Re: [RFC] de-asmify the x86-64 system call slowpath

[Oleg Nesterov]

On 01/27, Al Viro wrote:
>
> BTW, there's an additional pile of obfuscation:
> /* work to do on interrupt/exception return */
> #define _TIF_WORK_MASK                                                  \
>         (0x0000FFFF &                                                   \
>          ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|                       \
>            _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
>
> /* work to do on any return to user space */
> #define _TIF_ALLWORK_MASK                                               \
>         ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT |       \
>         _TIF_NOHZ)

Heh, yes ;)

> Why is _TIF_UPROBE *not* a part
> of _TIF_DO_NOTIFY_MASK, for example?

Yes, please see another email. That is why uprobe_deny_signal()
sets TIF_NOTIFY_RESUME along with TIF_UPROBE.

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/