Re: [Libguestfs] [PATCH v3 libguestfs] launch: Implement a safer getumask.
On 04/14/2016 07:57 AM, Richard W.M. Jones wrote:
On Thu, Apr 14, 2016 at 07:38:23AM -0600, Eric Blake wrote:
>> + /* Read the umask. */
>> + if (read (fd[0], &mask, sizeof mask) != sizeof mask) {
>> + perrorf (g, "read");
>> + close (fd[0]);
>> + return -1;
>
> Oops - this strands a child process. You have to reap the child, even
> if the read() failed.
Bleah that was stupid. Try attached version - the only difference is
I added a waitpid call to the error path above.
But without looping on EINTR...
+
+ /* Read the umask. */
+ if (read (fd[0], &mask, sizeof mask) != sizeof mask) {
+ perrorf (g, "read");
+ close (fd[0]);
+ waitpid (pid, NULL, 0);
I think it's enough to make this line:
while (waitpid (pid, &status, 0) == -1 && errno == EINTR);
+ return -1;
as you've already reported the initial error, and are merely focused on
cleanup of the child.
+ }
+ close (fd[0]);
+
+ again:
+ if (waitpid (pid, &status, 0) == -1) {
+ if (errno == EINTR) goto again;
+ perrorf (g, "waitpid");
+ return -1;
Anything else, like trying to reuse the again: loop, seems like it be
more complicated control flow.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
Attachments:
- signature.asc (application/pgp-signature — 604 bytes)