Re: [PATCH v15 04/13] arch/x86: add syscall_get_arch to syscall.h
From: Will Drewry
Date: Tue Apr 10 2012 - 23:13:59 EST
On Sun, Mar 25, 2012 at 2:34 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> On 03/14/2012 08:11 PM, Will Drewry wrote:
>>
>> +static inline int syscall_get_arch(struct task_struct *task,
>> + struct pt_regs *regs)
>> +{
>> +#ifdef CONFIG_IA32_EMULATION
>> + /*
>> + * TS_COMPAT is set for 32-bit syscall entries and then
>> + * remains set until we return to user mode.
>> + *
>> + * TIF_IA32 tasks should always have TS_COMPAT set at
>> + * system call time.
>> + */
>> + if (task_thread_info(task)->status & TS_COMPAT)
>> + return AUDIT_ARCH_I386;
>> +#endif
>> + return AUDIT_ARCH_X86_64;
>> +}
>> #endif /* CONFIG_X86_32 */
>>
>> #endif /* _ASM_X86_SYSCALL_H */
>
> Just one FYI on this: after the x32 changes are upstream this can be
> implemented in terms of is_ia32_task().
Now that I've seen is_ia32_task(), it appears to be exactly the same as above:
(1) If we're x86_32, it's ia32
(2) If we're x86_64, ia32 == !!(status & TS_COMPAT)
(3) Otherwise, it's x86_64, including x32
Am I missing something? Should is_ia32_task(void) take a task_struct?
Right now, I don't see any reason to change the code, as posted, but
maybe I am mis-reading?
thanks!
will
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