From: "David Hildenbrand (Arm)" <david@kernel.org>
To: "Mike Rapoport (Microsoft)" <rppt@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>,
Alexander Gordeev <agordeev@linux.ibm.com>,
Alexandre Ghiti <alex@ghiti.fr>, Borislav Petkov <bp@alien8.de>,
Catalin Marinas <catalin.marinas@arm.com>,
"Christophe Leroy (CS GROUP)" <chleroy@kernel.org>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Gerald Schaefer <gerald.schaefer@linux.ibm.com>,
Heiko Carstens <hca@linux.ibm.com>,
Ingo Molnar <mingo@redhat.com>,
"Liam R. Howlett" <liam@infradead.org>,
Lorenzo Stoakes <ljs@kernel.org>,
Madhavan Srinivasan <maddy@linux.ibm.com>,
Mark Rutland <mark.rutland@arm.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Michal Hocko <mhocko@suse.com>,
Nicholas Piggin <npiggin@gmail.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Paul Walmsley <pjw@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
Ritesh Harjani <ritesh.list@gmail.com>,
Russell King <linux@armlinux.org.uk>,
Shrikanth Hegde <sshegde@linux.ibm.com>,
Suren Baghdasaryan <surenb@google.com>,
Sven Schnelle <svens@linux.ibm.com>,
Thomas Gleixner <tglx@kernel.org>,
Vasily Gorbik <gor@linux.ibm.com>,
Vlastimil Babka <vbabka@kernel.org>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org,
linux-s390@vger.kernel.org
Subject: Re: [PATCH] arch, mm: promote DEBUG_WX to CHECK_WX
Date: Fri, 25 Sep 2026 13:01:51 +0200 [thread overview]
Message-ID: <91d800d6-03f3-4068-8c12-618529a81528@kernel.org> (raw)
In-Reply-To: <20260925-direct-map-verify-wx-v1-1-7fd2f7d6d23b@kernel.org>
On 9/25/26 11:53, Mike Rapoport (Microsoft) wrote:
> Verification that the kernel does not have writable + executable
> mappings is about detecting security risks rather than a pure debug
> feature.
>
> Major distribution configurations enable it in their kernels as well as
> defconfigs of most architectures that have ARCH_HAS_DEBUG_WX.
>
> Rename relevant generic configuration options to use CHECK_WX and move
> their definitions from mm/Kconfig.debug to mm/Kconfig.
>
> For arm that does not widely enable it, only rename its variants of the
> config options.
>
> Enabling CHECK_WX adds a few kilobytes to the kernel binary and while
> the added size can be slightly reduced with churny updates of
> architecture implementations of ptdump, the core functionality takes
> most of the added size. It cannot be moved to .init.text because the
> verification has to happen after init sections are freed.
>
> With this, make generic CHECK_WX default to STRICT_KERNEL_RWX while
> still leaving users targeting small kernels the possibility to opt-out.
>
> Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---
Makes sense to me
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
--
Cheers,
David
next prev parent reply other threads:[~2026-09-25 11:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-25 9:53 Mike Rapoport (Microsoft)
2026-09-25 11:01 ` David Hildenbrand (Arm) [this message]
2026-09-25 13:42 ` Heiko Carstens
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