From: Will Deacon <will@kernel.org>
To: linux-arm-kernel@lists.infradead.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>,
Linus Walleij <linusw@kernel.org>,
linux-kernel@vger.kernel.org, Mostafa Saleh <smostafa@google.com>,
Marc Zyngier <maz@kernel.org>,
David Hildenbrand <david@kernel.org>,
Lorenzo Stoakes <ljs@kernel.org>,
Oliver Upton <oupton@kernel.org>, Will Deacon <will@kernel.org>,
Ard Biesheuvel <ardb@kernel.org>
Subject: [PATCH 09/21] arm64: stackprotector: Re-enable per-task stackprotector
Date: Mon, 7 Sep 2026 17:42:34 +0100 [thread overview]
Message-ID: <20260907164247.17223-10-will@kernel.org> (raw)
In-Reply-To: <20260907164247.17223-1-will@kernel.org>
Now that 'current' resides in TPIDRRO_EL0, update the per-task
stackprotector compiler invocation to use the new register.
Note that this requires a very recent build of clang [1], as (unlike
GCC), it historically rejected all registers other than SP_EL0.
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://github.com/llvm/llvm-project/pull/188054 [1]
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/Kconfig | 3 +--
arch/arm64/Makefile | 2 +-
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b8270b301809..020fcaf36b1b 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2450,12 +2450,11 @@ config RANDOMIZE_MODULE_REGION_FULL
exhaustion, modules might be able to fall back to a larger 2GB area.
config CC_HAVE_STACKPROTECTOR_SYSREG
- def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
+ def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=tpidrro_el0 -mstack-protector-guard-offset=0)
config STACKPROTECTOR_PER_TASK
def_bool y
depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
- depends on BROKEN
config UNWIND_PATCH_PAC_INTO_SCS
bool "Enable shadow call stack dynamically using code patching"
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 6b005c8fef70..a293ab67818f 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -72,7 +72,7 @@ ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
prepare: stack_protector_prepare
stack_protector_prepare: prepare0
$(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg \
- -mstack-protector-guard-reg=sp_el0 \
+ -mstack-protector-guard-reg=tpidrro_el0 \
-mstack-protector-guard-offset=$(shell \
awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
$(objtree)/include/generated/asm-offsets.h))
--
2.55.0.979.g7e5102b832-goog
next prev parent reply other threads:[~2026-09-07 16:43 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-07 16:42 [PATCH 00/21] arm64: Move overflow sp into SP_EL1 and kernel sp into SP_EL0 Will Deacon
2026-09-07 16:42 ` [PATCH 01/21] arm64: entry: Defer setting of TPIDRRO_EL0 until exit to userspace Will Deacon
2026-09-11 7:53 ` Jinjie Ruan
2026-09-07 16:42 ` [PATCH 02/21] arm64: entry: Only check for stack overflow on exceptions from EL1 Will Deacon
2026-09-07 16:42 ` [PATCH 03/21] arm64: stackprotector: Temporarily disable per-task stackprotector Will Deacon
2026-09-07 16:42 ` [PATCH 04/21] arm64: bpf: Add support for generating reads of TPIDRRO_EL0 Will Deacon
2026-09-07 16:42 ` [PATCH 05/21] KVM: arm64: Protect TPIDRRO_EL0 across guest entry/exit Will Deacon
2026-09-07 16:42 ` [PATCH 06/21] arm64: Store 'current' in TPIDRRO_EL0 instead of SP_EL0 Will Deacon
2026-09-08 13:19 ` David Laight
2026-09-11 12:57 ` Will Deacon
2026-09-07 16:42 ` [PATCH 07/21] selftests/bpf: arm64: Use TPIDRRO_EL0 instead of SP_EL0 for 'current' Will Deacon
2026-09-07 16:42 ` [PATCH 08/21] scripts/gdb: " Will Deacon
2026-09-07 16:42 ` Will Deacon [this message]
2026-09-07 16:42 ` [PATCH 10/21] arm64: percpu: Specialise set_my_cpu_offset() for the primary CPU Will Deacon
2026-09-07 16:42 ` [PATCH 11/21] arm64: percpu: Annotate __kern_my_cpu_offset() as '__always_inline' Will Deacon
2026-09-07 16:42 ` [PATCH 12/21] KVM: arm64: Preserve handler/thread bit of EL1 mode in __finalise_el2() Will Deacon
2026-09-07 16:42 ` [PATCH 13/21] arm64: sdei: Guard most of asm/sdei.h with CONFIG_ARM_SDE_INTERFACE Will Deacon
2026-09-07 16:42 ` [PATCH 14/21] arm64: sdei: Support SDEI events from kernel handler and thread modes Will Deacon
2026-09-07 16:42 ` [PATCH 15/21] arm64: entry: Point SP_EL0 at the overflow stack Will Deacon
2026-09-07 16:42 ` [PATCH 16/21] arm64: entry: Implement EL1t exception handlers for " Will Deacon
2026-09-07 16:42 ` [PATCH 17/21] arm64: entry: Use SPSel to switch to " Will Deacon
2026-09-07 16:42 ` [PATCH 18/21] arm64: entry: Split up kernel_ventry macro into separate helper macros Will Deacon
2026-09-07 16:42 ` [PATCH 19/21] arm64: entry: The great stack switcheroo Will Deacon
2026-09-08 11:30 ` Will Deacon
2026-09-07 16:42 ` [PATCH 20/21] arm64: tracing: Advertise a mode of EL1t in synthetic kernel regs Will Deacon
2026-09-07 16:42 ` [PATCH 21/21] arm64: Rename 'overflow_stack' and OVERFLOW_STACK_SIZE Will Deacon
2026-09-09 10:39 ` [PATCH 00/21] arm64: Move overflow sp into SP_EL1 and kernel sp into SP_EL0 Vladimir Murzin
2026-09-09 11:29 ` Will Deacon
2026-09-10 13:49 ` Vladimir Murzin
2026-09-11 12:57 ` Will Deacon
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