Re: [PATCH v2 1/1] linux-user/signal: Decode waitid si_code

[Alistair Francis]

On Thu, Jan 21, 2021 at 7:15 AM Andreas K. Hüttel <dilfridge@gentoo.org> wrote:
>
> Am Mittwoch, 20. Januar 2021, 22:12:30 EET schrieb Andreas K. Hüttel:
> > > This patch just passes the waitid status directly back to the guest.
> >
> > This works at least as well as the previous versions, so ++ from me.
> >
> > Will do more testing over the next days to see if it maybe also improves the
> > additional oddities I observed.
> >
>
> So the patch is good since it clearly resolves the linked bug.
>
> However, something else is still broken (maybe related; unchanged compared to
> the previous patch version). I keep seeing hanging "qemu-riscv32 /bin/bash
> ..." processes using 100% cpu. If I attach strace (on the host arch x86-64) to
> qemu, I see an infinite loop:
>
> waitid(P_ALL, -1, {}, WNOHANG|WEXITED, NULL) = 0
> rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
> rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
> rt_sigprocmask(SIG_SETMASK, [CHLD], NULL, 8) = 0
> rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
> rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
> rt_sigprocmask(SIG_SETMASK, [CHLD], NULL, 8) = 0
> waitid(P_ALL, -1, {}, WNOHANG|WEXITED, NULL) = 0
> rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
> rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
> rt_sigprocmask(SIG_SETMASK, [CHLD], NULL, 8) = 0
> rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
> rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
> rt_sigprocmask(SIG_SETMASK, [CHLD], NULL, 8) = 0
> ...
>
> Unfortunately I do not have a simple reproducer. This is somewhere in the
> middle of our build system...
>
> Otherwise, I can re-build glibc, gcc, binutils, make  in the qemu chroot
> without obvious problems, with one striking strange detail - "make" refuses to
> run more than one concurrent process (even with MAKEOPTS="-j9"). Something is
> off there.

Ping!

Even though it seems like there are still issues with RV32, this is a
step in the right direction.

Alistair

>
> --
> Andreas K. Hüttel
> dilfridge@gentoo.org
> Gentoo Linux developer
> (council, qa, toolchain, base-system, perl, libreoffice)