ptrace: kill BKL in ptrace syscall
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 <f2c659f01951776204a6c5b902787d9019fbeebd@arndb.de>
Signed-off-by: Frederic Weisbecker <e8a1bf9163cb25e93cfd6540f223b3872ea7ee55@gmail.com>
Acked-by: Oleg Nesterov <20b70f0af00562e63758b9ee42012ecc96c58590@redhat.com>
Acked-by: Roland McGrath <0d270388f2f92757a5de0f4bd891d3b392c44c4f@redhat.com>
Cc: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Cc: Roland McGrath <0d270388f2f92757a5de0f4bd891d3b392c44c4f@redhat.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs