Commit 1a5454f6 authored by Willy Tarreau's avatar Willy Tarreau Committed by Paul E. McKenney
Browse files

selftests/nolibc: recreate and populate /dev and /proc if missing 



Most of the time the program will be run alone in an initramfs. There
is no value in requiring the user to populate /dev and /proc for such
tests, we can do it ourselves, and it participates to the tests at the
same time.

What's done here is that when called as init (getpid()==1) we check
if /dev exists or create it, if /dev/console and /dev/null exists,
otherwise we try to mount a devtmpfs there, and if it fails we fall
back to mknod. The console is reopened if stdout was closed. Finally
/proc is created and mounted if /proc/self cannot be found. This is
sufficient for most tests.

Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent aa73a86c

tools/testing/selftests/nolibc/nolibc-test.c

+56 −0
Original line number Diff line number Diff line
@@ -530,6 +530,54 @@ int run_stdlib(int min, int max) 
	return ret;

}



/* prepare what needs to be prepared for pid 1 (stdio, /dev, /proc, etc) */

int prepare(void)

{

	struct stat stat_buf;



	/* It's possible that /dev doesn't even exist or was not mounted, so

	 * we'll try to create it, mount it, or create minimal entries into it.

	 * We want at least /dev/null and /dev/console.

	 */

	if (stat("/dev/.", &stat_buf) == 0 || mkdir("/dev", 0755) == 0) {

		if (stat("/dev/console", &stat_buf) != 0 ||

		    stat("/dev/null", &stat_buf) != 0) {

			/* try devtmpfs first, otherwise fall back to manual creation */

			if (mount("/dev", "/dev", "devtmpfs", 0, 0) != 0) {

				mknod("/dev/console", 0600 | S_IFCHR, makedev(5, 1));

				mknod("/dev/null",    0666 | S_IFCHR, makedev(1, 3));

			}

		}

	}



	/* If no /dev/console was found before calling init, stdio is closed so

	 * we need to reopen it from /dev/console. If it failed above, it will

	 * still fail here and we cannot emit a message anyway.

	 */

	if (close(dup(1)) == -1) {

		int fd = open("/dev/console", O_RDWR);



		if (fd >= 0) {

			if (fd != 0)

				dup2(fd, 0);

			if (fd != 1)

				dup2(fd, 1);

			if (fd != 2)

				dup2(fd, 2);

			if (fd > 2)

				close(fd);

			puts("\nSuccessfully reopened /dev/console.");

		}

	}



	/* try to mount /proc if not mounted. Silently fail otherwise */

	if (stat("/proc/.", &stat_buf) == 0 || mkdir("/proc", 0755) == 0) {

		if (stat("/proc/self", &stat_buf) != 0)

			mount("/proc", "/proc", "proc", 0, 0);

	}



	return 0;

}



/* This is the definition of known test names, with their functions */

static struct test test_names[] = {
@@ -550,6 +598,14 @@ int main(int argc, char **argv, char **envp) 


	environ = envp;



	/* when called as init, it's possible that no console was opened, for

	 * example if no /dev file system was provided. We'll check that fd#1

	 * was opened, and if not we'll attempt to create and open /dev/console

	 * and /dev/null that we'll use for later tests.

	 */

	if (getpid() == 1)

		prepare();



	/* the definition of a series of tests comes from either argv[1] or the

	 * "NOLIBC_TEST" environment variable. It's made of a comma-delimited

	 * series of test names and optional ranges: