[Fix] Change copy strategy in strlcpy

diff --git a/src/libutil/str_util.c b/src/libutil/str_util.c
index 3552caa4e74951cf25e07f0aeaf87e8337e6ddc5..513c00d85bd9edc63d7109e70dcf007d80bde90a 100644 (file)
--- a/src/libutil/str_util.c
+++ b/src/libutil/str_util.c
@@ -307,10 +307,17 @@ rspamd_gstring_icase_hash (gconstpointer key)
        return rspamd_icase_hash (f->str, f->len);
 }
 
+/* https://graphics.stanford.edu/~seander/bithacks.html#ZeroInWord */
 #define MEM_ALIGN (sizeof(gsize)-1)
-#define ONES ((size_t)-1/UCHAR_MAX)
-#define HIGHS (ONES * (UCHAR_MAX/2+1))
-#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
+#if defined(__LP64__) || defined(_LP64)
+#define WORD_TYPE guint64
+#define ZEROMASK  0x7F7F7F7F7F7F7F7FLLU
+#else
+#define WORD_TYPE guint32
+#define ZEROMASK  0x7F7F7F7FU
+#endif
+
+#define HASZERO(x) ~(((((x) & ZEROMASK) + ZEROMASK) | (x)) | ZEROMASK)
 
 gsize
 rspamd_strlcpy (gchar *dst, const gchar *src, gsize siz)
@@ -318,24 +325,31 @@ rspamd_strlcpy (gchar *dst, const gchar *src, gsize siz)
        gchar *d = dst;
        const gchar *s = src;
        gsize n = siz;
-       gsize *wd;
-       const gsize *ws;
+       WORD_TYPE *wd;
+       const WORD_TYPE *ws;
 
        /* Copy as many bytes as will fit */
        if (n-- != 0) {
                if (((uintptr_t) s & MEM_ALIGN) == ((uintptr_t) d & MEM_ALIGN)) {
+                       /* Init copy byte by byte */
                        for (; ((uintptr_t) s & MEM_ALIGN) && n && (*d = *s); n--, s++, d++);
                        if (n && *s) {
                                wd = (void *) d;
                                ws = (const void *) s;
-                               for (; n >= sizeof (gsize) && !HASZERO(*ws);
-                                          n -= sizeof (gsize), ws++, wd++)
+                               /*
+                                * Copy by 32 or 64 bits (causes valgrind warnings)
+                                */
+                               for (; n >= sizeof (WORD_TYPE) && !HASZERO(*ws);
+                                          n -= sizeof (WORD_TYPE), ws++, wd++) {
                                        *wd = *ws;
+                               }
+
                                d = (void *) wd;
                                s = (const void *) ws;
                        }
                }
 
+               /* Copy the rest */
                for (; n && (*d = *s); n--, s++, d++);
 
                *d = 0;