From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Lawrence Date: Tue, 5 Mar 2019 10:44:55 -0800 Subject: [LTP] [ltp][PATCH v3] Add ltp pivot_root test Message-ID: <20190305184455.93440-1-paullawrence@google.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ltp@lists.linux.it Fixed too long line Added const to static struct test_case Made fail with TCONF when HAVE_LIBCAP not defined Signed-off-by: Paul Lawrence --- runtest/syscalls | 2 + testcases/kernel/syscalls/pivot_root/Makefile | 11 + .../kernel/syscalls/pivot_root/pivot_root01.c | 200 ++++++++++++++++++ 3 files changed, 213 insertions(+) create mode 100644 testcases/kernel/syscalls/pivot_root/Makefile create mode 100644 testcases/kernel/syscalls/pivot_root/pivot_root01.c diff --git a/runtest/syscalls b/runtest/syscalls index 668c87cd1..debda74b8 100644 --- a/runtest/syscalls +++ b/runtest/syscalls @@ -835,6 +835,8 @@ pipe11 pipe11 pipe2_01 pipe2_01 pipe2_02 pipe2_02 +pivot_root01 pivot_root01 + poll01 poll01 poll02 poll02 diff --git a/testcases/kernel/syscalls/pivot_root/Makefile b/testcases/kernel/syscalls/pivot_root/Makefile new file mode 100644 index 000000000..a16974d41 --- /dev/null +++ b/testcases/kernel/syscalls/pivot_root/Makefile @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0-or-later +# +# Copyright (c) 2019 Google, Inc. + +top_srcdir ?= ../../../.. + +include $(top_srcdir)/include/mk/testcases.mk + +LDLIBS := $(LDLIBS) $(CAP_LIBS) + +include $(top_srcdir)/include/mk/generic_leaf_target.mk diff --git a/testcases/kernel/syscalls/pivot_root/pivot_root01.c b/testcases/kernel/syscalls/pivot_root/pivot_root01.c new file mode 100644 index 000000000..c78428a91 --- /dev/null +++ b/testcases/kernel/syscalls/pivot_root/pivot_root01.c @@ -0,0 +1,200 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * Copyright (c) 2019 Google, Inc. + */ + +#define _GNU_SOURCE + +#include + +#include +#include +#include + +#include +#include + +#include "tst_test.h" + +#ifdef HAVE_LIBCAP +#include +#endif + +static const char* chroot_dir = "chroot"; +static const char* new_root = "/new_root"; +static const char* put_old = "/new_root/put_old"; +static const char* put_old_fs = "/put_old_fs"; +static const char* put_old_bad = "/put_old_fs/put_old"; + +/* + * Test consists of a series of steps that allow pivot_root to succeed, which + * is run when param is NORMAL. All other values tweak one of the steps to + * induce a failure, and check the errno is as expected. + */ +#define NORMAL 0 + +/* + * EBUSY + * new_root or put_old are on the current root file system + */ +#define NEW_ROOT_ON_CURRENT_ROOT 1 + +/* + * EINVAL + * put_old is not underneath new_root + * Note: if put_old and new_root are on the same fs, + * pivot_root fails with EBUSY before testing reachability + */ +#define PUT_OLD_NOT_UNDERNEATH_NEW_ROOT 2 + +/* + * ENOTDIR + * new_root or put_old is not a directory + */ +#define PUT_OLD_NOT_DIR 3 + +/* + * EPERM + * The calling process does not have the CAP_SYS_ADMIN capability. + */ +#define NO_CAP_SYS_ADMIN 4 + +static const struct test_case { + int test_case; + int expected_error; +} test_cases[] = { + {NORMAL, 0}, + {NEW_ROOT_ON_CURRENT_ROOT, EBUSY}, + {PUT_OLD_NOT_UNDERNEATH_NEW_ROOT, EINVAL}, + {PUT_OLD_NOT_DIR, ENOTDIR}, + {NO_CAP_SYS_ADMIN, EPERM}, +}; + +#ifdef HAVE_LIBCAP +static void drop_cap_sys_admin(void) +{ + cap_value_t cap_value[] = { CAP_SYS_ADMIN }; + cap_t cap = cap_get_proc(); + if (!cap) + tst_brk(TFAIL | TERRNO, "cap_get_proc failed"); + + if (cap_set_flag(cap, CAP_EFFECTIVE, 1, cap_value, CAP_CLEAR)) + tst_brk(TFAIL | TERRNO, "cap_set_flag failed"); + + if (cap_set_proc(cap)) + tst_brk(TFAIL | TERRNO, "cap_set_proc failed"); +} +#endif + +#ifdef HAVE_UNSHARE +static void run(unsigned int test_case) +{ + /* Work in child process - needed to undo unshare and chroot */ + if (SAFE_FORK()) { + tst_reap_children(); + return; + } + + /* pivot_root requires no shared mounts exist in process namespace */ + TEST(unshare(CLONE_NEWNS | CLONE_FS)); + if (TST_RET == -1) + tst_brk(TFAIL | TERRNO, "unshare failed"); + + /* + * Create an initial root dir. pivot_root doesn't work if the initial root + * dir is a initramfs, so use chroot to create a safe environment + */ + SAFE_MOUNT("none", "/", NULL, MS_REC|MS_PRIVATE, NULL); + SAFE_MOUNT("none", chroot_dir, "tmpfs", 0, 0); + SAFE_CHROOT(chroot_dir); + + /* Create our new root location */ + SAFE_MKDIR(new_root, 0777); + + /* + * pivot_root only works if new_root is a mount point, so mount a tmpfs + * unless testing for that fail mode + */ + if (test_cases[test_case].test_case != NEW_ROOT_ON_CURRENT_ROOT) + SAFE_MOUNT("none", new_root, "tmpfs", 0, 0); + + /* + * Create put_old under new_root, unless testing for that specific fail + * mode + */ + const char* actual_put_old = NULL; + if (test_cases[test_case].test_case == PUT_OLD_NOT_UNDERNEATH_NEW_ROOT) { + actual_put_old = put_old_bad; + SAFE_MKDIR(put_old_fs, 0777); + SAFE_MOUNT("none", put_old_fs, "tmpfs", 0, 0); + SAFE_MKDIR(put_old_bad, 0777); + } else { + actual_put_old = put_old; + + /* put_old must be a directory for success */ + if (test_cases[test_case].test_case == PUT_OLD_NOT_DIR) + SAFE_CREAT(put_old, 0777); + else + SAFE_MKDIR(put_old, 0777); + } + + if (test_cases[test_case].test_case == NO_CAP_SYS_ADMIN) +#ifdef HAVE_LIBCAP + drop_cap_sys_admin(); +#else + tst_brk(TCONF, + "System doesn't have POSIX capabilities support"); +#endif + + /* Test the syscall */ + TEST(syscall(__NR_pivot_root, new_root, actual_put_old)); + + /* If NORMAL it should have succeeded */ + if (test_cases[test_case].test_case == NORMAL) { + if (TST_RET) { + tst_res(TFAIL | TERRNO, "pivot_root failed"); + exit(TBROK); + } else { + tst_res(TPASS, "pivot_root succeeded"); + exit(TPASS); + } + } + + /* pivot_root is expected to fail */ + if (TST_RET == 0) { + tst_res(TFAIL, "pivot_root succeeded unexpectedly"); + exit(TBROK); + } + + /* Check error code is correct */ + if (errno != test_cases[test_case].expected_error) { + tst_res(TFAIL | TERRNO, "pivot_root failed with wrong errno"); + exit(TBROK); + } + + tst_res(TPASS, "pivot_root failed as expected with %s", + strerror(errno)); + exit(TPASS); +} + +#else +static void run(void) +{ + tst_brk(TCONF, NULL, "unshare is undefined."); +} +#endif + +static void setup(void) +{ + SAFE_MKDIR(chroot_dir, 0777); +} + +static struct tst_test test = { + .test = run, + .tcnt = ARRAY_SIZE(test_cases), + .needs_tmpdir = 1, + .needs_root = 1, + .forks_child = 1, + .setup = setup, +}; -- 2.21.0.352.gf09ad66450-goog