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Optimize __memset_chk, __memcpy_chk. DO NOT MERGE.

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This change creates assembler versions of __memcpy_chk/__memset_chk
that is implemented in the memcpy/memset assembler code. This change
avoids an extra call to memcpy/memset, instead allowing a simple fall
through to occur from the chk code into the body of the real
implementation.

Testing:

- Ran the libc_test on __memcpy_chk/__memset_chk on all nexus devices.
- Wrote a small test executable that has three calls to __memcpy_chk and
  three calls to __memset_chk. First call dest_len is length + 1. Second
  call dest_len is length. Third call dest_len is length - 1.
  Verified that the first two calls pass, and the third fails. Examined
  the logcat output on all nexus devices to verify that the fortify
  error message was sent properly.
- I benchmarked the new __memcpy_chk and __memset_chk on all systems. For
  __memcpy_chk and large copies, the savings is relatively small (about 1%).
  For small copies, the savings is large on cortex-a15/krait devices
  (between 5% to 30%).
  For cortex-a9 and small copies, the speed up is present, but relatively
  small (about 3% to 5%).
  For __memset_chk and large copies, the savings is also small (about 1%).
  However, all processors show larger speed-ups on small copies (about 30% to
  100%).

Bug: 9293744

Merge from internal master.

(cherry-picked from 7c860db074)

Change-Id: I916ad305e4001269460ca6ebd38aaa0be8ac7f52
This commit is contained in:
Christopher Ferris 2013-08-01 13:13:33 -07:00
parent c85e0dbb0b
commit 59a13c122e
13 changed files with 285 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
libc/Android.mk
View File

@ -62,7 +62,6 @@ libc_common_src_files := \
string/strcspn.c \
string/strdup.c \
string/strpbrk.c \
string/__strrchr_chk.c \
string/strsep.c \
string/strspn.c \
string/strstr.c \
@ -181,6 +180,25 @@ libc_common_src_files := \
netbsd/nameser/ns_print.c \
netbsd/nameser/ns_samedomain.c \
# Fortify implementations of libc functions.
libc_common_src_files += \
bionic/__fgets_chk.cpp \
bionic/__memcpy_chk.cpp \
bionic/__memmove_chk.cpp \
bionic/__memset_chk.cpp \
bionic/__strcat_chk.cpp \
bionic/__strchr_chk.cpp \
bionic/__strcpy_chk.cpp \
bionic/__strlcat_chk.cpp \
bionic/__strlcpy_chk.cpp \
bionic/__strlen_chk.cpp \
bionic/__strncat_chk.cpp \
bionic/__strncpy_chk.cpp \
bionic/__strrchr_chk.cpp \
bionic/__umask_chk.cpp \
bionic/__vsnprintf_chk.cpp \
bionic/__vsprintf_chk.cpp \
libc_bionic_src_files := \
bionic/abort.cpp \
bionic/assert.cpp \
@ -189,16 +207,12 @@ libc_bionic_src_files := \
bionic/__errno.c \
bionic/eventfd_read.cpp \
bionic/eventfd_write.cpp \
bionic/__fgets_chk.cpp \
bionic/futimens.cpp \
bionic/getauxval.cpp \
bionic/getcwd.cpp \
bionic/libc_init_common.cpp \
bionic/libc_logging.cpp \
bionic/libgen.cpp \
bionic/__memcpy_chk.cpp \
bionic/__memmove_chk.cpp \
bionic/__memset_chk.cpp \
bionic/mmap.cpp \
bionic/pthread_attr.cpp \
bionic/pthread_detach.cpp \
@ -221,24 +235,13 @@ libc_bionic_src_files := \
bionic/signalfd.cpp \
bionic/sigwait.cpp \
bionic/statvfs.cpp \
bionic/__strcat_chk.cpp \
bionic/__strchr_chk.cpp \
bionic/__strcpy_chk.cpp \
bionic/strerror.cpp \
bionic/strerror_r.cpp \
bionic/__strlcat_chk.cpp \
bionic/__strlcpy_chk.cpp \
bionic/__strlen_chk.cpp \
bionic/__strncat_chk.cpp \
bionic/__strncpy_chk.cpp \
bionic/strsignal.cpp \
bionic/stubs.cpp \
bionic/sysconf.cpp \
bionic/tdestroy.cpp \
bionic/tmpfile.cpp \
bionic/__umask_chk.cpp \
bionic/__vsnprintf_chk.cpp \
bionic/__vsprintf_chk.cpp \
bionic/wait.cpp \
bionic/wchar.cpp \

9
libc/arch-arm/arm.mk
View File

@ -26,6 +26,15 @@ _LIBC_ARCH_STATIC_SRC_FILES := \
_LIBC_ARCH_DYNAMIC_SRC_FILES := \
arch-arm/bionic/exidx_dynamic.c
# Remove the C++ fortify function implementations for which there is an
# arm assembler version.
_LIBC_FORTIFY_FILES_TO_REMOVE := \
bionic/__memcpy_chk.cpp \
bionic/__memset_chk.cpp \
libc_common_src_files := \
$(filter-out $(_LIBC_FORTIFY_FILES_TO_REMOVE),$(libc_common_src_files))
ifeq ($(strip $(wildcard bionic/libc/arch-arm/$(TARGET_CPU_VARIANT)/$(TARGET_CPU_VARIANT).mk)),)
$(error "TARGET_CPU_VARIANT not set or set to an unknown value. Possible values are cortex-a7, cortex-a8, cortex-a9, cortex-a15, krait. Use generic for devices that do not have a CPU similar to any of the supported cpu variants.")
endif

25
libc/arch-arm/cortex-a15/bionic/memcpy.S
View File

@ -59,6 +59,7 @@
#include <machine/cpu-features.h>
#include <machine/asm.h>
#include "libc_events.h"
.text
.syntax unified
@ -66,6 +67,13 @@
#define CACHE_LINE_SIZE 64
ENTRY(__memcpy_chk)
cmp r2, r3
bgt fortify_check_failed
// Fall through to memcpy...
END(__memcpy_chk)
ENTRY(memcpy)
// Assumes that n >= 0, and dst, src are valid pointers.
// For any sizes less than 832 use the neon code that doesn't
@ -321,4 +329,21 @@ dst_not_word_aligned:
// Src is guaranteed to be at least word aligned by this point.
b word_aligned
// Only reached when the __memcpy_chk check fails.
fortify_check_failed:
ldr r0, error_message
ldr r1, error_code
1:
add r0, pc
bl __fortify_chk_fail
error_code:
.word BIONIC_EVENT_MEMCPY_BUFFER_OVERFLOW
error_message:
.word error_string-(1b+8)
END(memcpy)
.data
error_string:
.string "memcpy buffer overflow"

29
libc/arch-arm/cortex-a15/bionic/memset.S
View File

@ -28,19 +28,38 @@
#include <machine/cpu-features.h>
#include <machine/asm.h>
#include "libc_events.h"
/*
* Optimized memset() for ARM.
/*
* Optimized memset() for ARM.
*
* memset() returns its first argument.
*/
*/
.fpu neon
.syntax unified
ENTRY(__memset_chk)
cmp r2, r3
bls done
ldr r0, error_message
ldr r1, error_code
1:
add r0, pc
bl __fortify_chk_fail
error_code:
.word BIONIC_EVENT_MEMSET_BUFFER_OVERFLOW
error_message:
.word error_string-(1b+8)
END(__memset_chk)
ENTRY(bzero)
mov r2, r1
mov r1, #0
done:
// Fall through to memset...
END(bzero)
@ -162,3 +181,7 @@ set_less_than_16_unknown_align:
ldmfd sp!, {r0}
bx lr
END(memset)
.data
error_string:
.string "memset buffer overflow"

25
libc/arch-arm/cortex-a9/bionic/memcpy.S
View File

@ -28,6 +28,7 @@
#include <machine/cpu-features.h>
#include <machine/asm.h>
#include "libc_events.h"
/*
* This code assumes it is running on a processor that supports all arm v7
@ -40,6 +41,13 @@
#define CACHE_LINE_SIZE 32
ENTRY(__memcpy_chk)
cmp r2, r3
bgt fortify_check_failed
// Fall through to memcpy...
END(__memcpy_chk)
ENTRY(memcpy)
.save {r0, lr}
/* start preloading as early as possible */
@ -208,4 +216,21 @@ ENTRY(memcpy)
6:
ldmfd sp!, {r4, r5, r6, r7, r8}
ldmfd sp!, {r0, pc}
// Only reached when the __memcpy_chk check fails.
fortify_check_failed:
ldr r0, error_message
ldr r1, error_code
1:
add r0, pc
bl __fortify_chk_fail
error_code:
.word BIONIC_EVENT_MEMCPY_BUFFER_OVERFLOW
error_message:
.word error_string-(1b+8)
END(memcpy)
.data
error_string:
.string "memcpy buffer overflow"

24
libc/arch-arm/cortex-a9/bionic/memset.S
View File

@ -28,6 +28,7 @@
#include <machine/cpu-features.h>
#include <machine/asm.h>
#include "libc_events.h"
/*
* This code assumes it is running on a processor that supports all arm v7
@ -36,9 +37,28 @@
.fpu neon
ENTRY(__memset_chk)
cmp r2, r3
bls done
ldr r0, error_message
ldr r1, error_code
1:
add r0, pc
bl __fortify_chk_fail
error_code:
.word BIONIC_EVENT_MEMSET_BUFFER_OVERFLOW
error_message:
.word error_string-(1b+8)
END(__memset_chk)
ENTRY(bzero)
mov r2, r1
mov r1, #0
done:
// Fall through to memset...
END(bzero)
/* memset() returns its first argument. */
@ -150,3 +170,7 @@ ENTRY(memset)
ldmfd sp!, {r0, r4-r7, lr}
bx lr
END(memset)
.data
error_string:
.string "memset buffer overflow"

24
libc/arch-arm/generic/bionic/memcpy.S
View File

@ -28,6 +28,7 @@
#include <machine/cpu-features.h>
#include <machine/asm.h>
#include "libc_events.h"
/*
* Optimized memcpy() for ARM.
@ -36,6 +37,13 @@
* so we have to preserve R0.
*/
ENTRY(__memcpy_chk)
cmp r2, r3
bgt fortify_check_failed
// Fall through to memcpy...
END(__memcpy_chk)
ENTRY(memcpy)
/* The stack must always be 64-bits aligned to be compliant with the
* ARM ABI. Since we have to save R0, we might as well save R4
@ -377,4 +385,20 @@ copy_last_3_and_return:
add sp, sp, #28
ldmfd sp!, {r0, r4, lr}
bx lr
// Only reached when the __memcpy_chk check fails.
fortify_check_failed:
ldr r0, error_message
ldr r1, error_code
1:
add r0, pc
bl __fortify_chk_fail
error_code:
.word BIONIC_EVENT_MEMCPY_BUFFER_OVERFLOW
error_message:
.word error_string-(1b+8)
END(memcpy)
.data
error_string:
.string "memcpy buffer overflow"

24
libc/arch-arm/generic/bionic/memset.S
View File

@ -27,6 +27,7 @@
*/
#include <machine/asm.h>
#include "libc_events.h"
/*
* Optimized memset() for ARM.
@ -34,9 +35,28 @@
* memset() returns its first argument.
*/
ENTRY(__memset_chk)
cmp r2, r3
bls done
ldr r0, error_message
ldr r1, error_code
1:
add r0, pc
bl __fortify_chk_fail
error_code:
.word BIONIC_EVENT_MEMSET_BUFFER_OVERFLOW
error_message:
.word error_string-(1b+8)
END(__memset_chk)
ENTRY(bzero)
mov r2, r1
mov r1, #0
done:
// Fall through to memset...
END(bzero)
ENTRY(memset)
@ -107,3 +127,7 @@ ENTRY(memset)
ldmfd sp!, {r0, r4-r7, lr}
bx lr
END(memset)
.data
error_string:
.string "memset buffer overflow"

26
libc/arch-arm/krait/bionic/memcpy.S
View File

@ -30,6 +30,7 @@
#include <machine/cpu-features.h>
#include <machine/asm.h>
#include "libc_events.h"
/*
* This code assumes it is running on a processor that supports all arm v7
@ -37,10 +38,17 @@
* cache line.
*/
#define CACHE_LINE_SIZE 32
.text
.fpu neon
#define CACHE_LINE_SIZE 32
ENTRY(__memcpy_chk)
cmp r2, r3
bgt fortify_check_failed
// Fall through to memcpy...
END(__memcpy_chk)
ENTRY(memcpy)
.save {r0, lr}
@ -143,4 +151,20 @@ ENTRY(memcpy)
ldmfd sp!, {r0, lr}
bx lr
// Only reached when the __memcpy_chk check fails.
fortify_check_failed:
ldr r0, error_message
ldr r1, error_code
1:
add r0, pc
bl __fortify_chk_fail
error_code:
.word BIONIC_EVENT_MEMCPY_BUFFER_OVERFLOW
error_message:
.word error_string-(1b+8)
END(memcpy)
.data
error_string:
.string "memcpy buffer overflow"

24
libc/arch-arm/krait/bionic/memset.S
View File

@ -28,6 +28,7 @@
#include <machine/cpu-features.h>
#include <machine/asm.h>
#include "libc_events.h"
/*
* This code assumes it is running on a processor that supports all arm v7
@ -37,9 +38,28 @@
.fpu neon
ENTRY(__memset_chk)
cmp r2, r3
bls done
ldr r0, error_message
ldr r1, error_code
1:
add r0, pc
bl __fortify_chk_fail
error_code:
.word BIONIC_EVENT_MEMSET_BUFFER_OVERFLOW
error_message:
.word error_string-(1b+8)
END(__memset_chk)
ENTRY(bzero)
mov r2, r1
mov r1, #0
done:
// Fall through to memset...
END(bzero)
/* memset() returns its first argument. */
@ -79,3 +99,7 @@ ENTRY(memset)
ldmfd sp!, {r0}
bx lr
END(memset)
.data
error_string:
.string "memset buffer overflow"

23
libc/string/__strrchr_chk.c → libc/bionic/__strrchr_chk.cpp
View File

@ -31,18 +31,17 @@
#include <string.h>
#include "libc_logging.h"
char *
__strrchr_chk(const char *p, int ch, size_t s_len)
extern "C" char* __strrchr_chk(const char *p, int ch, size_t s_len)
{
char *save;
char *save;
for (save = NULL;; ++p, s_len--) {
if (s_len == 0)
__fortify_chk_fail("strrchr read beyond buffer", 0);
if (*p == (char) ch)
save = (char *)p;
if (!*p)
return(save);
}
/* NOTREACHED */
for (save = NULL;; ++p, s_len--) {
if (s_len == 0)
__fortify_chk_fail("strrchr read beyond buffer", 0);
if (*p == (char) ch)
save = (char *)p;
if (!*p)
return(save);
}
/* NOTREACHED */
}

48
libc/private/libc_events.h Normal file
View File

@ -0,0 +1,48 @@
/*
* Copyright (C) 2013 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.
*/
#ifndef _LIBC_EVENTS_H
#define _LIBC_EVENTS_H
// This is going to be included in assembler code so only allow #define
// values instead of defining an enum.
#define BIONIC_EVENT_MEMCPY_BUFFER_OVERFLOW 80100
#define BIONIC_EVENT_STRCAT_BUFFER_OVERFLOW 80105
#define BIONIC_EVENT_MEMMOVE_BUFFER_OVERFLOW 80110
#define BIONIC_EVENT_STRNCAT_BUFFER_OVERFLOW 80115
#define BIONIC_EVENT_STRNCPY_BUFFER_OVERFLOW 80120
#define BIONIC_EVENT_MEMSET_BUFFER_OVERFLOW 80125
#define BIONIC_EVENT_STRCPY_BUFFER_OVERFLOW 80130
#define BIONIC_EVENT_RESOLVER_OLD_RESPONSE 80300
#define BIONIC_EVENT_RESOLVER_WRONG_SERVER 80305
#define BIONIC_EVENT_RESOLVER_WRONG_QUERY 80310
#endif // _LIBC_EVENTS_H

14
libc/private/libc_logging.h
View File

@ -36,19 +36,7 @@
__BEGIN_DECLS
enum {
BIONIC_EVENT_MEMCPY_BUFFER_OVERFLOW = 80100,
BIONIC_EVENT_STRCAT_BUFFER_OVERFLOW = 80105,
BIONIC_EVENT_MEMMOVE_BUFFER_OVERFLOW = 80110,
BIONIC_EVENT_STRNCAT_BUFFER_OVERFLOW = 80115,
BIONIC_EVENT_STRNCPY_BUFFER_OVERFLOW = 80120,
BIONIC_EVENT_MEMSET_BUFFER_OVERFLOW = 80125,
BIONIC_EVENT_STRCPY_BUFFER_OVERFLOW = 80130,
BIONIC_EVENT_RESOLVER_OLD_RESPONSE = 80300,
BIONIC_EVENT_RESOLVER_WRONG_SERVER = 80305,
BIONIC_EVENT_RESOLVER_WRONG_QUERY = 80310,
};
#include "libc_events.h"
enum {
ANDROID_LOG_UNKNOWN = 0,