Improve diagnostics from the assembler __strcpy_chk routines.
Change-Id: Ib95b598f7f8338cc1a618c00232a4259dc4a6319
diff --git a/libc/arch-arm/cortex-a15/bionic/__strcpy_chk_common.S b/libc/arch-arm/cortex-a15/bionic/__strcpy_chk_common.S
index 215e6c2..377e720 100644
--- a/libc/arch-arm/cortex-a15/bionic/__strcpy_chk_common.S
+++ b/libc/arch-arm/cortex-a15/bionic/__strcpy_chk_common.S
@@ -147,23 +147,15 @@
pld [r1, #0]
pld [r1, #64]
ldr r0, [sp]
- cmp r3, lr
- bhs .L_strcpy_chk_failed
// Add 1 for copy length to get the string terminator.
add r2, r3, #1
+ cmp r2, lr
+ itt hi
+ movhi r0, r2
+ bhi __strcpy_chk_fail
+
#include MEMCPY_BASE
-.L_strcpy_chk_failed:
- ldr r0, error_message
-1:
- add r0, pc
- bl __fortify_fatal
-error_message:
- .word error_string-(1b+4)
END(__strcpy_chk)
-
- .data
-error_string:
- .string "strcpy: prevented write past end of buffer"
diff --git a/libc/arch-arm/cortex-a9/bionic/__strcpy_chk.S b/libc/arch-arm/cortex-a9/bionic/__strcpy_chk.S
index 14741b6..1d5e70b 100644
--- a/libc/arch-arm/cortex-a9/bionic/__strcpy_chk.S
+++ b/libc/arch-arm/cortex-a9/bionic/__strcpy_chk.S
@@ -149,33 +149,18 @@
pld [r1, #0]
pld [r1, #64]
ldr r0, [sp]
- cmp r3, lr
- bhs __strcpy_chk_fail
// Add 1 for copy length to get the string terminator.
add r2, r3, #1
+ cmp r2, lr
+ itt hi
+ movhi r0, r2
+ bhi __strcpy_chk_fail
+
// Fall through into the memcpy_base function.
END(__strcpy_chk)
#define MEMCPY_BASE __strcpy_chk_memcpy_base
#define MEMCPY_BASE_ALIGNED __strcpy_chk_memcpy_base_aligned
#include "memcpy_base.S"
-
-ENTRY_PRIVATE(__strcpy_chk_fail)
- .cfi_def_cfa_offset 8
- .cfi_rel_offset r0, 0
- .cfi_rel_offset lr, 4
-
- ldr r0, error_message
-1:
- add r0, pc
- bl __fortify_fatal
-
-error_message:
- .word error_string-(1b+4)
-END(__strcpy_chk_fail)
-
- .data
-error_string:
- .string "strcpy: prevented write past end of buffer"
diff --git a/libc/arch-arm/denver/bionic/__strcpy_chk.S b/libc/arch-arm/denver/bionic/__strcpy_chk.S
index 36188b0..9b7ea91 100644
--- a/libc/arch-arm/denver/bionic/__strcpy_chk.S
+++ b/libc/arch-arm/denver/bionic/__strcpy_chk.S
@@ -147,30 +147,18 @@
pld [r1, #0]
pld [r1, #64]
ldr r0, [sp]
- cmp r3, lr
- bhs __strcpy_chk_failed
// Add 1 for copy length to get the string terminator.
add r2, r3, #1
+
+ cmp r2, lr
+ itt hi
+ movhi r0, r2
+ bhi __strcpy_chk_fail
+
+ // Fall through into the memcpy_base function.
END(__strcpy_chk)
#define MEMCPY_BASE __strcpy_chk_memcpy_base
#define MEMCPY_BASE_ALIGNED __strcpy_chk_memcpy_base_aligned
#include "memcpy_base.S"
-
-ENTRY_PRIVATE(__strcpy_chk_failed)
- .cfi_def_cfa_offset 8
- .cfi_rel_offset r0, 0
- .cfi_rel_offset lr, 4
-
- ldr r0, error_message
-1:
- add r0, pc
- bl __fortify_fatal
-error_message:
- .word error_string-(1b+4)
-END(__strcpy_chk_failed)
-
- .data
-error_string:
- .string "strcpy: prevented write past end of buffer"
diff --git a/libc/arch-arm/krait/bionic/__strcpy_chk.S b/libc/arch-arm/krait/bionic/__strcpy_chk.S
index ef908e6..9c2f66a 100644
--- a/libc/arch-arm/krait/bionic/__strcpy_chk.S
+++ b/libc/arch-arm/krait/bionic/__strcpy_chk.S
@@ -147,23 +147,15 @@
pld [r1, #0]
pld [r1, #64]
ldr r0, [sp]
- cmp r3, lr
- bhs .L_strcpy_chk_failed
// Add 1 for copy length to get the string terminator.
add r2, r3, #1
+ cmp r2, lr
+ itt hi
+ movhi r0, r2
+ bhi __strcpy_chk_fail
+
#include "memcpy_base.S"
-.L_strcpy_chk_failed:
- ldr r0, error_message
-1:
- add r0, pc
- bl __fortify_fatal
-error_message:
- .word error_string-(1b+4)
END(__strcpy_chk)
-
- .data
-error_string:
- .string "strcpy: prevented write past end of buffer"
diff --git a/libc/bionic/fortify.cpp b/libc/bionic/fortify.cpp
index 278c606..11abeb1 100644
--- a/libc/bionic/fortify.cpp
+++ b/libc/bionic/fortify.cpp
@@ -288,6 +288,12 @@
}
}
+// strcpy is performance-critical enough that we have assembler __strcpy_chk implementations.
+// This function is used to give better diagnostics than we can easily do from assembler.
+extern "C" void __strcpy_chk_fail(size_t dst_buf_size) {
+ __fortify_fatal("strcpy: prevented write past end of %zu-byte buffer", dst_buf_size);
+}
+
size_t __strlcat_chk(char* dst, const char* src,
size_t supplied_size, size_t dst_len_from_compiler) {
__check_buffer_access("strlcat", "write into", supplied_size, dst_len_from_compiler);
