[LTP] [PATCH] syscalls/mmap04: Validate mapping perms in /proc/self/maps
Avinesh Kumar
akumar@suse.de
Tue Sep 5 11:54:10 CEST 2023
Validating the various combinations of prot+flags arguments in mmap()
call and parsing the /proc/self/maps file to verifying resulting mapping
has the permission bits as requested in mmap() call.
Signed-off-by: Avinesh Kumar <akumar@suse.de>
---
testcases/kernel/syscalls/mmap/mmap04.c | 274 ++++++++----------------
1 file changed, 89 insertions(+), 185 deletions(-)
rewrite testcases/kernel/syscalls/mmap/mmap04.c (97%)
diff --git a/testcases/kernel/syscalls/mmap/mmap04.c b/testcases/kernel/syscalls/mmap/mmap04.c
dissimilarity index 97%
index 43f7b7525..a15dfedbe 100644
--- a/testcases/kernel/syscalls/mmap/mmap04.c
+++ b/testcases/kernel/syscalls/mmap/mmap04.c
@@ -1,185 +1,89 @@
-/*
- * 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 a mapped region with read/exec access
- * under the following conditions -
- * - The prot parameter is set to PROT_READ|PROT_EXEC
- * - The file descriptor is open for read
- * - The file being mapped has read and execute permission bit set.
- * - The minimum file permissions should be 0555.
- *
- * 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 the mapped region should contain the contents of the mapped file.
- *
- * 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 "test.h"
-
-#define TEMPFILE "mmapfile"
-
-char *TCID = "mmap04";
-int TST_TOTAL = 1;
-
-static size_t page_sz;
-static char *addr;
-static char *dummy;
-static int fildes;
-
-static void setup(void);
-static void cleanup(void);
-
-int main(int ac, char **av)
-{
- int lc;
-
- tst_parse_opts(ac, av, NULL, NULL);
-
- setup();
-
- for (lc = 0; TEST_LOOPING(lc); lc++) {
-
- tst_count = 0;
-
- /*
- * Call mmap to map the temporary file 'TEMPFILE'
- * with read and execute access.
- */
- errno = 0;
- addr = mmap(0, page_sz, PROT_READ | PROT_EXEC,
- MAP_FILE | MAP_SHARED, fildes, 0);
-
- /* Check for the return value of mmap() */
- if (addr == MAP_FAILED) {
- tst_resm(TFAIL | TERRNO, "mmap of %s failed", TEMPFILE);
- continue;
- }
-
- /*
- * Read the file contents into the dummy
- * variable.
- */
- if (read(fildes, dummy, page_sz) < 0) {
- tst_brkm(TFAIL, cleanup, "reading %s failed",
- TEMPFILE);
- }
-
- /*
- * Check whether the mapped memory region
- * has the file contents.
- */
- if (memcmp(dummy, addr, page_sz)) {
- tst_resm(TFAIL,
- "mapped memory region contains invalid "
- "data");
- } else {
- tst_resm(TPASS,
- "Functionality of mmap() successful");
- }
-
- /* Clean up things in case we are looping. */
- /* Unmap the mapped memory */
- if (munmap(addr, page_sz) != 0) {
- tst_brkm(TFAIL, cleanup, "munmapping failed");
- }
- }
-
- cleanup();
- tst_exit();
-}
-
-static void setup(void)
-{
- char *tst_buff;
-
- tst_sig(NOFORK, DEF_HANDLER, cleanup);
-
- TEST_PAUSE;
-
- page_sz = getpagesize();
-
- 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, cleanup, "opening %s failed", TEMPFILE);
- }
-
- /* Write test buffer contents into temporary file */
- if (write(fildes, tst_buff, page_sz) < (ssize_t)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, 0555) < 0) {
- tst_brkm(TFAIL, cleanup, "fchmod of %s failed", TEMPFILE);
- }
-
- /* Close the temporary file opened for write */
- if (close(fildes) < 0) {
- tst_brkm(TFAIL, cleanup, "closing %s failed", TEMPFILE);
- }
-
- /* Allocate and initialize dummy string of system page size bytes */
- if ((dummy = calloc(page_sz, sizeof(char))) == NULL) {
- tst_brkm(TFAIL, cleanup, "calloc failed (dummy)");
- }
-
- /* Open the temporary file again for reading */
- if ((fildes = open(TEMPFILE, O_RDONLY)) < 0) {
- tst_brkm(TFAIL, cleanup,
- "opening %s read-only failed", TEMPFILE);
- }
-}
-
-static void cleanup(void)
-{
- close(fildes);
- free(dummy);
- tst_rmdir();
-}
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) International Business Machines Corp., 2001
+ * 07/2001 Ported by Wayne Boyer
+ * Copyright (c) 2023 SUSE LLC Avinesh Kumar <avinesh.kumar@suse.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * Verify that, after a successful mmap() call, permission bits of the new
+ * mapping in /proc/pid/maps file matches the prot and flags arguments in
+ * mmap() call.
+ */
+
+#include "tst_test.h"
+#include "tst_safe_stdio.h"
+
+#define MMAPSIZE 1024
+static char *addr;
+
+static struct tcase {
+ int prot;
+ int flags;
+ char *exp_perms;
+} tcases[] = {
+ {PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, "---p"},
+ {PROT_NONE, MAP_ANONYMOUS | MAP_SHARED, "---s"},
+ {PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, "r--p"},
+ {PROT_READ, MAP_ANONYMOUS | MAP_SHARED, "r--s"},
+ {PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, "-w-p"},
+ {PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, "-w-s"},
+ {PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, "rw-p"},
+ {PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, "rw-s"},
+ {PROT_READ | PROT_EXEC, MAP_ANONYMOUS | MAP_PRIVATE, "r-xp"},
+ {PROT_READ | PROT_EXEC, MAP_ANONYMOUS | MAP_SHARED, "r-xs"},
+ {PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_PRIVATE, "-wxp"},
+ {PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_SHARED, "-wxs"},
+ {PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_PRIVATE, "rwxp"},
+ {PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_SHARED, "rwxs"}
+};
+
+static void get_map_perms(char *addr_str, char *perms)
+{
+ FILE *file;
+ char line[BUFSIZ];
+
+ file = SAFE_FOPEN("/proc/self/maps", "r");
+
+ while (fgets(line, sizeof(line), file)) {
+ if (strstr(line, addr_str) != NULL) {
+ if (sscanf(line, "%*x-%*x %s", perms) != 1)
+ tst_brk(TBROK, "failed to find permission string in %s", line);
+ break;
+ }
+ }
+
+ SAFE_FCLOSE(file);
+ file = NULL;
+}
+
+static void run(unsigned int i)
+{
+ struct tcase *tc = &tcases[i];
+ char addr_str[20];
+ char perms[8];
+
+ addr = SAFE_MMAP(NULL, MMAPSIZE, tc->prot, tc->flags, -1, 0);
+
+ sprintf(addr_str, "%p", addr);
+ if (sscanf(addr_str, "0x%s", addr_str) != 1)
+ tst_brk(TBROK, "failed to find address string");
+
+ get_map_perms(addr_str, perms);
+
+ if (!strcmp(perms, tc->exp_perms))
+ tst_res(TPASS, "mapping permissions in /proc matched: %s", perms);
+ else
+ tst_res(TFAIL, "mapping permissions in /proc mismatched,"
+ " expected: %s, found: %s",
+ tc->exp_perms, perms);
+
+ SAFE_MUNMAP(addr, MMAPSIZE);
+}
+
+static struct tst_test test = {
+ .test = run,
+ .tcnt = ARRAY_SIZE(tcases),
+};
--
2.41.0
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