From: Kees Cook <kees@kernel.org>
To: Julia Lawall <Julia.Lawall@inria.fr>
Cc: cocci@inria.fr
Subject: Re: [cocci] __free() attribute inhibits matching?
Date: Tue, 18 Mar 2025 09:30:58 -0700 [thread overview]
Message-ID: <202503180924.2135CF8FD@keescook> (raw)
In-Reply-To: <14B17EC1-3D43-4D47-8A0C-9DFFA06D23E8@inria.fr>
On Tue, Mar 18, 2025 at 04:43:30PM +0100, Julia Lawall wrote:
> > On 18 Mar 2025, at 16:39, Kees Cook <kees@kernel.org> wrote:
> >
> > On Tue, Mar 18, 2025 at 12:13:15AM +0100, Julia Lawall wrote:
> >> It makes the call just disappear.
> >
> > Right, unfortunately this breaks replacement, because the __free
> > vanishes completely even in the replacement:
> >
> > - struct platform_profile_handler *pprof __free(kfree) = kzalloc(
> > - sizeof(*pprof), GFP_KERNEL);
> > + struct platform_profile_handler *pprof = kzalloc_obj(*pprof, GFP_KERNEL);
> >
> > How do we get __free to be treated like any other variable attribute?
> >
>
> It would certainly be good to suppôt it better. But I have the impression that you are removing and recreating the whole part to the left of the equal? It could work better to remove and recreate only the kzalloc call.
Oh! Yes, thank you. That works. :)
Okay, next question. Based on your advise on constructing matches for
arbitrarily long dereferences[1], I am trying to apply the same logic,
but to also tie identifiers to types:
@direct depends on !(file in "tools") && !(file in "samples")@
type TYPE;
TYPE *P;
TYPE *MEMBER;
TYPE INST;
expression COMP;
identifier ALLOC =~ "^kv?[mz]alloc";
fresh identifier ALLOC_OBJ = ALLOC ## "_obj";
@@
\(\(P\|COMP.MEMBER\|COMP->MEMBER\) \& VAR\)
- = ALLOC((\(sizeof(*VAR)\|sizeof(TYPE)\|sizeof(INST)\)), GFP);
+ = ALLOC_OBJ(*VAR, GFP);
This won't parse:
minus: parse error:
File "scripts/coccinelle/api/kmalloc_objs.cocci", line 58, column 13, charpos = 1303
around = 'MEMBER',
whole content = \(\(P\|COMP.MEMBER\|COMP->MEMBER\) \& VAR\)
If I change MEMBER to:
identifier MEMBER;
it parses, but then I lose the association of "MEMBER" being a "TYPE"
pointer. Is there some why to make that work?
Thanks!
-Kees
[1] https://lore.kernel.org/cocci/alpine.DEB.2.22.394.2006182155260.2367@hadrien/
--
Kees Cook
next prev parent reply other threads:[~2025-03-19 9:29 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-17 18:44 [cocci] __free() attribute inhibits matching? Kees Cook
2025-03-17 20:59 ` Julia Lawall
2025-03-17 23:02 ` Kees Cook
2025-03-17 23:13 ` Julia Lawall
2025-03-18 15:39 ` Kees Cook
2025-03-18 15:43 ` Julia Lawall
2025-03-18 16:30 ` Kees Cook [this message]
2025-03-18 17:56 ` Julia Lawall
2025-03-19 3:31 ` Kees Cook
2025-03-19 5:55 ` Julia Lawall
2025-03-19 7:20 ` [cocci] Checking the determination of type information? Markus Elfring
2025-03-19 7:44 ` [cocci] __free() attribute inhibits matching? Julia Lawall
2025-03-19 20:06 ` Kees Cook
2025-03-19 21:30 ` Kees Cook
2025-03-19 23:25 ` Julia Lawall
2025-03-21 13:52 ` Markus Elfring
2025-03-19 10:24 ` Markus Elfring
2025-03-19 10:57 ` Markus Elfring
2025-03-18 17:43 ` Markus Elfring
2025-03-18 18:02 ` Kees Cook
2025-03-18 19:18 ` Markus Elfring
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=202503180924.2135CF8FD@keescook \
--to=kees@kernel.org \
--cc=Julia.Lawall@inria.fr \
--cc=cocci@inria.fr \
/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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).