Implement strscpy() and implement strscpy_pad() on top of that. Fixes the

return value in case of truncation.

ok jsg@

diff --git a/sys/dev/pci/drm/include/linux/string.h b/sys/dev/pci/drm/include/linux/string.h
index b19c465..f76ddf6 100644 (file)
--- a/sys/dev/pci/drm/include/linux/string.h
+++ b/sys/dev/pci/drm/include/linux/string.h
@@ -81,17 +81,21 @@ match_string(const char * const *array,  size_t n, const char *str)
        return -EINVAL;
 }
 
-/* returns chars written excluding NUL */
 static inline ssize_t
-strscpy_pad(char *dst, const char *src, size_t dstsize)
+strscpy(char *dst, const char *src, size_t dstsize)
 {
        ssize_t r;
-       memset(dst, 0, dstsize);
        r = strlcpy(dst, src, dstsize);
-       /* truncation */
-       if (r >= dstsize)
-               r = dstsize - 1;
+       if (dstsize == 0 || r >= dstsize)
+               return -E2BIG;
        return r;
 }
 
+static inline ssize_t
+strscpy_pad(char *dst, const char *src, size_t dstsize)
+{
+       memset(dst, 0, dstsize);
+       return strscpy(dst, src, dstsize);
+}
+
 #endif