diff options
Diffstat (limited to 'tests/sys/vm/mlock_test.c')
| -rw-r--r-- | tests/sys/vm/mlock_test.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/tests/sys/vm/mlock_test.c b/tests/sys/vm/mlock_test.c new file mode 100644 index 000000000000..8c8ce4a2e8de --- /dev/null +++ b/tests/sys/vm/mlock_test.c @@ -0,0 +1,286 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2019 Mark Johnston <markj@FreeBSD.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +#include <sys/mman.h> +#include <sys/ptrace.h> +#include <sys/resource.h> +#include <sys/wait.h> + +#include <errno.h> +#include <fcntl.h> +#include <signal.h> +#include <stdatomic.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <atf-c.h> + +static void +test_wired_copy_on_write(void *addr, size_t len) +{ + int status, val; + pid_t pid; + + pid = fork(); + if (pid == -1) + atf_tc_fail("fork() failed: %s", strerror(errno)); + if (pid == 0) { + if (mlock(addr, len) != 0) + _exit(1); + if (ptrace(PT_TRACE_ME, 0, NULL, 0) != 0) + _exit(2); + if (raise(SIGSTOP) != 0) + _exit(3); + if (munlock(addr, len) != 0) + _exit(4); + _exit(0); + } + + ATF_REQUIRE(waitpid(pid, &status, 0) == pid); + ATF_REQUIRE_MSG(!WIFEXITED(status), + "child exited with status %d", WEXITSTATUS(status)); + ATF_REQUIRE(WIFSTOPPED(status)); + ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP); + + errno = 0; + val = ptrace(PT_READ_D, pid, addr, 0); + ATF_REQUIRE(errno == 0); + ATF_REQUIRE(ptrace(PT_WRITE_D, pid, addr, val) == 0); + ATF_REQUIRE(ptrace(PT_CONTINUE, pid, (caddr_t)1, 0) == 0); + ATF_REQUIRE(waitpid(pid, &status, 0) == pid); + ATF_REQUIRE(WIFEXITED(status)); + ATF_REQUIRE_MSG(WEXITSTATUS(status) == 0, + "child exited with status %d", WSTOPSIG(status)); +} + +/* + * Use ptrace(2) to trigger a copy-on-write fault of anonymous memory. + */ +ATF_TC_WITHOUT_HEAD(mlock__copy_on_write_anon); +ATF_TC_BODY(mlock__copy_on_write_anon, tc) +{ + char *addr; + int len; + + len = getpagesize(); + addr = mmap(NULL, len, PROT_READ, MAP_ANON, -1, 0); + ATF_REQUIRE(addr != MAP_FAILED); + + test_wired_copy_on_write(addr, len); +} + +/* + * Use ptrace(2) to trigger a copy-on-write fault of a read-only text page. + */ +ATF_TC_WITHOUT_HEAD(mlock__copy_on_write_vnode); +ATF_TC_BODY(mlock__copy_on_write_vnode, tc) +{ + void *addr; + int len; + + len = getpagesize(); + addr = (void *)((uintptr_t)test_wired_copy_on_write & ~(len - 1)); + + test_wired_copy_on_write(addr, len); +} + +/* + * Try truncating and then resizing an mlock()ed mapping. + */ +ATF_TC_WITHOUT_HEAD(mlock__truncate_and_resize); +ATF_TC_BODY(mlock__truncate_and_resize, tc) +{ + char filename[16]; + char *addr; + int fd, i, len; + + snprintf(filename, sizeof(filename), "tmp.XXXXXX"); + fd = mkstemp(filename); + ATF_REQUIRE(fd >= 0); + ATF_REQUIRE(unlink(filename) == 0); + + len = getpagesize(); + ATF_REQUIRE(ftruncate(fd, len) == 0); + + addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + ATF_REQUIRE(addr != MAP_FAILED); + ATF_REQUIRE(mlock(addr, len) == 0); + memset(addr, 1, len); + ATF_REQUIRE(ftruncate(fd, 0) == 0); + ATF_REQUIRE(ftruncate(fd, len) == 0); + for (i = 0; i < len; i++) + ATF_REQUIRE(addr[i] == 0); + ATF_REQUIRE(munlock(addr, len) == 0); +} + +/* + * Make sure that we can munlock() a truncated mapping. + */ +ATF_TC_WITHOUT_HEAD(mlock__truncate_and_unlock); +ATF_TC_BODY(mlock__truncate_and_unlock, tc) +{ + char filename[16]; + void *addr; + int fd, len; + + snprintf(filename, sizeof(filename), "tmp.XXXXXX"); + fd = mkstemp(filename); + ATF_REQUIRE(fd >= 0); + ATF_REQUIRE(unlink(filename) == 0); + + len = getpagesize(); + ATF_REQUIRE(ftruncate(fd, len) == 0); + + addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + ATF_REQUIRE(addr != MAP_FAILED); + ATF_REQUIRE(mlock(addr, len) == 0); + ATF_REQUIRE(ftruncate(fd, 0) == 0); + ATF_REQUIRE(munlock(addr, len) == 0); +} + +/* + * Exercise a corner case involving an interaction between mlock() and superpage + * creation: a truncation of the object backing a mapping results in the + * truncated region being unmapped by the pmap, but does not affect the logical + * mapping. In particular, the truncated region remains mlock()ed. If the + * mapping is later extended, a page fault in the formerly truncated region can + * result in superpage creation via a call to pmap_enter(psind = 1). + */ +ATF_TC(mlock__superpage_fault); +ATF_TC_HEAD(mlock__superpage_fault, tc) +{ + atf_tc_set_md_var(tc, "require.user", "root"); +} +ATF_TC_BODY(mlock__superpage_fault, tc) +{ + struct rlimit rlim; + void *addr1, *addr2; + size_t len, pagesizes[MAXPAGESIZES]; + int count, error, shmfd; + char vec; + + count = getpagesizes(pagesizes, MAXPAGESIZES); + ATF_REQUIRE_MSG(count >= 1, + "failed to get page sizes: %s", strerror(errno)); + if (count == 1) + atf_tc_skip("system does not support multiple page sizes"); + len = pagesizes[1]; + + error = getrlimit(RLIMIT_MEMLOCK, &rlim); + ATF_REQUIRE_MSG(error == 0, "getrlimit: %s", strerror(errno)); + rlim.rlim_cur += len; + rlim.rlim_max += len; + error = setrlimit(RLIMIT_MEMLOCK, &rlim); + ATF_REQUIRE_MSG(error == 0, "setrlimit: %s", strerror(errno)); + + shmfd = shm_open(SHM_ANON, O_RDWR | O_CREAT, 0600); + ATF_REQUIRE_MSG(shmfd >= 0, "shm_open: %s", strerror(errno)); + error = ftruncate(shmfd, len); + ATF_REQUIRE_MSG(error == 0, "ftruncate: %s", strerror(errno)); + + addr1 = mmap(NULL, len, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_ALIGNED_SUPER, shmfd, 0); + ATF_REQUIRE_MSG(addr1 != MAP_FAILED, "mmap: %s", strerror(errno)); + ATF_REQUIRE_MSG(((uintptr_t)addr1 & (len - 1)) == 0, + "addr %p is misaligned", addr1); + addr2 = mmap(NULL, len, PROT_READ, + MAP_SHARED | MAP_ALIGNED_SUPER, shmfd, 0); + ATF_REQUIRE_MSG(addr2 != MAP_FAILED, "mmap: %s", strerror(errno)); + ATF_REQUIRE_MSG(((uintptr_t)addr2 & (len - 1)) == 0, + "addr %p is misaligned", addr2); + + memset(addr1, 0x42, len); + error = mincore(addr1, pagesizes[0], &vec); + ATF_REQUIRE_MSG(error == 0, "mincore: %s", strerror(errno)); + if ((vec & MINCORE_SUPER) == 0) + atf_tc_skip("initial superpage promotion failed"); + + error = mlock(addr2, len); + ATF_REQUIRE_MSG(error == 0, "mlock: %s", strerror(errno)); + error = mincore(addr2, pagesizes[0], &vec); + ATF_REQUIRE_MSG(error == 0, "mincore: %s", strerror(errno)); + ATF_REQUIRE((vec & MINCORE_SUPER) != 0); + + /* + * Free a page back to the superpage reservation, demoting both + * mappings. + */ + error = ftruncate(shmfd, len - pagesizes[0]); + ATF_REQUIRE_MSG(error == 0, "ftruncate: %s", strerror(errno)); + + /* + * Extend the mapping back to its original size. + */ + error = ftruncate(shmfd, len); + ATF_REQUIRE_MSG(error == 0, "ftruncate: %s", strerror(errno)); + + /* + * Trigger re-promotion. + */ + error = mincore(addr1, pagesizes[0], &vec); + ATF_REQUIRE_MSG(error == 0, "mincore: %s", strerror(errno)); + ATF_REQUIRE((vec & MINCORE_SUPER) == 0); + memset((char *)addr1 + len - pagesizes[0], 0x43, pagesizes[0]); + error = mincore(addr1, pagesizes[0], &vec); + ATF_REQUIRE_MSG(error == 0, "mincore: %s", strerror(errno)); + ATF_REQUIRE((vec & MINCORE_SUPER) != 0); + + /* + * Trigger a read fault, which should install a superpage mapping + * without promotion. + */ + error = mincore(addr2, pagesizes[0], &vec); + ATF_REQUIRE_MSG(error == 0, "mincore: %s", strerror(errno)); + ATF_REQUIRE((vec & MINCORE_SUPER) == 0); + (void)atomic_load( + (_Atomic int *)(void *)((char *)addr2 + len - pagesizes[0])); + error = mincore(addr2, pagesizes[0], &vec); + ATF_REQUIRE_MSG(error == 0, "mincore: %s", strerror(errno)); + ATF_REQUIRE((vec & MINCORE_SUPER) != 0); + + /* + * Trigger demotion of the wired mapping. + */ + error = munlock(addr2, pagesizes[0]); + ATF_REQUIRE_MSG(error == 0, "munlock: %s", strerror(errno)); + + ATF_REQUIRE(close(shmfd) == 0); +} + +ATF_TP_ADD_TCS(tp) +{ + ATF_TP_ADD_TC(tp, mlock__copy_on_write_anon); + ATF_TP_ADD_TC(tp, mlock__copy_on_write_vnode); + ATF_TP_ADD_TC(tp, mlock__truncate_and_resize); + ATF_TP_ADD_TC(tp, mlock__truncate_and_unlock); + ATF_TP_ADD_TC(tp, mlock__superpage_fault); + + return (atf_no_error()); +} |