Merge tag 'irq-core-2020-12-23' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux-2.6-microblaze.git] / lib / nlattr.c

diff --git a/lib/nlattr.c b/lib/nlattr.c
index 74019c8..5b6116e 100644 (file)
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -432,7 +432,7 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
                        err = -EINVAL;
                        goto out_err;
                }
-               /* fall through */
+               fallthrough;
 
        case NLA_STRING:
                if (attrlen < 1)
@@ -709,35 +709,47 @@ struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype)
 EXPORT_SYMBOL(nla_find);
 
 /**
- * nla_strlcpy - Copy string attribute payload into a sized buffer
- * @dst: where to copy the string to
- * @nla: attribute to copy the string from
- * @dstsize: size of destination buffer
+ * nla_strscpy - Copy string attribute payload into a sized buffer
+ * @dst: Where to copy the string to.
+ * @nla: Attribute to copy the string from.
+ * @dstsize: Size of destination buffer.
  *
  * Copies at most dstsize - 1 bytes into the destination buffer.
- * The result is always a valid NUL-terminated string. Unlike
- * strlcpy the destination buffer is always padded out.
+ * Unlike strlcpy the destination buffer is always padded out.
  *
- * Returns the length of the source buffer.
+ * Return:
+ * * srclen - Returns @nla length (not including the trailing %NUL).
+ * * -E2BIG - If @dstsize is 0 or greater than U16_MAX or @nla length greater
+ *            than @dstsize.
  */
-size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize)
+ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize)
 {
        size_t srclen = nla_len(nla);
        char *src = nla_data(nla);
+       ssize_t ret;
+       size_t len;
+
+       if (dstsize == 0 || WARN_ON_ONCE(dstsize > U16_MAX))
+               return -E2BIG;
 
        if (srclen > 0 && src[srclen - 1] == '\0')
                srclen--;
 
-       if (dstsize > 0) {
-               size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen;
-
-               memset(dst, 0, dstsize);
-               memcpy(dst, src, len);
+       if (srclen >= dstsize) {
+               len = dstsize - 1;
+               ret = -E2BIG;
+       } else {
+               len = srclen;
+               ret = len;
        }
 
-       return srclen;
+       memcpy(dst, src, len);
+       /* Zero pad end of dst. */
+       memset(dst + len, 0, dstsize - len);
+
+       return ret;
 }
-EXPORT_SYMBOL(nla_strlcpy);
+EXPORT_SYMBOL(nla_strscpy);
 
 /**
  * nla_strdup - Copy string attribute payload into a newly allocated buffer