Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220430090518.3127980-1-chenhuacai@loongson.cn> <20220430090518.3127980-14-chenhuacai@loongson.cn>
In-Reply-To: <20220430090518.3127980-14-chenhuacai@loongson.cn>
From:   Arnd Bergmann <arnd@arndb.de>
Date:   Sat, 30 Apr 2022 11:44:47 +0200
Message-ID: <CAK8P3a0A9dW4mwJ6JHDiJxizL7vWfr4r4c5KhbjtAY0sWbZJVA@mail.gmail.com>
Subject: Re: [PATCH V9 13/24] LoongArch: Add system call support
To:     Huacai Chen <chenhuacai@loongson.cn>
Cc:     Arnd Bergmann <arnd@arndb.de>, Andy Lutomirski <luto@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        David Airlie <airlied@linux.ie>,
        Jonathan Corbet <corbet@lwn.net>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Xuefeng Li <lixuefeng@loongson.cn>,
        Yanteng Si <siyanteng@loongson.cn>,
        Huacai Chen <chenhuacai@gmail.com>,
        Guo Ren <guoren@kernel.org>, Xuerui Wang <kernel@xen0n.name>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

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.

       Arnd