[RESEND PATCH v4 0/2] arm64: Add seccomp support

[takahiro.akashi@linaro.org (AKASHI Takahiro)]

(I don't think that discussions below about ptrace() have impact on
this patchset.
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-July/268923.html
)

(Please apply this patch after my audit patch in order to avoid some
conflict on arm64/Kconfig.)

This patch enables secure computing (system call filtering) on arm64.
System calls can be allowed or denied by loaded bpf-style rules.
Architecture specific part is to run secure_computing() on syscall entry
and check the result. See [2/2]

This code is tested on ARMv8 fast model using libseccomp v2.1.1 with
modifications for arm64 and verified by its "live" tests, 20, 21 and 24.

Changes v3 -> v4:
* removed the following patch and moved it to "arm64: prerequisites for
  audit and ftrace" patchset since it is required for audit and ftrace in
  case of !COMPAT, too.
  "arm64: is_compat_task is defined both in asm/compat.h and linux/compat.h"

Changes v2 -> v3:
* removed unnecessary 'type cast' operations [2/3]
* check for a return value (-1) of secure_computing() explicitly [2/3]
* aligned with the patch, "arm64: split syscall_trace() into separate
  functions for enter/exit" [2/3]
* changed default of CONFIG_SECCOMP to n [2/3]

Changes v1 -> v2:
* added generic seccomp.h for arm64 to utilize it [1,2/3] 
* changed syscall_trace() to return more meaningful value (-EPERM)
  on seccomp failure case [2/3]
* aligned with the change in "arm64: make a single hook to syscall_trace()
  for all syscall features" v2 [2/3]
* removed is_compat_task() definition from compat.h [3/3]

AKASHI Takahiro (2):
  asm-generic: Add generic seccomp.h for secure computing mode 1
  arm64: Add seccomp support

 arch/arm64/Kconfig               |   14 ++++++++++++++
 arch/arm64/include/asm/seccomp.h |   25 +++++++++++++++++++++++++
 arch/arm64/include/asm/unistd.h  |    3 +++
 arch/arm64/kernel/entry.S        |    4 ++++
 arch/arm64/kernel/ptrace.c       |    6 ++++++
 include/asm-generic/seccomp.h    |   28 ++++++++++++++++++++++++++++
 6 files changed, 80 insertions(+)
 create mode 100644 arch/arm64/include/asm/seccomp.h
 create mode 100644 include/asm-generic/seccomp.h

-- 
1.7.9.5