Re: [PATCH v2 0/5] pid: add pidfd_open()

On Sat, Mar 30, 2019 at 9:09 AM Linus Torvalds
[off-list ref] wrote:

On Fri, Mar 29, 2019 at 8:54 AM Christian Brauner [off-list ref] wrote:

quoted

/* Introduction */
This adds the pidfd_open() syscall.
pidfd_open() allows to retrieve file descriptors for a given pid. This
includes both file descriptors for processes and file descriptors for
threads.

I'm ok with the pidfd_open() call to just get a pidfd, but that
"pidfd_to_profs()" needs to go away.

If you want to open the /proc/<pid>/status file, then just do that.
This whole "do one and convert to the other" needs to die. No, no, no.

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?