From: Linus Walleij <linusw@kernel.org>
To: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Ard Biesheuvel <ardb@kernel.org>,
Ada Couprie Diaz <ada.coupriediaz@arm.com>,
David Hildenbrand <david@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Vladimir Murzin <vladimir.murzin@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Mostafa Saleh <smostafa@google.com>,
Lorenzo Stoakes <ljs@kernel.org>,
Oliver Upton <oupton@kernel.org>, Marc Zyngier <maz@kernel.org>
Subject: Re: [PATCH v2 16/21] arm64: entry: Implement EL1t exception handlers for overflow stack
Date: Wed, 30 Sep 2026 23:17:38 +0200 [thread overview]
Message-ID: <CAD++jLmyeK_ofduD6fTqSDxBMn6Uw4RcqLzWrVAxHBFfrNi89A@mail.gmail.com> (raw)
In-Reply-To: <20260918161407.2300-17-will@kernel.org>
On Fri, Sep 18, 2026 at 6:15 PM Will Deacon <will@kernel.org> wrote:
> In preparation for using EL1t to handle exceptions taken whilst running
> on the overflow stack, implement some simple wrappers around the EL1h
> handlers which perform a best-effort stack overflow check before
> proceeding.
>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Signed-off-by: Will Deacon <will@kernel.org>
In the commit message, say something about the fact that EL1t handlers
architecturally use the stack pointer from SP_EL0 which we
have now started to repurpose for the kernel-internal overflow stack
and not EL0 (as the name says) at all, and handlers here will
by definition be running on the kernel overflow stack, so people
understand what is going on here.
If I understood it right:
Reviewed-by: Linus Walleij <linusw@kernel.org>
Yours,
Linus Walleij
next prev parent reply other threads:[~2026-09-30 21:17 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-18 16:13 [PATCH v2 00/21] arm64: Move overflow sp into SP_EL1 and kernel sp into SP_EL0 Will Deacon
2026-09-18 16:13 ` [PATCH v2 01/21] arm64: entry: Defer setting of TPIDRRO_EL0 until exit to userspace Will Deacon
2026-09-30 20:47 ` Linus Walleij
2026-09-18 16:13 ` [PATCH v2 02/21] arm64: entry: Only check for stack overflow on exceptions from EL1 Will Deacon
2026-09-30 20:50 ` Linus Walleij
2026-09-18 16:13 ` [PATCH v2 03/21] arm64: stackprotector: Temporarily disable per-task stackprotector Will Deacon
2026-09-30 21:01 ` Linus Walleij
2026-09-18 16:13 ` [PATCH v2 04/21] arm64: bpf: Add support for generating reads of TPIDRRO_EL0 Will Deacon
2026-09-30 20:53 ` Linus Walleij
2026-09-18 16:13 ` [PATCH v2 05/21] KVM: arm64: Protect TPIDRRO_EL0 across guest entry/exit Will Deacon
2026-09-30 20:55 ` Linus Walleij
2026-09-18 16:13 ` [PATCH v2 06/21] arm64: Store 'current' in TPIDRRO_EL0 instead of SP_EL0 Will Deacon
2026-09-30 20:58 ` Linus Walleij
2026-09-18 16:13 ` [PATCH v2 07/21] selftests/bpf: arm64: Use TPIDRRO_EL0 instead of SP_EL0 for 'current' Will Deacon
2026-09-30 20:58 ` Linus Walleij
2026-09-18 16:13 ` [PATCH v2 08/21] scripts/gdb: " Will Deacon
2026-09-30 20:59 ` Linus Walleij
2026-09-18 16:13 ` [PATCH v2 09/21] arm64: stackprotector: Re-enable per-task stackprotector Will Deacon
2026-09-30 21:00 ` Linus Walleij
2026-09-18 16:13 ` [PATCH v2 10/21] arm64: percpu: Specialise set_my_cpu_offset() for the primary CPU Will Deacon
2026-09-30 21:02 ` Linus Walleij
2026-09-18 16:13 ` [PATCH v2 11/21] arm64: percpu: Annotate __kern_my_cpu_offset() as '__always_inline' Will Deacon
2026-09-30 21:05 ` Linus Walleij
2026-09-30 21:05 ` Linus Walleij
2026-09-18 16:13 ` [PATCH v2 12/21] KVM: arm64: Preserve handler/thread bit of EL1 mode in __finalise_el2() Will Deacon
2026-09-18 16:13 ` [PATCH v2 13/21] arm64: sdei: Guard most of asm/sdei.h with CONFIG_ARM_SDE_INTERFACE Will Deacon
2026-09-18 16:13 ` [PATCH v2 14/21] arm64: sdei: Support SDEI events from kernel handler and thread modes Will Deacon
2026-09-18 16:13 ` [PATCH v2 15/21] arm64: entry: Point SP_EL0 at the overflow stack Will Deacon
2026-09-21 15:56 ` Catalin Marinas
2026-09-18 16:14 ` [PATCH v2 16/21] arm64: entry: Implement EL1t exception handlers for " Will Deacon
2026-09-30 21:17 ` Linus Walleij [this message]
2026-09-18 16:14 ` [PATCH v2 17/21] arm64: entry: Use SPSel to switch to " Will Deacon
2026-09-30 21:22 ` Linus Walleij
2026-09-18 16:14 ` [PATCH v2 18/21] arm64: entry: Split up kernel_ventry macro into separate helper macros Will Deacon
2026-09-30 21:26 ` Linus Walleij
2026-09-18 16:14 ` [PATCH v2 19/21] arm64: entry: The great stack switcheroo Will Deacon
2026-09-19 11:41 ` Bradley Morgan
2026-09-22 13:51 ` Catalin Marinas
2026-09-30 21:36 ` Linus Walleij
2026-10-01 7:27 ` Will Deacon
2026-10-01 8:38 ` Linus Walleij
2026-10-01 11:32 ` Will Deacon
2026-10-01 11:35 ` Linus Walleij
2026-09-18 16:14 ` [PATCH v2 20/21] arm64: tracing: Advertise a mode of EL1t in synthetic kernel regs Will Deacon
2026-09-22 14:00 ` Catalin Marinas
2026-09-18 16:14 ` [PATCH v2 21/21] arm64: Rename 'overflow_stack' and OVERFLOW_STACK_SIZE Will Deacon
2026-09-22 14:01 ` Catalin Marinas
2026-09-24 12:30 ` [PATCH v2 00/21] arm64: Move overflow sp into SP_EL1 and kernel sp into SP_EL0 Usama Anjum
2026-09-30 21:42 ` Linus Walleij
2026-10-01 7:21 ` Will Deacon
2026-10-01 9:00 ` Muhammad Usama Anjum
2026-10-01 21:19 ` Linus Walleij
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