diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/pidfd/pidfd_fdinfo_test.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/pidfd/pidfd_fdinfo_test.c')
-rw-r--r-- | tools/testing/selftests/pidfd/pidfd_fdinfo_test.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c new file mode 100644 index 000000000..3bc46d615 --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c @@ -0,0 +1,310 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include <assert.h> +#include <errno.h> +#include <fcntl.h> +#include <linux/types.h> +#include <sched.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <syscall.h> +#include <sys/wait.h> +#include <sys/mman.h> + +#include "pidfd.h" +#include "../kselftest.h" + +struct error { + int code; + char msg[512]; +}; + +static int error_set(struct error *err, int code, const char *fmt, ...) +{ + va_list args; + int r; + + if (code == PIDFD_PASS || !err || err->code != PIDFD_PASS) + return code; + + err->code = code; + va_start(args, fmt); + r = vsnprintf(err->msg, sizeof(err->msg), fmt, args); + assert((size_t)r < sizeof(err->msg)); + va_end(args); + + return code; +} + +static void error_report(struct error *err, const char *test_name) +{ + switch (err->code) { + case PIDFD_ERROR: + ksft_exit_fail_msg("%s test: Fatal: %s\n", test_name, err->msg); + break; + + case PIDFD_FAIL: + /* will be: not ok %d # error %s test: %s */ + ksft_test_result_error("%s test: %s\n", test_name, err->msg); + break; + + case PIDFD_SKIP: + /* will be: not ok %d # SKIP %s test: %s */ + ksft_test_result_skip("%s test: %s\n", test_name, err->msg); + break; + + case PIDFD_XFAIL: + ksft_test_result_pass("%s test: Expected failure: %s\n", + test_name, err->msg); + break; + + case PIDFD_PASS: + ksft_test_result_pass("%s test: Passed\n", test_name); + break; + + default: + ksft_exit_fail_msg("%s test: Unknown code: %d %s\n", + test_name, err->code, err->msg); + break; + } +} + +static inline int error_check(struct error *err, const char *test_name) +{ + /* In case of error we bail out and terminate the test program */ + if (err->code == PIDFD_ERROR) + error_report(err, test_name); + + return err->code; +} + +#define CHILD_STACK_SIZE 8192 + +struct child { + char *stack; + pid_t pid; + int fd; +}; + +static struct child clone_newns(int (*fn)(void *), void *args, + struct error *err) +{ + static int flags = CLONE_PIDFD | CLONE_NEWPID | CLONE_NEWNS | SIGCHLD; + struct child ret; + + if (!(flags & CLONE_NEWUSER) && geteuid() != 0) + flags |= CLONE_NEWUSER; + + ret.stack = mmap(NULL, CHILD_STACK_SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); + if (ret.stack == MAP_FAILED) { + error_set(err, -1, "mmap of stack failed (errno %d)", errno); + return ret; + } + +#ifdef __ia64__ + ret.pid = __clone2(fn, ret.stack, CHILD_STACK_SIZE, flags, args, &ret.fd); +#else + ret.pid = clone(fn, ret.stack + CHILD_STACK_SIZE, flags, args, &ret.fd); +#endif + + if (ret.pid < 0) { + error_set(err, PIDFD_ERROR, "clone failed (ret %d, errno %d)", + ret.fd, errno); + return ret; + } + + ksft_print_msg("New child: %d, fd: %d\n", ret.pid, ret.fd); + + return ret; +} + +static inline void child_close(struct child *child) +{ + close(child->fd); +} + +static inline int child_join(struct child *child, struct error *err) +{ + int r; + + r = wait_for_pid(child->pid); + if (r < 0) + error_set(err, PIDFD_ERROR, "waitpid failed (ret %d, errno %d)", + r, errno); + else if (r > 0) + error_set(err, r, "child %d reported: %d", child->pid, r); + + if (munmap(child->stack, CHILD_STACK_SIZE)) { + error_set(err, -1, "munmap of child stack failed (errno %d)", errno); + r = -1; + } + + return r; +} + +static inline int child_join_close(struct child *child, struct error *err) +{ + child_close(child); + return child_join(child, err); +} + +static inline void trim_newline(char *str) +{ + char *pos = strrchr(str, '\n'); + + if (pos) + *pos = '\0'; +} + +static int verify_fdinfo(int pidfd, struct error *err, const char *prefix, + size_t prefix_len, const char *expect, ...) +{ + char buffer[512] = {0, }; + char path[512] = {0, }; + va_list args; + FILE *f; + char *line = NULL; + size_t n = 0; + int found = 0; + int r; + + va_start(args, expect); + r = vsnprintf(buffer, sizeof(buffer), expect, args); + assert((size_t)r < sizeof(buffer)); + va_end(args); + + snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", pidfd); + f = fopen(path, "re"); + if (!f) + return error_set(err, PIDFD_ERROR, "fdinfo open failed for %d", + pidfd); + + while (getline(&line, &n, f) != -1) { + char *val; + + if (strncmp(line, prefix, prefix_len)) + continue; + + found = 1; + + val = line + prefix_len; + r = strcmp(val, buffer); + if (r != 0) { + trim_newline(line); + trim_newline(buffer); + error_set(err, PIDFD_FAIL, "%s '%s' != '%s'", + prefix, val, buffer); + } + break; + } + + free(line); + fclose(f); + + if (found == 0) + return error_set(err, PIDFD_FAIL, "%s not found for fd %d", + prefix, pidfd); + + return PIDFD_PASS; +} + +static int child_fdinfo_nspid_test(void *args) +{ + struct error err; + int pidfd; + int r; + + /* if we got no fd for the sibling, we are done */ + if (!args) + return PIDFD_PASS; + + /* verify that we can not resolve the pidfd for a process + * in a sibling pid namespace, i.e. a pid namespace it is + * not in our or a descended namespace + */ + r = mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0); + if (r < 0) { + ksft_print_msg("Failed to remount / private\n"); + return PIDFD_ERROR; + } + + (void)umount2("/proc", MNT_DETACH); + r = mount("proc", "/proc", "proc", 0, NULL); + if (r < 0) { + ksft_print_msg("Failed to remount /proc\n"); + return PIDFD_ERROR; + } + + pidfd = *(int *)args; + r = verify_fdinfo(pidfd, &err, "NSpid:", 6, "\t0\n"); + + if (r != PIDFD_PASS) + ksft_print_msg("NSpid fdinfo check failed: %s\n", err.msg); + + return r; +} + +static void test_pidfd_fdinfo_nspid(void) +{ + struct child a, b; + struct error err = {0, }; + const char *test_name = "pidfd check for NSpid in fdinfo"; + + /* Create a new child in a new pid and mount namespace */ + a = clone_newns(child_fdinfo_nspid_test, NULL, &err); + error_check(&err, test_name); + + /* Pass the pidfd representing the first child to the + * second child, which will be in a sibling pid namespace, + * which means that the fdinfo NSpid entry for the pidfd + * should only contain '0'. + */ + b = clone_newns(child_fdinfo_nspid_test, &a.fd, &err); + error_check(&err, test_name); + + /* The children will have pid 1 in the new pid namespace, + * so the line must be 'NSPid:\t<pid>\t1'. + */ + verify_fdinfo(a.fd, &err, "NSpid:", 6, "\t%d\t%d\n", a.pid, 1); + verify_fdinfo(b.fd, &err, "NSpid:", 6, "\t%d\t%d\n", b.pid, 1); + + /* wait for the process, check the exit status and set + * 'err' accordingly, if it is not already set. + */ + child_join_close(&a, &err); + child_join_close(&b, &err); + + error_report(&err, test_name); +} + +static void test_pidfd_dead_fdinfo(void) +{ + struct child a; + struct error err = {0, }; + const char *test_name = "pidfd check fdinfo for dead process"; + + /* Create a new child in a new pid and mount namespace */ + a = clone_newns(child_fdinfo_nspid_test, NULL, &err); + error_check(&err, test_name); + child_join(&a, &err); + + verify_fdinfo(a.fd, &err, "Pid:", 4, "\t-1\n"); + verify_fdinfo(a.fd, &err, "NSpid:", 6, "\t-1\n"); + child_close(&a); + error_report(&err, test_name); +} + +int main(int argc, char **argv) +{ + ksft_print_header(); + ksft_set_plan(2); + + test_pidfd_fdinfo_nspid(); + test_pidfd_dead_fdinfo(); + + return ksft_exit_pass(); +} |