proc: test /proc/sysvipc vs setns(CLONE_NEWIPC) (7dbbade1) · Commits · e / devices / android_kernel_fairphone_FP5

tools/testing/selftests/proc/.gitignore

+1 −0

Original line number	Diff line number	Diff line
		@@ -12,4 +12,5 @@
		/read
		/self
		/setns-dcache
		/setns-sysvipc
		/thread-self

tools/testing/selftests/proc/Makefile

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Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@ TEST_GEN_PROGS += proc-uptime-002
		TEST_GEN_PROGS += read
		TEST_GEN_PROGS += self
		TEST_GEN_PROGS += setns-dcache
		TEST_GEN_PROGS += setns-sysvipc
		TEST_GEN_PROGS += thread-self

		include ../lib.mk

tools/testing/selftests/proc/setns-sysvipc.c

0 → 100644

+133 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright © 2019 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 setns(CLONE_NEWIPC) points to new /proc/sysvipc content even
		* if old one is in dcache.
		*/
		#undef NDEBUG
		#include <assert.h>
		#include <errno.h>
		#include <stdio.h>
		#include <sched.h>
		#include <signal.h>
		#include <stdlib.h>
		#include <string.h>
		#include <unistd.h>
		#include <sys/types.h>
		#include <sys/stat.h>
		#include <fcntl.h>
		#include <sys/ipc.h>
		#include <sys/shm.h>

		static pid_t pid = -1;

		static void f(void)
		{
		if (pid > 0) {
		kill(pid, SIGTERM);
		}
		}

		int main(void)
		{
		int fd[2];
		char _ = 0;
		int nsfd;

		atexit(f);

		/* Check for priviledges and syscall availability straight away. */
		if (unshare(CLONE_NEWIPC) == -1) {
		if (errno == ENOSYS \|\| errno == EPERM) {
		return 4;
		}
		return 1;
		}
		/* Distinguisher between two otherwise empty IPC namespaces. */
		if (shmget(IPC_PRIVATE, 1, IPC_CREAT) == -1) {
		return 1;
		}

		if (pipe(fd) == -1) {
		return 1;
		}

		pid = fork();
		if (pid == -1) {
		return 1;
		}

		if (pid == 0) {
		if (unshare(CLONE_NEWIPC) == -1) {
		return 1;
		}

		if (write(fd[1], &_, 1) != 1) {
		return 1;
		}

		pause();

		return 0;
		}

		if (read(fd[0], &_, 1) != 1) {
		return 1;
		}

		{
		char buf[64];
		snprintf(buf, sizeof(buf), "/proc/%u/ns/ipc", pid);
		nsfd = open(buf, O_RDONLY);
		if (nsfd == -1) {
		return 1;
		}
		}

		/* Reliably pin dentry into dcache. */
		(void)open("/proc/sysvipc/shm", O_RDONLY);

		if (setns(nsfd, CLONE_NEWIPC) == -1) {
		return 1;
		}

		kill(pid, SIGTERM);
		pid = 0;

		{
		char buf[4096];
		ssize_t rv;
		int fd;

		fd = open("/proc/sysvipc/shm", O_RDONLY);
		if (fd == -1) {
		return 1;
		}

		#define S32 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n"
		#define S64 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n"
		rv = read(fd, buf, sizeof(buf));
		if (rv == strlen(S32)) {
		assert(memcmp(buf, S32, strlen(S32)) == 0);
		} else if (rv == strlen(S64)) {
		assert(memcmp(buf, S64, strlen(S64)) == 0);
		} else {
		assert(0);
		}
		}

		return 0;
		}