Split our FORTIFY implementation into libc_fortify
As requested in the bug. This also rips __memcpy_chk out of memcpy.S,
which lets us cut down on copypasta (all of the implementations look
identical).
Bug: 12231437
Test: mma on aosp_{arm,arm64,mips,x86,x86_64} internal master;
checkbuild on bullhead internal master; CtsBionicTestCases on bullhead.
No new failures.
Change-Id: I88c39ca166bacde0b692aa3063e743bb046a5d2f
diff --git a/libc/arch-arm/generic/bionic/__memcpy_chk.S b/libc/arch-arm/generic/bionic/__memcpy_chk.S
new file mode 100644
index 0000000..7044e5f
--- /dev/null
+++ b/libc/arch-arm/generic/bionic/__memcpy_chk.S
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <private/bionic_asm.h>
+
+ .syntax unified
+
+ENTRY(__memcpy_chk)
+ cmp r2, r3
+ bls memcpy
+
+ // Preserve lr for backtrace.
+ push {lr}
+ .cfi_def_cfa_offset 4
+ .cfi_rel_offset lr, 0
+
+ bl __memcpy_chk_fail
+END(__memcpy_chk)