From patchwork Fri Jan 10 15:23:49 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Patchwork-Id: 13935052 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B48D1E77188 for ; Fri, 10 Jan 2025 15:40:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:In-Reply-To:References:Message-Id :MIME-Version:Subject:Date:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=o/diYCM+N6Q1dVEP6yEnjw6VGFeIbqXmjlh0zyLJPuA=; b=AhjJk8CEAmjNjX K4WvGsMLXqMtZ9+SmDgmcmf0PO2vM+4enzXPlV87HG6E32ImSfI+VticnwN0125BjWhhli/B1Nxsf lbHmTU0+XzznJpr+utYJ5oanV02lKUW0vlM+Ea5xINBTU/e0QgTPvpnUd9di0frj5V6XIN2TRP5cY 5Vo5GQexL6Ozp4daXfXmNdDpay4zTChUsyWefu5sU4jn2kTekU+ukwkE+VWHA4feFSv8W2NpGcdXC Ab5Sim8KSfyj/4dAtP/XooGlcAPdqjzfL5ZUPUunxvA0L3ZtVzHjyUNRjrKX9zkq4R6TLPmOUhdq8 jsSuxAOBwRFa+YzLC6XA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tWH7P-0000000G0na-1yMQ; Fri, 10 Jan 2025 15:40:15 +0000 Received: from galois.linutronix.de ([193.142.43.55]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tWGrg-0000000FtkD-3KP3; Fri, 10 Jan 2025 15:24:03 +0000 From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1736522637; h=from:from: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=c5g8Es2lILv2fPtDHMOjRp5eiRMizTjVxvwXG1R+yoQ=; b=IvdbjUdO1wy5mV2sqgy7NZJW8VzasRCMriEd+0W3OmhTQYrv0itYnheDwks9dn6nJITtzc udQH2Qga2U6Ylw++05wHxx1m2OR+78Uz0giv60zfwGTaVNB83GyMsaHjvWz5S/iDerGpJf V9CRIaO1Jojm15tQg0pg7RoJV/7KnWeeRNVXd6JktMbuNOfgGTgnLhzO4juroyadzRtFfs KjptSjqr/bJ6LZ8IcjTwrsJJSG39uf5xLDqPrVy4eEClgtEQLXmmOYHt6Qqcw6vfqna/XN /YorL4Siwj3pFzcI0ZxPzly6ZRJ4Ae+kaaIkXy+zmLSGP83YQEl9scHsf/KRNQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1736522637; h=from:from: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=c5g8Es2lILv2fPtDHMOjRp5eiRMizTjVxvwXG1R+yoQ=; b=9pX0lLR5xCo+0zAihX5swYowZxXjA0d1BETBg5/L64HPlShfScNLljWZZi4XpO8p5Yf4g4 pcNGtrlOSZd9xZAw== Date: Fri, 10 Jan 2025 16:23:49 +0100 Subject: [PATCH v2 10/18] LoongArch: vDSO: Switch to generic storage implementation MIME-Version: 1.0 Message-Id: <20250110-vdso-store-rng-v2-10-350c9179bbf1@linutronix.de> References: <20250110-vdso-store-rng-v2-0-350c9179bbf1@linutronix.de> In-Reply-To: <20250110-vdso-store-rng-v2-0-350c9179bbf1@linutronix.de> To: "James E.J. Bottomley" , Helge Deller , Andy Lutomirski , Thomas Gleixner , Vincenzo Frascino , Anna-Maria Behnsen , Frederic Weisbecker , Andrew Morton , Catalin Marinas , Will Deacon , Theodore Ts'o , "Jason A. Donenfeld" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Huacai Chen , WANG Xuerui , Russell King , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Thomas Bogendoerfer , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Madhavan Srinivasan , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Arnd Bergmann , Guo Ren Cc: linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, loongarch@lists.linux.dev, linux-s390@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arch@vger.kernel.org, Nam Cao , =?utf-8?q?Thom?= =?utf-8?q?as_Wei=C3=9Fschuh?= , linux-csky@vger.kernel.org X-Developer-Signature: v=1; a=ed25519-sha256; t=1736522629; l=14049; i=thomas.weissschuh@linutronix.de; s=20240209; h=from:subject:message-id; bh=GtB8tf66uCWbgFixpY3uJro/95XOGO6Tu9/ePvIFZ9Y=; b=r7IamTAm1OqNXyDyO58fA4YCL7vXtlGzihGc0QO82eDiiVIO4gTTTa9jDN5CkuChNrid8HSjA Od6FTI9qw1mBmxWDCkPo2tfawtWDx5UBJHXwTIRBJXYqArc0YSuyvp8 X-Developer-Key: i=thomas.weissschuh@linutronix.de; a=ed25519; pk=pfvxvpFUDJV2h2nY0FidLUml22uGLSjByFbM6aqQQws= X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250110_072401_167895_E5A51A6A X-CRM114-Status: GOOD ( 25.16 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org The generic storage implementation provides the same features as the custom one. However it can be shared between architectures, making maintenance easier. Co-developed-by: Nam Cao Signed-off-by: Nam Cao Signed-off-by: Thomas Weißschuh --- arch/loongarch/Kconfig | 2 + arch/loongarch/include/asm/vdso.h | 1 - arch/loongarch/include/asm/vdso/arch_data.h | 25 +++++++ arch/loongarch/include/asm/vdso/getrandom.h | 5 -- arch/loongarch/include/asm/vdso/gettimeofday.h | 14 +--- arch/loongarch/include/asm/vdso/vdso.h | 38 +---------- arch/loongarch/include/asm/vdso/vsyscall.h | 17 ----- arch/loongarch/kernel/asm-offsets.c | 2 +- arch/loongarch/kernel/vdso.c | 92 +------------------------- arch/loongarch/vdso/vdso.lds.S | 8 +-- arch/loongarch/vdso/vgetcpu.c | 12 +--- 11 files changed, 39 insertions(+), 177 deletions(-) diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index dae3a9104ca6584133d9b6a3059ee666c216d31b..6ec7ef705199fdd4039afd23ec9050a28aa894eb 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -29,6 +29,7 @@ config LOONGARCH select ARCH_HAS_SET_MEMORY select ARCH_HAS_SET_DIRECT_MAP select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST + select ARCH_HAS_VDSO_ARCH_DATA select ARCH_INLINE_READ_LOCK if !PREEMPTION select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION @@ -104,6 +105,7 @@ config LOONGARCH select GENERIC_SCHED_CLOCK select GENERIC_SMP_IDLE_THREAD select GENERIC_TIME_VSYSCALL + select GENERIC_VDSO_DATA_STORE select GENERIC_VDSO_TIME_NS select GPIOLIB select HAS_IOPORT diff --git a/arch/loongarch/include/asm/vdso.h b/arch/loongarch/include/asm/vdso.h index d3ba35eb23e77082ea8ed564fe7378ad80df81b2..f72ec79e2dde52f8888750a53c4af85d6ab77b45 100644 --- a/arch/loongarch/include/asm/vdso.h +++ b/arch/loongarch/include/asm/vdso.h @@ -31,7 +31,6 @@ struct loongarch_vdso_info { unsigned long size; unsigned long offset_sigreturn; struct vm_special_mapping code_mapping; - struct vm_special_mapping data_mapping; }; extern struct loongarch_vdso_info vdso_info; diff --git a/arch/loongarch/include/asm/vdso/arch_data.h b/arch/loongarch/include/asm/vdso/arch_data.h new file mode 100644 index 0000000000000000000000000000000000000000..322d0a5f1c844f02de9b074d6021e8e15116f8a2 --- /dev/null +++ b/arch/loongarch/include/asm/vdso/arch_data.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Author: Huacai Chen + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited + */ + +#ifndef _VDSO_ARCH_DATA_H +#define _VDSO_ARCH_DATA_H + +#ifndef __ASSEMBLY__ + +#include +#include + +struct vdso_pcpu_data { + u32 node; +} ____cacheline_aligned_in_smp; + +struct vdso_arch_data { + struct vdso_pcpu_data pdata[NR_CPUS]; +}; + +#endif /* __ASSEMBLY__ */ + +#endif diff --git a/arch/loongarch/include/asm/vdso/getrandom.h b/arch/loongarch/include/asm/vdso/getrandom.h index e80f3c4ac7481ba7f9f5d9210fefa78c3293243b..48c43f55b039b42168698614d0479b7a872d20f3 100644 --- a/arch/loongarch/include/asm/vdso/getrandom.h +++ b/arch/loongarch/include/asm/vdso/getrandom.h @@ -28,11 +28,6 @@ static __always_inline ssize_t getrandom_syscall(void *_buffer, size_t _len, uns return ret; } -static __always_inline const struct vdso_rng_data *__arch_get_vdso_rng_data(void) -{ - return &_loongarch_data.rng_data; -} - #endif /* !__ASSEMBLY__ */ #endif /* __ASM_VDSO_GETRANDOM_H */ diff --git a/arch/loongarch/include/asm/vdso/gettimeofday.h b/arch/loongarch/include/asm/vdso/gettimeofday.h index 7eb3f041af764d141b005f821593a358096874ba..88cfcf13311630ed5f1a734d23a2bc3f65d79a88 100644 --- a/arch/loongarch/include/asm/vdso/gettimeofday.h +++ b/arch/loongarch/include/asm/vdso/gettimeofday.h @@ -72,7 +72,7 @@ static __always_inline int clock_getres_fallback( } static __always_inline u64 __arch_get_hw_counter(s32 clock_mode, - const struct vdso_data *vd) + const struct vdso_time_data *vd) { uint64_t count; @@ -89,18 +89,6 @@ static inline bool loongarch_vdso_hres_capable(void) } #define __arch_vdso_hres_capable loongarch_vdso_hres_capable -static __always_inline const struct vdso_data *__arch_get_vdso_data(void) -{ - return _vdso_data; -} - -#ifdef CONFIG_TIME_NS -static __always_inline -const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd) -{ - return _timens_data; -} -#endif #endif /* !__ASSEMBLY__ */ #endif /* __ASM_VDSO_GETTIMEOFDAY_H */ diff --git a/arch/loongarch/include/asm/vdso/vdso.h b/arch/loongarch/include/asm/vdso/vdso.h index 1c183a9b2115a29a997ec8db0e788d87fb191dce..50c65fb29dafb464f36615f49db8954ee0a775e3 100644 --- a/arch/loongarch/include/asm/vdso/vdso.h +++ b/arch/loongarch/include/asm/vdso/vdso.h @@ -12,43 +12,9 @@ #include #include #include +#include -struct vdso_pcpu_data { - u32 node; -} ____cacheline_aligned_in_smp; - -struct loongarch_vdso_data { - struct vdso_pcpu_data pdata[NR_CPUS]; - struct vdso_rng_data rng_data; -}; - -/* - * The layout of vvar: - * - * high - * +---------------------+--------------------------+ - * | loongarch vdso data | LOONGARCH_VDSO_DATA_SIZE | - * +---------------------+--------------------------+ - * | time-ns vdso data | PAGE_SIZE | - * +---------------------+--------------------------+ - * | generic vdso data | PAGE_SIZE | - * +---------------------+--------------------------+ - * low - */ -#define LOONGARCH_VDSO_DATA_SIZE PAGE_ALIGN(sizeof(struct loongarch_vdso_data)) -#define LOONGARCH_VDSO_DATA_PAGES (LOONGARCH_VDSO_DATA_SIZE >> PAGE_SHIFT) - -enum vvar_pages { - VVAR_GENERIC_PAGE_OFFSET, - VVAR_TIMENS_PAGE_OFFSET, - VVAR_LOONGARCH_PAGES_START, - VVAR_LOONGARCH_PAGES_END = VVAR_LOONGARCH_PAGES_START + LOONGARCH_VDSO_DATA_PAGES - 1, - VVAR_NR_PAGES, -}; - -#define VVAR_SIZE (VVAR_NR_PAGES << PAGE_SHIFT) - -extern struct loongarch_vdso_data _loongarch_data __attribute__((visibility("hidden"))); +#define VVAR_SIZE (VDSO_NR_PAGES << PAGE_SHIFT) #endif /* __ASSEMBLY__ */ diff --git a/arch/loongarch/include/asm/vdso/vsyscall.h b/arch/loongarch/include/asm/vdso/vsyscall.h index 8987e951d0a93c34ca75de676fb9c191ff4ef3c2..1140b54b4bc8278d7a322036cd9f84f71258f246 100644 --- a/arch/loongarch/include/asm/vdso/vsyscall.h +++ b/arch/loongarch/include/asm/vdso/vsyscall.h @@ -6,23 +6,6 @@ #include -extern struct vdso_data *vdso_data; -extern struct vdso_rng_data *vdso_rng_data; - -static __always_inline -struct vdso_data *__loongarch_get_k_vdso_data(void) -{ - return vdso_data; -} -#define __arch_get_k_vdso_data __loongarch_get_k_vdso_data - -static __always_inline -struct vdso_rng_data *__loongarch_get_k_vdso_rng_data(void) -{ - return vdso_rng_data; -} -#define __arch_get_k_vdso_rng_data __loongarch_get_k_vdso_rng_data - /* The asm-generic header needs to be included after the definitions above */ #include diff --git a/arch/loongarch/kernel/asm-offsets.c b/arch/loongarch/kernel/asm-offsets.c index 049c5c3e370cbb00fdaf6730f7777847c7325fb4..7dcf4980dbead0249ef4daeab431c7d482abfeb5 100644 --- a/arch/loongarch/kernel/asm-offsets.c +++ b/arch/loongarch/kernel/asm-offsets.c @@ -327,6 +327,6 @@ static void __used output_vdso_defines(void) { COMMENT("LoongArch vDSO offsets."); - DEFINE(__VVAR_PAGES, VVAR_NR_PAGES); + DEFINE(__VDSO_PAGES, VDSO_NR_PAGES); BLANK(); } diff --git a/arch/loongarch/kernel/vdso.c b/arch/loongarch/kernel/vdso.c index 05e5fbac102a902016e633db75d9aff7ed550c50..10cf1608c7b32f8e03bc2c942b51413cf8b9c505 100644 --- a/arch/loongarch/kernel/vdso.c +++ b/arch/loongarch/kernel/vdso.c @@ -14,7 +14,7 @@ #include #include #include -#include +#include #include #include @@ -25,18 +25,6 @@ extern char vdso_start[], vdso_end[]; -/* Kernel-provided data used by the VDSO. */ -static union vdso_data_store generic_vdso_data __page_aligned_data; - -static union { - u8 page[LOONGARCH_VDSO_DATA_SIZE]; - struct loongarch_vdso_data vdata; -} loongarch_vdso_data __page_aligned_data; - -struct vdso_data *vdso_data = generic_vdso_data.data; -struct vdso_pcpu_data *vdso_pdata = loongarch_vdso_data.vdata.pdata; -struct vdso_rng_data *vdso_rng_data = &loongarch_vdso_data.vdata.rng_data; - static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma) { current->mm->context.vdso = (void *)(new_vma->vm_start); @@ -44,53 +32,12 @@ static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struc return 0; } -static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, - struct vm_area_struct *vma, struct vm_fault *vmf) -{ - unsigned long pfn; - struct page *timens_page = find_timens_vvar_page(vma); - - switch (vmf->pgoff) { - case VVAR_GENERIC_PAGE_OFFSET: - if (!timens_page) - pfn = sym_to_pfn(vdso_data); - else - pfn = page_to_pfn(timens_page); - break; -#ifdef CONFIG_TIME_NS - case VVAR_TIMENS_PAGE_OFFSET: - /* - * If a task belongs to a time namespace then a namespace specific - * VVAR is mapped with the VVAR_GENERIC_PAGE_OFFSET and the real - * VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET offset. - * See also the comment near timens_setup_vdso_data(). - */ - if (!timens_page) - return VM_FAULT_SIGBUS; - else - pfn = sym_to_pfn(vdso_data); - break; -#endif /* CONFIG_TIME_NS */ - case VVAR_LOONGARCH_PAGES_START ... VVAR_LOONGARCH_PAGES_END: - pfn = sym_to_pfn(&loongarch_vdso_data) + vmf->pgoff - VVAR_LOONGARCH_PAGES_START; - break; - default: - return VM_FAULT_SIGBUS; - } - - return vmf_insert_pfn(vma, vmf->address, pfn); -} - struct loongarch_vdso_info vdso_info = { .vdso = vdso_start, .code_mapping = { .name = "[vdso]", .mremap = vdso_mremap, }, - .data_mapping = { - .name = "[vvar]", - .fault = vvar_fault, - }, .offset_sigreturn = vdso_offset_sigreturn, }; @@ -101,7 +48,7 @@ static int __init init_vdso(void) BUG_ON(!PAGE_ALIGNED(vdso_info.vdso)); for_each_possible_cpu(cpu) - vdso_pdata[cpu].node = cpu_to_node(cpu); + vdso_k_arch_data->pdata[cpu].node = cpu_to_node(cpu); vdso_info.size = PAGE_ALIGN(vdso_end - vdso_start); vdso_info.code_mapping.pages = @@ -115,37 +62,6 @@ static int __init init_vdso(void) } subsys_initcall(init_vdso); -#ifdef CONFIG_TIME_NS -struct vdso_data *arch_get_vdso_data(void *vvar_page) -{ - return (struct vdso_data *)(vvar_page); -} - -/* - * The vvar mapping contains data for a specific time namespace, so when a - * task changes namespace we must unmap its vvar data for the old namespace. - * Subsequent faults will map in data for the new namespace. - * - * For more details see timens_setup_vdso_data(). - */ -int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) -{ - struct mm_struct *mm = task->mm; - struct vm_area_struct *vma; - - VMA_ITERATOR(vmi, mm, 0); - - mmap_read_lock(mm); - for_each_vma(vmi, vma) { - if (vma_is_special_mapping(vma, &vdso_info.data_mapping)) - zap_vma_pages(vma); - } - mmap_read_unlock(mm); - - return 0; -} -#endif - static unsigned long vdso_base(void) { unsigned long base = STACK_TOP; @@ -181,9 +97,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) goto out; } - vma = _install_special_mapping(mm, data_addr, VVAR_SIZE, - VM_READ | VM_MAYREAD | VM_PFNMAP, - &info->data_mapping); + vma = vdso_install_vvar_mapping(mm, data_addr); if (IS_ERR(vma)) { ret = PTR_ERR(vma); goto out; diff --git a/arch/loongarch/vdso/vdso.lds.S b/arch/loongarch/vdso/vdso.lds.S index 160cfaef2de45b1243502c7356f8a913658548fe..8ff98649994750e74b30a91270d9d9ea2ba751e8 100644 --- a/arch/loongarch/vdso/vdso.lds.S +++ b/arch/loongarch/vdso/vdso.lds.S @@ -5,6 +5,7 @@ */ #include #include +#include OUTPUT_FORMAT("elf64-loongarch", "elf64-loongarch", "elf64-loongarch") @@ -12,11 +13,8 @@ OUTPUT_ARCH(loongarch) SECTIONS { - PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE); -#ifdef CONFIG_TIME_NS - PROVIDE(_timens_data = _vdso_data + PAGE_SIZE); -#endif - PROVIDE(_loongarch_data = _vdso_data + 2 * PAGE_SIZE); + VDSO_VVAR_SYMS + . = SIZEOF_HEADERS; .hash : { *(.hash) } :text diff --git a/arch/loongarch/vdso/vgetcpu.c b/arch/loongarch/vdso/vgetcpu.c index 0db51258b2a7ca7e44d2eb68ea514face48393f7..5301cd9d0f839eb0fd7b73a1d36e80aaa75d5e76 100644 --- a/arch/loongarch/vdso/vgetcpu.c +++ b/arch/loongarch/vdso/vgetcpu.c @@ -19,27 +19,19 @@ static __always_inline int read_cpu_id(void) return cpu_id; } -static __always_inline const struct vdso_pcpu_data *get_pcpu_data(void) -{ - return _loongarch_data.pdata; -} - extern int __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused); int __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused) { int cpu_id; - const struct vdso_pcpu_data *data; cpu_id = read_cpu_id(); if (cpu) *cpu = cpu_id; - if (node) { - data = get_pcpu_data(); - *node = data[cpu_id].node; - } + if (node) + *node = vdso_u_arch_data.pdata[cpu_id].node; return 0; }