From: Paolo Bonzini <pbonzini@redhat.com>
To: "Gonglei (Arei)" <arei.gonglei@huawei.com>,
Don Slutz <don.slutz@gmail.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Cc: Peter Crosthwaite <crosthwaite.peter@gmail.com>,
Richard Henderson <rth@twiddle.net>
Subject: Re: [Qemu-devel] [PATCH] exec: Stop using memory after free
Date: Wed, 2 Dec 2015 10:47:29 +0100 [thread overview]
Message-ID: <565EBE31.7010304@redhat.com> (raw)
In-Reply-To: <33183CC9F5247A488A2544077AF19020B02AC190@SZXEMA503-MBS.china.huawei.com>
On 02/12/2015 08:59, Gonglei (Arei) wrote:
>>>> static void phys_section_destroy(MemoryRegion *mr) {
>>>> + bool have_sub_page = mr->subpage;
>>>> +
>>>> memory_region_unref(mr);
>>>>
>>>> - if (mr->subpage) {
>>>> + if (have_sub_page) {
>>>> subpage_t *subpage = container_of(mr, subpage_t, iomem);
>
> Can we use the *mr* here again?
Yes, in the subpage case the memory is allocated by exec.c. Accessing
mr->subpage is only problematic if memory_region_unref destroys a device.
> IMO we should invoke memory_region_unref(mr) after the if check.
That's also possible.
Paolo
next prev parent reply other threads:[~2015-12-02 9:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-30 22:11 [Qemu-devel] [PATCH] exec: Stop using memory after free Don Slutz
2015-12-01 9:52 ` Paolo Bonzini
2015-12-01 13:05 ` Gonglei (Arei)
2015-12-02 7:59 ` Gonglei (Arei)
2015-12-02 9:47 ` Paolo Bonzini [this message]
2015-12-02 22:01 ` Don Slutz
2015-12-02 22:04 ` Don Slutz
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