Re: [musl] SA_RESTORER for rv64?

[enh <enh@google.com>]

yes, that looks like what we have in bionic for riscv64 (and what we
had for mips before it was removed). thanks!

On Wed, Feb 8, 2023 at 1:45 PM Rich Felker <dalias@libc.org> wrote:
>
> On Mon, Feb 06, 2023 at 12:49:53PM -0500, Rich Felker wrote:
> > On Mon, Feb 06, 2023 at 08:51:13AM -0800, enh wrote:
> > > On Sun, Feb 5, 2023 at 3:54 PM Rich Felker <dalias@libc.org> wrote:
> > > >
> > > > On Fri, Feb 03, 2023 at 10:44:56AM -0800, enh wrote:
> > > > > oops, never actually sent the patch. attached...
> > > > >
> > > > > On Thu, Nov 10, 2022 at 9:31 AM Khem Raj <raj.khem@gmail.com> wrote:
> > > > > >
> > > > > > On Thu, Nov 10, 2022 at 9:19 AM Rich Felker <dalias@libc.org> wrote:
> > > > > > >
> > > > > > > On Thu, Nov 10, 2022 at 07:44:23AM -0800, enh wrote:
> > > > > > > > arch/riscv64/bits/signal.h has contained a definition for SA_RESTORER since
> > > > > > > > the initial commit, but i think that's just copy & paste from whichever
> > > > > > > > architecture the rv64 headers were based on? the linux kernel itself
> > > > > > > > doesn't have SA_RESTORER for rv64, unless i'm missing something?
> > > > > > >
> > > > > > > I suspect this is just a mistake. Have you seen any ill effects from
> > > > > > > it? If riscv folks can confirm it's wrong, I'll remove it.
> > > > > >
> > > > > > Yeah I think it should be removed. Perhaps mips is in same boat.
> > > > > >
> > > > > > >
> > > > > > > Rich
> > > >
> > > > > From 6413de6d9f785c98e5bc0cf40be947f1169d2fd7 Mon Sep 17 00:00:00 2001
> > > > > From: Elliott Hughes <enh@google.com>
> > > > > Date: Fri, 3 Feb 2023 10:42:55 -0800
> > > > > Subject: [PATCH] risc-v does not have SA_RESTORER.
> > > > >
> > > > > The kernel's include/uapi/asm-generic/signal-defs.h explicitly calls
> > > > > this out as obsolete. New architectures like risc-v do not define it.
> > > > > ---
> > > > >  arch/riscv64/bits/signal.h | 1 -
> > > > >  1 file changed, 1 deletion(-)
> > > > >
> > > > > diff --git a/arch/riscv64/bits/signal.h b/arch/riscv64/bits/signal.h
> > > > > index 287367db..fd6157a3 100644
> > > > > --- a/arch/riscv64/bits/signal.h
> > > > > +++ b/arch/riscv64/bits/signal.h
> > > > > @@ -76,7 +76,6 @@ typedef struct __ucontext
> > > > >  #define SA_RESTART   0x10000000
> > > > >  #define SA_NODEFER   0x40000000
> > > > >  #define SA_RESETHAND 0x80000000
> > > > > -#define SA_RESTORER  0x04000000
> > > > >
> > > > >  #endif
> > > > >
> > > > > --
> > > > > 2.39.1.519.gcb327c4b5f-goog
> > > > >
> > > >
> > > > I don't think this patch works as-is, since musl unconditionally uses
> > > > SA_RESTORER. We probably need to make that conditional on its
> > > > presence, and it looks like there's also a wrong-struct-layout issue
> > > > on archs where it's absent...
> > >
> > > yeah, bionic just uses the kernel uapi headers directly, and they look
> > > like this:
> > >
> > > struct sigaction {
> > >   __sighandler_t sa_handler;
> > >   unsigned long sa_flags;
> > > #ifdef SA_RESTORER
> > >   __sigrestore_t sa_restorer;
> > > #endif
> > >   sigset_t sa_mask;
> > > };
> >
> > OK. It looks like we need to remove the wrong SA_RESTORER for archs
> > that aren't supposed to have it *and* add such an #ifdef. Right now,
> > we're passing bogus sa_mask on these archs... :(
>
> How does the attached look?
>
> Rich