[LTP] [PATCH v3] Refactor fork14 using new LTP API
Andrea Cervesato
andrea.cervesato@suse.de
Tue Mar 12 16:48:47 CET 2024
From: Andrea Cervesato <andrea.cervesato@suse.com>
Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
SAFE_MMAP() usage
Check if memvec is NULL before munmap() and free()
testcases/kernel/syscalls/fork/fork14.c | 197 ++++++++++--------------
1 file changed, 81 insertions(+), 116 deletions(-)
diff --git a/testcases/kernel/syscalls/fork/fork14.c b/testcases/kernel/syscalls/fork/fork14.c
index 93af2ebac..a1cf13c3e 100644
--- a/testcases/kernel/syscalls/fork/fork14.c
+++ b/testcases/kernel/syscalls/fork/fork14.c
@@ -1,143 +1,108 @@
-/*********************************************************************
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
* Copyright (C) 2014 Red Hat, Inc.
+ * Copyright (C) 2023 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * [Description]
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- *
- * Further, this software is distributed without any warranty that it
- * is free of the rightful claim of any third person regarding
- * infringement or the like. Any license provided herein, whether
- * implied or otherwise, applies only to this software file. Patent
- * licenses, if any, provided herein do not apply to combinations of
- * this program with other software, or any other product whatsoever.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
- *
- * This test is a reporducer for this patch:
- * https://lkml.org/lkml/2012/4/24/328
+ * This test is a reporducer for this patch: https://lkml.org/lkml/2012/4/24/328
* Since vma length in dup_mmap is calculated and stored in a unsigned
* int, it will overflow when length of mmaped memory > 16 TB. When
- * overflow occur, fork will incorrectly succeed. The patch above
- * fixed it.
- ********************************************************************/
+ * overflow occur, fork will incorrectly succeed. The patch above fixed it.
+ */
-#include <sys/mman.h>
-#include <sys/wait.h>
-#include <stdio.h>
-#include <unistd.h>
-#include "test.h"
-#include "safe_macros.h"
-#include "lapi/abisize.h"
+#include "tst_test.h"
-char *TCID = "fork14";
-int TST_TOTAL = 1;
+#ifndef TST_ABI32
-#define GB (1024 * 1024 * 1024L)
+#include <stdlib.h>
+#include <sys/wait.h>
-/* set mmap threshold to 16TB */
#define LARGE (16 * 1024)
#define EXTENT (16 * 1024 + 10)
-static char **pointer_vec;
-
-static void setup(void);
-static void cleanup(void);
-static int fork_test(void);
+static char **memvec;
-int main(int ac, char **av)
+static void run(void)
{
- int lc, reproduced;
-
- tst_parse_opts(ac, av, NULL, NULL);
-/*
- * Tested on ppc64/x86_64/i386/s390x. And only 64bit has this issue.
- * Since a 32bit program can't mmap so many memory.
- */
-#ifdef TST_ABI32
- tst_brkm(TCONF, NULL, "This test is only for 64bit.");
-#endif
- setup();
- for (lc = 0; TEST_LOOPING(lc); lc++) {
- tst_count = 0;
+ int i, j, ret;
+ pid_t pid;
+ void *mem;
+ int prev_failed = 0;
+ int passed = 1;
- reproduced = fork_test();
- if (reproduced == 0)
- tst_resm(TPASS, "fork failed as expected.");
- }
- cleanup();
- tst_exit();
-}
+ for (i = 0; i < EXTENT; i++) {
+ mem = SAFE_MMAP(NULL, 1 * TST_GB,
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS,
+ 0, 0);
-static void setup(void)
-{
- tst_sig(FORK, DEF_HANDLER, cleanup);
- TEST_PAUSE;
+ memvec[i] = mem;
- pointer_vec = SAFE_MALLOC(cleanup, EXTENT * sizeof(char *));
-}
+ pid = fork();
-static void cleanup(void)
-{
- free(pointer_vec);
-}
-
-static int fork_test(void)
-{
- int i, j, prev_failed = 0, fails = 0, cnt = 0;
- int reproduced = 0;
- void *addr;
-
- for (i = 0; i < EXTENT; i++) {
- addr = mmap(NULL, 1 * GB, PROT_READ | PROT_WRITE,
- MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
- if (addr == MAP_FAILED) {
- pointer_vec[i] = NULL;
- fails++;
- /*
- * EXTENT is "16*1024+10", if fails count exceeds 10,
- * we are almost impossible to get an vm_area_struct
- * sized 16TB
+ if (pid == -1) {
+ /* keep track of the failed fork() and verify that next one
+ * is failing as well.
*/
- if (fails == 11) {
- tst_brkm(TCONF, cleanup, "mmap() fails too many"
- "times, so we are almost impossible to"
- " get an vm_area_struct sized 16TB.");
- }
- } else {
- pointer_vec[i] = addr;
+ prev_failed = 1;
+ continue;
}
- cnt++;
- switch (tst_fork()) {
- case -1:
- prev_failed = 1;
- break;
- case 0:
+ if (!pid)
exit(0);
- default:
- SAFE_WAITPID(cleanup, -1, NULL, 0);
-
- if (prev_failed > 0 && i >= LARGE) {
- tst_resm(TFAIL, "Fork succeeds incorrectly");
- reproduced = 1;
- goto clear_memory_map;
- }
+
+ ret = waitpid(pid, NULL, 0);
+ if (ret == -1 && errno != ECHILD)
+ tst_brk(TBROK | TERRNO, "waitpid() error");
+
+ if (prev_failed && i >= LARGE) {
+ passed = 0;
+ break;
}
+
+ prev_failed = 0;
+
+ tst_res(TINFO, "fork() passed at %d attempt", i);
}
-clear_memory_map:
- for (j = 0; j < cnt; j++) {
- if (pointer_vec[j])
- SAFE_MUNMAP(cleanup, pointer_vec[j], 1 * GB);
+ for (j = 0; j < i; j++) {
+ if (memvec[j])
+ SAFE_MUNMAP(memvec[j], 1 * TST_GB);
}
- return reproduced;
+ if (passed)
+ tst_res(TPASS, "fork() failed as expected");
+ else
+ tst_res(TFAIL, "fork() succeeded incorrectly");
}
+
+static void setup(void)
+{
+ memvec = SAFE_MALLOC(EXTENT * sizeof(char *));
+ memset(memvec, 0, EXTENT);
+}
+
+static void cleanup(void)
+{
+ for (long i = 0; i < EXTENT; i++) {
+ if (memvec && memvec[i])
+ SAFE_MUNMAP(memvec[i], 1 * TST_GB);
+ }
+
+ if (memvec)
+ free(memvec);
+}
+
+static struct tst_test test = {
+ .test_all = run,
+ .setup = setup,
+ .cleanup = cleanup,
+ .forks_child = 1,
+};
+
+#else /* TST_ABI32 */
+ TST_TEST_TCONF("Test doesn't supports 32bits architecture");
+#endif
--
2.35.3
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