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* changes:
  Implement setjmp cookies on AArch64.
  Implement setjmp cookies on ARM.
This commit is contained in:
Josh Gao 2015-09-17 21:09:23 +00:00 committed by Gerrit Code Review
commit 823cff847b
6 changed files with 282 additions and 61 deletions
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5
libc/Android.mk
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@ -250,10 +250,11 @@ libc_bionic_src_files += bionic/fork.cpp
# dereferences.
libc_bionic_src_files += bionic/getauxval.cpp
# These three require getauxval, which isn't available on older platforms.
# These four require getauxval, which isn't available on older platforms.
libc_bionic_src_files += bionic/getentropy_linux.c
libc_bionic_src_files += bionic/sysconf.cpp
libc_bionic_src_files += bionic/vdso.cpp
libc_bionic_src_files += bionic/setjmp_cookie.cpp
libc_cxa_src_files := \
bionic/__cxa_guard.cpp \
@ -347,7 +348,7 @@ libc_upstream_openbsd_gdtoa_src_files_64 := \
$(libc_upstream_openbsd_gdtoa_src_files) \
upstream-openbsd/lib/libc/gdtoa/strtorQ.c \
# These two depend on getentropy_linux.cpp, which isn't in libc_ndk.a.
# These two depend on getentropy_linux.c, which isn't in libc_ndk.a.
libc_upstream_openbsd_src_files := \
upstream-openbsd/lib/libc/crypt/arc4random.c \
upstream-openbsd/lib/libc/crypt/arc4random_uniform.c \

139
libc/arch-arm/bionic/setjmp.S
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@ -51,13 +51,13 @@
// The internal structure of a jmp_buf is totally private.
// Current layout (may change in the future):
//
// word name description
// 0 magic magic number
// 1 sigmask signal mask (not used with _setjmp / _longjmp)
// 2 float_base base of float registers (d8 to d15)
// 18 float_state floating-point status and control register
// 19 core_base base of core registers (r4 to r14)
// 30 reserved reserved entries (room to grow)
// word name description
// 0 sigflag/cookie setjmp cookie in top 31 bits, signal mask flag in low bit
// 1 sigmask signal mask (not used with _setjmp / _longjmp)
// 2 float_base base of float registers (d8 to d15)
// 18 float_state floating-point status and control register
// 19 core_base base of core registers (r4 to r14)
// 30 reserved reserved entries (room to grow)
// 64
//
// NOTE: float_base must be at an even word index, since the
@ -80,33 +80,79 @@ ENTRY(_setjmp)
b sigsetjmp
END(_setjmp)
#define MANGLE_REGISTERS 1
.macro m_mangle_registers reg
#if MANGLE_REGISTERS
eor r4, r4, \reg
eor r5, r5, \reg
eor r6, r6, \reg
eor r7, r7, \reg
eor r8, r8, \reg
eor r9, r9, \reg
eor r10, r10, \reg
eor r11, r11, \reg
eor r12, r12, \reg
eor r13, r13, \reg
eor r14, r14, \reg
#endif
.endm
.macro m_unmangle_registers reg
m_mangle_registers \reg
.endm
// int sigsetjmp(sigjmp_buf env, int save_signal_mask);
ENTRY(sigsetjmp)
// Record whether or not we're saving the signal mask.
stmfd sp!, {r0, lr}
.cfi_def_cfa_offset 8
.cfi_rel_offset r0, 0
.cfi_rel_offset lr, 4
mov r0, r1
bl __bionic_setjmp_cookie_get
mov r1, r0
ldmfd sp, {r0}
// Save the setjmp cookie for later.
bic r2, r1, #1
stmfd sp!, {r2}
.cfi_adjust_cfa_offset 4
// Record the setjmp cookie and whether or not we're saving the signal mask.
str r1, [r0, #(_JB_SIGFLAG * 4)]
// Do we need to save the signal mask?
teq r1, #0
tst r1, #1
beq 1f
// Get current signal mask.
stmfd sp!, {r0, r14}
.cfi_def_cfa_offset 8
.cfi_rel_offset r0, 0
.cfi_rel_offset r14, 4
mov r0, #0
bl sigblock
mov r1, r0
ldmfd sp!, {r0, r14}
.cfi_def_cfa_offset 0
// Align the stack.
sub sp, #4
.cfi_adjust_cfa_offset 4
// Save the signal mask.
str r1, [r0, #(_JB_SIGMASK * 4)]
// Save the current signal mask.
add r2, r0, #(_JB_SIGMASK * 4)
mov r0, #2 // SIG_SETMASK
mov r1, #0
bl sigprocmask
// Unalign the stack.
add sp, #4
.cfi_adjust_cfa_offset -4
1:
ldmfd sp!, {r2}
.cfi_adjust_cfa_offset -4
ldmfd sp!, {r0, lr}
.cfi_adjust_cfa_offset -8
.cfi_restore r0
.cfi_restore lr
// Save core registers.
add r1, r0, #(_JB_CORE_BASE * 4)
m_mangle_registers r2
stmia r1, {r4-r14}
m_unmangle_registers r2
// Save floating-point registers.
add r1, r0, #(_JB_FLOAT_BASE * 4)
@ -122,29 +168,30 @@ END(sigsetjmp)
// void siglongjmp(sigjmp_buf env, int value);
ENTRY(siglongjmp)
// Do we need to restore the signal mask?
ldr r2, [r0, #(_JB_SIGFLAG * 4)]
teq r2, #0
beq 1f
// Restore the signal mask.
stmfd sp!, {r0, r1, r14}
stmfd sp!, {r0, r1, lr}
.cfi_def_cfa_offset 12
.cfi_rel_offset r0, 0
.cfi_rel_offset r1, 4
.cfi_rel_offset r14, 8
sub sp, sp, #4 // Align the stack.
.cfi_adjust_cfa_offset 4
.cfi_rel_offset lr, 8
// Fetch the signal flag.
ldr r1, [r0, #(_JB_SIGFLAG * 4)]
// Do we need to restore the signal mask?
ands r1, r1, #1
beq 1f
// Restore the signal mask.
ldr r0, [r0, #(_JB_SIGMASK * 4)]
bl sigsetmask
add sp, sp, #4 // Unalign the stack.
.cfi_adjust_cfa_offset -4
ldmfd sp!, {r0, r1, r14}
.cfi_def_cfa_offset 0
1:
ldmfd sp!, {r0, r1, lr}
.cfi_adjust_cfa_offset -12
.cfi_restore r0
.cfi_restore r1
.cfi_restore lr
// Restore floating-point registers.
add r2, r0, #(_JB_FLOAT_BASE * 4)
vldmia r2, {d8-d15}
@ -154,16 +201,24 @@ ENTRY(siglongjmp)
fmxr fpscr, r2
// Restore core registers.
ldr r3, [r0, #(_JB_SIGFLAG * 4)]
bic r3, r3, #1
add r2, r0, #(_JB_CORE_BASE * 4)
ldmia r2, {r4-r14}
m_unmangle_registers r3
// Validate sp and r14.
teq sp, #0
teqne r14, #0
bleq longjmperror
// Save the return value/address and check the setjmp cookie.
stmfd sp!, {r1, lr}
.cfi_adjust_cfa_offset 8
.cfi_rel_offset lr, 4
mov r0, r3
bl __bionic_setjmp_cookie_check
// Restore return value/address.
ldmfd sp!, {r0, lr}
.cfi_adjust_cfa_offset -8
.cfi_restore lr
// Set return value.
mov r0, r1
teq r0, #0
moveq r0, #1
bx lr

105
libc/arch-arm64/bionic/setjmp.S
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@ -52,6 +52,29 @@
#define _JB_D10_D11 (_JB_D12_D13 + 2)
#define _JB_D8_D9 (_JB_D10_D11 + 2)
#define MANGLE_REGISTERS 1
.macro m_mangle_registers reg, sp_reg
#if MANGLE_REGISTERS
eor x19, x19, \reg
eor x20, x20, \reg
eor x21, x21, \reg
eor x22, x22, \reg
eor x23, x23, \reg
eor x24, x24, \reg
eor x25, x25, \reg
eor x26, x26, \reg
eor x27, x27, \reg
eor x28, x28, \reg
eor x29, x29, \reg
eor x30, x30, \reg
eor \sp_reg, \sp_reg, \reg
#endif
.endm
.macro m_unmangle_registers reg, sp_reg
m_mangle_registers \reg, sp_reg=\sp_reg
.endm
ENTRY(setjmp)
mov w1, #1
b sigsetjmp
@ -64,23 +87,47 @@ END(_setjmp)
// int sigsetjmp(sigjmp_buf env, int save_signal_mask);
ENTRY(sigsetjmp)
// Record whether or not we're saving the signal mask.
str w1, [x0, #(_JB_SIGFLAG * 8)]
stp x0, x30, [sp, #-16]!
.cfi_def_cfa_offset 16
.cfi_rel_offset x0, 0
.cfi_rel_offset x30, 8
// Get the cookie and store it along with the signal flag.
mov x0, x1
bl __bionic_setjmp_cookie_get
mov x1, x0
ldr x0, [sp, #0]
str x1, [x0, #(_JB_SIGFLAG * 8)]
// Do we need to save the signal mask?
cbz w1, 1f
tbz w1, #0, 1f
// Save the cookie for later.
stp x1, xzr, [sp, #-16]!
.cfi_adjust_cfa_offset 16
// Save current signal mask.
stp x0, x30, [sp, #-16]!
// The 'how' argument is ignored if new_mask is NULL.
mov x1, #0 // NULL.
add x2, x0, #(_JB_SIGMASK * 8) // old_mask.
bl sigprocmask
ldp x0, x30, [sp], #16
ldp x1, xzr, [sp], #16
.cfi_adjust_cfa_offset -16
1:
// Restore original x0 and lr.
ldp x0, x30, [sp], #16
.cfi_adjust_cfa_offset -16
.cfi_restore x0
.cfi_restore x30
// Mask off the signal flag bit.
bic x1, x1, #1
// Save core registers.
mov x10, sp
m_mangle_registers x1, sp_reg=x10
stp x30, x10, [x0, #(_JB_X30_SP * 8)]
stp x28, x29, [x0, #(_JB_X28_X29 * 8)]
stp x26, x27, [x0, #(_JB_X26_X27 * 8)]
@ -88,6 +135,7 @@ ENTRY(sigsetjmp)
stp x22, x23, [x0, #(_JB_X22_X23 * 8)]
stp x20, x21, [x0, #(_JB_X20_X21 * 8)]
str x19, [x0, #(_JB_X19 * 8)]
m_unmangle_registers x1, sp_reg=x10
// Save floating point registers.
stp d14, d15, [x0, #(_JB_D14_D15 * 8)]
@ -102,30 +150,60 @@ END(sigsetjmp)
// void siglongjmp(sigjmp_buf env, int value);
ENTRY(siglongjmp)
// Do we need to restore the signal mask?
ldr w9, [x0, #(_JB_SIGFLAG * 8)]
cbz w9, 1f
ldr x2, [x0, #(_JB_SIGFLAG * 8)]
tbz w2, #0, 1f
stp x0, x30, [sp, #-16]!
.cfi_adjust_cfa_offset 16
.cfi_rel_offset x0, 0
.cfi_rel_offset x30, 8
// Restore signal mask.
stp x0, x30, [sp, #-16]!
mov x19, x1 // Save 'value'.
mov x2, x0
mov x0, #2 // SIG_SETMASK
add x1, x2, #(_JB_SIGMASK * 8) // new_mask.
mov x2, #0 // NULL.
bl sigprocmask
mov x1, x19 // Restore 'value'.
ldp x0, x30, [sp], #16
// Restore original x0 and lr.
ldp x0, x30, [sp], #16
.cfi_adjust_cfa_offset -16
.cfi_restore x0
.cfi_restore x30
ldr x2, [x0, #(_JB_SIGFLAG * 8)]
1:
// Restore core registers.
bic x2, x2, #1
ldp x30, x10, [x0, #(_JB_X30_SP * 8)]
mov sp, x10
ldp x28, x29, [x0, #(_JB_X28_X29 * 8)]
ldp x26, x27, [x0, #(_JB_X26_X27 * 8)]
ldp x24, x25, [x0, #(_JB_X24_X25 * 8)]
ldp x22, x23, [x0, #(_JB_X22_X23 * 8)]
ldp x20, x21, [x0, #(_JB_X20_X21 * 8)]
ldr x19, [x0, #(_JB_X19 * 8)]
m_unmangle_registers x2, sp_reg=x10
mov sp, x10
stp x0, x1, [sp, #-16]!
.cfi_adjust_cfa_offset 16
.cfi_rel_offset x0, 0
.cfi_rel_offset x1, 8
stp x30, xzr, [sp, #-16]!
.cfi_adjust_cfa_offset 16
.cfi_rel_offset x30, 0
ldr x0, [x0, #(_JB_SIGFLAG * 8)]
bl __bionic_setjmp_cookie_check
ldp x30, xzr, [sp], #16
.cfi_adjust_cfa_offset -16
.cfi_restore x30
ldp x0, x1, [sp], #16
.cfi_adjust_cfa_offset -16
.cfi_restore x0
.cfi_restore x1
// Restore floating point registers.
ldp d14, d15, [x0, #(_JB_D14_D15 * 8)]
@ -133,13 +211,6 @@ ENTRY(siglongjmp)
ldp d10, d11, [x0, #(_JB_D10_D11 * 8)]
ldp d8, d9, [x0, #(_JB_D8_D9 * 8)]
// Validate sp (sp mod 16 = 0) and lr (lr mod 4 = 0).
tst x30, #3
b.ne longjmperror
mov x10, sp
tst x10, #15
b.ne longjmperror
// Set return value.
cmp w1, wzr
csinc w0, w1, wzr, ne

2
libc/bionic/libc_init_common.cpp
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@ -49,6 +49,7 @@
#include "pthread_internal.h"
extern "C" abort_msg_t** __abort_message_ptr;
extern "C" void __bionic_setjmp_cookie_init(void);
extern "C" int __system_properties_init(void);
extern "C" int __set_tls(void* ptr);
extern "C" int __set_tid_address(int* tid_address);
@ -121,6 +122,7 @@ void __libc_init_common(KernelArgumentBlock& args) {
__system_properties_init(); // Requires 'environ'.
__bionic_setjmp_cookie_init();
__libc_init_vdso();
}

65
libc/bionic/setjmp_cookie.cpp Normal file
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@ -0,0 +1,65 @@
/*
* Copyright (C) 2015 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 <assert.h>
#include <errno.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <sys/auxv.h>
#include <sys/cdefs.h>
#include "private/libc_logging.h"
extern "C" __LIBC_HIDDEN__ int getentropy(void*, size_t);
static long __bionic_setjmp_cookie;
extern "C" void __bionic_setjmp_cookie_init() {
char* random_data = reinterpret_cast<char*>(getauxval(AT_RANDOM));
long value = *reinterpret_cast<long*>(random_data + 8);
// Mask off the last bit to store the signal flag.
__bionic_setjmp_cookie = value & ~1;
}
extern "C" long __bionic_setjmp_cookie_get(long sigflag) {
if (sigflag & ~1) {
__libc_fatal("unexpected sigflag value: %ld", sigflag);
}
return __bionic_setjmp_cookie | sigflag;
}
// Aborts if cookie doesn't match, returns the signal flag otherwise.
extern "C" long __bionic_setjmp_cookie_check(long cookie) {
if (__bionic_setjmp_cookie != (cookie & ~1)) {
__libc_fatal("setjmp cookie mismatch");
}
return cookie & 1;
}

27
tests/setjmp_test.cpp
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@ -212,3 +212,30 @@ TEST(setjmp, setjmp_fp_registers) {
CHECK_FREGS;
}
}
#if defined(__arm__)
#define __JB_SIGFLAG 0
#elif defined(__aarch64__)
#define __JB_SIGFLAG 0
#elif defined(__i386__)
#define __JB_SIGFLAG 7
#elif defined(__x86_64)
#define __JB_SIGFLAG 8
#endif
TEST(setjmp, setjmp_cookie) {
#if !defined(__mips__)
jmp_buf jb;
int value = setjmp(jb);
ASSERT_EQ(0, value);
long* sigflag = reinterpret_cast<long*>(jb) + __JB_SIGFLAG;
// Make sure there's actually a cookie.
EXPECT_NE(0, *sigflag & ~1);
// Wipe it out
*sigflag &= 1;
EXPECT_DEATH(longjmp(jb, 0), "");
#endif
}