Messages in this thread | | | Date | Tue, 10 Apr 2012 20:20:53 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH v15 04/13] arch/x86: add syscall_get_arch to syscall.h |
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On 04/10/2012 08:13 PM, Will Drewry wrote: > On Sun, Mar 25, 2012 at 2:34 PM, H. Peter Anvin <hpa@zytor.com> 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? >
Sorry, answered the wrong question. Yes, it is the same as above... just wandered if we could centralize this test. It might indeed make sense to provide general predicates which take a task pointer.
-hpa
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