On Tue, Sep 20, 2016 at 10:25:16PM -0500, Josh Poimboeuf wrote: > 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. > */ > GLOBAL_ENTRY(ia64_invoke_schedule_tail) > ...
(But I should note that I'm a complete ia64 neophyte, so I could be misreading that...) -- Josh
