| /* |
| * Copyright (c) International Business Machines Corp., 2001 |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
| * the GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /* |
| * DESCRIPTION |
| * Testcase to check the mprotect(2) system call. |
| * |
| * ALGORITHM |
| * Create a mapped region using mmap with READ permission. |
| * Try to write into that region in a child process using memcpy. |
| * Verify that a SIGSEGV is generated. |
| * Now change the protection to WRITE using mprotect(2). |
| * Again try to write into the mapped region. |
| * Verify that no SIGSEGV is generated. |
| * |
| * HISTORY |
| * 07/2001 Ported by Wayne Boyer |
| * 05/2002 changed over to use tst_sig instead of sigaction |
| */ |
| |
| #include <sys/mman.h> |
| #include <sys/wait.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <limits.h> |
| #include <stdlib.h> |
| #include "test.h" |
| #include "usctest.h" |
| |
| #include "safe_macros.h" |
| |
| static void sighandler(int sig); |
| static void cleanup(void); |
| static void setup(void); |
| |
| char *TCID = "mprotect02"; |
| int TST_TOTAL = 1; |
| static int fd, status; |
| static char file1[BUFSIZ]; |
| |
| static char *addr = MAP_FAILED; |
| static char buf[] = "abcdefghijklmnopqrstuvwxyz"; |
| |
| int main(int ac, char **av) |
| { |
| int lc; |
| char *msg; |
| |
| int bytes_to_write, fd, num_bytes; |
| pid_t pid; |
| |
| if ((msg = parse_opts(ac, av, NULL, NULL)) != NULL) |
| tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg); |
| |
| setup(); |
| |
| for (lc = 0; TEST_LOOPING(lc); lc++) { |
| |
| tst_count = 0; |
| |
| fd = SAFE_OPEN(cleanup, file1, O_RDWR | O_CREAT, 0777); |
| |
| num_bytes = getpagesize(); |
| |
| do { |
| |
| if (num_bytes > strlen(buf)) |
| bytes_to_write = strlen(buf); |
| else |
| bytes_to_write = num_bytes; |
| |
| num_bytes -= |
| SAFE_WRITE(cleanup, 1, fd, buf, bytes_to_write); |
| |
| } while (0 < num_bytes); |
| |
| /* mmap the PAGESIZE bytes as read only. */ |
| addr = SAFE_MMAP(cleanup, 0, sizeof(buf), PROT_READ, |
| MAP_SHARED, fd, 0); |
| |
| if ((pid = FORK_OR_VFORK()) == -1) |
| tst_brkm(TBROK | TERRNO, cleanup, "fork #1 failed"); |
| |
| if (pid == 0) { |
| memcpy(addr, buf, strlen(buf)); |
| exit(255); |
| } |
| |
| if (waitpid(pid, &status, 0) == -1) |
| tst_brkm(TBROK | TERRNO, cleanup, "waitpid failed"); |
| if (!WIFEXITED(status)) |
| tst_brkm(TBROK, cleanup, "child exited abnormally " |
| "with status: %d", status); |
| switch (status) { |
| case 255: |
| tst_brkm(TBROK, cleanup, |
| "memcpy did not generate SIGSEGV"); |
| case 0: |
| tst_resm(TPASS, "got SIGSEGV as expected"); |
| break; |
| default: |
| tst_brkm(TBROK, cleanup, "got unexpected signal: %d", |
| status); |
| break; |
| } |
| |
| /* Change the protection to WRITE. */ |
| TEST(mprotect(addr, sizeof(buf), PROT_WRITE)); |
| |
| if (TEST_RETURN != -1) { |
| |
| if (STD_FUNCTIONAL_TEST) { |
| |
| if ((pid = FORK_OR_VFORK()) == -1) |
| tst_brkm(TBROK | TERRNO, cleanup, |
| "fork #2 failed"); |
| |
| if (pid == 0) { |
| memcpy(addr, buf, strlen(buf)); |
| exit(0); |
| } |
| |
| if (waitpid(pid, &status, 0) == -1) |
| tst_brkm(TBROK | TERRNO, cleanup, |
| "waitpid failed"); |
| |
| if (WIFEXITED(status) && |
| WEXITSTATUS(status) == 0) |
| tst_resm(TPASS, "didn't get SIGSEGV"); |
| else |
| tst_brkm(TBROK, cleanup, |
| "child exited abnormally"); |
| |
| } else |
| tst_resm(TPASS, "call succeeded"); |
| |
| } else { |
| tst_resm(TFAIL | TERRNO, "mprotect failed"); |
| continue; |
| } |
| |
| SAFE_MUNMAP(cleanup, addr, sizeof(buf)); |
| addr = MAP_FAILED; |
| |
| SAFE_CLOSE(cleanup, fd); |
| |
| SAFE_UNLINK(cleanup, file1); |
| |
| } |
| |
| cleanup(); |
| tst_exit(); |
| } |
| |
| static void sighandler(int sig) |
| { |
| _exit((sig == SIGSEGV) ? 0 : sig); |
| } |
| |
| static void setup(void) |
| { |
| tst_sig(FORK, sighandler, cleanup); |
| |
| TEST_PAUSE; |
| |
| tst_tmpdir(); |
| |
| sprintf(file1, "mprotect02.tmp.%d", getpid()); |
| } |
| |
| static void cleanup(void) |
| { |
| TEST_CLEANUP; |
| |
| if (addr != MAP_FAILED) { |
| SAFE_MUNMAP(NULL, addr, sizeof(buf)); |
| SAFE_CLOSE(NULL, fd); |
| } |
| |
| tst_rmdir(); |
| } |