From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 059CDC4332F for ; Mon, 17 Oct 2022 14:57:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231201AbiJQO5W (ORCPT ); Mon, 17 Oct 2022 10:57:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231317AbiJQOzW (ORCPT ); Mon, 17 Oct 2022 10:55:22 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82785696EF; Mon, 17 Oct 2022 07:54:15 -0700 (PDT) Date: Mon, 17 Oct 2022 14:54:06 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1666018447; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=slcpjwvmUivkfDM6rePvZomTFDKVkh69xF82qRvShag=; b=Nt+PtXyXfA+w9LY/WD4mquwBoM0+vlATcvN5lWB6Qx7HBaYQtJ3dSqwlU+EXZD7Q14FQow Wz7RfkGwVjHTvaHneMmPQN/S0HSXvP0z1bcWpLxrCvRLrONxebOQ9vf30znNwBKZYbplDi ggntPGGt6nNcB4ZEK1z4vrZqa5uWnSDK83oARrTqjKDdXHBnfIySkdIY9gOx0AjZUurorA sqpSDg3GUUoOQXdl3eNf/NJdQV8/zl/LhvHR8Wx2+eX4c8jDUsot7YgqchwWEoh4kC6suE 65OaWDheeQnnXrwkyLZyLHd10YeQNG1POMkGg7CO1z0O/ba5Sbx8Nyw91NGaFA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1666018447; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=slcpjwvmUivkfDM6rePvZomTFDKVkh69xF82qRvShag=; b=hHtcGKOg+Ypqk1Q3P04d1pKQrI0+BVF7Tmu0tcwIcYDOGZYlbPGtG+Poi6+nC9CsSYewh4 rdP17t//ctoWKADA== From: "tip-bot2 for Thomas Gleixner" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/core] x86/percpu: Move current_top_of_stack next to current_task Cc: Thomas Gleixner , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20220915111145.493038635@infradead.org> References: <20220915111145.493038635@infradead.org> MIME-Version: 1.0 Message-ID: <166601844653.401.2714011756689788842.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/core branch of tip: Commit-ID: c063a217bc0726c2560138229de5673dbb253a02 Gitweb: https://git.kernel.org/tip/c063a217bc0726c2560138229de5673dbb253a02 Author: Thomas Gleixner AuthorDate: Thu, 15 Sep 2022 13:11:04 +02:00 Committer: Peter Zijlstra CommitterDate: Mon, 17 Oct 2022 16:41:05 +02:00 x86/percpu: Move current_top_of_stack next to current_task Extend the struct pcpu_hot cacheline with current_top_of_stack; another very frequently used value. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220915111145.493038635@infradead.org --- arch/x86/entry/entry_32.S | 4 ++-- arch/x86/entry/entry_64.S | 6 +++--- arch/x86/entry/entry_64_compat.S | 6 +++--- arch/x86/include/asm/current.h | 1 + arch/x86/include/asm/processor.h | 4 +--- arch/x86/kernel/asm-offsets.c | 2 ++ arch/x86/kernel/cpu/common.c | 12 +----------- arch/x86/kernel/process_32.c | 4 ++-- arch/x86/kernel/process_64.c | 2 +- arch/x86/kernel/smpboot.c | 2 +- arch/x86/kernel/traps.c | 4 ++-- 11 files changed, 19 insertions(+), 28 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index e309e71..91397f5 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -1181,7 +1181,7 @@ SYM_CODE_START(asm_exc_nmi) * is using the thread stack right now, so it's safe for us to use it. */ movl %esp, %ebx - movl PER_CPU_VAR(cpu_current_top_of_stack), %esp + movl PER_CPU_VAR(pcpu_hot + X86_top_of_stack), %esp call exc_nmi movl %ebx, %esp @@ -1243,7 +1243,7 @@ SYM_CODE_START(rewind_stack_and_make_dead) /* Prevent any naive code from trying to unwind to our caller. */ xorl %ebp, %ebp - movl PER_CPU_VAR(cpu_current_top_of_stack), %esi + movl PER_CPU_VAR(pcpu_hot + X86_top_of_stack), %esi leal -TOP_OF_KERNEL_STACK_PADDING-PTREGS_SIZE(%esi), %esp call make_task_dead diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index e635f96..9249a45 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -92,7 +92,7 @@ SYM_CODE_START(entry_SYSCALL_64) /* tss.sp2 is scratch space. */ movq %rsp, PER_CPU_VAR(cpu_tss_rw + TSS_sp2) SWITCH_TO_KERNEL_CR3 scratch_reg=%rsp - movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp + movq PER_CPU_VAR(pcpu_hot + X86_top_of_stack), %rsp SYM_INNER_LABEL(entry_SYSCALL_64_safe_stack, SYM_L_GLOBAL) ANNOTATE_NOENDBR @@ -1209,7 +1209,7 @@ SYM_CODE_START(asm_exc_nmi) FENCE_SWAPGS_USER_ENTRY SWITCH_TO_KERNEL_CR3 scratch_reg=%rdx movq %rsp, %rdx - movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp + movq PER_CPU_VAR(pcpu_hot + X86_top_of_stack), %rsp UNWIND_HINT_IRET_REGS base=%rdx offset=8 pushq 5*8(%rdx) /* pt_regs->ss */ pushq 4*8(%rdx) /* pt_regs->rsp */ @@ -1525,7 +1525,7 @@ SYM_CODE_START_NOALIGN(rewind_stack_and_make_dead) /* Prevent any naive code from trying to unwind to our caller. */ xorl %ebp, %ebp - movq PER_CPU_VAR(cpu_current_top_of_stack), %rax + movq PER_CPU_VAR(pcpu_hot + X86_top_of_stack), %rax leaq -PTREGS_SIZE(%rax), %rsp UNWIND_HINT_REGS diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 4dd1981..1dfee86 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -58,7 +58,7 @@ SYM_CODE_START(entry_SYSENTER_compat) SWITCH_TO_KERNEL_CR3 scratch_reg=%rax popq %rax - movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp + movq PER_CPU_VAR(pcpu_hot + X86_top_of_stack), %rsp /* Construct struct pt_regs on stack */ pushq $__USER32_DS /* pt_regs->ss */ @@ -191,7 +191,7 @@ SYM_CODE_START(entry_SYSCALL_compat) SWITCH_TO_KERNEL_CR3 scratch_reg=%rsp /* Switch to the kernel stack */ - movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp + movq PER_CPU_VAR(pcpu_hot + X86_top_of_stack), %rsp SYM_INNER_LABEL(entry_SYSCALL_compat_safe_stack, SYM_L_GLOBAL) ANNOTATE_NOENDBR @@ -332,7 +332,7 @@ SYM_CODE_START(entry_INT80_compat) ALTERNATIVE "", "jmp .Lint80_keep_stack", X86_FEATURE_XENPV movq %rsp, %rax - movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp + movq PER_CPU_VAR(pcpu_hot + X86_top_of_stack), %rsp pushq 5*8(%rax) /* regs->ss */ pushq 4*8(%rax) /* regs->rsp */ diff --git a/arch/x86/include/asm/current.h b/arch/x86/include/asm/current.h index 8ac6589..2dd0131 100644 --- a/arch/x86/include/asm/current.h +++ b/arch/x86/include/asm/current.h @@ -17,6 +17,7 @@ struct pcpu_hot { struct task_struct *current_task; int preempt_count; int cpu_number; + unsigned long top_of_stack; }; u8 pad[64]; }; diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index c660700..c345f30 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -426,8 +426,6 @@ struct irq_stack { char stack[IRQ_STACK_SIZE]; } __aligned(IRQ_STACK_SIZE); -DECLARE_PER_CPU(unsigned long, cpu_current_top_of_stack); - #ifdef CONFIG_X86_64 struct fixed_percpu_data { /* @@ -566,7 +564,7 @@ static __always_inline unsigned long current_top_of_stack(void) * and around vm86 mode and sp0 on x86_64 is special because of the * entry trampoline. */ - return this_cpu_read_stable(cpu_current_top_of_stack); + return this_cpu_read_stable(pcpu_hot.top_of_stack); } static __always_inline bool on_thread_stack(void) diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index cb50589..a982431 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -109,6 +109,8 @@ static void __used common(void) OFFSET(TSS_sp1, tss_struct, x86_tss.sp1); OFFSET(TSS_sp2, tss_struct, x86_tss.sp2); + OFFSET(X86_top_of_stack, pcpu_hot, top_of_stack); + if (IS_ENABLED(CONFIG_KVM_INTEL)) { BLANK(); OFFSET(VMX_spec_ctrl, vcpu_vmx, spec_ctrl); diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index cafb6bd..408245c 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2015,6 +2015,7 @@ __setup("clearcpuid=", setup_clearcpuid); DEFINE_PER_CPU_ALIGNED(struct pcpu_hot, pcpu_hot) = { .current_task = &init_task, .preempt_count = INIT_PREEMPT_COUNT, + .top_of_stack = TOP_OF_INIT_STACK, }; EXPORT_PER_CPU_SYMBOL(pcpu_hot); @@ -2026,8 +2027,6 @@ EXPORT_PER_CPU_SYMBOL_GPL(fixed_percpu_data); DEFINE_PER_CPU(void *, hardirq_stack_ptr); DEFINE_PER_CPU(bool, hardirq_stack_inuse); -DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack) = TOP_OF_INIT_STACK; - static void wrmsrl_cstar(unsigned long val) { /* @@ -2078,15 +2077,6 @@ void syscall_init(void) #else /* CONFIG_X86_64 */ -/* - * On x86_32, vm86 modifies tss.sp0, so sp0 isn't a reliable way to find - * the top of the kernel stack. Use an extra percpu variable to track the - * top of the kernel stack directly. - */ -DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack) = - (unsigned long)&init_thread_union + THREAD_SIZE; -EXPORT_PER_CPU_SYMBOL(cpu_current_top_of_stack); - #ifdef CONFIG_STACKPROTECTOR DEFINE_PER_CPU(unsigned long, __stack_chk_guard); EXPORT_PER_CPU_SYMBOL(__stack_chk_guard); diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 807da45..470c128 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -191,13 +191,13 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) arch_end_context_switch(next_p); /* - * Reload esp0 and cpu_current_top_of_stack. This changes + * Reload esp0 and pcpu_hot.top_of_stack. This changes * current_thread_info(). Refresh the SYSENTER configuration in * case prev or next is vm86. */ update_task_stack(next_p); refresh_sysenter_cs(next); - this_cpu_write(cpu_current_top_of_stack, + this_cpu_write(pcpu_hot.top_of_stack, (unsigned long)task_stack_page(next_p) + THREAD_SIZE); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index c4f6cac..7f807e8 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -618,7 +618,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) * Switch the PDA and FPU contexts. */ raw_cpu_write(pcpu_hot.current_task, next_p); - this_cpu_write(cpu_current_top_of_stack, task_top_of_stack(next_p)); + raw_cpu_write(pcpu_hot.top_of_stack, task_top_of_stack(next_p)); switch_fpu_finish(); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 05f3157..87863a9 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1056,7 +1056,7 @@ int common_cpu_up(unsigned int cpu, struct task_struct *idle) #ifdef CONFIG_X86_32 /* Stack for startup_32 can be just as for start_secondary onwards */ - per_cpu(cpu_current_top_of_stack, cpu) = task_top_of_stack(idle); + per_cpu(pcpu_hot.top_of_stack, cpu) = task_top_of_stack(idle); #else initial_gs = per_cpu_offset(cpu); #endif diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 178015a..7ac19ab 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -851,7 +851,7 @@ DEFINE_IDTENTRY_RAW(exc_int3) */ asmlinkage __visible noinstr struct pt_regs *sync_regs(struct pt_regs *eregs) { - struct pt_regs *regs = (struct pt_regs *)this_cpu_read(cpu_current_top_of_stack) - 1; + struct pt_regs *regs = (struct pt_regs *)this_cpu_read(pcpu_hot.top_of_stack) - 1; if (regs != eregs) *regs = *eregs; return regs; @@ -869,7 +869,7 @@ asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *r * trust it and switch to the current kernel stack */ if (ip_within_syscall_gap(regs)) { - sp = this_cpu_read(cpu_current_top_of_stack); + sp = this_cpu_read(pcpu_hot.top_of_stack); goto sync; }