From: Will Deacon <will.deacon@arm.com>
To: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Kees Cook <keescook@chromium.org>,
Catalin Marinas <Catalin.Marinas@arm.com>,
Deepak Saxena <dsaxena@linaro.org>,
"arndb@arndb.de" <arndb@arndb.de>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linaro-kernel@lists.linaro.org" <linaro-kernel@lists.linaro.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 2/6] arm64: ptrace: allow tracer to skip a system call
Date: Fri, 3 Oct 2014 16:23:28 +0100 [thread overview]
Message-ID: <20141003152328.GB32451@arm.com> (raw)
In-Reply-To: <542BE095.3010107@linaro.org>
On Wed, Oct 01, 2014 at 12:08:05PM +0100, AKASHI Takahiro wrote:
> Will,
>
> When I was looking into syscall_trace_exit() more closely, I found
> another (big) problem.
> There are two system calls, execve() and rt_sigreturn(), which change
> 'syscallno' in pt_regs to -1 in start_thread() and restore_sigframe(),
> respectively.
>
> Since syscallno is not valid anymore in syscall_trace_exit() for these
> system calls, we cannot create a correct syscall exit record for tracepoint
> in trace_sys_exit() (=> ftrace_syscall_exit()) and for audit in audit_syscall_exit().
>
> This does not happen on arm because syscall numbers are kept in
> thread_info on arm.
>
> How can we deal with this issue?
How is this handled on other architectures? x86, for example, seems to zero
orig_ax when restoring the sigcontext, but leaves it alone in start_thread.
What is the impact of this problem? AFAICT, we just miss some exits, right
(as opposed to an OOPs or the like)?
Will
next prev parent reply other threads:[~2014-10-03 15:23 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-21 8:56 [PATCH v6 0/6] arm64: add seccomp support AKASHI Takahiro
2014-08-21 8:56 ` [PATCH v6 1/6] arm64: ptrace: add PTRACE_SET_SYSCALL AKASHI Takahiro
2014-08-21 16:47 ` Kees Cook
2014-08-22 0:19 ` AKASHI Takahiro
2014-08-26 17:46 ` Will Deacon
2014-08-27 5:32 ` AKASHI Takahiro
2014-09-03 18:34 ` Kees Cook
2014-08-21 8:56 ` [PATCH v6 2/6] arm64: ptrace: allow tracer to skip a system call AKASHI Takahiro
2014-08-21 17:08 ` Kees Cook
2014-08-22 0:35 ` AKASHI Takahiro
2014-08-26 17:51 ` Will Deacon
2014-08-27 5:55 ` AKASHI Takahiro
2014-09-01 11:37 ` Will Deacon
2014-09-02 7:58 ` AKASHI Takahiro
2014-09-01 11:47 ` Russell King - ARM Linux
2014-09-02 8:47 ` AKASHI Takahiro
2014-09-02 9:16 ` Russell King - ARM Linux
2014-09-02 9:31 ` Russell King - ARM Linux
2014-09-05 10:08 ` AKASHI Takahiro
2014-10-01 11:08 ` AKASHI Takahiro
2014-10-03 15:23 ` Will Deacon [this message]
2014-10-06 8:04 ` AKASHI Takahiro
2014-08-21 8:56 ` [PATCH v6 3/6] asm-generic: add generic seccomp.h for secure computing mode 1 AKASHI Takahiro
2014-08-21 17:51 ` Kees Cook
2014-08-22 0:38 ` AKASHI Takahiro
2014-08-21 8:56 ` [PATCH v6 4/6] arm64: add seccomp syscall for compat task AKASHI Takahiro
2014-08-21 17:52 ` Kees Cook
2014-08-22 0:39 ` AKASHI Takahiro
2014-08-26 17:53 ` Will Deacon
2014-08-27 5:57 ` AKASHI Takahiro
2014-08-21 8:56 ` [PATCH v6 5/6] arm64: add SIGSYS siginfo " AKASHI Takahiro
2014-08-21 17:54 ` Kees Cook
2014-08-22 0:44 ` AKASHI Takahiro
2014-08-26 17:55 ` Will Deacon
2014-08-27 5:58 ` AKASHI Takahiro
2014-08-21 8:56 ` [PATCH v6 6/6] arm64: add seccomp support AKASHI Takahiro
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