From: Andrew Morton <akpm@linux-foundation.org>
To: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Cc: "Andrey Konovalov" <andreyknvl@gmail.com>,
"Catalin Marinas" <catalin.marinas@arm.com>,
"Matthias Brugger" <matthias.bgg@gmail.com>,
"Chinwen Chang" <chinwen.chang@mediatek.com>,
"Nicholas Tang" <nicholas.tang@mediatek.com>,
"James Hsu" <James.Hsu@mediatek.com>,
"Yee Lee" <Yee.Lee@mediatek.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-mediatek@lists.infradead.org"
<linux-mediatek@lists.infradead.org>,
kasan-dev <kasan-dev@googlegroups.com>,
kuan-ying.lee@mediatek.com
Subject: Re: [PATCH] kmemleak: fix kmemleak false positive report with HW tag-based kasan enable
Date: Fri, 19 Nov 2021 14:43:59 -0800 [thread overview]
Message-ID: <20211119144359.b70d2fde7631bd14cd9652e3@linux-foundation.org> (raw)
In-Reply-To: <c5cfd0c41dee93cd923762a6e0d61baea52cec8d.camel@mediatek.com>
On Fri, 19 Nov 2021 23:12:55 +0800 Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> wrote:
> > > > Call sequence:
> > > > ptr = kmalloc(size, GFP_KERNEL);
> > > > page = virt_to_page(ptr);
> > > > kfree(page_address(page));
> > > > ptr = kmalloc(size, GFP_KERNEL);
> >
> > How is this call sequence valid? page_address returns the address of
> > the start of the page, while kmalloced object could have been located
> > in the middle of it.
>
> Thanks for pointing out. I miss the offset.
>
> It should be listed as below.
>
> ptr = kmalloc(size, GFP_KERNEL);
> page = virt_to_page(ptr);
> offset = offset_in_page(ptr);
> kfree(page_address(page) + offset);
> ptr = kmalloc(size, GFP_KERNEL);
I updated the changelog to reflect this.
next prev parent reply other threads:[~2021-11-19 22:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-18 5:44 [PATCH] kmemleak: fix kmemleak false positive report with HW tag-based kasan enable Kuan-Ying Lee
2021-11-18 9:20 ` Kuan-Ying Lee
2021-11-19 14:15 ` Andrey Konovalov
2021-11-19 15:12 ` Kuan-Ying Lee
2021-11-19 22:43 ` Andrew Morton [this message]
2021-11-24 2:00 ` Kuan-Ying Lee
2021-11-25 16:13 ` Andrey Konovalov
2021-11-28 0:20 ` Andrew Morton
2021-12-02 18:19 ` Catalin Marinas
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