156 lines
3.6 KiB
C
156 lines
3.6 KiB
C
/*
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* Copyright (c) International Business Machines Corp., 2001
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*
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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 2 of the License, or
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* (at your option) any later version.
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*
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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
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* the GNU General Public License for more details.
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*
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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, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/*
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* NAME
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* mprotect03.c
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*
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* DESCRIPTION
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* Testcase to check the mprotect(2) system call.
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*
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* ALGORITHM
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* Create a shared mapped file region with PROT_READ | PROT_WRITE
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* using the mmap(2) call. Then, use mprotect(2) to disable the
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* write permission on the mapped region. Then, attempt to write to
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* the mapped region using memcpy(). This would generate a sigsegv.
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* Since the sigsegv is generated, this needs to be done in a child
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* process (as sigsegv would repeatedly be generated). The testcase
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* succeeds only when this sigsegv is generated while attempting to
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* memcpy() on a shared region with only read permission.
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*
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* HISTORY
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* 07/2001 Ported by Wayne Boyer
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* 05/2002 changed over to use tst_sig instead of sigaction
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*/
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#include <errno.h>
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#include <fcntl.h>
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#include <sys/mman.h>
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#include <limits.h>
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#include <signal.h>
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#include <sys/wait.h>
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#include "test.h"
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#include "safe_macros.h"
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#ifndef PAGESIZE
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#define PAGESIZE 4096
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#endif
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#define FAILED 1
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static void cleanup(void);
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static void setup(void);
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char *TCID = "mprotect03";
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int TST_TOTAL = 1;
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int status;
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char file1[BUFSIZ];
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int main(int ac, char **av)
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{
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int lc;
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char *addr;
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int fd, pid;
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char *buf = "abcdefghijklmnopqrstuvwxyz";
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tst_parse_opts(ac, av, NULL, NULL);
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setup();
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for (lc = 0; TEST_LOOPING(lc); lc++) {
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tst_count = 0;
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if ((fd = open(file1, O_RDWR | O_CREAT, 0777)) < 0)
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tst_brkm(TBROK, cleanup, "open failed");
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SAFE_WRITE(cleanup, 1, fd, buf, strlen(buf));
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/*
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* mmap the PAGESIZE bytes as read only.
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*/
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addr = mmap(0, strlen(buf), PROT_READ | PROT_WRITE, MAP_SHARED,
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fd, 0);
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if (addr == MAP_FAILED)
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tst_brkm(TBROK, cleanup, "mmap failed");
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/*
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* Try to change the protection to WRITE.
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*/
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TEST(mprotect(addr, strlen(buf), PROT_READ));
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if (TEST_RETURN != -1) {
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if ((pid = FORK_OR_VFORK()) == -1) {
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tst_brkm(TBROK, cleanup, "fork failed");
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}
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if (pid == 0) {
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memcpy(addr, buf, strlen(buf));
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tst_resm(TINFO, "memcpy() did "
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"not generate SIGSEGV");
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exit(1);
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}
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waitpid(pid, &status, 0);
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if (WEXITSTATUS(status) != 0) {
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tst_resm(TFAIL, "child returned "
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"unexpected status");
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} else {
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tst_resm(TPASS, "SIGSEGV generated "
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"as expected");
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}
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} else {
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tst_resm(TFAIL, "mprotect failed "
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"unexpectedly, errno: %d", errno);
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}
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/* clean up things in case we are looping */
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SAFE_MUNMAP(cleanup, addr, strlen(buf));
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SAFE_CLOSE(cleanup, fd);
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SAFE_UNLINK(cleanup, file1);
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}
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cleanup();
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tst_exit();
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}
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static void sighandler(int sig)
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{
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if (sig == SIGSEGV) {
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tst_resm(TINFO, "received signal: SIGSEGV");
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tst_exit();
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} else
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tst_brkm(TBROK, 0, "Unexpected signal %d received.", sig);
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}
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static void setup(void)
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{
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tst_sig(FORK, sighandler, NULL);
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TEST_PAUSE;
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tst_tmpdir();
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sprintf(file1, "mprotect03.tmp.%d", getpid());
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}
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static void cleanup(void)
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{
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tst_rmdir();
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}
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