From: Arjun Sreedharan <arjun024@gmail.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86,boot: standardize strcmp()
Date: Tue, 17 Mar 2015 19:43:16 +0530 [thread overview]
Message-ID: <CAJFMrCFdUo=St93aWbjfZ5sz15WWjuG1ejfqC9t30u7hLwzdzA@mail.gmail.com> (raw)
In-Reply-To: <20150317074608.GB27687@gmail.com>
On 17 March 2015 at 13:16, Ingo Molnar <mingo@kernel.org> wrote:
>
> * Arjun Sreedharan <arjun024@gmail.com> wrote:
>
>> strcmp() is always expected to return 0 when args are
>> same, <0 when arg1 is lesser and >0 otherwise.
>> Previously strcmp("a","b") returned 1. Now it gives -1.
>
> I'd also add the following to the changelog:
>
> Until now this bug never triggered, because all uses for strcmp() in
> the boot code tested for nonzero:
On a related note, IMO strcmp() should return {-1,0,1} since many
programmers just expect this behavior. just my opinion.
Arjun Sreedharan
>
> triton:~/tip> git grep strcmp arch/x86/boot/
> arch/x86/boot/boot.h:int strcmp(const char *str1, const char *str2);
> arch/x86/boot/edd.c: if (!strcmp(eddarg, "skipmbr") || !strcmp(eddarg, "skip")) {
> arch/x86/boot/edd.c: else if (!strcmp(eddarg, "off"))
> arch/x86/boot/edd.c: else if (!strcmp(eddarg, "on"))
>
> should in the future strcmp() be used in a comparative way in the boot
> code, it might have led to (not so subtle) bugs.
>
> Thanks,
>
> Ingo
next prev parent reply other threads:[~2015-03-17 14:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-16 15:37 [PATCH] x86,boot: standardize strcmp() Arjun Sreedharan
2015-03-16 18:16 ` Borislav Petkov
2015-03-17 7:46 ` Ingo Molnar
2015-03-17 14:13 ` Arjun Sreedharan [this message]
2015-03-18 1:36 ` Bernd Petrovitsch
2015-03-18 18:10 ` Arjun Sreedharan
2015-03-18 18:37 ` Arjun Sreedharan
2015-03-19 17:34 ` H. Peter Anvin
2015-03-20 11:42 ` Bernd Petrovitsch
2015-03-17 14:28 ` Borislav Petkov
2015-03-23 12:23 ` [tip:x86/boot] x86/boot: Standardize strcmp() tip-bot for Arjun Sreedharan
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