ad88a08631
Based on a pair of patches from Intel: https://android-review.googlesource.com/#/c/43909/ https://android-review.googlesource.com/#/c/44903/ For x86, this patch supports _both_ the global that ARM/MIPS use and the per-thread TLS entry (%gs:20) that GCC uses by default. This lets us support binaries built with any x86 toolchain (right now, the NDK is emitting x86 code that uses the global). I've also extended the original tests to cover ARM/MIPS too, and be a little more thorough for x86. Change-Id: I02f279a80c6b626aecad449771dec91df235ad01
76 lines
2.4 KiB
C
76 lines
2.4 KiB
C
/*
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* Copyright (C) 2012 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef _PRIVATE_SSP_H
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#define _PRIVATE_SSP_H
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#include <errno.h>
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#include <sys/cdefs.h>
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__BEGIN_DECLS
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/** WARNING WARNING WARNING
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**
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** This header file is *NOT* part of the public Bionic ABI/API
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** and should not be used/included by user-serviceable parts of
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** the system (e.g. applications).
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**/
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/* GCC uses this on ARM and MIPS. */
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extern void* __stack_chk_guard;
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/* GCC calls this if a stack guard check fails. */
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extern void __stack_chk_fail();
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__inline__ static void* __attribute__((always_inline)) __generate_stack_chk_guard(void) {
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union {
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uintptr_t value;
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char bytes[sizeof(uintptr_t)];
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} u;
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/* Try pulling random bytes from /dev/urandom. */
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int fd = TEMP_FAILURE_RETRY(open("/dev/urandom", O_RDONLY));
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if (fd != -1) {
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ssize_t byte_count = TEMP_FAILURE_RETRY(read(fd, &u.bytes, sizeof(u)));
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close(fd);
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if (byte_count == sizeof(u)) {
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return (void*) u.value;
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}
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}
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/* If that failed, switch to 'terminator canary'. */
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u.bytes[0] = 0;
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u.bytes[1] = 0;
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u.bytes[2] = '\n';
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u.bytes[3] = 255;
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return (void*) u.value;
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}
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__END_DECLS
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#endif
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