On Sat, Mar 30, 2019 at 9:11 AM Daniel Colascione <dancol@xxxxxxxxxx> wrote: > > How do you propose that someone open the /proc/<pid>/status file in a > race-free manner starting with the result of calling pidfd_open? CXhrist. If you want to open a /proc file, then open a /proc file. Don't use pidfd_open(). Just open /proc/<pid>/ Then you can use openat() to open whatever sub-files you want. You have two choices: either you use /proc, or you don't. Don't mix the two. And no, we are *NOT* making pidfd_open() into some "let's expose /proc even when it's not mounted" horror. Seriously. That's disgusting, wrong, insecure and stupid. Linus