tree b20b51848380b708f4158852b1bb4afa29ffc5f0
parent b1b4c6799fb59e710454bfe0ab477cb8523a8667
author Oleg Nesterov <oleg@redhat.com> 1238716694 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1238724299 -0700

ptrace: fix possible zombie leak on PTRACE_DETACH

When ptrace_detach() takes tasklist, the tracee can be SIGKILL'ed.  If it
has already passed exit_notify() we can leak a zombie, because a) ptracing
disables the auto-reaping logic, and b) ->real_parent was not notified
about the child's death.

ptrace_detach() should follow the ptrace_exit's logic, change the code
accordingly.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Tested-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>