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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun, 26 Jun 2022 13:54:28 -0700
Message-ID: <CAHk-=wi4snadB1LiV=FAUTpHNumsF=GN=U5vckWaLMbnU5nfQA@mail.gmail.com>
Subject: Re: [RFC[ Alloc in vsprintf
To:     Joe Perches <joe@perches.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        David Laight <David.Laight@aculab.com>,
        Petr Mladek <pmladek@suse.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Matthew Wilcox <willy@infradead.org>,
        Miguel Ojeda <ojeda@kernel.org>,
        Kent Overstreet <kent.overstreet@gmail.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>
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On Sun, Jun 26, 2022 at 1:39 PM Joe Perches <joe@perches.com> wrote:
>
> OK, and that's true for all the temp stack buffers in every %p<foo>.

Yup.

A lot of them are simply due to it just being simple, and when the
temp buffer is of a fairly limited size, "simple is good".

But yeah, that KSYM_SYMBOL_LEN thing was questionable before, and as
it grows with KSYM_NAME_LEN growing, it's getting pretty ridiculous.

For example, the buffer in "number()" looks very reasonable to me,
since it's not only pretty small (24 bytes on 64-bit architectures).
it has that special alignment requirement too.

So I don't think those temporary stack buffers are necessarily wrong
in general, but there's a point where they go from "ok, there's being
_simple_ and then there's _overly_simplistic_".

                   Linus