From: Will Deacon <will@kernel.org>
To: Linus Walleij <linusw@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
Vladimir Murzin <vladimir.murzin@arm.com>,
Arnd Bergmann <arnd@arndb.de>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, Mostafa Saleh <smostafa@google.com>,
Usama Anjum <usama.anjum@arm.com>, Marc Zyngier <maz@kernel.org>,
David Hildenbrand <david@kernel.org>,
Lorenzo Stoakes <ljs@kernel.org>,
Oliver Upton <oupton@kernel.org>,
Ard Biesheuvel <ardb@kernel.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 00/21] arm64: Move overflow sp into SP_EL1 and kernel sp into SP_EL0
Date: Thu, 1 Oct 2026 08:21:51 +0100 [thread overview]
Message-ID: <ar4KD6FTZzw2Wq6w@willie-the-truck> (raw)
In-Reply-To: <CAD++jL=O30YiraMzpe=wd-s-ZHoiMWkXcr3B_qb_dp3TUk2A7g@mail.gmail.com>
On Wed, Sep 30, 2026 at 11:42:51PM +0200, Linus Walleij wrote:
> On Fri, Sep 18, 2026 at 6:14 PM Will Deacon <will@kernel.org> wrote:
>
> > This is version two of the kernel stack juggling patches I previously
> > posted here:
> >
> > https://lore.kernel.org/r/20260907164247.17223-1-will@kernel.org
> >
> > Changes since v1 include:
> > * Fixed suspend/resume paths to handle the stack pointers properly
> > * Fixed restoration of ptrauth keys on resume
> > * Added tags
>
> Overall I like what I see, but can we split it in two... like first the patches
> up to fixing the overflow handling using SP_EL0 and finalize that?
Yes, that makes sense (and thanks for going through it). The whole thing
is bisectable, so lemme go through the feedback I've got so far and send
out a prefix that we could consider merging as preparatory work.
> Hopefully Usama can test just that part and see if it has a lesser
> performance impact as well.
I'd like to see those numbers at various points during the series, tbh,
so we can rule out any stack-protector changes etc.
Will
next prev parent reply other threads:[~2026-10-01 7:22 UTC|newest]
Thread overview: 65+ 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
2026-10-08 6:54 ` Jinjie Ruan
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
2026-10-08 7:07 ` Jinjie Ruan
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
2026-10-08 7:45 ` Jinjie Ruan
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
2026-10-08 7:29 ` Jinjie Ruan
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
2026-10-08 7:55 ` Jinjie Ruan
2026-09-18 16:13 ` [PATCH v2 08/21] scripts/gdb: " Will Deacon
2026-09-30 20:59 ` Linus Walleij
2026-10-08 7:56 ` Jinjie Ruan
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
2026-10-08 7:58 ` Jinjie Ruan
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
2026-10-08 8:12 ` Jinjie Ruan
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
2026-10-08 8:14 ` Jinjie Ruan
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
2026-10-08 11:22 ` Jinjie Ruan
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
2026-10-08 11:47 ` Jinjie Ruan
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
2026-10-08 11:59 ` Jinjie Ruan
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
2026-10-08 8:53 ` Jinjie Ruan
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 [this message]
2026-10-01 9:00 ` Muhammad Usama Anjum
2026-10-01 21:19 ` Linus Walleij
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