diff options
Diffstat (limited to 'tools/testing/selftests/proc/proc-subset-pid.c')
-rw-r--r-- | tools/testing/selftests/proc/proc-subset-pid.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/tools/testing/selftests/proc/proc-subset-pid.c b/tools/testing/selftests/proc/proc-subset-pid.c new file mode 100644 index 000000000..d1052bcab --- /dev/null +++ b/tools/testing/selftests/proc/proc-subset-pid.c @@ -0,0 +1,121 @@ +/* + * Copyright (c) 2021 Alexey Dobriyan <adobriyan@gmail.com> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +/* + * Test that "mount -t proc -o subset=pid" hides everything but pids, + * /proc/self and /proc/thread-self. + */ +#undef NDEBUG +#include <assert.h> +#include <errno.h> +#include <sched.h> +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> +#include <sys/mount.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <dirent.h> +#include <unistd.h> +#include <stdio.h> + +static inline bool streq(const char *a, const char *b) +{ + return strcmp(a, b) == 0; +} + +static void make_private_proc(void) +{ + if (unshare(CLONE_NEWNS) == -1) { + if (errno == ENOSYS || errno == EPERM) { + exit(4); + } + exit(1); + } + if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) { + exit(1); + } + if (mount(NULL, "/proc", "proc", 0, "subset=pid") == -1) { + exit(1); + } +} + +static bool string_is_pid(const char *s) +{ + while (1) { + switch (*s++) { + case '0':case '1':case '2':case '3':case '4': + case '5':case '6':case '7':case '8':case '9': + continue; + + case '\0': + return true; + + default: + return false; + } + } +} + +int main(void) +{ + make_private_proc(); + + DIR *d = opendir("/proc"); + assert(d); + + struct dirent *de; + + bool dot = false; + bool dot_dot = false; + bool self = false; + bool thread_self = false; + + while ((de = readdir(d))) { + if (streq(de->d_name, ".")) { + assert(!dot); + dot = true; + assert(de->d_type == DT_DIR); + } else if (streq(de->d_name, "..")) { + assert(!dot_dot); + dot_dot = true; + assert(de->d_type == DT_DIR); + } else if (streq(de->d_name, "self")) { + assert(!self); + self = true; + assert(de->d_type == DT_LNK); + } else if (streq(de->d_name, "thread-self")) { + assert(!thread_self); + thread_self = true; + assert(de->d_type == DT_LNK); + } else { + if (!string_is_pid(de->d_name)) { + fprintf(stderr, "d_name '%s'\n", de->d_name); + assert(0); + } + assert(de->d_type == DT_DIR); + } + } + + char c; + int rv = readlink("/proc/cpuinfo", &c, 1); + assert(rv == -1 && errno == ENOENT); + + int fd = open("/proc/cpuinfo", O_RDONLY); + assert(fd == -1 && errno == ENOENT); + + return 0; +} |