@@ -74,6 +74,7 @@ AC_CHECK_FUNCS([ \
pidfd_send_signal \
preadv \
preadv2 \
+ pkey_mprotect \
profil \
pwritev \
pwritev2 \
@@ -721,6 +721,8 @@ mprotect02 mprotect02
mprotect03 mprotect03
mprotect04 mprotect04
+pkey01 pkey01
+
mq_notify01 mq_notify01
mq_notify02 mq_notify02
mq_open01 mq_open01
new file mode 100644
@@ -0,0 +1 @@
+/pkey01
new file mode 100644
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2019 Red Hat, Inc.
+
+top_srcdir ?= ../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
new file mode 100644
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 Red Hat, Inc.
+ */
+
+#ifndef PKEYS_H
+#define PKEYS_H
+
+#include "tst_test.h"
+#include "lapi/syscalls.h"
+
+#ifndef PKEY_DISABLE_ACCESS
+# define PKEY_DISABLE_ACCESS 0x1
+# define PKEY_DISABLE_WRITE 0x2
+#endif
+
+#ifndef HAVE_PKEY_MPROTECT
+static inline int pkey_mprotect(void *addr, size_t len, int prot, int pkey)
+{
+ return tst_syscall(SYS_pkey_mprotect, addr, len, prot, pkey);
+}
+
+static inline int pkey_alloc(unsigned int flags, unsigned int access_rights)
+{
+ return tst_syscall(SYS_pkey_alloc, flags, access_rights);
+}
+
+static inline int pkey_free(int pkey)
+{
+ return tst_syscall(SYS_pkey_free, pkey);
+}
+#endif /* HAVE_PKEY_MPROTECT */
+
+static inline void check_pkey_support(void)
+{
+ int pkey = pkey_alloc(0, 0);
+
+ if (pkey == -1) {
+ if (errno == ENOSYS)
+ tst_brk(TCONF, "pkey_alloc is not implemented");
+ if (errno == EINVAL)
+ tst_brk(TCONF, "pku is not supported on this CPU");
+ if (errno == ENOSPC)
+ tst_brk(TCONF, "pkeys are not available for test");
+ }
+
+ pkey_free(pkey);
+}
+
+#endif /* PKEYS_H */
new file mode 100644
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 Red Hat, Inc.
+ *
+ * Memory Protection Keys for Userspace (PKU aka PKEYs) is a Skylake-SP
+ * server feature that provides a mechanism for enforcing page-based
+ * protections, but without requiring modification of the page tables
+ * when an application changes protection domains. It works by dedicating
+ * 4 previously ignored bits in each page table entry to a "protection key",
+ * giving 16 possible keys.
+ *
+ * Test for Memory Protection Keys:
+ * 1. test allocates a pkey(e.g. PKEY_DISABLE_ACCESS) via pkey_alloc()
+ * 2. pkey_mprotect() apply this pkey to a piece of shared memory(buffer)
+ * 3. check if access right of the buffer has been changed and take effect
+ * 4. remove the access right(pkey) from this buffer via pkey_mprotect()
+ * 5. check if buffer area can be read or write after removing pkey
+ * 6. pkey_free() releases the pkey after using it
+ *
+ * Reference: https://lwn.net/Articles/689395/
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/syscall.h>
+#include <sys/mman.h>
+#include <sys/wait.h>
+
+#include "pkey.h"
+
+static int psize;
+static char *buffer;
+
+static struct tcase {
+ unsigned long flags;
+ unsigned long access_rights;
+ char *name;
+} tcases[] = {
+ {0, PKEY_DISABLE_ACCESS, "PKEY_DISABLE_ACCESS"},
+ {0, PKEY_DISABLE_WRITE, "PKEY_DISABLE_WRITE"},
+};
+
+static void setup(void)
+{
+ check_pkey_support();
+
+ psize = getpagesize();
+ buffer = SAFE_MMAP(NULL, psize, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_SHARED, -1, 0);
+ memset(buffer, 'a', psize);
+}
+
+static void verify_pkey(unsigned int i)
+{
+ int pkey, status;
+ pid_t pid;
+
+ struct tcase *tc = &tcases[i];
+
+ pkey = pkey_alloc(tc->flags, tc->access_rights);
+ if (pkey == -1)
+ tst_brk(TBROK, "pkey_alloc failed");
+
+ tst_res(TINFO, "Set %s on buffer", tc->name);
+ if (pkey_mprotect(buffer, psize, PROT_READ | PROT_WRITE, pkey) == -1)
+ tst_brk(TBROK, "pkey_mprotect failed");
+
+ pid = SAFE_FORK();
+ if (pid == 0) {
+ /* Children crash are expected, avoid dumping corefile */
+ struct rlimit r;
+
+ r.rlim_cur = 1;
+ r.rlim_max = 1;
+ SAFE_SETRLIMIT(RLIMIT_CORE, &r);
+
+ switch (tc->access_rights) {
+ case PKEY_DISABLE_ACCESS:
+ tst_res(TFAIL, "Read buffer success, buffer[0] = %d", *buffer);
+ break;
+ case PKEY_DISABLE_WRITE:
+ *buffer = 'b';
+ break;
+ }
+ exit(0);
+ }
+
+ SAFE_WAITPID(pid, &status, 0);
+ if (WIFSIGNALED(status)) {
+ if (WTERMSIG(status) == SIGSEGV) {
+ tst_res(TPASS, "Child ended by %s as expected",
+ tst_strsig(SIGSEGV));
+ } else {
+ tst_res(TFAIL, "Child ended by %s unexpected" ,
+ tst_strsig(WTERMSIG(status)));
+ }
+ } else {
+ tst_res(TFAIL, "Child unexpectedly ended");
+ }
+
+ tst_res(TINFO, "Remove %s from buffer", tc->name);
+ if (pkey_mprotect(buffer, psize, PROT_READ | PROT_WRITE, 0x0) == -1)
+ tst_brk(TBROK, "pkey_mprotect failed");
+ *buffer = i;
+ tst_res(TPASS, "Write buffer success, buffer[0] = %d", *buffer);
+
+ if (pkey_free(pkey) == -1)
+ tst_brk(TBROK, "pkey_free failed");
+}
+
+static void cleanup(void)
+{
+ if (buffer)
+ SAFE_MUNMAP(buffer, psize);
+}
+
+static struct tst_test test = {
+ .tcnt = ARRAY_SIZE(tcases),
+ .forks_child = 1,
+ .test = verify_pkey,
+ .setup = setup,
+ .cleanup = cleanup,
+};
Memory Protection Keys for Userspace (PKU aka PKEYs) is a Skylake-SP server feature that provides a mechanism for enforcing page-based protections, but without requiring modification of the page tables when an application changes protection domains. It works by dedicating 4 previously ignored bits in each page table entry to a "protection key", giving 16 possible keys. Test for Memory Protection Keys: 1. test allocates a pkey(e.g. PKEY_DISABLE_ACCESS) via pkey_alloc() 2. pkey_mprotect() apply this pkey to a piece of shared memory(buffer) 3. check if the access right of buffer has been changed and take effect 4. remove the access right(pkey) from this buffer via pkey_mprotect() 5. check if buffer area can be read or write after removing pkey 6. pkey_free() releases the pkey after using it Signed-off-by: Li Wang <liwang@redhat.com> --- configure.ac | 1 + runtest/syscalls | 2 + testcases/kernel/syscalls/pkeys/.gitignore | 1 + testcases/kernel/syscalls/pkeys/Makefile | 8 ++ testcases/kernel/syscalls/pkeys/pkey.h | 50 ++++++++ testcases/kernel/syscalls/pkeys/pkey01.c | 126 +++++++++++++++++++++ 6 files changed, 188 insertions(+) create mode 100644 testcases/kernel/syscalls/pkeys/.gitignore create mode 100644 testcases/kernel/syscalls/pkeys/Makefile create mode 100644 testcases/kernel/syscalls/pkeys/pkey.h create mode 100644 testcases/kernel/syscalls/pkeys/pkey01.c