Re: [PATCH V9 13/24] LoongArch: Add system call support

[Arnd Bergmann <arnd@arndb.de>]

On Sat, Apr 30, 2022 at 12:05 PM Huacai Chen <chenhuacai@gmail.com> wrote:
> On Sat, Apr 30, 2022 at 5:45 PM Arnd Bergmann <arnd@arndb.de> wrote:
> > On Sat, Apr 30, 2022 at 11:05 AM Huacai Chen <chenhuacai@loongson.cn> wrote:
> > >
> > > This patch adds system call support and related uaccess.h for LoongArch.
> > >
> > > Q: Why keep __ARCH_WANT_NEW_STAT definition while there is statx:
> > > A: Until the latest glibc release (2.34), statx is only used for 32-bit
> > >    platforms, or 64-bit platforms with 32-bit timestamp. I.e., Most 64-
> > >    bit platforms still use newstat now.
> > >
> > > Q: Why keep _ARCH_WANT_SYS_CLONE definition while there is clone3:
> > > A: The latest glibc release (2.34) has some basic support for clone3 but
> > >    it isn't complete. E.g., pthread_create() and spawni() have converted
> > >    to use clone3 but fork() will still use clone. Moreover, some seccomp
> > >    related applications can still not work perfectly with clone3. E.g.,
> > >    Chromium sandbox cannot work at all and there is no solution for it,
> > >    which is more terrible than the fork() story [1].
> > >
> > > [1] https://chromium-review.googlesource.com/c/chromium/src/+/2936184
> >
> > I still think these have to be removed. There is no mainline glibc or musl
> > port yet, and neither of them should actually be required. Please remove
> > them here, and modify your libc patches accordingly when you send those
> > upstream.
>
> If this is just a problem that can be resolved by upgrading
> glibc/musl, I will remove them. But the Chromium problem (or sandbox
> problem in general) seems to have no solution now.

I added Christian Brauner to Cc now, maybe he has come across the
sandbox problem before and has an idea for a solution.

        Arnd