On Thu, Jan 17, 2019 at 11:55:49AM +0100, Greg KH wrote:
On Thu, Jan 17, 2019 at 11:28:21AM +0100, Christian Brauner wrote:
This adds the promised selftest for binderfs. It will verify the following things:
- binderfs mounting works
- binder device allocation works
- performing a binder ioctl() request through a binderfs device works
- binder device removal works
- binder-control removal fails
- binderfs unmounting works
The tests are performed both privileged and unprivileged. The latter verifies that binderfs behaves correctly in user namespaces.
Cc: Todd Kjos tkjos@google.com Signed-off-by: Christian Brauner christian.brauner@ubuntu.com
Now I am just nit-picking:
I would've been surprised if someone wouldn't have. :)
+static void write_to_file(const char *filename, const void *buf, size_t count,
int allowed_errno)+{
- int fd, saved_errno;
- ssize_t ret;
- fd = open(filename, O_WRONLY | O_CLOEXEC);
- if (fd < 0)
ksft_exit_fail_msg("%s - Failed to open file %s\n",strerror(errno), filename);- ret = write_nointr(fd, buf, count);
- if (ret < 0) {
if (allowed_errno && (errno == allowed_errno)) {close(fd);return;}goto on_error;- }
- if ((size_t)ret != count)
goto on_error;if ret < count, you are supposed to try again with the remaining data, right? A write() implementation can just take one byte at a time.
Yes, for your example here that isn't going to happen as the kernel should be handling a larger buffer than that, but note that if you use this code elsewhere, it's not really correct because:
Yeah, I know you should retry but for the test I'm not really willing to keep track of where I was in the buffer and so on. If the test fails because of that I'd say to count it as failed and move on.
- close(fd);
- return;
+on_error:
- saved_errno = errno;
If you do a short write, there is no error, so who knows what errno you end up with here.
Anyway, just one other minor question that might be relevant:
- printf("Allocated new binder device with major %d, minor %d, and name %s\n",
device.major, device.minor, device.name);Aren't tests supposed to print their output in some sort of normal format? I thought you were supposed to use ksft_print_msg() so that tools can properly parse the output.
I can switch the printf()s over to ksft_print_msg().
Thanks! Christian