1. 10 Apr, 2010 1 commit
    • Arnd Bergmann's avatar
      ptrace: kill BKL in ptrace syscall · 5534ecb2
      Arnd Bergmann authored
      The comment suggests that this usage is stale. There is no bkl in the
      exec path so if there is a race lurking there, the bkl in ptrace is
      not going to help in this regard.
      
      Overview of the possibility of "accidental" races this bkl might
      protect:
      
      - ptrace_traceme() is protected against task removal and concurrent
      read/write on current->ptrace as it locks write tasklist_lock.
      
      - arch_ptrace_attach() is serialized by ptrace_traceme() against
      concurrent PTRACE_TRACEME or PTRACE_ATTACH
      
      - ptrace_attach() is protected the same way ptrace_traceme() and
      in turn serializes arch_ptrace_attach()
      
      - ptrace_check_attach() does its own well described serializing too.
      
      There is no obvious race here.
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: default avatarOleg Nesterov <oleg@redhat.com>
      Acked-by: default avatarRoland McGrath <roland@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Roland McGrath <roland@redhat.com>
      5534ecb2
  2. 30 Mar, 2010 6 commits
  3. 29 Mar, 2010 33 commits