mirror of
https://github.com/mstorsjo/llvm-mingw
synced 2026-06-21 14:01:00 +00:00
Martin Storsjö
516c9779fb
If the low byte of the stack cookie happens to be zero, we previously wouldn't trigger any error. This avoids accidentally failing to trigger the stack protector once per 256 runs, roughly.
40 lines
1.3 KiB
C
40 lines
1.3 KiB
C
/*
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* Copyright (c) 2018 Martin Storsjo
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*
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* This file is part of llvm-mingw.
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <stdio.h>
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__attribute__((noinline))
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void func(char *ptr, int idx) {
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ptr[idx] ^= 1;
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}
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int main(int argc, char *argv[]) {
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char buf[10];
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if (argc > 1) {
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fprintf(stderr, "smashing stack\n");
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fflush(stderr);
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func(buf, 10);
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} else {
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func(buf, 9);
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fprintf(stderr, "%s: A test tool for detecting stack smashing.\n"
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"Run this with a command line argument to trigger an "
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"error.\n", argv[0]);
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}
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return 0;
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}
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