From: James Bottomley <jejb@linux.ibm.com>
To: Denis Kenzior <denkenz@gmail.com>,
ndesaulniers@google.com, dhowells@redhat.com
Cc: natechancellor@gmail.com, ebiggers@google.com,
Mimi Zohar <zohar@linux.vnet.ibm.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
linux-integrity@vger.kernel.org, keyrings@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KEYS: trusted: fix -Wvarags warning
Date: Fri, 12 Oct 2018 15:46:21 +0000 [thread overview]
Message-ID: <1539359181.2656.13.camel@linux.ibm.com> (raw)
In-Reply-To: <16de2bb3-815a-f534-4618-af854c906017@gmail.com>
On Fri, 2018-10-12 at 10:44 -0500, Denis Kenzior wrote:
> Hi James,
>
> > > So instead of having unsigned char h3, can't we simply have bool
> > > h3 or unsigned int h3?
> >
> > Given the ambiguity in the standards, the safe thing that will work
> > for all time and all potential compilers is a char *
> >
>
> All right. You state this with certainty, but I'd still like you to
> educate me why?
>
> From the links provided in the patch it seems that one cannot pass
> char/float/short to va_start(). Fair enough. So if we make h3 an
> unsigned int, the issue goes away, no?
For the current version of clang, yes. However, if we're fixing this
for good a char * pointer is the only guaranteed thing because it
mirrors current use in printf.
James
WARNING: multiple messages have this Message-ID (diff)
From: James Bottomley <jejb@linux.ibm.com>
To: Denis Kenzior <denkenz@gmail.com>,
ndesaulniers@google.com, dhowells@redhat.com
Cc: natechancellor@gmail.com, ebiggers@google.com,
Mimi Zohar <zohar@linux.vnet.ibm.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
linux-integrity@vger.kernel.org, keyrings@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KEYS: trusted: fix -Wvarags warning
Date: Fri, 12 Oct 2018 08:46:21 -0700 [thread overview]
Message-ID: <1539359181.2656.13.camel@linux.ibm.com> (raw)
In-Reply-To: <16de2bb3-815a-f534-4618-af854c906017@gmail.com>
On Fri, 2018-10-12 at 10:44 -0500, Denis Kenzior wrote:
> Hi James,
>
> > > So instead of having unsigned char h3, can't we simply have bool
> > > h3 or unsigned int h3?
> >
> > Given the ambiguity in the standards, the safe thing that will work
> > for all time and all potential compilers is a char *
> >
>
> All right. You state this with certainty, but I'd still like you to
> educate me why?
>
> From the links provided in the patch it seems that one cannot pass
> char/float/short to va_start(). Fair enough. So if we make h3 an
> unsigned int, the issue goes away, no?
For the current version of clang, yes. However, if we're fixing this
for good a char * pointer is the only guaranteed thing because it
mirrors current use in printf.
James
next prev parent reply other threads:[~2018-10-12 15:46 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-09 22:11 undefined behavior (-Wvarargs) in security/keys/trusted.c#TSS_authhmac() Nick Desaulniers
2018-10-09 22:11 ` Nick Desaulniers
2018-10-11 16:02 ` Arnd Bergmann
2018-10-11 16:02 ` Arnd Bergmann
2018-10-11 16:10 ` James Bottomley
2018-10-11 16:10 ` James Bottomley
2018-10-11 20:31 ` [PATCH] KEYS: trusted: fix -Wvarags warning ndesaulniers
2018-10-11 20:31 ` ndesaulniers
2018-10-12 1:50 ` Nathan Chancellor
2018-10-12 1:50 ` Nathan Chancellor
2018-10-12 16:55 ` Nick Desaulniers
2018-10-12 16:55 ` Nick Desaulniers
2018-10-12 17:03 ` Nathan Chancellor
2018-10-12 17:03 ` Nathan Chancellor
2018-10-12 12:29 ` Denis Kenzior
2018-10-12 12:29 ` Denis Kenzior
2018-10-12 15:05 ` James Bottomley
2018-10-12 15:05 ` James Bottomley
2018-10-12 15:13 ` Denis Kenzior
2018-10-12 15:13 ` Denis Kenzior
2018-10-12 15:22 ` James Bottomley
2018-10-12 15:22 ` James Bottomley
2018-10-12 15:44 ` Denis Kenzior
2018-10-12 15:44 ` Denis Kenzior
2018-10-12 15:46 ` James Bottomley [this message]
2018-10-12 15:46 ` James Bottomley
2018-10-12 15:53 ` Denis Kenzior
2018-10-12 15:53 ` Denis Kenzior
2018-10-12 16:01 ` James Bottomley
2018-10-12 16:01 ` James Bottomley
2018-10-12 17:14 ` Nick Desaulniers
2018-10-12 17:14 ` Nick Desaulniers
2018-10-12 15:25 ` James Bottomley
2018-10-12 15:25 ` James Bottomley
2018-10-12 17:05 ` Nick Desaulniers
2018-10-12 17:05 ` Nick Desaulniers
2018-10-12 17:17 ` Nick Desaulniers
2018-10-12 17:17 ` Nick Desaulniers
2018-10-12 17:27 ` Denis Kenzior
2018-10-12 17:27 ` Denis Kenzior
2018-10-12 18:39 ` Nick Desaulniers
2018-10-12 18:39 ` Nick Desaulniers
2018-10-12 17:02 ` Nick Desaulniers
2018-10-12 17:02 ` Nick Desaulniers
2018-10-12 17:15 ` Denis Kenzior
2018-10-12 17:15 ` Denis Kenzior
2018-10-15 9:26 ` David Laight
2018-10-15 9:26 ` David Laight
2018-10-15 21:53 ` Nick Desaulniers
2018-10-15 21:53 ` Nick Desaulniers
2018-10-16 8:13 ` David Laight
2018-10-16 8:13 ` David Laight
2018-10-22 23:43 ` [PATCH v2] " ndesaulniers
2018-10-22 23:43 ` ndesaulniers
2018-10-23 0:00 ` Nathan Chancellor
2018-10-23 0:00 ` Nathan Chancellor
2018-10-24 8:36 ` Jarkko Sakkinen
2018-10-24 8:36 ` Jarkko Sakkinen
2018-10-29 17:54 ` Nick Desaulniers
2018-10-29 17:54 ` Nick Desaulniers
2019-02-11 18:36 ` Nick Desaulniers
2019-02-11 18:36 ` Nick Desaulniers
2019-02-12 23:12 ` Jarkko Sakkinen
2019-02-12 23:12 ` Jarkko Sakkinen
2019-02-14 10:52 ` Jarkko Sakkinen
2019-02-14 10:52 ` Jarkko Sakkinen
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