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Date:   Wed, 15 May 2019 15:21:11 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To:     Geert Uytterhoeven <geert@linux-m68k.org>
Cc:     Steven Rostedt <rostedt@goodmis.org>,
        David Laight <David.Laight@aculab.com>,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Petr Mladek <pmladek@suse.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        christophe leroy <christophe.leroy@c-s.fr>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        "Tobin C . Harding" <me@tobin.cc>, Michal Hocko <mhocko@suse.cz>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
        Russell Currey <ruscur@russell.cc>,
        Stephen Rothwell <sfr@ozlabs.org>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
        "linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [PATCH] vsprintf: Do not break early boot with probing addresses
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On (05/14/19 21:13), Geert Uytterhoeven wrote:
> I would immediately understand there's a missing IS_ERR() check in a
> function that can return  -EINVAL, without having to add a new printk()
> to find out what kind of bogus value has been received, and without
> having to reboot, and trying to reproduce...

But chances are that missing IS_ERR() will crash the kernel sooner
or later (in general case), if not in sprintf() then somewhere else.

	-ss