Re: Dovetail 5.10.y sync

[Florian Bezdeka <florian.bezdeka@siemens.com>]

On Thu, 2023-03-16 at 20:11 +0100, Jan Kiszka wrote:
> On 16.03.23 19:57, Giulio Moro wrote:
> > I am totally not involved with the change at hand, but it looks like it
> > is related to this:
> > 
> >  #define TIF_SIGPENDING        0    /* signal pending */
> >  #define TIF_NEED_RESCHED    1    /* rescheduling necessary */
> >  #define TIF_NOTIFY_RESUME    2    /* callback before returning to user */
> >  #define TIF_FOREIGN_FPSTATE    3    /* CPU's FP state is not current's */
> >  #define TIF_UPROBE        4    /* uprobe breakpoint or singlestep */
> >  #define TIF_FSCHECK        5    /* Check FS is USER_DS on return */
> >  #define TIF_MTE_ASYNC_FAULT    6    /* MTE Asynchronous Tag Check Fault */
> >  #define TIF_NOTIFY_SIGNAL    7    /* signal notifications exist */
> >  #define TIF_SYSCALL_TRACE    8    /* syscall trace active */
> >  #define TIF_SYSCALL_AUDIT    9    /* syscall auditing */
> >  #define TIF_SYSCALL_TRACEPOINT    10    /* syscall tracepoint for
> > ftrace */
> >  #define TIF_SECCOMP        11    /* syscall secure computing */
> >  #define TIF_SYSCALL_EMU        12    /* syscall emulation active */
> > +#define TIF_RETUSER        13    /* INBAND_TASK_RETUSER is pending */
> > 
> > ...
> > 
> >  #define _TIF_WORK_MASK        (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
> >                   _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \
> >                   _TIF_UPROBE | _TIF_FSCHECK | _TIF_MTE_ASYNC_FAULT | \
> > -                 _TIF_NOTIFY_SIGNAL)
> > +                 _TIF_NOTIFY_SIGNAL | _TIF_RETUSER)
> > 
> > as _TIF_RETUSER is (1 << 13), then _TIF_WORK_MASK no longer fits into 8
> > bits and can no longer be used as a flexible second operand to AND.
> > Instead, it needs its dedicated MOV instruction.
> > 
> 
> Ah, that makes sense. Thanks for clarifying!

That was the build failure we saw on arm64 a few weeks ago in the rt-
stable tree...

> 
> Jan
>