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Subject: Re: Chromium sandbox on LoongArch and statx -- seccomp deep
 argument inspection again?
From: Xi Ruoyao <xry111@xry111.site>
To: WANG Xuerui <kernel@xen0n.name>, linux-api@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>, Christian Brauner <brauner@kernel.org>, 
 Kees Cook <keescook@chromium.org>, Huacai Chen <chenhuacai@kernel.org>,
 Xuefeng Li <lixuefeng@loongson.cn>, Jianmin Lv <lvjianmin@loongson.cn>,
 Xiaotian Wu <wuxiaotian@loongson.cn>, WANG Rui <wangrui@loongson.cn>, Miao
 Wang <shankerwangmiao@gmail.com>, Icenowy Zheng <uwu@icenowy.me>, 
 "loongarch@lists.linux.dev" <loongarch@lists.linux.dev>, linux-arch
 <linux-arch@vger.kernel.org>, Linux Kernel Mailing List
 <linux-kernel@vger.kernel.org>
Date: Wed, 21 Feb 2024 14:31:02 +0800
In-Reply-To: <599df4a3-47a4-49be-9c81-8e21ea1f988a@xen0n.name>
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On Wed, 2024-02-21 at 14:09 +0800, WANG Xuerui wrote:

> - just restore fstat and be done with it;
> - add a flag to statx so we can do the equivalent of just fstat(fd,=20
> &out) with statx, and ensuring an error happens if path is not empty in=
=20
> that case;

It's worse than "just restore fstat" considering the performance.  Read
this thread:
https://sourceware.org/pipermail/libc-alpha/2023-September/151320.html

> - tackle the long-standing problem of seccomp deep argument inspection (!=
).

Frankly I'm never a fan of syscall blocklisting.  When I develop the
Online Judge system for the programming contest training in Xidian
University I deliberately avoid using seccomp.  This thing is very
likely to break innocent programs with some system change innocent as
well (for example Glibc or libstdc++ update).

--=20
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University