Current kernel (v3.10) or older has a problem on no resv mapping.
If there is a region with MAP_SHARED and MAP_NORESERVE, it is considered
to have reserved pages. So reserved page can be stolen by no resv mapping.
This test case is to detect this situation.
Signed-off-by: Joonsoo Kim <iamjoonsoo....@lge.com>
diff --git a/tests/Makefile b/tests/Makefile
index 7d28c7d..43afe5c 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -13,7 +13,7 @@ LIB_TESTS = gethugepagesize test_root find_path unlinked_fd
misalign \
shm-perms \
mremap-expand-slice-collision \
mremap-fixed-normal-near-huge mremap-fixed-huge-near-normal \
- corrupt-by-cow-opt
+ corrupt-by-cow-opt noresv-preserve-resv-page
LIB_TESTS_64 =
LIB_TESTS_64_STATIC = straddle_4GB huge_at_4GB_normal_below \
huge_below_4GB_normal_above
diff --git a/tests/noresv-preserve-resv-page.c
b/tests/noresv-preserve-resv-page.c
new file mode 100644
index 0000000..54a1e7b
--- /dev/null
+++ b/tests/noresv-preserve-resv-page.c
@@ -0,0 +1,109 @@
+/*
+ * libhugetlbfs - Easy use of Linux hugepages
+ * Copyright (C) 2013 Joonsoo Kim, LG Electronics.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <signal.h>
+#include <setjmp.h>
+#include <sys/mman.h>
+#include <hugetlbfs.h>
+#include "hugetests.h"
+
+#define P "noresv-preserve-resv-page"
+#define DESC \
+ "* Test to preserve a reserved page against no-reserved maping. *\n"\
+ "* If all hugepages are reserved, access to no-reserved shared *\n"\
+ "* mapping cause a process die, instead of stealing a hugepage *\n"\
+ "* which is reserved for other process *\n"
+
+static sigjmp_buf sig_escape;
+static void *sig_expected = MAP_FAILED;
+
+static void sig_handler(int signum, siginfo_t *si, void *uc)
+{
+ if (signum == SIGBUS) {
+ verbose_printf("SIGBUS at %p (sig_expected=%p)\n", si->si_addr,
+ sig_expected);
+ if (si->si_addr == sig_expected) {
+ siglongjmp(sig_escape, 1);
+ }
+ FAIL("SIGBUS somewhere unexpected");
+ }
+ FAIL("Unexpected signal %s", strsignal(signum));
+}
+
+static void test_write(void *p)
+{
+ volatile char *pl = p;
+
+ if (sigsetjmp(sig_escape, 1)) {
+ /* We got a SIGBUS */
+ PASS();
+ }
+
+ sig_expected = p;
+ barrier();
+ *pl = 's';
+}
+
+int main(int argc, char *argv[])
+{
+ long hpage_size;
+ int nr_hugepages;
+ int fd1, fd2, err;
+ char *p, *q;
+ struct sigaction sa = {
+ .sa_sigaction = sig_handler,
+ .sa_flags = SA_SIGINFO,
+ };
+
+ test_init(argc, argv);
+
+ hpage_size = check_hugepagesize();
+ nr_hugepages = get_huge_page_counter(hpage_size, HUGEPAGES_FREE);
+
+ fd1 = hugetlbfs_unlinked_fd();
+ if (fd1 < 0)
+ FAIL("hugetlbfs_unlinked_fd()");
+
+ fd2 = hugetlbfs_unlinked_fd();
+ if (fd2 < 0)
+ FAIL("hugetlbfs_unlinked_fd()");
+
+ err = sigaction(SIGBUS, &sa, NULL);
+ if (err)
+ FAIL("Can't install SIGBUS handler: %s", strerror(errno));
+
+ p = mmap(NULL, hpage_size * nr_hugepages,
+ PROT_READ | PROT_WRITE, MAP_SHARED, fd1, 0);
+ if (p == MAP_FAILED)
+ FAIL("mmap() 1: %s", strerror(errno));
+
+ verbose_printf("Reserve all hugepages %d\n", nr_hugepages);
+
+ q = mmap(NULL, hpage_size,
+ PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NORESERVE, fd2, 0);
+ if (q == MAP_FAILED)
+ FAIL("mmap() 2: %s", strerror(errno));
+
+ verbose_printf("Write %c to %p to steal reserved page\n", *q, q);
+
+ test_write(q);
+ FAIL("Steal reserved page");
+}
diff --git a/tests/run_tests.py b/tests/run_tests.py
index 9570547..98d233e 100755
--- a/tests/run_tests.py
+++ b/tests/run_tests.py
@@ -537,6 +537,7 @@ def functional_tests():
do_test("task-size-overrun")
do_test_with_rlimit(resource.RLIMIT_STACK, -1, "stack_grow_into_huge")
do_test("corrupt-by-cow-opt")
+ do_test("noresv-preserve-resv-page")
if dangerous == 1:
do_test("readahead_reserve")
--
1.7.9.5
------------------------------------------------------------------------------
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