Re: [PATCH v5 0/3] arm64: Add seccomp support

From: Kees Cook <keescook@chromium.org>
To: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Will Drewry <wad@chromium.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	dsaxena@linaro.org,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	linaro-kernel@lists.linaro.org,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5 0/3] arm64: Add seccomp support
Date: Tue, 22 Jul 2014 13:16:41 -0700	[thread overview]
Message-ID: <CAGXu5j+1huPbBKH25HK6PmAL3Mi-zgD5UDRp-6wx8vuPVOBDEg@mail.gmail.com> (raw)
In-Reply-To: <1406020499-5537-1-git-send-email-takahiro.akashi@linaro.org>

On Tue, Jul 22, 2014 at 2:14 AM, AKASHI Takahiro
<takahiro.akashi@linaro.org> wrote:
> (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 [3/3]

Thanks for working on this!

> Prerequisites are:
>  * "arm64: Add audit support" patch
>
> 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.
>  * modified version of Kees' seccomp test for 'changing/skipping a syscall'
>    behavior

Would you be able to share this? I'd love to add it to the seccomp
regression suite for the arm64-specific parts.

Thanks!

-Kees

>
> 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 (3):
>   arm64: ptrace: reload a syscall number after ptrace operations
>   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        |    2 ++
>  arch/arm64/kernel/ptrace.c       |   18 ++++++++++++++++++
>  include/asm-generic/seccomp.h    |   28 ++++++++++++++++++++++++++++
>  6 files changed, 90 insertions(+)
>  create mode 100644 arch/arm64/include/asm/seccomp.h
>  create mode 100644 include/asm-generic/seccomp.h
>
> --
> 1.7.9.5
>

-- 
Kees Cook
Chrome OS Security