From: David Laight <david.laight.linux@gmail.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
Arnd Bergmann <arnd@arndb.de>, Kees Cook <kees@kernel.org>
Subject: Re: [PATCH 1/2] uaccess: Simplify code pattern for masked user copies
Date: Sun, 9 Feb 2025 19:02:11 +0000 [thread overview]
Message-ID: <20250209190211.5a11d6d6@pumpkin> (raw)
In-Reply-To: <CAHk-=wjv5x4ee-nKLfwoYwgJ9OqBkd+wqGn-dgWpHdpA2oZqqw@mail.gmail.com>
On Sun, 9 Feb 2025 10:46:03 -0800
Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Sun, 9 Feb 2025 at 10:40, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > It's *really* easy to miss the "oh, that changes X" when the only
> > little tiny sign of it is that "&" character inside the argument list,
> > and then the *normal* mental model is that arguments are arguments
> > *to* the function, not returns *from* the function.
>
> While I'm ranting, this is just another case of "C++ really got this
> very very wrong".
>
> C++ made pass-by-reference really easy, and removed the need for even
> that tiny marker in the caller.
>
> So then you really can't even visually see that "oh, that call changes
> its argument", and have to just know.
Or make a habit of appending '+ 0' to every argument :-)
>
> Linus
next prev parent reply other threads:[~2025-02-09 19:02 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-09 10:55 [PATCH 0/2] uaccess: Add masked_user_read_access_begin David Laight
2025-02-09 10:55 ` [PATCH 1/2] uaccess: Simplify code pattern for masked user copies David Laight
2025-02-09 17:40 ` Linus Torvalds
2025-02-09 18:34 ` David Laight
2025-02-09 18:40 ` Linus Torvalds
2025-02-09 18:46 ` Linus Torvalds
2025-02-09 19:02 ` David Laight [this message]
2025-02-09 19:47 ` David Laight
2025-02-09 20:40 ` Linus Torvalds
2025-02-09 21:18 ` David Laight
2025-02-09 21:38 ` Linus Torvalds
2025-02-09 10:56 ` [PATCH 2/2] fs: Use masked_user_read_access_begin() David Laight
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