| /* |
| * 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 |
| */ |
| |
| /* |
| * Test Description: |
| * Call mmap() to map a file creating mapped memory with no access under |
| * the following conditions - |
| * - The prot parameter is set to PROT_NONE |
| * - The file descriptor is open for read(any mode other than write) |
| * - The minimum file permissions should be 0444. |
| * |
| * The call should succeed to map the file creating mapped memory with the |
| * required attributes. |
| * |
| * Expected Result: |
| * mmap() should succeed returning the address of the mapped region, |
| * and an attempt to access the contents of the mapped region should give |
| * rise to the signal SIGSEGV. |
| * |
| * HISTORY |
| * 07/2001 Ported by Wayne Boyer |
| */ |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/types.h> |
| #include <errno.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <string.h> |
| #include <signal.h> |
| #include <sys/stat.h> |
| #include <sys/mman.h> |
| #include <setjmp.h> |
| |
| #include "test.h" |
| |
| #define TEMPFILE "mmapfile" |
| |
| char *TCID = "mmap05"; |
| int TST_TOTAL = 1; |
| |
| static size_t page_sz; |
| static volatile char *addr; |
| static int fildes; |
| static volatile int pass = 0; |
| static sigjmp_buf env; |
| |
| static void setup(void); |
| static void cleanup(void); |
| static void sig_handler(int sig); |
| |
| int main(int ac, char **av) |
| { |
| int lc; |
| const char *msg; |
| char file_content; |
| |
| 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; |
| |
| /* |
| * Call mmap to map the temporary file 'TEMPFILE' |
| * with no access. |
| */ |
| errno = 0; |
| addr = mmap(0, page_sz, PROT_NONE, |
| MAP_FILE | MAP_SHARED, fildes, 0); |
| TEST_ERRNO = errno; |
| |
| /* Check for the return value of mmap() */ |
| if (addr == MAP_FAILED) { |
| tst_resm(TFAIL | TERRNO, "mmap() failed on %s", |
| TEMPFILE); |
| continue; |
| } |
| |
| /* |
| * Try to access the mapped region. This should |
| * generate a SIGSEGV which will be caught below. |
| * |
| * This is wrapped by the sigsetjmp() call that will |
| * take care of restoring the program's context in an |
| * elegant way in conjunction with the call to |
| * siglongjmp() in the signal handler. |
| */ |
| if (sigsetjmp(env, 1) == 0) { |
| file_content = addr[0]; |
| } |
| |
| if (pass) { |
| tst_resm(TPASS, "Got SIGSEGV as expected"); |
| } else { |
| tst_resm(TFAIL, "Mapped memory region with NO " |
| "access is accessible"); |
| } |
| |
| /* Unmap mapped memory and reset pass in case we are looping */ |
| if (munmap((void *)addr, page_sz) != 0) { |
| tst_brkm(TFAIL | TERRNO, cleanup, "munmap failed"); |
| } |
| pass = 0; |
| |
| } |
| |
| cleanup(); |
| tst_exit(); |
| } |
| |
| static void setup(void) |
| { |
| char *tst_buff; |
| |
| tst_sig(NOFORK, sig_handler, cleanup); |
| |
| TEST_PAUSE; |
| |
| page_sz = getpagesize(); |
| |
| /* Allocate space for the test buffer */ |
| if ((tst_buff = calloc(page_sz, sizeof(char))) == NULL) { |
| tst_brkm(TFAIL, NULL, "calloc failed (tst_buff)"); |
| } |
| |
| /* Fill the test buffer with the known data */ |
| memset(tst_buff, 'A', page_sz); |
| |
| tst_tmpdir(); |
| |
| /* Creat a temporary file used for mapping */ |
| if ((fildes = open(TEMPFILE, O_WRONLY | O_CREAT, 0666)) < 0) { |
| free(tst_buff); |
| tst_brkm(TFAIL | TERRNO, cleanup, "opening %s failed", |
| TEMPFILE); |
| } |
| |
| /* Write test buffer contents into temporary file */ |
| if (write(fildes, tst_buff, page_sz) != page_sz) { |
| free(tst_buff); |
| tst_brkm(TFAIL, cleanup, "writing to %s failed", TEMPFILE); |
| } |
| |
| /* Free the memory allocated for test buffer */ |
| free(tst_buff); |
| |
| /* Make sure proper permissions set on file */ |
| if (fchmod(fildes, 0444) < 0) { |
| tst_brkm(TFAIL | TERRNO, cleanup, "fchmod of %s failed", |
| TEMPFILE); |
| } |
| |
| /* Close the temporary file opened for write */ |
| if (close(fildes) < 0) { |
| tst_brkm(TFAIL | TERRNO, cleanup, "closing %s failed", |
| TEMPFILE); |
| } |
| |
| /* Open the temporary file again for reading */ |
| if ((fildes = open(TEMPFILE, O_RDONLY)) < 0) { |
| tst_brkm(TFAIL | TERRNO, cleanup, "opening %s readonly failed", |
| TEMPFILE); |
| } |
| } |
| |
| /* |
| * sig_handler() - Signal Catching function. |
| * This function gets executed when the test process receives |
| * the signal SIGSEGV while trying to access the contents of memory which |
| * is not accessible. |
| */ |
| static void sig_handler(int sig) |
| { |
| if (sig == SIGSEGV) { |
| /* set the global variable and jump back */ |
| pass = 1; |
| siglongjmp(env, 1); |
| } else { |
| tst_brkm(TBROK, cleanup, "received an unexpected signal: %d", |
| sig); |
| } |
| } |
| |
| static void cleanup(void) |
| { |
| close(fildes); |
| tst_rmdir(); |
| } |