Re: [PATCH v6 5/6] arm64: add SIGSYS siginfo for compat task

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

On 08/27/2014 02:55 AM, Will Deacon wrote:
> On Thu, Aug 21, 2014 at 09:56:44AM +0100, AKASHI Takahiro wrote:
>> SIGSYS is primarily used in secure computing to notify tracer.
>> This patch allows signal handler on compat task to get correct information
>> with SA_SYSINFO specified when this signal is delivered.
>>
>> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
>> ---
>>   arch/arm64/include/asm/compat.h |    7 +++++++
>>   arch/arm64/kernel/signal32.c    |    8 ++++++++
>>   2 files changed, 15 insertions(+)
>>
>> diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
>> index 253e33b..c877915 100644
>> --- a/arch/arm64/include/asm/compat.h
>> +++ b/arch/arm64/include/asm/compat.h
>> @@ -205,6 +205,13 @@ typedef struct compat_siginfo {
>>   			compat_long_t _band;	/* POLL_IN, POLL_OUT, POLL_MSG */
>>   			int _fd;
>>   		} _sigpoll;h
>> +
>> +		/* SIGSYS */
>> +		struct {
>> +			compat_uptr_t _call_addr; /* calling user insn */
>> +			int _syscall;	/* triggering system call number */
>> +			unsigned int _arch;	/* AUDIT_ARCH_* of syscall */
>> +		} _sigsys;
>>   	} _sifields;
>>   } compat_siginfo_t;
>>
>> diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
>> index 1b9ad02..aa550d6 100644
>> --- a/arch/arm64/kernel/signal32.c
>> +++ b/arch/arm64/kernel/signal32.c
>> @@ -186,6 +186,14 @@ int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
>>   		err |= __put_user(from->si_uid, &to->si_uid);
>>   		err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
>>   		break;
>> +#ifdef __ARCH_SIGSYS
>> +	case __SI_SYS:
>> +		err |= __put_user((compat_uptr_t)(unsigned long)
>> +				from->si_call_addr, &to->si_call_addr);
>> +		err |= __put_user(from->si_syscall, &to->si_syscall);
>> +		err |= __put_user(from->si_arch, &to->si_arch);
>> +		break;
>> +#endif
>
> I think you should drop this #ifdef. We care about whether arch/arm/ defines
> __ARCH_SIGSYS, not whether arm64 defines it (they both happen to define it
> anyway).

Thanks. Done

-Takahiro AKASHI

> Will
>