@@ -1,6 +1,8 @@
hugefallocate01 hugefallocate01
hugefallocate02 hugefallocate02
+hugefork01 hugefork01
+
hugemmap01 hugemmap01
hugemmap02 hugemmap02
hugemmap04 hugemmap04
@@ -1,6 +1,7 @@
/cpuset/cpuset01
/hugetlb/hugefallocate/hugefallocate01
/hugetlb/hugefallocate/hugefallocate02
+/hugetlb/hugefork/hugefork01
/hugetlb/hugemmap/hugemmap01
/hugetlb/hugemmap/hugemmap02
/hugetlb/hugemmap/hugemmap04
new file mode 100644
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2009, Cisco Systems Inc.
+# Ngie Cooper, July 2009
+
+top_srcdir ?= ../../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+include $(abs_srcdir)/../Makefile.inc
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
+
new file mode 100644
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ * Copyright (C) 2008 David Gibson, IBM Corporation.
+ * Author: David Gibson
+ */
+
+/*\
+ * [Description]
+ *
+ * This checks copy-on-write semantics, specifically the semantics of a
+ * MAP_PRIVATE mapping across a fork(). Some versions of the powerpc
+ * kernel had a bug in huge_ptep_set_wrprotect() which would fail to
+ * flush the hash table after setting the write protect bit in the parent's
+ * page tables, thus allowing the parent to pollute the child's mapping.
+ *
+ */
+
+#include <sys/wait.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+#include "hugetlb.h"
+
+#define C1 0x1234ABCD
+#define C2 ~0x1234ABCD
+#define C3 0xfeef5678
+#define MNTPOINT "hugetlbfs/"
+static int fd = -1;
+static long hpage_size;
+
+static void run_test(void)
+{
+ volatile unsigned int *p;
+ int parent_readback;
+ pid_t pid;
+
+ p = SAFE_MMAP(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
+ *p = C1;
+
+ pid = SAFE_FORK();
+ if (pid != 0) {
+ *p = C2;
+ TST_CHECKPOINT_WAKE_AND_WAIT(0);
+ parent_readback = *p;
+ TST_CHECKPOINT_WAKE(0);
+ } else {
+ unsigned int child_readback = 0;
+
+ TST_CHECKPOINT_WAIT(0);
+ child_readback = *p;
+ *p = C3;
+ TST_CHECKPOINT_WAKE_AND_WAIT(0);
+ TST_EXP_EXPR(child_readback == C1, "0x%x == child_readback (0x%x)",
+ C1, child_readback);
+ exit(0);
+ }
+ tst_reap_children();
+ TST_EXP_EXPR(parent_readback == C2, "0x%x == parent_readback (0x%x)",
+ C2, parent_readback);
+
+ SAFE_MUNMAP((void *)p, hpage_size);
+}
+
+static void setup(void)
+{
+ hpage_size = SAFE_READ_MEMINFO("Hugepagesize:")*1024;
+ fd = tst_creat_unlinked(MNTPOINT, 0);
+}
+
+static void cleanup(void)
+{
+ if (fd > 0)
+ SAFE_CLOSE(fd);
+}
+
+static struct tst_test test = {
+ .tags = (struct tst_tag[]) {
+ {"linux-git", "86df86424939"},
+ {}
+ },
+ .needs_root = 1,
+ .needs_checkpoints = 1,
+ .mntpoint = MNTPOINT,
+ .needs_hugetlbfs = 1,
+ .forks_child = 1,
+ .setup = setup,
+ .cleanup = cleanup,
+ .test_all = run_test,
+ .hugepages = {2, TST_NEEDS},
+};
Migrating the libhugetlbfs/testcases/fork-cow.c test Test Description: This checks copy-on-write semantics, specifically the semantics of a MAP_PRIVATE mapping across a fork(). Some versions of the powerpc kernel had a bug in huge_ptep_set_wrprotect() which would fail to flush the hash table after setting the write protect bit in the parent's page tables, thus allowing the parent to pollute the child's mapping. Signed-off-by: Tarun Sahu <tsahu@linux.ibm.com> --- runtest/hugetlb | 2 + testcases/kernel/mem/.gitignore | 1 + .../kernel/mem/hugetlb/hugefork/Makefile | 10 ++ .../kernel/mem/hugetlb/hugefork/hugefork01.c | 92 +++++++++++++++++++ 4 files changed, 105 insertions(+) create mode 100644 testcases/kernel/mem/hugetlb/hugefork/Makefile create mode 100644 testcases/kernel/mem/hugetlb/hugefork/hugefork01.c