All of lore.kernel.org
 help / color / mirror / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: Olaf Hering <olaf@aepfle.de>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: xen-devel@lists.xensource.com, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] qemu-upstream compile failure in intel_iommu.c:vtd_context_device_invalidate
Date: Thu, 28 Jan 2016 09:45:25 +0100	[thread overview]
Message-ID: <56A9D525.7060607@redhat.com> (raw)
In-Reply-To: <20160127182352.GA5526@aepfle.de>



On 27/01/2016 19:23, Olaf Hering wrote:
> 
> xen.git/tools/qemu-xen-dir/hw/i386/intel_iommu.c: In function ‘vtd_context_device_invalidate’:
> xen.git/tools/qemu-xen-dir/hw/i386/intel_iommu.c:911:46: error: ‘mask’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
>              if (vtd_as && ((devfn_it & mask) == (devfn & mask))) {
>                                               ^
> It works with -O2. From the code flow its clear that mask is always
> initialized. Looks like gcc 5.2.1 does no proper diagnostic at -O1.
> What should be done with such issues, are they fixed in the code?

It's probably simplest to add a

	default:
	    abort();

to the switch statement above.

Paolo

WARNING: multiple messages have this Message-ID (diff)
From: Paolo Bonzini <pbonzini@redhat.com>
To: Olaf Hering <olaf@aepfle.de>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: xen-devel@lists.xensource.com, qemu-devel@nongnu.org
Subject: Re: qemu-upstream compile failure in intel_iommu.c:vtd_context_device_invalidate
Date: Thu, 28 Jan 2016 09:45:25 +0100	[thread overview]
Message-ID: <56A9D525.7060607@redhat.com> (raw)
In-Reply-To: <20160127182352.GA5526@aepfle.de>



On 27/01/2016 19:23, Olaf Hering wrote:
> 
> xen.git/tools/qemu-xen-dir/hw/i386/intel_iommu.c: In function ‘vtd_context_device_invalidate’:
> xen.git/tools/qemu-xen-dir/hw/i386/intel_iommu.c:911:46: error: ‘mask’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
>              if (vtd_as && ((devfn_it & mask) == (devfn & mask))) {
>                                               ^
> It works with -O2. From the code flow its clear that mask is always
> initialized. Looks like gcc 5.2.1 does no proper diagnostic at -O1.
> What should be done with such issues, are they fixed in the code?

It's probably simplest to add a

	default:
	    abort();

to the switch statement above.

Paolo

  reply	other threads:[~2016-01-28  8:45 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-27 18:23 [Qemu-devel] qemu-upstream compile failure in intel_iommu.c:vtd_context_device_invalidate Olaf Hering
2016-01-27 18:23 ` Olaf Hering
2016-01-28  8:45 ` Paolo Bonzini [this message]
2016-01-28  8:45   ` Paolo Bonzini
2016-01-28 10:07   ` [Qemu-devel] " Peter Maydell
2016-01-28 10:07     ` Peter Maydell

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=56A9D525.7060607@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=olaf@aepfle.de \
    --cc=qemu-devel@nongnu.org \
    --cc=stefano.stabellini@eu.citrix.com \
    --cc=xen-devel@lists.xensource.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.