qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Jan Kiszka <jan.kiszka@web.de>
To: Alan Amaral <alan.amaral@virtualcomputer.com>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	Richard Henderson <rth@twiddle.net>
Subject: Re: [Qemu-devel] pci_change_irq_level is broken...
Date: Tue, 20 Sep 2011 21:41:47 +0200	[thread overview]
Message-ID: <4E78EC7B.9030808@web.de> (raw)
In-Reply-To: <E7BCD741-8D2C-43E1-863E-928A598E41CC@mimectl>

[-- Attachment #1: Type: text/plain, Size: 840 bytes --]

On 2011-09-20 21:19, Alan Amaral wrote:
> QEMU emulator version 0.14.50, Copyright (c) 2003-2008 Fabrice Bellard

(That's an ambitious development version.)

> 
> You are correct, it's not hardcoded to 4.  However, when it's allocated the number of elements IS 4.  Also,
> there's a comment just above pci_set_irq which says:
> 
> /* 0 <= irq_num <= 3. level must be 0 or 1 */
> static void pci_set_irq(void *opaque, int irq_num, int level)
> 
> so, that implies to me that it's probably always 4...  Sorry for the confusion.

Assuming you look at PIIX3: Yes, it allocates 4 IRQs - but only returns
0..3 via pci_slot_get_pirq. Xen uses some more, but also looks safe.

Can you provide a backtrace where irq_num gets larger than 3 and writes
beyond the end of irq_count? Do you have private patches in your tree?

Jan


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 262 bytes --]

  reply	other threads:[~2011-09-20 19:41 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-20 17:24 [Qemu-devel] pci_change_irq_level is broken Alan Amaral
2011-09-20 18:57 ` Richard Henderson
2011-09-20 19:19   ` Alan Amaral
2011-09-20 19:41     ` Jan Kiszka [this message]
2011-09-20 19:56     ` Richard Henderson
2011-09-21 16:34       ` Alan Amaral
  -- strict thread matches above, loose matches on Subject: below --
2011-09-21 16:26 Alan Amaral
2011-09-21 16:33 ` Jan Kiszka
2011-09-21 16:38 ` Alan Amaral

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=4E78EC7B.9030808@web.de \
    --to=jan.kiszka@web.de \
    --cc=alan.amaral@virtualcomputer.com \
    --cc=qemu-devel@nongnu.org \
    --cc=rth@twiddle.net \
    /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).