Re: [PATCH v4 1/5] gcc-plugins: arm-ssp: Prepare for THREAD_INFO_IN_TASK support
From: Kees Cook <hidden>
Date: 2021-09-15 16:28:48
On Wed, Sep 15, 2021 at 08:37:44AM +0200, Ard Biesheuvel wrote:
On Wed, 15 Sept 2021 at 00:04, Linus Walleij [off-list ref] wrote:quoted
Hi Ard, thanks for this patch series! On Mon, Sep 13, 2021 at 12:40 PM Ard Biesheuvel [off-list ref] wrote:quoted
config STACKPROTECTOR_PER_TASK bool "Use a unique stack canary value for each task" - depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA + depends on GCC_PLUGINS && STACKPROTECTOR && THREAD_INFO_IN_TASK && !XIP_DEFLATED_DATA select GCC_PLUGIN_ARM_SSP_PER_TASKAm I reading this right that STACKPROTECTOR_PER_TASK was available for ARMv6 with SMP before this change and after this change it will only be available for ARMv7 since THREAD_INFO_IN_TASK which is now a dependency will only be available for ARMv7 (or ARMv6k)?Yes. We could potentially keep the old code path in the plugin as well, but what I would really prefer to do is get -mstack-protector-guard=tls implemented in GCC, so we can phase out the plugin entirely.
For tracking, I've added this for arm32 support: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102352 (And updated https://github.com/KSPP/linux/issues/29) -- Kees Cook _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel