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From: Julia Lawall <Julia.Lawall@inria.fr>
To: Kees Cook <kees@kernel.org>
Cc: cocci@inria.fr
Subject: Re: [cocci] __free() attribute inhibits matching?
Date: Mon, 17 Mar 2025 21:59:55 +0100	[thread overview]
Message-ID: <26B3A647-3A45-425C-B758-6CC6DCEF5A6C@inria.fr> (raw)
In-Reply-To: <202503171135.B1CCC51FA@keescook>


Sent from my iPhone

> On 17 Mar 2025, at 19:44, Kees Cook <kees@kernel.org> wrote:
> 
> Hi!
> 
> It seems that the mere presence of the "__free" attribute breaks
> matching:
> 
> $ cat test.c
> static void why(void)
> {
>        u64 *rates_64 __free(kfree) = NULL;
>        rates_64 = kcalloc(count, sizeof(*rates_64), GFP_KERNEL);
> }
> 
> $ cat match.cocci
> @replace@
> expression THING, COUNT;
> expression GFP;
> @@
> 
> -       kcalloc(COUNT, sizeof(*THING), GFP)
> +       kzalloc_objs(*THING, COUNT, GFP)
> 
> 
> $ spatch --very-quiet --cocci-file match.cocci test.c
> 
> 
> Which doesn't match. If I comment out the "__free()" it works:
> 
> $ cat test.c
> static void why(void)
> {
>        u64 *rates_64 /*__free(kfree)*/ = NULL;
>        rates_64 = kcalloc(count, sizeof(*rates_64), GFP_KERNEL);
> }
> 
> $ spatch --very-quiet --cocci-file match.cocci test.c
> --- test.c
> +++ cocci-output-1466652-b8a5c5-test.c
> @@ -1,5 +1,5 @@
> static void why(void)
> {
>        u64 *rates_64 /*__free(kfree)*/ = NULL;
> -       rates_64 = kcalloc(count, sizeof(*rates_64), GFP_KERNEL);
> +       rates_64 = kzalloc_objs(*rates_64, count, GFP_KERNEL);
> }
> 
> 
> I have tried adding "attribute name __free;" to the rule (which didn't
> seem sane, but also didn't work). I have tried adding this line to my
> standard.h:
> #define __free(x) MACROANNOTATION

Try the above with an empty definition.

> but that didn't work either.
> 
> What is going wrong here?
> 
> Thanks!
> 
> -Kees
> 
> --
> Kees Cook


  reply	other threads:[~2025-03-17 21:00 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 [this message]
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
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

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