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Message-ID: <530497DD.2020806@linaro.org>
Date: Wed, 19 Feb 2014 20:39:09 +0900
From: AKASHI Takahiro <takahiro.akashi@linaro.org>
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To: Catalin Marinas <catalin.marinas@arm.com>
CC: "wad@chromium.org" <wad@chromium.org>, Will Deacon <Will.Deacon@arm.com>,
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Subject: Re: [PATCH 1/2] arm64: Add seccomp support
References: <1391767892-5395-1-git-send-email-takahiro.akashi@linaro.org> <1391767892-5395-2-git-send-email-takahiro.akashi@linaro.org> <20140218153856.GB904@localhost>
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On 02/19/2014 12:38 AM, Catalin Marinas wrote:
> On Fri, Feb 07, 2014 at 10:11:31AM +0000, AKASHI Takahiro wrote:
>> --- a/arch/arm64/kernel/ptrace.c
>> +++ b/arch/arm64/kernel/ptrace.c
>> @@ -26,6 +26,7 @@
>>   #include <linux/smp.h>
>>   #include <linux/ptrace.h>
>>   #include <linux/user.h>
>> +#include <linux/seccomp.h>
>>   #include <linux/security.h>
>>   #include <linux/init.h>
>>   #include <linux/signal.h>
>> @@ -1064,6 +1065,10 @@ asmlinkage int syscall_trace(int dir, struct pt_regs *regs)
>>   {
>>   	unsigned long saved_reg;
>>
>> +	if (!dir && secure_computing((int)regs->syscallno))
>> +		/* seccomp failures shouldn't expose any additional code. */
>> +		return -1;
>
> That's only restricted to the arm64 code but could we use a more
> meaningful error number?

Other architectures, including arm, also return just -1 in syscall_trace_enter(),
but of course, we can use another value, say, -EPERM or -ENOSYS?

-Takahiro AKASHI