74 lines
1.8 KiB
C
74 lines
1.8 KiB
C
/* This testcase is part of GDB, the GNU debugger.
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Copyright 2014-2018 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <sys/mman.h>
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#include <unistd.h>
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#include <assert.h>
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void *global_invalid_ptr = NULL;
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void
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func2 (void)
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{
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/* Replace the current stack pointer and frame pointer with the invalid
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pointer. */
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asm ("mov %0, %%rsp\n\tmov %0, %%rbp" : : "r" (global_invalid_ptr));
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/* Create a label for a breakpoint. */
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asm (".global breakpt\nbreakpt:");
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}
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void
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func1 (void *ptr)
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{
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global_invalid_ptr = ptr;
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func2 ();
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}
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/* Finds and returns an invalid pointer, mmaps in a page, grabs a pointer
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to it then unmaps the page again. This is almost certainly "undefined"
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behaviour, but should be good enough for this small test program. */
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static void *
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make_invalid_ptr (void)
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{
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int page_size, ans;
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void *ptr;
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page_size = getpagesize ();
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ptr = mmap (0, page_size, PROT_NONE,
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MAP_PRIVATE | MAP_ANONYMOUS,
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-1, 0);
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assert (ptr != MAP_FAILED);
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ans = munmap (ptr, page_size);
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assert (ans == 0);
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return ptr;
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}
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int
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main (void)
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{
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void *invalid_ptr;
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invalid_ptr = make_invalid_ptr ();
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func1 (invalid_ptr);
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return 0;
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}
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