Re: [PATCH 1/2] linux-user/ppc: Fix sigmask endianness issue in sigreturn

[Ilya Leoshkevich <iii@linux.ibm.com>]

On Fri, 2024-10-25 at 16:53 +0300, Michael Tokarev wrote:
> 17.10.2024 15:54, Ilya Leoshkevich wrote:
> > do_setcontext() copies the target sigmask without endianness
> > handling
> > and then uses target_to_host_sigset_internal(), which expects a
> > byte-swapped one. Use target_to_host_sigset() instead.
> > 
> > Fixes: bcd4933a23f1 ("linux-user: ppc signal handling")
> > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> > ---
> >   linux-user/ppc/signal.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/linux-user/ppc/signal.c b/linux-user/ppc/signal.c
> > index a1d8c0bccc1..24e5a02a782 100644
> > --- a/linux-user/ppc/signal.c
> > +++ b/linux-user/ppc/signal.c
> > @@ -628,7 +628,7 @@ static int do_setcontext(struct target_ucontext
> > *ucp, CPUPPCState *env, int sig)
> >       if (!lock_user_struct(VERIFY_READ, mcp, mcp_addr, 1))
> >           return 1;
> >   
> > -    target_to_host_sigset_internal(&blocked, &set);
> > +    target_to_host_sigset(&blocked, &set);
> >       set_sigmask(&blocked);
> >       restore_user_regs(env, mcp, sig);
> 
> Shouldn't this change be picked for all stable releases too?
> Yes, the issue is very old so probably does not have big impact,
> but it looks like it should be okay to fix it finally?
> 
> I'm picking it up, please let me know if I shouldn't.
> 
> Thanks,
> 
> /mjt

I think it's worth taking it, since it leads to weird qemu-user
crashes. I actually intended to Cc: stable here and forgot to do it,
so thanks for bringing this up.