From: Zong Li <zong.li@sifive.com>
To: Will Deacon <will@kernel.org>
Cc: akpm@linux-foundation.org, linux-mm@kvack.org,
"linux-kernel@vger.kernel.org List"
<linux-kernel@vger.kernel.org>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
linux-riscv <linux-riscv@lists.infradead.org>,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
x86@kernel.org, hpa@zytor.com, catalin.marinas@arm.com,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 1/4] mm: add DEBUG_WX support
Date: Mon, 27 Apr 2020 16:47:47 +0800 [thread overview]
Message-ID: <CANXhq0rW5j+uAymXbfsND9AXHYvM+fPUX9YYYRVXY-Y1u6yo0Q@mail.gmail.com> (raw)
In-Reply-To: <20200427074915.GA11787@willie-the-truck>
On Mon, Apr 27, 2020 at 3:49 PM Will Deacon <will@kernel.org> wrote:
>
> On Tue, Apr 21, 2020 at 04:17:12PM +0800, Zong Li wrote:
> > Some architectures support DEBUG_WX function, it's verbatim from each
> > others. Extract to mm/Kconfig.debug for shared use.
> >
> > Signed-off-by: Zong Li <zong.li@sifive.com>
> > Suggested-by: Palmer Dabbelt <palmer@dabbelt.com>
> > ---
> > mm/Kconfig.debug | 33 +++++++++++++++++++++++++++++++++
> > 1 file changed, 33 insertions(+)
> >
> > diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
> > index 0271b22e063f..077458ad968d 100644
> > --- a/mm/Kconfig.debug
> > +++ b/mm/Kconfig.debug
> > @@ -118,6 +118,39 @@ config DEBUG_RODATA_TEST
> > ---help---
> > This option enables a testcase for the setting rodata read-only.
> >
> > +config ARCH_HAS_DEBUG_WX
> > + bool
> > +
> > +config DEBUG_WX
> > + bool "Warn on W+X mappings at boot"
> > + depends on ARCH_HAS_DEBUG_WX
> > + select PTDUMP_CORE
> > + help
> > + Generate a warning if any W+X mappings are found at boot.
> > +
> > + This is useful for discovering cases where the kernel is leaving
> > + W+X mappings after applying NX, as such mappings are a security risk.
> > + This check also includes UXN, which should be set on all kernel
> > + mappings.
>
> "UXN" is the name of a bit in the arm64 page-table descriptors, so this
> should be reworded now that it's in generic help text.
>
It's exactly. Sorry for missing the statement.
Hi Andrew,
Shall I send a next version patch to fix it? It should be "This is
useful for discovering cases where the kernel is leaving W+X mappings
after applying NX, as such mappings are a security risk." here.
> Will
next prev parent reply other threads:[~2020-04-27 8:47 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-21 8:17 [PATCH 0/4] Extract DEBUG_WX to shared use Zong Li
2020-04-21 8:17 ` [PATCH 1/4] mm: add DEBUG_WX support Zong Li
2020-04-27 7:49 ` Will Deacon
2020-04-27 8:47 ` Zong Li [this message]
2020-04-27 19:42 ` Andrew Morton
2020-04-21 8:17 ` [PATCH 2/4] riscv: support DEBUG_WX Zong Li
2020-04-26 1:05 ` Andrew Morton
2020-04-21 8:17 ` [PATCH 3/4] x86: mm: use ARCH_HAS_DEBUG_WX instead of arch defined Zong Li
2020-04-21 8:17 ` [PATCH 4/4] arm64: " Zong Li
2020-04-27 7:49 ` Will Deacon
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