From patchwork Tue Apr 28 13:16:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 1278480 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 49BMhq6ss7z9sT4 for ; Tue, 28 Apr 2020 23:20:43 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=c-s.fr header.i=@c-s.fr header.a=rsa-sha256 header.s=mail header.b=dIvGN/2E; dkim-atps=neutral Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49BMhp67s3zDqWT for ; Tue, 28 Apr 2020 23:20:42 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=c-s.fr (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@c-s.fr; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=c-s.fr header.i=@c-s.fr header.a=rsa-sha256 header.s=mail header.b=dIvGN/2E; dkim-atps=neutral Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 49BMcQ6FFSzDqqY for ; Tue, 28 Apr 2020 23:16:52 +1000 (AEST) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 49BMcH316rz9v099; Tue, 28 Apr 2020 15:16:47 +0200 (CEST) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=dIvGN/2E; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id u-Z4vwJfTzCx; Tue, 28 Apr 2020 15:16:47 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 49BMcH1p7Zz9tyb5; Tue, 28 Apr 2020 15:16:47 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1588079807; bh=cY2GLqK/++8NNjXMzRS7Sd3wJCUx6gk6wPlGW3FvvFA=; h=In-Reply-To:References:From:Subject:To:Cc:Date:From; b=dIvGN/2EhXoIvhxefomhBI8AgSzhup8n/XbKOOjBmkwWGFEp6bFiYFj5YCXRFAxtu 0u06v/8wBlWar5kuc9nWLzlkT2yLrwnF38S/w0bYyzLoEJEfHGRfDhPyWOvs2ZfXLX upGxVGv9nlM9cAeakU8Pf/DHcf4TFm7YGDwMZy34= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C01B98B82D; Tue, 28 Apr 2020 15:16:48 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id XoZxHab3Yzw2; Tue, 28 Apr 2020 15:16:48 +0200 (CEST) Received: from pc16570vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 6C1328B82C; Tue, 28 Apr 2020 15:16:48 +0200 (CEST) Received: by pc16570vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 3E044658AD; Tue, 28 Apr 2020 13:16:48 +0000 (UTC) Message-Id: <0d2201efe3c7727f2acc718aefd7c5bb22c66c57.1588079622.git.christophe.leroy@c-s.fr> In-Reply-To: References: From: Christophe Leroy Subject: [PATCH v8 2/8] powerpc/vdso: Remove __kernel_datapage_offset and simplify __get_datapage() To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , nathanl@linux.ibm.com Date: Tue, 28 Apr 2020 13:16:48 +0000 (UTC) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, arnd@arndb.de, linux-kernel@vger.kernel.org, luto@kernel.org, tglx@linutronix.de, vincenzo.frascino@arm.com, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" The VDSO datapage and the text pages are always located immediately next to each other, so it can be hardcoded without an indirection through __kernel_datapage_offset In order to ease things, move the data page in front like other arches, that way there is no need to know the size of the library to locate the data page. Before: clock-getres-realtime-coarse: vdso: 714 nsec/call clock-gettime-realtime-coarse: vdso: 792 nsec/call clock-gettime-realtime: vdso: 1243 nsec/call After: clock-getres-realtime-coarse: vdso: 699 nsec/call clock-gettime-realtime-coarse: vdso: 784 nsec/call clock-gettime-realtime: vdso: 1231 nsec/call Signed-off-by: Christophe Leroy --- v7: - Moved the removal of the tmp param of __get_datapage() in a subsequent patch - Included the addition of the offset param to __get_datapage() in the further preparatory patch --- arch/powerpc/include/asm/vdso_datapage.h | 8 ++-- arch/powerpc/kernel/vdso.c | 53 ++++-------------------- arch/powerpc/kernel/vdso32/datapage.S | 3 -- arch/powerpc/kernel/vdso32/vdso32.lds.S | 7 +--- arch/powerpc/kernel/vdso64/datapage.S | 3 -- arch/powerpc/kernel/vdso64/vdso64.lds.S | 7 +--- 6 files changed, 16 insertions(+), 65 deletions(-) diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h index b9ef6cf50ea5..11886467dfdf 100644 --- a/arch/powerpc/include/asm/vdso_datapage.h +++ b/arch/powerpc/include/asm/vdso_datapage.h @@ -118,10 +118,12 @@ extern struct vdso_data *vdso_data; .macro get_datapage ptr, tmp bcl 20, 31, .+4 +999: mflr \ptr - addi \ptr, \ptr, (__kernel_datapage_offset - (.-4))@l - lwz \tmp, 0(\ptr) - add \ptr, \tmp, \ptr +#if CONFIG_PPC_PAGE_SHIFT > 14 + addis \ptr, \ptr, (_vdso_datapage - 999b)@ha +#endif + addi \ptr, \ptr, (_vdso_datapage - 999b)@l .endm #endif /* __ASSEMBLY__ */ diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index f38f26e844b6..d33fa22ddbed 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -190,7 +190,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) * install_special_mapping or the perf counter mmap tracking code * will fail to recognise it as a vDSO (since arch_vma_name fails). */ - current->mm->context.vdso_base = vdso_base; + current->mm->context.vdso_base = vdso_base + PAGE_SIZE; /* * our vma flags don't have VM_WRITE so by default, the process isn't @@ -482,42 +482,6 @@ static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32, vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32"); } -static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32, - struct lib64_elfinfo *v64) -{ -#ifdef CONFIG_VDSO32 - Elf32_Sym *sym32; -#endif -#ifdef CONFIG_PPC64 - Elf64_Sym *sym64; - - sym64 = find_symbol64(v64, "__kernel_datapage_offset"); - if (sym64 == NULL) { - printk(KERN_ERR "vDSO64: Can't find symbol " - "__kernel_datapage_offset !\n"); - return -1; - } - *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) = - (vdso64_pages << PAGE_SHIFT) - - (sym64->st_value - VDSO64_LBASE); -#endif /* CONFIG_PPC64 */ - -#ifdef CONFIG_VDSO32 - sym32 = find_symbol32(v32, "__kernel_datapage_offset"); - if (sym32 == NULL) { - printk(KERN_ERR "vDSO32: Can't find symbol " - "__kernel_datapage_offset !\n"); - return -1; - } - *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) = - (vdso32_pages << PAGE_SHIFT) - - (sym32->st_value - VDSO32_LBASE); -#endif - - return 0; -} - - static __init int vdso_fixup_features(struct lib32_elfinfo *v32, struct lib64_elfinfo *v64) { @@ -618,9 +582,6 @@ static __init int vdso_setup(void) if (vdso_do_find_sections(&v32, &v64)) return -1; - if (vdso_fixup_datapage(&v32, &v64)) - return -1; - if (vdso_fixup_features(&v32, &v64)) return -1; @@ -761,26 +722,26 @@ static int __init vdso_init(void) vdso32_pagelist = kcalloc(vdso32_pages + 2, sizeof(struct page *), GFP_KERNEL); BUG_ON(vdso32_pagelist == NULL); + vdso32_pagelist[0] = virt_to_page(vdso_data); for (i = 0; i < vdso32_pages; i++) { struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE); get_page(pg); - vdso32_pagelist[i] = pg; + vdso32_pagelist[i + 1] = pg; } - vdso32_pagelist[i++] = virt_to_page(vdso_data); - vdso32_pagelist[i] = NULL; + vdso32_pagelist[i + 1] = NULL; #endif #ifdef CONFIG_PPC64 vdso64_pagelist = kcalloc(vdso64_pages + 2, sizeof(struct page *), GFP_KERNEL); BUG_ON(vdso64_pagelist == NULL); + vdso64_pagelist[0] = virt_to_page(vdso_data); for (i = 0; i < vdso64_pages; i++) { struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE); get_page(pg); - vdso64_pagelist[i] = pg; + vdso64_pagelist[i + 1] = pg; } - vdso64_pagelist[i++] = virt_to_page(vdso_data); - vdso64_pagelist[i] = NULL; + vdso64_pagelist[i + 1] = NULL; #endif /* CONFIG_PPC64 */ get_page(virt_to_page(vdso_data)); diff --git a/arch/powerpc/kernel/vdso32/datapage.S b/arch/powerpc/kernel/vdso32/datapage.S index 217bb630f8f9..5513a4f8253e 100644 --- a/arch/powerpc/kernel/vdso32/datapage.S +++ b/arch/powerpc/kernel/vdso32/datapage.S @@ -13,9 +13,6 @@ #include .text - .global __kernel_datapage_offset; -__kernel_datapage_offset: - .long 0 /* * void *__kernel_get_syscall_map(unsigned int *syscall_count) ; diff --git a/arch/powerpc/kernel/vdso32/vdso32.lds.S b/arch/powerpc/kernel/vdso32/vdso32.lds.S index 5206c2eb2a1d..6cf729612268 100644 --- a/arch/powerpc/kernel/vdso32/vdso32.lds.S +++ b/arch/powerpc/kernel/vdso32/vdso32.lds.S @@ -4,6 +4,7 @@ * library */ #include +#include #ifdef __LITTLE_ENDIAN__ OUTPUT_FORMAT("elf32-powerpcle", "elf32-powerpcle", "elf32-powerpcle") @@ -15,6 +16,7 @@ ENTRY(_start) SECTIONS { + PROVIDE(_vdso_datapage = . - PAGE_SIZE); . = VDSO32_LBASE + SIZEOF_HEADERS; .hash : { *(.hash) } :text @@ -138,11 +140,6 @@ VERSION { VDSO_VERSION_STRING { global: - /* - * Has to be there for the kernel to find - */ - __kernel_datapage_offset; - __kernel_get_syscall_map; #ifndef CONFIG_PPC_BOOK3S_601 __kernel_gettimeofday; diff --git a/arch/powerpc/kernel/vdso64/datapage.S b/arch/powerpc/kernel/vdso64/datapage.S index 067247d3efb9..03bb72c440dc 100644 --- a/arch/powerpc/kernel/vdso64/datapage.S +++ b/arch/powerpc/kernel/vdso64/datapage.S @@ -13,9 +13,6 @@ #include .text -.global __kernel_datapage_offset; -__kernel_datapage_offset: - .long 0 /* * void *__kernel_get_syscall_map(unsigned int *syscall_count) ; diff --git a/arch/powerpc/kernel/vdso64/vdso64.lds.S b/arch/powerpc/kernel/vdso64/vdso64.lds.S index 256fb9720298..f58c7e2e9cbd 100644 --- a/arch/powerpc/kernel/vdso64/vdso64.lds.S +++ b/arch/powerpc/kernel/vdso64/vdso64.lds.S @@ -4,6 +4,7 @@ * library */ #include +#include #ifdef __LITTLE_ENDIAN__ OUTPUT_FORMAT("elf64-powerpcle", "elf64-powerpcle", "elf64-powerpcle") @@ -15,6 +16,7 @@ ENTRY(_start) SECTIONS { + PROVIDE(_vdso_datapage = . - PAGE_SIZE); . = VDSO64_LBASE + SIZEOF_HEADERS; .hash : { *(.hash) } :text @@ -138,11 +140,6 @@ VERSION { VDSO_VERSION_STRING { global: - /* - * Has to be there for the kernel to find - */ - __kernel_datapage_offset; - __kernel_get_syscall_map; __kernel_gettimeofday; __kernel_clock_gettime;