[PATCH v5 0/4] arch/arm: support seccomp

[Kees Cook]

This adds support for seccomp BPF to ARM. When built with the seccomp
improvement patch waiting in linux-next ("seccomp: Make syscall skipping
and nr changes more consistent"), this passes the seccomp regression
test suite: https://github.com/redpig/seccomp

Thanks,

-Kees

---
v5:
 - clean up seccomp failure path, as requested by Will Deacon.
v4:
 - fixed syscall_get_arch, thanks to Will Deacon.
v3:
 - updates suggested by Russell King:
   - reduced scope of expansion
   - leveraged TIF_SYSCALL_WORK bit mask
   - fixed syscall==-1 short-circuit logic
v2:
 - expanded ptrace_syscall_trace() into both callers and do
   secure_computing() hookup there, as requested by Al Viro.