[PATCH v9 2/6] arch: move SA_* definitions to generic headers

[Peter Collingbourne]

On Wed, Aug 19, 2020 at 12:14 AM Geert Uytterhoeven
<geert at linux-m68k.org> wrote:
>
> Hi Peter,
>
> On Tue, Aug 18, 2020 at 5:39 AM Peter Collingbourne <pcc at google.com> wrote:
> > Most architectures with the exception of alpha, mips, parisc and
> > sparc use the same values for these flags. Move their definitions into
> > asm-generic/signal-defs.h and allow the architectures with non-standard
> > values to override them. Also, document the non-standard flag values
> > in order to make it easier to add new generic flags in the future.
> >
> > Signed-off-by: Peter Collingbourne <pcc at google.com>
>
> Thanks for your patch!
>
> >  arch/m68k/include/uapi/asm/signal.h    | 24 -------------
>
> Acked-by: Geert Uytterhoeven <geert at linux-m68k.org>
>
> > --- a/include/uapi/asm-generic/signal-defs.h
> > +++ b/include/uapi/asm-generic/signal-defs.h
> > @@ -4,6 +4,53 @@
> >
> >  #include <linux/compiler.h>
> >
> > +/*
> > + * SA_FLAGS values:
> > + *
> > + * SA_ONSTACK indicates that a registered stack_t will be used.
> > + * SA_RESTART flag to get restarting signals (which were the default long ago)
> > + * SA_NOCLDSTOP flag to turn off SIGCHLD when children stop.
> > + * SA_RESETHAND clears the handler when the signal is delivered.
> > + * SA_NOCLDWAIT flag on SIGCHLD to inhibit zombies.
> > + * SA_NODEFER prevents the current signal from being masked in the handler.
>
> Perhaps the order should match the order of the definitions below?
> Then it becomes obvious SA_SIGINFO is not documented (it was on arm).

That makes sense. I'll copy the deleted arm comment for SA_SIGINFO here as well.

> > + *
> > + * SA_ONESHOT and SA_NOMASK are the historical Linux names for the Single
> > + * Unix names RESETHAND and NODEFER respectively.
>
> I think moving this last comment below, just above the definitions of
> SA_NOMASK and SA_ONESHOT, would make this easier to read.
>
> > + */
> > +#ifndef SA_NOCLDSTOP
> > +#define SA_NOCLDSTOP   0x00000001
> > +#endif
> > +#ifndef SA_NOCLDWAIT
> > +#define SA_NOCLDWAIT   0x00000002
> > +#endif
> > +#ifndef SA_SIGINFO
> > +#define SA_SIGINFO     0x00000004
> > +#endif
> > +#ifndef SA_ONSTACK
> > +#define SA_ONSTACK     0x08000000
> > +#endif
> > +#ifndef SA_RESTART
> > +#define SA_RESTART     0x10000000
> > +#endif
> > +#ifndef SA_NODEFER
> > +#define SA_NODEFER     0x40000000
> > +#endif
> > +#ifndef SA_RESETHAND
> > +#define SA_RESETHAND   0x80000000
> > +#endif
> > +/*
> > + * The following bits are used in architecture-specific SA_* definitions and
> > + * should be avoided for new generic flags: 3, 4, 5, 6, 7, 8, 9, 16, 24, 25, 26.
>
> And I think this belongs to the previous comment block.

I put the comment block here to make it more likely that it will be
seen when adding new flags, but either location is fine with me.

Peter