Module Name: src
Committed By: gson
Date: Wed Apr 6 10:02:55 UTC 2022
Modified Files:
src/tests/lib/libc/sys: Makefile t_mmap.c
Log Message:
Add a regression test for PR kern/52239, "Changing protections of
already mmap'ed region can fail", based on the test program in the PR.
To generate a diff of this commit:
cvs rdiff -u -r1.70 -r1.71 src/tests/lib/libc/sys/Makefile
cvs rdiff -u -r1.16 -r1.17 src/tests/lib/libc/sys/t_mmap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/tests/lib/libc/sys/Makefile
diff -u src/tests/lib/libc/sys/Makefile:1.70 src/tests/lib/libc/sys/Makefile:1.71
--- src/tests/lib/libc/sys/Makefile:1.70 Mon Nov 1 14:33:41 2021
+++ src/tests/lib/libc/sys/Makefile Wed Apr 6 10:02:55 2022
@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.70 2021/11/01 14:33:41 hannken Exp $
+# $NetBSD: Makefile,v 1.71 2022/04/06 10:02:55 gson Exp $
MKMAN= no
@@ -97,6 +97,7 @@ SRCS.t_mprotect= t_mprotect.c ${SRCS_EXE
LDADD.t_eventfd+= -lpthread
LDADD.t_getpid+= -lpthread
+LDADD.t_mmap+= -lpthread
LDADD.t_timerfd+= -lpthread
LDADD.t_ptrace_sigchld+= -pthread -lm
Index: src/tests/lib/libc/sys/t_mmap.c
diff -u src/tests/lib/libc/sys/t_mmap.c:1.16 src/tests/lib/libc/sys/t_mmap.c:1.17
--- src/tests/lib/libc/sys/t_mmap.c:1.16 Tue Apr 5 15:59:22 2022
+++ src/tests/lib/libc/sys/t_mmap.c Wed Apr 6 10:02:55 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: t_mmap.c,v 1.16 2022/04/05 15:59:22 gson Exp $ */
+/* $NetBSD: t_mmap.c,v 1.17 2022/04/06 10:02:55 gson Exp $ */
/*-
* Copyright (c) 2011 The NetBSD Foundation, Inc.
@@ -55,7 +55,7 @@
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
-__RCSID("$NetBSD: t_mmap.c,v 1.16 2022/04/05 15:59:22 gson Exp $");
+__RCSID("$NetBSD: t_mmap.c,v 1.17 2022/04/06 10:02:55 gson Exp $");
#include <sys/param.h>
#include <sys/disklabel.h>
@@ -74,6 +74,7 @@ __RCSID("$NetBSD: t_mmap.c,v 1.16 2022/0
#include <string.h>
#include <unistd.h>
#include <paths.h>
+#include <pthread.h>
static long page = 0;
static char path[] = "mmap";
@@ -413,6 +414,65 @@ ATF_TC_CLEANUP(mmap_prot_3, tc)
(void)unlink(path);
}
+ATF_TC(mmap_reprotect_race);
+
+ATF_TC_HEAD(mmap_reprotect_race, tc)
+{
+ atf_tc_set_md_var(tc, "descr", "Test for the race condition of PR 52239");
+}
+
+const int mmap_reprotect_race_npages = 13;
+const int mmap_reprotect_iterations = 1000000;
+
+static void *
+mmap_reprotect_race_thread(void *arg)
+{
+ int i, r;
+ void *p;
+
+ for (i = 0; i < mmap_reprotect_iterations; i++) {
+ /* Get some unrelated memory */
+ p = mmap(0, mmap_reprotect_race_npages * page,
+ PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
+ ATF_REQUIRE(p);
+ r = munmap(p, mmap_reprotect_race_npages * page);
+ ATF_REQUIRE(r == 0);
+ }
+ return 0;
+}
+
+ATF_TC_BODY(mmap_reprotect_race, tc)
+{
+ pthread_t thread;
+ void *p, *q;
+ int i, r;
+
+ r = pthread_create(&thread, 0, mmap_reprotect_race_thread, 0);
+ ATF_REQUIRE(r == 0);
+
+ for (i = 0; i < mmap_reprotect_iterations; i++) {
+ /* Get a placeholder region */
+ p = mmap(0, mmap_reprotect_race_npages * page,
+ PROT_NONE, MAP_ANON|MAP_PRIVATE, -1, 0);
+ if (p == MAP_FAILED)
+ atf_tc_fail("mmap: %s", strerror(errno));
+
+ /* Upgrade placeholder to read/write access */
+ q = mmap(p, mmap_reprotect_race_npages * page,
+ PROT_READ|PROT_WRITE,
+ MAP_ANON|MAP_PRIVATE|MAP_FIXED, -1, 0);
+ if (q == MAP_FAILED)
+ atf_tc_fail("update mmap: %s", strerror(errno));
+ ATF_REQUIRE(q == p);
+
+ /* Free it */
+ r = munmap(q, mmap_reprotect_race_npages * page);
+ if (r != 0)
+ atf_tc_fail("munmap: %s", strerror(errno));
+ }
+ pthread_join(thread, NULL);
+}
+
ATF_TC_WITH_CLEANUP(mmap_truncate);
ATF_TC_HEAD(mmap_truncate, tc)
{
@@ -570,6 +630,7 @@ ATF_TP_ADD_TCS(tp)
ATF_TP_ADD_TC(tp, mmap_prot_1);
ATF_TP_ADD_TC(tp, mmap_prot_2);
ATF_TP_ADD_TC(tp, mmap_prot_3);
+ ATF_TP_ADD_TC(tp, mmap_reprotect_race);
ATF_TP_ADD_TC(tp, mmap_truncate);
ATF_TP_ADD_TC(tp, mmap_truncate_signal);
ATF_TP_ADD_TC(tp, mmap_va0);
