From: Alice Ryhl <aliceryhl@google.com>
To: Fushuai Wang <fushuai.wang@linux.dev>
Cc: tglx@kernel.org, peterz@infradead.org,
mathieu.desnoyers@efficios.com, akpm@linux-foundation.org,
yury.norov@gmail.com, vmalik@redhat.com, kees@kernel.org,
dave.hansen@linux.intel.com, luto@kernel.org, mingo@redhat.com,
bp@alien8.de, hpa@zytor.com, rostedt@goodmis.org,
mhiramat@kernel.org, brauner@kernel.org, jack@suse.cz,
cyphar@cyphar.com, linux-kernel@vger.kernel.org, x86@kernel.org,
linux-trace-kernel@vger.kernel.org, wangfushuai@baidu.com
Subject: Re: [PATCH v2 1/6] uaccess: Add copy_from_user_nul helper
Date: Mon, 12 Jan 2026 09:23:40 +0000 [thread overview]
Message-ID: <aWS9nOj4MAa7pYmS@google.com> (raw)
In-Reply-To: <20260112073039.1185-2-fushuai.wang@linux.dev>
On Mon, Jan 12, 2026 at 03:30:34PM +0800, Fushuai Wang wrote:
> From: Fushuai Wang <wangfushuai@baidu.com>
>
> Many places call copy_from_user() to copy a buffer from user space,
> and then manually add a NULL terminator to the destination buffer,
> e.g.:
>
> if (copy_from_user(dest, src, len))
> return -EFAULT;
> dest[len] = '\0';
>
> This is repetitive and error-prone. Add a copy_from_user_nul() helper to
> simplify such patterns. It copied n bytes from user space to kernel space,
> and NUL-terminates the destination buffer.
>
> Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Hmm, this function is very very similar to strncpy_from_user(). Should
they be using that instead?
Alice
next prev parent reply other threads:[~2026-01-12 9:23 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-12 7:30 [PATCH v2 0/6] uaccess: Introduce copy_from_user_nul helper Fushuai Wang
2026-01-12 7:30 ` [PATCH v2 1/6] uaccess: Add " Fushuai Wang
2026-01-12 9:23 ` Alice Ryhl [this message]
2026-01-12 10:00 ` Fushuai Wang
2026-01-12 11:20 ` Alice Ryhl
2026-01-12 12:22 ` Fushuai Wang
2026-01-12 13:22 ` Borislav Petkov
2026-01-12 15:40 ` Alice Ryhl
2026-01-12 16:28 ` Steven Rostedt
2026-01-12 16:37 ` Alice Ryhl
2026-01-13 18:00 ` Yury Norov
2026-01-13 18:17 ` Yury Norov
2026-01-16 8:42 ` Fushuai Wang
2026-01-12 7:30 ` [PATCH v2 2/6] x86/tlb: Use copy_from_user_nul() instead of copy_from_user() Fushuai Wang
2026-01-12 7:30 ` [PATCH v2 3/6] tracing: " Fushuai Wang
2026-01-12 15:43 ` Steven Rostedt
2026-01-13 17:05 ` Yury Norov
2026-01-13 18:03 ` Steven Rostedt
2026-01-12 7:30 ` [PATCH v2 4/6] userns: " Fushuai Wang
2026-01-12 7:30 ` [PATCH v2 5/6] time: " Fushuai Wang
2026-01-12 7:30 ` [PATCH v2 6/6] kstrtox: " Fushuai Wang
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