tests: skip test_get_process_cmdline_harder if mount --make-rslave / fails with EPERM or EACCESS

That call to mount was added as a safeguard against a kernel bug which was fixed in
torvalds/linux@bbd5192.

In principle, the error could be ignored because

* normally everything mounted on /proc/PID should disappear as soon as the PID has gone away
* test-mount-util that had been confused by those phantom entries in /proc/self/mountinfo was
  taught to ignore them in 112cc3b.

On the other hand, in practice, if the mount fails, then the next one is extremely unlikely to
succeed, so it seems to be reasonable to just skip the rest of `test_get_process_cmdline_harder`
if that happens.

Closes https://github.com/systemd/systemd/issues/9649.
This commit is contained in:
Evgeny Vereshchagin 2018-07-19 10:24:07 +00:00 committed by Lennart Poettering
parent ba9778d9b7
commit 0ffa4c7c4b

View file

@ -206,15 +206,21 @@ static void test_get_process_cmdline_harder(void) {
assert_se(pid == 0);
assert_se(unshare(CLONE_NEWNS) >= 0);
assert_se(mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) >= 0);
if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) {
log_warning_errno(errno, "mount(..., \"/\", MS_SLAVE|MS_REC, ...) failed: %m");
assert_se(IN_SET(errno, EPERM, EACCES));
return;
}
fd = mkostemp(path, O_CLOEXEC);
assert_se(fd >= 0);
/* Note that we don't unmount the following bind-mount at the end of the test because the kernel
* will clear up its /proc/PID/ hierarchy automatically as soon as the test stops. */
if (mount(path, "/proc/self/cmdline", "bind", MS_BIND, NULL) < 0) {
/* This happens under selinux… Abort the test in this case. */
log_warning_errno(errno, "mount(..., \"/proc/self/cmdline\", \"bind\", ...) failed: %m");
assert(errno == EACCES);
assert_se(IN_SET(errno, EPERM, EACCES));
return;
}