ptrace: PTRACE_GETFDPIC: fix the unsafe usage of child->mm

Now that Mike Frysinger unified the FDPIC ptrace code, we can fix the
unsafe usage of child->mm in ptrace_request(PTRACE_GETFDPIC).

We have the reference to task_struct, and ptrace_check_attach() verified
the tracee is stopped.  But nothing can protect from SIGKILL after that,
we must not assume child->mm != NULL.

Signed-off-by: Oleg Nesterov <[email protected]>
Acked-by: Mike Frysinger <[email protected]>
Acked-by: David Howells <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Greg Ungerer <[email protected]>
Acked-by: Roland McGrath <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions