From: Steven Rostedt <rostedt@goodmis.org>
To: Kees Cook <kees@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Linux Trace Kernel <linux-trace-kernel@vger.kernel.org>,
Thorsten Blum <thorsten.blum@linux.dev>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
David Laight <david.laight.linux@gmail.com>
Subject: Re: [PATCH] unwind: Show that entries of struct unwind_cache is not bound by nr_entries
Date: Wed, 17 Dec 2025 15:11:59 -0500 [thread overview]
Message-ID: <20251217151159.2eee1081@gandalf.local.home> (raw)
In-Reply-To: <202511171303.1623D77@keescook>
On Mon, 17 Nov 2025 13:28:59 -0800
Kees Cook <kees@kernel.org> wrote:
> struct unwind_cache {
> struct_group_tagged(unwind_cache_hdr, hdr,
> unsigned long unwind_completed;
> unsigned int nr_entries;
> );
> unsigned long entries[(SZ_4K - sizeof(struct unwind_cache_hdr)) / sizeof(long)];
> };
This may help automated tooling, but it is horrendous to read. I value
readability much higher than static analyzers.
Hence, I'm leaving the code as is, and just keep NAKing patches that try to
add __counted_by() to entries.
-- Steve
>
> #define UNWIND_MAX_ENTRIES ARRAY_SIZE(((struct unwind_cache*)NULL)->entries)
>
> And this checks out for me:
>
> UNWIND_MAX_ENTRIES:510
> sizeof(struct unwind_cache):4096
>
> No hiding things from the compiler, and you can treat "entries" like a
> real array (since it is one now).
prev parent reply other threads:[~2025-12-17 20:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-14 17:13 [PATCH] unwind: Show that entries of struct unwind_cache is not bound by nr_entries Steven Rostedt
2025-11-17 21:28 ` Kees Cook
2025-12-17 20:11 ` Steven Rostedt [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20251217151159.2eee1081@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=david.laight.linux@gmail.com \
--cc=gustavoars@kernel.org \
--cc=jpoimboe@kernel.org \
--cc=kees@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=thorsten.blum@linux.dev \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox