - n;
+}
+
 #endif  /* _LINUX_STRING_H_ */