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d="scan'208";a="3092177" Received: from davehans-spike.ostc.intel.com (HELO localhost.localdomain) ([10.165.164.11]) by orviesa007.jf.intel.com with ESMTP; 21 Oct 2026 12:51:41 -0700 Subject: [RFC][PATCH 15/24] x86/task: Hook up arch hook to detect shadow stack enabling To: linux-kernel@vger.kernel.org Cc: Andy Lutomirski , Peter Zijlstra , Edgecombe, Rick P , Andrew Cooper , the arch/x86 maintainers , Kees Cook , Pawan Gupta , Borislav Petkov , Thomas Gleixner , Dave Hansen From: Dave Hansen Date: Wed, 21 Oct 2026 12:51:41 -0700 References: <20261021195120.E61EC737@davehans-spike.ostc.intel.com> In-Reply-To: <20261021195120.E61EC737@davehans-spike.ostc.intel.com> Message-Id: <20261021195141.2A1FD9F9@davehans-spike.ostc.intel.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Provide an x86 definition for arch_kernel_shstk_enabled(), used in the generic code to skip any attempts to clear shadow stack pages. --- b/arch/x86/include/asm/thread_info.h | 6 ++++++ 1 file changed, 6 insertions(+) diff -puN arch/x86/include/asm/thread_info.h~x86-shadow-stacks-enabled arch/x86/include/asm/thread_info.h --- a/arch/x86/include/asm/thread_info.h~x86-shadow-stacks-enabled 2026-10-21 12:36:39.920884876 -0700 +++ b/arch/x86/include/asm/thread_info.h 2026-10-21 12:36:39.922884879 -0700 @@ -231,6 +231,12 @@ extern void arch_setup_new_exec(void); struct thread_stacks; extern void arch_init_thread_stacks(struct thread_stacks *ts); #define arch_init_thread_stacks arch_init_thread_stacks + +static inline bool arch_kernel_shstk_enabled(void) +{ + return cpu_feature_enabled(X86_FEATURE_KERN_SHSTK); +} +#define arch_kernel_shstk_enabled arch_kernel_shstk_enabled #endif #endif /* !__ASSEMBLER__ */ _