From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Lutomirski Subject: [PATCH v4 20/29] x86/smp: Remove stack_smp_processor_id() Date: Sun, 26 Jun 2016 14:55:42 -0700 Message-ID: <6c8610ea4d224d14699f62c07e569e2f01499234.1466974736.git.luto@kernel.org> References: Reply-To: kernel-hardening@lists.openwall.com Return-path: List-Post: List-Help: List-Unsubscribe: List-Subscribe: In-Reply-To: In-Reply-To: References: To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Borislav Petkov , Nadav Amit , Kees Cook , Brian Gerst , "kernel-hardening@lists.openwall.com" , Linus Torvalds , Josh Poimboeuf , Jann Horn , Heiko Carstens , Andy Lutomirski List-Id: linux-arch.vger.kernel.org It serves no purpose -- raw_smp_processor_id() works fine. This change will be needed to move thread_info off the stack. Signed-off-by: Andy Lutomirski --- arch/x86/include/asm/cpu.h | 1 - arch/x86/include/asm/smp.h | 6 ------ arch/x86/kernel/cpu/common.c | 2 +- 3 files changed, 1 insertion(+), 8 deletions(-) diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 678637ad7476..59d34c521d96 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -17,7 +17,6 @@ static inline void prefill_possible_map(void) {} #define cpu_physical_id(cpu) boot_cpu_physical_apicid #define safe_smp_processor_id() 0 -#define stack_smp_processor_id() 0 #endif /* CONFIG_SMP */ diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 66b057306f40..0576b6157f3a 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -172,12 +172,6 @@ extern int safe_smp_processor_id(void); #elif defined(CONFIG_X86_64_SMP) #define raw_smp_processor_id() (this_cpu_read(cpu_number)) -#define stack_smp_processor_id() \ -({ \ - struct thread_info *ti; \ - __asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (CURRENT_MASK)); \ - ti->cpu; \ -}) #define safe_smp_processor_id() smp_processor_id() #endif diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 0fe6953f421c..d22a7b9c4f0e 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1452,7 +1452,7 @@ void cpu_init(void) struct task_struct *me; struct tss_struct *t; unsigned long v; - int cpu = stack_smp_processor_id(); + int cpu = raw_smp_processor_id(); int i; wait_for_master_cpu(cpu); -- 2.7.4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:60324 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751865AbcFZV41 (ORCPT ); Sun, 26 Jun 2016 17:56:27 -0400 From: Andy Lutomirski Subject: [PATCH v4 20/29] x86/smp: Remove stack_smp_processor_id() Date: Sun, 26 Jun 2016 14:55:42 -0700 Message-ID: <6c8610ea4d224d14699f62c07e569e2f01499234.1466974736.git.luto@kernel.org> In-Reply-To: References: In-Reply-To: References: Sender: linux-arch-owner@vger.kernel.org List-ID: To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Borislav Petkov , Nadav Amit , Kees Cook , Brian Gerst , "kernel-hardening@lists.openwall.com" , Linus Torvalds , Josh Poimboeuf , Jann Horn , Heiko Carstens , Andy Lutomirski Message-ID: <20160626215542.6DZm71iQdgKBxOnkXYvZFK24zhIaElwmAqt_KOa-9oc@z> It serves no purpose -- raw_smp_processor_id() works fine. This change will be needed to move thread_info off the stack. Signed-off-by: Andy Lutomirski --- arch/x86/include/asm/cpu.h | 1 - arch/x86/include/asm/smp.h | 6 ------ arch/x86/kernel/cpu/common.c | 2 +- 3 files changed, 1 insertion(+), 8 deletions(-) diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 678637ad7476..59d34c521d96 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -17,7 +17,6 @@ static inline void prefill_possible_map(void) {} #define cpu_physical_id(cpu) boot_cpu_physical_apicid #define safe_smp_processor_id() 0 -#define stack_smp_processor_id() 0 #endif /* CONFIG_SMP */ diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 66b057306f40..0576b6157f3a 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -172,12 +172,6 @@ extern int safe_smp_processor_id(void); #elif defined(CONFIG_X86_64_SMP) #define raw_smp_processor_id() (this_cpu_read(cpu_number)) -#define stack_smp_processor_id() \ -({ \ - struct thread_info *ti; \ - __asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (CURRENT_MASK)); \ - ti->cpu; \ -}) #define safe_smp_processor_id() smp_processor_id() #endif diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 0fe6953f421c..d22a7b9c4f0e 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1452,7 +1452,7 @@ void cpu_init(void) struct task_struct *me; struct tss_struct *t; unsigned long v; - int cpu = stack_smp_processor_id(); + int cpu = raw_smp_processor_id(); int i; wait_for_master_cpu(cpu); -- 2.7.4