Coccinelle archive mirror
 help / color / mirror / Atom feed
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: Wed, 19 Mar 2025 14:30:14 -0700	[thread overview]
Message-ID: <202503191424.2FA8A7E@keescook> (raw)
In-Reply-To: <8714afb-4938-9beb-9f0-4a4972f4b81@inria.fr>

On Wed, Mar 19, 2025 at 08:44:38AM +0100, Julia Lawall wrote:
> On Tue, 18 Mar 2025, Kees Cook wrote:
> > On Tue, Mar 18, 2025 at 06:56:40PM +0100, Julia Lawall wrote:
> > > I think you want
> > >
> > > Expression *m;
> > >
> > > A->@m b
> > >
> > > B would be an identifier
> >
> > But how does "B" get correctly type restricted? (Or in my example,
> > "NAME"?)
> >
> > I tried:
> >
> > @direct depends on !(file in "tools") && !(file in "samples")@
> > type TYPE;
> > TYPE *P;
> > TYPE *MEMBER;
> > TYPE INST;
> > identifier NAME;
> > expression COMP;
> > identifier ALLOC =~ "^kv?[mz]alloc";
> > fresh identifier ALLOC_OBJ = ALLOC ## "_obj";
> > @@
> >
> >        \(\(P\|COMP.@MEMBER NAME\|COMP->@MEMBER NAME\) \& VAR\)
> > -       = ALLOC((\(sizeof(*VAR)\|sizeof(TYPE)\|sizeof(INST)\)), GFP);
> > +       = ALLOC_OBJ(*VAR, GFP);
> >
> > This parses, but don't match (from crypto/asymmetric_keys/x509_cert_parser.c):
> >
> > 	cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
> >
> > But does match (via "P"):
> >
> > 	cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
> 
> What is the command line, eg --all-includes?  You can try
> --verbose-includes to see what is happening with #include "x509_parser.h"

Okay, my hiccups continue.

I do not seem to be able to mix a "type" metavariable with anything else.
For example, instead of these rules repeated:

@direct depends on patch@
type TYPE;
TYPE INST;
identifier PTR;
expression GFP;
expression TYPED;
identifier ALLOC =~ "^kv?[mz]alloc$";
fresh identifier ALLOC_OBJ = ALLOC ## "_obj";
@@

(
        TYPE *PTR
-       = ALLOC((sizeof(*PTR)), GFP);
+       = ALLOC_OBJ(*PTR, GFP);
|
        TYPE *PTR
-       = ALLOC((sizeof(INST)), GFP);
+       = ALLOC_OBJ(INST, GFP);
|
        TYPE *PTR
-       = ALLOC((sizeof(TYPE)), GFP);
+       = ALLOC_OBJ(TYPE, GFP);
)

I wanted to write it as:

        TYPE *PTR
-       = ALLOC((sizeof(\(\(*PTR\|INST\|TYPE\) \& TYPED\))), GFP);
+       = ALLOC_OBJ(TYPED, GFP);

But this doesn't let me even put "TYPE" in the \( \) at all, much less
put it into the TYPED expression:

minus: parse error: 
  File "scripts/coccinelle/api/kmalloc_objs.cocci", line 55, column 34, charpos = 1235
  around = 'TYPE',
  whole content = -     = ALLOC((sizeof(\(\(*PTR\|INST\|TYPE\) \& TYPED\))), GFP);

How do I collapse these three into 1 rule?

-- 
Kees Cook

  parent reply	other threads:[~2025-03-21 13:45 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
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 [this message]
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=202503191424.2FA8A7E@keescook \
    --to=kees@kernel.org \
    --cc=cocci@inria.fr \
    --cc=julia.lawall@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).