binfmt_misc: reuse string_unescape_inplace()

There is string_unescape_inplace() function which decodes strings in generic
way. Let's use it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 20 deletions

diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index 751df5e4f61a..1c740e152f38 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -23,6 +23,7 @@
 #include <linux/binfmts.h>
 #include <linux/slab.h>
 #include <linux/ctype.h>
+#include <linux/string_helpers.h>
 #include <linux/file.h>
 #include <linux/pagemap.h>
 #include <linux/namei.h>
@@ -234,24 +235,6 @@ static char *scanarg(char *s, char del)
         return s;
 }
 
-static int unquote(char *from)
-{
-        char c = 0, *s = from, *p = from;
-
-        while ((c = *s++) != '\0') {
-                if (c == '\\' && *s == 'x') {
-                        s++;
-                        c = toupper(*s++);
-                        *p = (c - (isdigit(c) ? '0' : 'A' - 10)) << 4;
-                        c = toupper(*s++);
-                        *p++ |= c - (isdigit(c) ? '0' : 'A' - 10);
-                        continue;
-                }
-                *p++ = c;
-        }
-        return p - from;
-}
-
 static char * check_special_flags (char * sfs, Node * e)
 {
         char * p = sfs;
@@ -354,8 +337,9 @@ static Node *create_entry(const char __user *buffer, size_t count)
                 p[-1] = '\0';
                 if (!e->mask[0])
                         e->mask = NULL;
-                e->size = unquote(e->magic);
-                if (e->mask && unquote(e->mask) != e->size)
+                e->size = string_unescape_inplace(e->magic, UNESCAPE_HEX);
+                if (e->mask &&
+                    string_unescape_inplace(e->mask, UNESCAPE_HEX) != e->size)
                         goto Einval;
                 if (e->size + e->offset > BINPRM_BUF_SIZE)
                         goto Einval;