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From:   Andreas Schwab <schwab@linux-m68k.org>
To:     Marco Elver <elver@google.com>
Cc:     Christophe Leroy <christophe.leroy@csgroup.eu>,
        LKML <linux-kernel@vger.kernel.org>,
        kasan-dev <kasan-dev@googlegroups.com>,
        Alexander Potapenko <glider@google.com>,
        Paul Mackerras <paulus@samba.org>,
        linuxppc-dev@lists.ozlabs.org, Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [RFC PATCH v1] powerpc: Enable KFENCE for PPC32
References: <51c397a23631d8bb2e2a6515c63440d88bf74afd.1614674144.git.christophe.leroy@csgroup.eu>
        <CANpmjNPOJfL_qsSZYRbwMUrxnXxtF5L3k9hursZZ7k9H1jLEuA@mail.gmail.com>
        <b9dc8d35-a3b0-261a-b1a4-5f4d33406095@csgroup.eu>
        <CAG_fn=WFffkVzqC9b6pyNuweFhFswZfa8RRio2nL9-Wq10nBbw@mail.gmail.com>
        <f806de26-daf9-9317-fdaa-a0f7a32d8fe0@csgroup.eu>
        <CANpmjNPGj4C2rr2FbSD+FC-GnWUvJrtdLyX5TYpJE_Um8CGu1Q@mail.gmail.com>
        <3abbe4c9-16ad-c168-a90f-087978ccd8f7@csgroup.eu>
        <CANpmjNMKEObjf=WyfDQB5vPmR5RuyUMBJyfr6P2ykCd67wyMbA__49537.1361424745$1614767987$gmane$org@mail.gmail.com>
Date:   Wed, 03 Mar 2021 11:46:34 +0100
In-Reply-To: <CANpmjNMKEObjf=WyfDQB5vPmR5RuyUMBJyfr6P2ykCd67wyMbA__49537.1361424745$1614767987$gmane$org@mail.gmail.com>
        (Marco Elver's message of "Wed, 3 Mar 2021 11:39:02 +0100")
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On Mär 03 2021, Marco Elver wrote:

> On Wed, 3 Mar 2021 at 11:32, Christophe Leroy
> <christophe.leroy@csgroup.eu> wrote:
>> ./include/linux/kern_levels.h:5:18: warning: format '%zd' expects argument of type 'signed size_t',
>> but argument 3 has type 'ptrdiff_t' {aka 'const long int'} [-Wformat=]
>>      5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
>>        |                  ^~~~~~
>> ./include/linux/kern_levels.h:11:18: note: in expansion of macro 'KERN_SOH'
>>     11 | #define KERN_ERR KERN_SOH "3" /* error conditions */
>>        |                  ^~~~~~~~
>> ./include/linux/printk.h:343:9: note: in expansion of macro 'KERN_ERR'
>>    343 |  printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
>>        |         ^~~~~~~~
>> mm/kfence/report.c:233:3: note: in expansion of macro 'pr_err'
>>    233 |   pr_err("Invalid free of 0x%p (in kfence-#%zd):\n", (void *)address,
>>        |   ^~~~~~
>>
>> Christophe
>
> No this is not expected. Is 'signed size_t' != 'long int' on ppc32?

If you want to format a ptrdiff_t you should use %td.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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