qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: "Philippe Mathieu-Daudé" <philmd@redhat.com>
To: Thomas Huth <thuth@redhat.com>,
	"Daniel P . Berrange" <berrange@redhat.com>,
	Stefano Garzarella <sgarzare@redhat.com>
Cc: qemu-s390x <qemu-s390x@nongnu.org>,
	Richard Henderson <richard.henderson@linaro.org>,
	qemu-devel <qemu-devel@nongnu.org>
Subject: s390-ccw: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
Date: Thu, 22 Apr 2021 06:18:52 +0200	[thread overview]
Message-ID: <4e327c80-8f5d-c848-b524-7f2c75255da4@redhat.com> (raw)

Hi Thomas, Daniel, Stefano,

Regarding the following warning (GCC 11 on Fedora 34):

In file included from pc-bios/s390-ccw/main.c:11:

In function ‘memset’,

    inlined from ‘boot_setup’ at pc-bios/s390-ccw/main.c:185:5,

    inlined from ‘main’ at pc-bios/s390-ccw/main.c:288:5:

pc-bios/s390-ccw/libc.h:28:14: warning: writing 1 byte into a region of
size 0 [-Wstringop-overflow=]

   28 |         p[i] = c;

      |         ~~~~~^~~

Daniel were right on IRC:

danpb: it is from a call  memset((char *)S390EP, 0, 6)     where  S390EP
is just a constant address 0x10008
danpb: the compiler doesn't now how big that is, so it seems to assume
it is zero length

This is a known GCC issue:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578
"gcc-11 -Warray-bounds or -Wstringop-overread warning when accessing a
pointer from integer literal"

Regards,

Phil.



             reply	other threads:[~2021-04-22  4:20 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-22  4:18 Philippe Mathieu-Daudé [this message]
2021-04-22  4:47 ` s390-ccw: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=] Thomas Huth
2021-04-22  6:04   ` Christian Borntraeger
2021-04-22 10:15   ` Daniel P. Berrangé
2021-04-22 10:30     ` Peter Maydell
2021-04-22 11:24       ` Philippe Mathieu-Daudé
2021-04-22 11:47         ` Thomas Huth
2021-04-22 12:41           ` Christian Borntraeger
2021-04-22 14:31             ` Philippe Mathieu-Daudé
2021-04-22 15:38               ` Thomas Huth
2021-04-22 15:43                 ` Philippe Mathieu-Daudé
2021-04-22 15:52                 ` Stefano Garzarella
2021-04-22 16:07                   ` Thomas Huth
2021-04-22 16:54                     ` Philippe Mathieu-Daudé
2021-04-23  6:40                       ` Stefano Garzarella
2021-04-23  6:52                         ` Christian Borntraeger
2021-04-23  7:57                           ` Compiling the s390-ccw bios with clang (was: Re: s390-ccw: warning: writing 1 byte into a region of size 0) Thomas Huth
2021-04-23  8:05                             ` Compiling the s390-ccw bios with clang Christian Borntraeger
2021-04-23  8:07                             ` Compiling the s390-ccw bios with clang (was: Re: s390-ccw: warning: writing 1 byte into a region of size 0) Cornelia Huck
2021-04-23  8:22                               ` Thomas Huth
2021-04-23  8:47                                 ` Daniel P. Berrangé
2021-04-23  8:52                                   ` Thomas Huth
2021-04-23  9:00                                     ` Daniel P. Berrangé
2021-04-22 11:48         ` s390-ccw: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=] Daniel P. Berrangé
2021-04-22 14:34           ` Philippe Mathieu-Daudé

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=4e327c80-8f5d-c848-b524-7f2c75255da4@redhat.com \
    --to=philmd@redhat.com \
    --cc=berrange@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --cc=qemu-s390x@nongnu.org \
    --cc=richard.henderson@linaro.org \
    --cc=sgarzare@redhat.com \
    --cc=thuth@redhat.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).