File patches.rpmify-arm64-make-STACKPROTECTOR_PER_TASK-configurable.patch of Package kernel-firefly-itx-3588j
From ea4739eb39ef2c1dac0094d27ffbc2123fdde437 Mon Sep 17 00:00:00 2001 From: Michal Suchanek <msuchanek@suse.de> Date: Tue, 9 Mar 2021 13:25:44 +0100 Subject: [PATCH] arm64: make STACKPROTECTOR_PER_TASK configurable. To: linux-arm-kernel@lists.infradead.org Cc: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: bsc#1181862 Patch-mainline: submitted https://patchwork.kernel.org/project/linux-arm-kernel/patch/20210309123544.14040-1-msuchanek@suse.de/ When using dummy-tools STACKPROTECTOR_PER_TASK is unconditionally selected. This defeats the purpose of the all-enabled tool. Description copied from arm Cc: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Michal Suchanek <msuchanek@suse.de> --- arch/arm64/Kconfig | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index a8ff7cd5f096..f59d391e31a4 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1549,9 +1549,20 @@ config RANDOMIZE_MODULE_REGION_FULL config CC_HAVE_STACKPROTECTOR_SYSREG def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) + config STACKPROTECTOR_PER_TASK - def_bool y + bool "Use a unique stack canary value for each task" depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG + default y + help + Due to the fact that GCC uses an ordinary symbol reference from + which to load the value of the stack canary, this value can only + change at reboot time on SMP systems, and all tasks running in the + kernel's address space are forced to use the same canary value for + the entire duration that the system is up. + + Enable this option to switch to a different method that uses a + different canary value for each task. endmenu -- 2.26.2
