From: Ard Biesheuvel <ardb@kernel.org>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
cuigaosheng <cuigaosheng1@huawei.com>,
Russell King - ARM Linux <linux@armlinux.org.uk>,
Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
Andrew Lunn <andrew@lunn.ch>,
Gregory CLEMENT <gregory.clement@bootlin.com>,
Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
Viresh Kumar <vireshk@kernel.org>,
Shiraz Hashim <shiraz.linux.kernel@gmail.com>,
SoC Team <soc@kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
"moderated list:ARM/SAMSUNG EXYNOS ARM ARCHITECTURES"
<linux-samsung-soc@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
gongruiqi1@huawei.com, wangweiyang2@huawei.com
Subject: Re: [PATCH -next 0/3] replace open coded VA->PA calculation
Date: Wed, 22 Dec 2021 10:29:49 +0100 [thread overview]
Message-ID: <CAMj1kXHgptq47g3mSPTKW9KMnqTH4K2Q7riBVwX4iA1V9YWYiA@mail.gmail.com> (raw)
In-Reply-To: <CACRpkdaNv7850mOyXRMgmPf8TQxiM-C5VEkGnLfd+wvffW8FAg@mail.gmail.com>
On Wed, 22 Dec 2021 at 03:31, Linus Walleij <linus.walleij@linaro.org> wrote:
>
> On Tue, Dec 21, 2021 at 10:16 AM Arnd Bergmann <arnd@arndb.de> wrote:
>
> > I think for CPUs that can use LPAE, we want to eventually move to the 4G:4G
> > memory model, which in turn depends on having the kernel in vmalloc space, as
> > implemented by Linus Walleij in
> > https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator.git/log/?h=kernel-in-vmalloc-v5.14-rc1
>
> Yeah I'm still working on this series. The 4/4 split works pretty well,
> but it breaks KASan and I was in the process of fixing that when I left
> for parental leave.
>
> The reason it breaks would be related to KASan not expecting
> executable code in the vmalloc area, and since the shadowing
> algorithm is a simple pointer offset, and since we go to lengths
> to chisel shadow memory out of lowmem at a fixed offset from
> TEXT_OFFSET, we have a problem.
>
Vmap'ed stacks actually has a similar problem, which is why it is
disabled when KAsan is enabled. But this can be fixed by enabling arch
support for KASAN_VMALLOC, and I suspect it may address the vmap'ed
kernel as well.
WARNING: multiple messages have this Message-ID (diff)
From: Ard Biesheuvel <ardb@kernel.org>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
cuigaosheng <cuigaosheng1@huawei.com>,
Russell King - ARM Linux <linux@armlinux.org.uk>,
Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
Andrew Lunn <andrew@lunn.ch>,
Gregory CLEMENT <gregory.clement@bootlin.com>,
Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
Viresh Kumar <vireshk@kernel.org>,
Shiraz Hashim <shiraz.linux.kernel@gmail.com>,
SoC Team <soc@kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
"moderated list:ARM/SAMSUNG EXYNOS ARM ARCHITECTURES"
<linux-samsung-soc@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
gongruiqi1@huawei.com, wangweiyang2@huawei.com
Subject: Re: [PATCH -next 0/3] replace open coded VA->PA calculation
Date: Wed, 22 Dec 2021 10:29:49 +0100 [thread overview]
Message-ID: <CAMj1kXHgptq47g3mSPTKW9KMnqTH4K2Q7riBVwX4iA1V9YWYiA@mail.gmail.com> (raw)
In-Reply-To: <CACRpkdaNv7850mOyXRMgmPf8TQxiM-C5VEkGnLfd+wvffW8FAg@mail.gmail.com>
On Wed, 22 Dec 2021 at 03:31, Linus Walleij <linus.walleij@linaro.org> wrote:
>
> On Tue, Dec 21, 2021 at 10:16 AM Arnd Bergmann <arnd@arndb.de> wrote:
>
> > I think for CPUs that can use LPAE, we want to eventually move to the 4G:4G
> > memory model, which in turn depends on having the kernel in vmalloc space, as
> > implemented by Linus Walleij in
> > https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator.git/log/?h=kernel-in-vmalloc-v5.14-rc1
>
> Yeah I'm still working on this series. The 4/4 split works pretty well,
> but it breaks KASan and I was in the process of fixing that when I left
> for parental leave.
>
> The reason it breaks would be related to KASan not expecting
> executable code in the vmalloc area, and since the shadowing
> algorithm is a simple pointer offset, and since we go to lengths
> to chisel shadow memory out of lowmem at a fixed offset from
> TEXT_OFFSET, we have a problem.
>
Vmap'ed stacks actually has a similar problem, which is why it is
disabled when KAsan is enabled. But this can be fixed by enabling arch
support for KASAN_VMALLOC, and I suspect it may address the vmap'ed
kernel as well.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-12-22 9:30 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-18 8:58 [PATCH -next 0/3] replace open coded VA->PA calculation Gaosheng Cui
2021-12-18 8:58 ` Gaosheng Cui
2021-12-18 8:58 ` [PATCH -next 1/3] arm-soc: exynos: replace open coded VA->PA conversions Gaosheng Cui
2021-12-18 8:58 ` Gaosheng Cui
2021-12-18 8:58 ` [PATCH -next 2/3] arm-soc: mvebu: replace open coded VA->PA conversion Gaosheng Cui
2021-12-18 8:58 ` Gaosheng Cui
2021-12-18 8:58 ` [PATCH -next 3/3] arm-soc: various: replace open coded VA->PA calculation Gaosheng Cui
2021-12-18 8:58 ` Gaosheng Cui
2021-12-20 15:39 ` [PATCH -next 0/3] " Arnd Bergmann
2021-12-20 15:39 ` Arnd Bergmann
2021-12-20 18:06 ` Andrew Lunn
2021-12-20 18:06 ` Andrew Lunn
2021-12-20 18:16 ` Ard Biesheuvel
2021-12-20 18:16 ` Ard Biesheuvel
2021-12-21 1:41 ` cuigaosheng
2021-12-21 1:41 ` cuigaosheng
2021-12-21 9:15 ` Arnd Bergmann
2021-12-21 9:15 ` Arnd Bergmann
2021-12-22 2:31 ` Linus Walleij
2021-12-22 2:31 ` Linus Walleij
2021-12-22 9:29 ` Ard Biesheuvel [this message]
2021-12-22 9:29 ` Ard Biesheuvel
2021-12-24 4:05 ` Linus Walleij
2021-12-24 4:05 ` Linus Walleij
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