[PATCH v6 0/6] arm64: add seccomp support

[AKASHI Takahiro]

This patch series enable secure computing (system call filtering) on arm64,
and contain related enhancements and bug fixes.

This code was tested on ARMv8 fast model with 64-bit/32-bit userspace
using
 * libseccomp v2.1.1 with modifications for arm64, especially its "live"
   tests: No.20, 21 and 24.
 * modified version of Kees' seccomp test for 'changing/skipping a syscall'
   and seccomp() system call
 * in-house tests for 'changing/skipping a system call' in tracing with
   ptrace(PTRACE_SYSCALL) (that is, without seccomp)'
with and without audit tracing.

Changes v5 -> v6:
* rebased to v3.17-rc
* changed the interface of changing/skipping a system call from re-writing
  x8 register [v5 1/3] to using dedicated PTRACE_SET_SYSCALL command
  [1/6, 2/6]
  Patch [1/6] contains a checkpatch error around a switch statement, but it
  won't be fixed as in compat_arch_ptrace().
* added a new system call, seccomp(), for compat task [4/6]
* added SIGSYS siginfo for compat task [5/6]
* changed to always execute audit exit tracing to avoid OOPs [2/6, 6/6]

Changes v4 -> v5:
* rebased to v3.16-rc
* add patch [1/3] to allow ptrace to change a system call
  (please note that this patch should be applied even without seccomp.)

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 (6):
  arm64: ptrace: add PTRACE_SET_SYSCALL
  arm64: ptrace: allow tracer to skip a system call
  asm-generic: add generic seccomp.h for secure computing mode 1
  arm64: add seccomp syscall for compat task
  arm64: add SIGSYS siginfo for compat task
  arm64: add seccomp support

 arch/arm64/Kconfig                   |   14 ++++++++++++
 arch/arm64/include/asm/compat.h      |    7 ++++++
 arch/arm64/include/asm/ptrace.h      |    9 ++++++++
 arch/arm64/include/asm/seccomp.h     |   25 ++++++++++++++++++++++
 arch/arm64/include/asm/unistd.h      |    5 ++++-
 arch/arm64/include/asm/unistd32.h    |    3 +++
 arch/arm64/include/uapi/asm/ptrace.h |    1 +
 arch/arm64/kernel/entry.S            |    6 ++++++
 arch/arm64/kernel/ptrace.c           |   39 +++++++++++++++++++++++++++++++++-
 arch/arm64/kernel/signal32.c         |    8 +++++++
 include/asm-generic/seccomp.h        |   28 ++++++++++++++++++++++++
 11 files changed, 143 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm64/include/asm/seccomp.h
 create mode 100644 include/asm-generic/seccomp.h

-- 
1.7.9.5