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From: Huacai Chen <chenhuacai@kernel.org>
Date: Sat, 15 Jun 2024 17:29:10 +0800
Message-ID: <CAAhV-H4R_HJAB0baqUgA8ucbwWNVN4sc9EV91zAk9Ch302_7zg@mail.gmail.com>
Subject: Re: [PATCH] LoongArch: Define __ARCH_WANT_NEW_STAT in unistd.h
To: Xi Ruoyao <xry111@xry111.site>
Cc: Arnd Bergmann <arnd@arndb.de>, Huacai Chen <chenhuacai@loongson.cn>, loongarch@lists.linux.dev, 
	Linux-Arch <linux-arch@vger.kernel.org>, Xuefeng Li <lixuefeng@loongson.cn>, 
	guoren <guoren@kernel.org>, WANG Xuerui <kernel@xen0n.name>, 
	Jiaxun Yang <jiaxun.yang@flygoat.com>, linux-kernel@vger.kernel.org, 
	loongson-kernel@lists.loongnix.cn, stable@vger.kernel.org
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On Sat, Jun 15, 2024 at 4:55=E2=80=AFPM Xi Ruoyao <xry111@xry111.site> wrot=
e:
>
> On Sat, 2024-06-15 at 16:52 +0800, Huacai Chen wrote:
> > Hi, Arnd,
> >
> > On Sun, May 12, 2024 at 3:53=E2=80=AFPM Arnd Bergmann <arnd@arndb.de> w=
rote:
> > >
> > > On Sun, May 12, 2024, at 05:11, Huacai Chen wrote:
> > > > On Sat, May 11, 2024 at 11:39=E2=80=AFPM Arnd Bergmann <arnd@arndb.=
de> wrote:
> > > > > On Sat, May 11, 2024, at 16:28, Huacai Chen wrote:
> > > > > > On Sat, May 11, 2024 at 8:17=E2=80=AFPM Arnd Bergmann <arnd@arn=
db.de> wrote:
> > > > > CONFIG_COMPAT_32BIT_TIME is equally affected here. On riscv32
> > > > > this is the only allowed configuration, while on others (arm32
> > > > > or x86-32 userland) you can turn off COMPAT_32BIT_TIME on
> > > > > both 32-bit kernel and on 64-bit kernels with compat mode.
> > > > I don't know too much detail, but I think riscv32 can do something
> > > > similar to arm32 and x86-32, or we can wait for Xuerui to improve
> > > > seccomp. But there is no much time for loongarch because the Debian
> > > > loong64 port is coming soon.
> > >
> > > What I meant is that the other architectures only work by
> > > accident if COMPAT_32BIT_TIME is enabled and statx() gets
> > > blocked, but then they truncate the timestamps to the tim32
> > > range, which is not acceptable behavior. Actually mips64 is
> > > in the same situation because it also only supports 32-bit
> > > timestamps in newstatat(), despite being a 64-bit
> > > architecture with a 64-bit time_t in all other syscalls.
> > We can only wait for the seccomp side to be fixed now? Or we can get
> > this patch upstream for LoongArch64 at the moment, and wait for
> > seccomp to fix RISCV32 (and LoongArch32) in future?
>
> I'm wondering why not just introduce a new syscall or extend statx with
> a new flag, as we've discussed many times.  They have their own
> disadvantages but better than this, IMO.
We should move things forward, in any way. :)

Huacai

>
> --
> Xi Ruoyao <xry111@xry111.site>
> School of Aerospace Science and Technology, Xidian University
>