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: Willy Tarreau w@1wt.eu --- tools/testing/selftests/nolibc/nolibc-test.c | 56 ++++++++++++++++++++ 1 file changed, 56 insertions(+)
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 45793b6f2244..0bbfe0b3b648 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -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: