From patchwork Tue Jan 15 13:55:29 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincenzo Frascino X-Patchwork-Id: 10764535 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0AB471390 for ; Tue, 15 Jan 2019 14:01:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ED02B2C474 for ; Tue, 15 Jan 2019 14:01:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EB27C2C4B4; Tue, 15 Jan 2019 14:01:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 905C72C474 for ; Tue, 15 Jan 2019 14:01:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=4FkaTBRWTvGljhSXmveXDuZ7dmiYMkwMjHaxblETuMc=; b=cufDYWE9rknqZk /yCMrgtdfMhPeFLPP9e+hRK1JdKQo0DpVfq9kLvC/ww2MW3GYb84zivHntYsbxX0K3Azy2N/PXhRm MnIe78HlTwZY57vV5RqG11PEgIiHvRNZdUOATBfmZe1GPAvE5QpAoy0NzE7oWk5a9XHMP01CR5M07 DgweZBlOvhTwIJbX5CLK9j/9Sm+EgXNhV6SXckZSw6bJr/9C3ATUdAabMS79IZk/+UVjQPK1PW0Fx O0Mx09ZAHfrWBXEmViip62NxD+7KAqYGO4AYfW8iTabN0/faqM09PRJrm4kQluhoqP1V0uQwqDuBB Iy6wB0yI5I1nmvTIxLQw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gjPHP-00015k-Mw; Tue, 15 Jan 2019 14:01:23 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gjPD7-00041z-9m for linux-arm-kernel@lists.infradead.org; Tue, 15 Jan 2019 13:57:20 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BA7A715AB; Tue, 15 Jan 2019 05:56:56 -0800 (PST) Received: from e119884-lin.cambridge.arm.com (e119884-lin.cambridge.arm.com [10.1.196.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A76603F70D; Tue, 15 Jan 2019 05:56:54 -0800 (PST) From: Vincenzo Frascino To: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 14/24] arm64: Refactor vDSO code Date: Tue, 15 Jan 2019 13:55:29 +0000 Message-Id: <20190115135539.24762-15-vincenzo.frascino@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190115135539.24762-1-vincenzo.frascino@arm.com> References: <20190115135539.24762-1-vincenzo.frascino@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190115_055657_926149_A6354BD8 X-CRM114-Status: GOOD ( 21.23 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Arnd Bergmann , Catalin Marinas , Daniel Lezcano , Will Deacon , Russell King , Ralf Baechle , Mark Salyzyn , Paul Burton , Thomas Gleixner , Peter Collingbourne Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Most of the code for initializing the vDSOs in arm64 and compat will be in common, hence a refactor of the current code is required to avoid duplication and simplify maintainability. This patch refactors vdso.c to simplify the implementation of arm64 vDSO compat (which will be pushed with a future patch). Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Vincenzo Frascino --- arch/arm64/kernel/vdso.c | 208 +++++++++++++++++++++++++-------------- 1 file changed, 135 insertions(+), 73 deletions(-) diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 7ee3d21350ec..7d1ad20fdb7b 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -41,7 +41,30 @@ #include extern char vdso_start[], vdso_end[]; -static unsigned long vdso_pages __ro_after_init; + +/* vdso_lookup arch_index */ +enum arch_vdso_type { + ARM64_VDSO = 0, +}; + +struct __vdso_lookup_t { + const char *name; + const char *vdso_code_start; + const char *vdso_code_end; + unsigned long vdso_pages; + /* Data Mapping */ + struct vm_special_mapping *dm; + /* Code Mapping */ + struct vm_special_mapping *cm; +}; + +static struct __vdso_lookup_t vdso_lookup[2] __ro_after_init = { + { + .name = "vdso", + .vdso_code_start = vdso_start, + .vdso_code_end = vdso_end, + }, +}; /* * The vDSO data page. @@ -52,6 +75,106 @@ static union { } vdso_data_store __page_aligned_data; struct vdso_data *vdso_data = &vdso_data_store.data; +static int __vdso_remap(enum arch_vdso_type arch_index, + const struct vm_special_mapping *sm, + struct vm_area_struct *new_vma) +{ + unsigned long new_size = new_vma->vm_end - new_vma->vm_start; + unsigned long vdso_size = vdso_lookup[arch_index].vdso_code_end - + vdso_lookup[arch_index].vdso_code_start; + + if (vdso_size != new_size) + return -EINVAL; + + current->mm->context.vdso = (void *)new_vma->vm_start; + + return 0; +} + +static int __vdso_init(enum arch_vdso_type arch_index) +{ + int i; + struct page **vdso_pagelist; + unsigned long pfn; + + if (memcmp(vdso_lookup[arch_index].vdso_code_start, "\177ELF", 4)) { + pr_err("vDSO is not a valid ELF object!\n"); + return -EINVAL; + } + + vdso_lookup[arch_index].vdso_pages = ( + vdso_lookup[arch_index].vdso_code_end - + vdso_lookup[arch_index].vdso_code_start) >> + PAGE_SHIFT; + pr_info("%s: %ld pages (%ld code @ %p, %ld data @ %p)\n", + vdso_lookup[arch_index].name, + vdso_lookup[arch_index].vdso_pages + 1, + vdso_lookup[arch_index].vdso_pages, + vdso_lookup[arch_index].vdso_code_start, 1L, vdso_data); + + /* Allocate the vDSO pagelist, plus a page for the data. */ + vdso_pagelist = kcalloc(vdso_lookup[arch_index].vdso_pages + 1, + sizeof(struct page *), + GFP_KERNEL); + if (vdso_pagelist == NULL) + return -ENOMEM; + + /* Grab the vDSO data page. */ + vdso_pagelist[0] = phys_to_page(__pa_symbol(vdso_data)); + + + /* Grab the vDSO code pages. */ + pfn = sym_to_pfn(vdso_lookup[arch_index].vdso_code_start); + + for (i = 0; i < vdso_lookup[arch_index].vdso_pages; i++) + vdso_pagelist[i + 1] = pfn_to_page(pfn + i); + + vdso_lookup[arch_index].dm->pages = &vdso_pagelist[0]; + vdso_lookup[arch_index].cm->pages = &vdso_pagelist[1]; + + return 0; +} + +static int __setup_additional_pages(enum arch_vdso_type arch_index, + struct mm_struct *mm, + struct linux_binprm *bprm, + int uses_interp) +{ + unsigned long vdso_base, vdso_text_len, vdso_mapping_len; + void *ret; + + vdso_text_len = vdso_lookup[arch_index].vdso_pages << PAGE_SHIFT; + /* Be sure to map the data page */ + vdso_mapping_len = vdso_text_len + PAGE_SIZE; + + vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0); + if (IS_ERR_VALUE(vdso_base)) { + ret = ERR_PTR(vdso_base); + goto up_fail; + } + + ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE, + VM_READ|VM_MAYREAD, + vdso_lookup[arch_index].dm); + if (IS_ERR(ret)) + goto up_fail; + + vdso_base += PAGE_SIZE; + mm->context.vdso = (void *)vdso_base; + ret = _install_special_mapping(mm, vdso_base, vdso_text_len, + VM_READ|VM_EXEC| + VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, + vdso_lookup[arch_index].cm); + if (IS_ERR(ret)) + goto up_fail; + + return 0; + +up_fail: + mm->context.vdso = NULL; + return PTR_ERR(ret); +} + #ifdef CONFIG_COMPAT /* * Create and map the vectors page for AArch32 tasks. @@ -62,7 +185,7 @@ struct vdso_data *vdso_data = &vdso_data_store.data; * 1 - sigreturn code */ static struct page *aarch32_vdso_pages[2] __ro_after_init; -static const struct vm_special_mapping aarch32_vdso_spec[2] = { +static struct vm_special_mapping aarch32_vdso_spec[2] __ro_after_init = { { /* Must be named [vectors] for compatibility with arm. */ .name = "[vectors]", @@ -202,15 +325,7 @@ int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma) { - unsigned long new_size = new_vma->vm_end - new_vma->vm_start; - unsigned long vdso_size = vdso_end - vdso_start; - - if (vdso_size != new_size) - return -EINVAL; - - current->mm->context.vdso = (void *)new_vma->vm_start; - - return 0; + return __vdso_remap(ARM64_VDSO, sm, new_vma); } static struct vm_special_mapping vdso_spec[2] __ro_after_init = { @@ -225,39 +340,10 @@ static struct vm_special_mapping vdso_spec[2] __ro_after_init = { static int __init vdso_init(void) { - int i; - struct page **vdso_pagelist; - unsigned long pfn; + vdso_lookup[ARM64_VDSO].dm = &vdso_spec[0]; + vdso_lookup[ARM64_VDSO].cm = &vdso_spec[1]; - if (memcmp(vdso_start, "\177ELF", 4)) { - pr_err("vDSO is not a valid ELF object!\n"); - return -EINVAL; - } - - vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT; - pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n", - vdso_pages + 1, vdso_pages, vdso_start, 1L, vdso_data); - - /* Allocate the vDSO pagelist, plus a page for the data. */ - vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *), - GFP_KERNEL); - if (vdso_pagelist == NULL) - return -ENOMEM; - - /* Grab the vDSO data page. */ - vdso_pagelist[0] = phys_to_page(__pa_symbol(vdso_data)); - - - /* Grab the vDSO code pages. */ - pfn = sym_to_pfn(vdso_start); - - for (i = 0; i < vdso_pages; i++) - vdso_pagelist[i + 1] = pfn_to_page(pfn + i); - - vdso_spec[0].pages = &vdso_pagelist[0]; - vdso_spec[1].pages = &vdso_pagelist[1]; - - return 0; + return __vdso_init(ARM64_VDSO); } arch_initcall(vdso_init); @@ -265,43 +351,19 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { struct mm_struct *mm = current->mm; - unsigned long vdso_base, vdso_text_len, vdso_mapping_len; - void *ret; - - vdso_text_len = vdso_pages << PAGE_SHIFT; - /* Be sure to map the data page */ - vdso_mapping_len = vdso_text_len + PAGE_SIZE; + int ret; if (down_write_killable(&mm->mmap_sem)) return -EINTR; - vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0); - if (IS_ERR_VALUE(vdso_base)) { - ret = ERR_PTR(vdso_base); - goto up_fail; - } - ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE, - VM_READ|VM_MAYREAD, - &vdso_spec[0]); - if (IS_ERR(ret)) - goto up_fail; - - vdso_base += PAGE_SIZE; - mm->context.vdso = (void *)vdso_base; - ret = _install_special_mapping(mm, vdso_base, vdso_text_len, - VM_READ|VM_EXEC| - VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, - &vdso_spec[1]); - if (IS_ERR(ret)) - goto up_fail; + ret = __setup_additional_pages(ARM64_VDSO, + mm, + bprm, + uses_interp); up_write(&mm->mmap_sem); - return 0; -up_fail: - mm->context.vdso = NULL; - up_write(&mm->mmap_sem); - return PTR_ERR(ret); + return ret; } #define VDSO_PRECISION_MASK ~(0xFF00ULL<<48)