On Tue, Sep 20, 2016 at 09:10:55PM -0400, Brian Gerst wrote:
> Dropping asmlinkage from schedule_tail() would be a better option if possible.
My understanding is that it's still needed for ia64. AFAICT, ia64
relies on schedule_tail() having the syscall_linkage function attribute.
>From the gcc manual:
This attribute is used to modify the IA64 calling convention by
marking all input registers as live at all function exits. This makes
it possible to restart a system call after an interrupt without having
to save/restore the input registers. This also prevents kernel data
from leaking into application code.
And the ia64 entry code has some similar language:
* Invoke schedule_tail(task) while preserving in0-in7, which
may be needed
* in case a system call gets restarted.