commit c37fc1ab6a3ac3956a8c9ba3ac089d41969815ed
author Nick Kralevich <nnk@google.com> Fri Jul 13 17:49:10 2012 -0700
committer Nick Kralevich <nnk@google.com> Fri Jul 13 17:58:37 2012 -0700
tree 8fd21828b1fc97423bbe5e3652513772260604f3
parent e1d909f71e183ac3d1e21af5bb1af35d30e9de5b

FORTIFY_SOURCE: revert memcpy changes.

Performance regressions.  Hopefully this is a temporary
rollback.

Bug: 6821003
Change-Id: I84abbb89e1739d506b583f2f1668f31534127764

libc/include/string.h

diff --git a/libc/include/string.h b/libc/include/string.h
index 8730ea3..8e472e7 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -93,10 +93,6 @@
     __attribute__((__error__("memcpy called with size bigger than source")));
 extern void __memcpy_overlap_error()
     __attribute__((__error__("memcpy called with overlapping regions")));
-extern void *__memcpy_real(void *, const void *, size_t)
-    __asm__(__USER_LABEL_PREFIX__ "memcpy");
-extern void *__memcpy_chk2(void *, const void *, size_t, size_t, size_t);
-
 
 __BIONIC_FORTIFY_INLINE
 void *memcpy (void *dest, const void *src, size_t copy_amount) {
@@ -118,11 +114,7 @@
         __memcpy_overlap_error();
     }
 
-    if (__builtin_constant_p(copy_amount) && __builtin_constant_p(d - s)) {
-         return __memcpy_real(dest, src, copy_amount);
-    }
-
-    return __memcpy_chk2(dest, src, copy_amount, d_len, s_len);
+    return __builtin___memcpy_chk(dest, src, copy_amount, d_len);
 }
 
 __BIONIC_FORTIFY_INLINE

libc/string/__memcpy_chk.c

diff --git a/libc/string/__memcpy_chk.c b/libc/string/__memcpy_chk.c
index 934ed67..10334ba 100644
--- a/libc/string/__memcpy_chk.c
+++ b/libc/string/__memcpy_chk.c
@@ -32,7 +32,7 @@
 #include <private/logd.h>
 
 /*
- * Runtime implementation of __memcpy_chk2.
+ * Runtime implementation of __memcpy_chk.
  *
  * See
  *   http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
@@ -42,12 +42,9 @@
  * This memcpy check is called if _FORTIFY_SOURCE is defined and
  * greater than 0.
  */
-void *__memcpy_chk2(void *dest, const void *src,
-              size_t copy_amount, size_t dest_len, size_t src_len)
+void *__memcpy_chk(void *dest, const void *src,
+              size_t copy_amount, size_t dest_len)
 {
-    char *d = (char *) dest;
-    const char *s = (const char *) src;
-
     if (__builtin_expect(copy_amount > dest_len, 0)) {
         __libc_android_log_print(ANDROID_LOG_FATAL, "libc",
             "*** memcpy buffer overflow detected ***\n");
@@ -55,28 +52,5 @@
         abort();
     }
 
-    if (__builtin_expect(copy_amount > src_len, 0)) {
-        __libc_android_log_print(ANDROID_LOG_FATAL, "libc",
-            "*** memcpy read overflow detected ***\n");
-        abort();
-    }
-
-    if (__builtin_expect(((d <= s) && ((size_t)(s - d) < copy_amount))
-                      || ((d >= s) && ((size_t)(d - s) < copy_amount)), 0)) {
-        __libc_android_log_print(ANDROID_LOG_FATAL, "libc",
-            "*** memcpy memory overlap detected ***\n");
-        abort();
-    }
-
     return memcpy(dest, src, copy_amount);
 }
-
-/*
- * GCC can create references to __memcpy_chk when using
- * __builtin__memmove_chk().
- */
-void *__memcpy_chk(void *dest, const void *src,
-              size_t copy_amount, size_t dest_len)
-{
-    return __memcpy_chk2(dest, src, copy_amount, dest_len, (size_t) -1);
-}