ptrace: kill BKL in ptrace syscall

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: Arnd Bergmann <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
Acked-by: Oleg Nesterov <[email protected]>
Acked-by: Roland McGrath <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Roland McGrath <[email protected]>

0 files changed, 0 insertions, 0 deletions