Improve diagnostics from the assembler __memcpy_chk routines.

Change-Id: Iec16c92ed80beee505cba2121ea33e3550197b02
diff --git a/libc/arch-arm/cortex-a15/bionic/memcpy_common.S b/libc/arch-arm/cortex-a15/bionic/memcpy_common.S
index 955ffb8..4d1167f 100644
--- a/libc/arch-arm/cortex-a15/bionic/memcpy_common.S
+++ b/libc/arch-arm/cortex-a15/bionic/memcpy_common.S
@@ -60,10 +60,14 @@
         .fpu    neon
 
 ENTRY(__memcpy_chk)
-        cmp     r2, r3
-        bhi     .L_memcpy_chk_fail
+        cmp r2, r3
+        bls memcpy
 
-        // Fall through to memcpy...
+        // Preserve lr for backtrace.
+        push        {lr}
+        .cfi_def_cfa_offset 4
+        .cfi_rel_offset lr, 0
+        bl          __memcpy_chk_fail
 END(__memcpy_chk)
 
 // Prototype: void *memcpy (void *dst, const void *src, size_t count).
@@ -75,25 +79,4 @@
         .cfi_rel_offset lr, 4
 
 #include MEMCPY_BASE
-
-        // Undo the cfi instructions from above.
-        .cfi_def_cfa_offset 0
-        .cfi_restore r0
-        .cfi_restore lr
-.L_memcpy_chk_fail:
-        // Preserve lr for backtrace.
-        push    {lr}
-        .cfi_adjust_cfa_offset 4
-        .cfi_rel_offset lr, 0
-
-        ldr     r0, error_message
-1:
-        add     r0, pc
-        bl      __fortify_fatal
-error_message:
-        .word   error_string-(1b+8)
 END(memcpy)
-
-        .data
-error_string:
-        .string "memcpy: prevented write past end of buffer"
diff --git a/libc/arch-arm/cortex-a9/bionic/memcpy.S b/libc/arch-arm/cortex-a9/bionic/memcpy.S
index fc0bba1..93a8629 100644
--- a/libc/arch-arm/cortex-a9/bionic/memcpy.S
+++ b/libc/arch-arm/cortex-a9/bionic/memcpy.S
@@ -41,9 +41,14 @@
 
 ENTRY(__memcpy_chk)
         cmp         r2, r3
-        bhi         __memcpy_chk_fail
+        bls         memcpy
 
-        // Fall through to memcpy...
+        // Preserve lr for backtrace.
+        push        {lr}
+        .cfi_def_cfa_offset 4
+        .cfi_rel_offset lr, 0
+
+        bl          __memcpy_chk_fail
 END(__memcpy_chk)
 
 ENTRY(memcpy)
@@ -58,21 +63,3 @@
 #define MEMCPY_BASE         __memcpy_base
 #define MEMCPY_BASE_ALIGNED __memcpy_base_aligned
 #include "memcpy_base.S"
-
-ENTRY_PRIVATE(__memcpy_chk_fail)
-        // Preserve lr for backtrace.
-        push    {lr}
-        .cfi_def_cfa_offset 4
-        .cfi_rel_offset lr, 0
-
-        ldr     r0, error_message
-1:
-        add     r0, pc
-        bl      __fortify_fatal
-error_message:
-        .word   error_string-(1b+4)
-END(__memcpy_chk_fail)
-
-        .data
-error_string:
-        .string     "memcpy: prevented write past end of buffer"
diff --git a/libc/arch-arm/denver/bionic/memcpy.S b/libc/arch-arm/denver/bionic/memcpy.S
index c1db06c..d4e0fb4 100644
--- a/libc/arch-arm/denver/bionic/memcpy.S
+++ b/libc/arch-arm/denver/bionic/memcpy.S
@@ -63,9 +63,14 @@
 
 ENTRY(__memcpy_chk)
         cmp     r2, r3
-        bhi     __memcpy_chk_fail
+        bls     memcpy
 
-        // Fall through to memcpy...
+        // Preserve lr for backtrace.
+        push    {lr}
+        .cfi_def_cfa_offset 4
+        .cfi_rel_offset lr, 0
+
+        bl      __memcpy_chk_fail
 END(__memcpy_chk)
 
 ENTRY(memcpy)
@@ -79,21 +84,3 @@
 #define MEMCPY_BASE         __memcpy_base
 #define MEMCPY_BASE_ALIGNED __memcpy_base_aligned
 #include "memcpy_base.S"
-
-ENTRY_PRIVATE(__memcpy_chk_fail)
-        // Preserve lr for backtrace.
-        push    {lr}
-        .cfi_def_cfa_offset 4
-        .cfi_rel_offset lr, 0
-
-        ldr     r0, error_message
-1:
-        add     r0, pc
-        bl      __fortify_fatal
-error_message:
-        .word   error_string-(1b+8)
-END(__memcpy_chk_fail)
-
-        .data
-error_string:
-        .string "memcpy: prevented write past end of buffer"
diff --git a/libc/arch-arm/generic/bionic/memcpy.S b/libc/arch-arm/generic/bionic/memcpy.S
index 54c3060..f5e97f2 100644
--- a/libc/arch-arm/generic/bionic/memcpy.S
+++ b/libc/arch-arm/generic/bionic/memcpy.S
@@ -40,9 +40,14 @@
 
 ENTRY(__memcpy_chk)
         cmp         r2, r3
-        bhi         __memcpy_chk_fail
+        bls         memcpy
 
-        // Fall through to memcpy...
+        // Preserve lr for backtrace.
+        push        {lr}
+        .cfi_def_cfa_offset 4
+        .cfi_rel_offset lr, 0
+
+        bl          __memcpy_chk_fail
 END(__memcpy_chk)
 
 ENTRY(memcpy)
@@ -385,22 +390,3 @@
         add         sp,  sp, #28
         ldmfd       sp!, {r0, r4, pc}
 END(memcpy)
-
-        // Only reached when the __memcpy_chk check fails.
-ENTRY_PRIVATE(__memcpy_chk_fail)
-        // Preserve lr for backtrace.
-        push    {lr}
-        .cfi_def_cfa_offset 4
-        .cfi_rel_offset lr, 0
-
-        ldr     r0, error_message
-1:
-        add     r0, pc
-        bl      __fortify_fatal
-error_message:
-        .word   error_string-(1b+8)
-END(__memcpy_chk_fail)
-
-        .data
-error_string:
-        .string     "memcpy: prevented write past end of buffer"
diff --git a/libc/arch-arm/krait/bionic/memcpy.S b/libc/arch-arm/krait/bionic/memcpy.S
index 189a097..de6f432 100644
--- a/libc/arch-arm/krait/bionic/memcpy.S
+++ b/libc/arch-arm/krait/bionic/memcpy.S
@@ -44,9 +44,14 @@
 
 ENTRY(__memcpy_chk)
         cmp         r2, r3
-        bhi         .L_memcpy_chk_fail
+        bls         memcpy
 
-        // Fall through to memcpy...
+        // Preserve lr for backtrace.
+        push        {lr}
+        .cfi_def_cfa_offset 4
+        .cfi_rel_offset lr, 0
+
+        bl          __memcpy_chk_fail
 END(__memcpy_chk)
 
 ENTRY(memcpy)
@@ -57,25 +62,4 @@
         .cfi_rel_offset lr, 4
 
 #include "memcpy_base.S"
-
-        // Undo the cfi directives from above.
-        .cfi_adjust_cfa_offset -8
-        .cfi_restore r0
-        .cfi_restore lr
-.L_memcpy_chk_fail:
-        // Preserve lr for backtrace.
-        push    {lr}
-        .cfi_adjust_cfa_offset 4
-        .cfi_rel_offset lr, 0
-
-        ldr     r0, error_message
-1:
-        add     r0, pc
-        bl      __fortify_fatal
-error_message:
-        .word   error_string-(1b+4)
 END(memcpy)
-
-        .data
-error_string:
-        .string     "memcpy: prevented write past end of buffer"