From: Jan Beulich <jbeulich@suse.com>
To: Stefano Stabellini <sstabellini@kernel.org>
Cc: boris.ostrovsky@oracle.com, xen-devel@lists.xenproject.org,
linux-kernel@vger.kernel.org,
Stefano Stabellini <stefano.stabellini@xilinx.com>,
stable@vger.kernel.org, jgross@suse.com
Subject: Re: [PATCH v2] xen: detect uninitialized xenbus in xenbus_init
Date: Mon, 22 Nov 2021 08:57:32 +0100 [thread overview]
Message-ID: <bc47bbe2-b330-7744-8d6b-869e3c7523e4@suse.com> (raw)
In-Reply-To: <20211119202951.403525-1-sstabellini@kernel.org>
On 19.11.2021 21:29, Stefano Stabellini wrote:
> --- a/drivers/xen/xenbus/xenbus_probe.c
> +++ b/drivers/xen/xenbus/xenbus_probe.c
> @@ -951,6 +951,20 @@ static int __init xenbus_init(void)
> err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
> if (err)
> goto out_error;
> + /* Uninitialized. */
> + if (v == 0 || v == ULLONG_MAX) {
Didn't you have a comment in v1 here regarding the check against 0? Or was that
just like now only in the description? IOW I think there ought to be a code
comment justifying the theoretically wrong check ...
Also, while I realize there are various other similar assumptions elsewhere, I
would generally recommend to avoid such: There's no guarantee that now and
forever unsigned long long and uint64_t are the same thing. And it's easy in
cases like this one:
if (!v || !(v + 1)) {
Jan
next prev parent reply other threads:[~2021-11-22 7:57 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-19 20:29 Stefano Stabellini
2021-11-19 22:32 ` Boris Ostrovsky
2021-11-22 7:57 ` Jan Beulich [this message]
2021-11-22 22:03 ` Stefano Stabellini
2021-11-22 22:17 ` Stefano Stabellini
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=bc47bbe2-b330-7744-8d6b-869e3c7523e4@suse.com \
--to=jbeulich@suse.com \
--cc=boris.ostrovsky@oracle.com \
--cc=jgross@suse.com \
--cc=linux-kernel@vger.kernel.org \
--cc=sstabellini@kernel.org \
--cc=stable@vger.kernel.org \
--cc=stefano.stabellini@xilinx.com \
--cc=xen-devel@lists.xenproject.org \
/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
all inboxes | Powered by JetHome®