From patchwork Mon Sep 9 18:12:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pasha Tatashin X-Patchwork-Id: 11138381 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4768C1599 for ; Mon, 9 Sep 2019 18:16:23 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 1CC98218DE for ; Mon, 9 Sep 2019 18:16:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="UK8NbccC"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=soleen.com header.i=@soleen.com header.b="fWLhzckv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1CC98218DE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=soleen.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org 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: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:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=hmIlOv+cqdaGX89DhXjNR+bCLOMaLBpNEACSMCYgr1k=; b=UK8NbccC5cMKVU PeeYv6x7k93K2gHiv149hMexONEPzSdm2SNZsECRNHUEA8yatC2MRp4oZ/+6mQs3SEL69gXZ6rjs2 +PUno8RhK8kVWHKMLv0S4kmNknGzujyXaHw/8/enAgm5L5UcstnDxLU18SuhNhvhG8+IsQi5T9Nkx DF0STtj2qTKr8L0kIaLTEQnroScblHEyDZ6HdT0dCsmV8aCeMN2Occan2h4OPdGuERJH+vKNR/Seh ZzTT9h2a+9OHKzh3pP7aWLX5F0tb9y1bmchq+xbH2HN8Ihwnc9n3qqqqE1Vn4cy01I0o3B5WIh6Uh isBrXAzmlbqDAPjrKx6w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i7OCx-0004xw-Et; Mon, 09 Sep 2019 18:16:11 +0000 Received: from mail-qk1-x744.google.com ([2607:f8b0:4864:20::744]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i7O9W-0008VD-Nf for linux-arm-kernel@lists.infradead.org; Mon, 09 Sep 2019 18:12:42 +0000 Received: by mail-qk1-x744.google.com with SMTP id h126so6313220qke.10 for ; Mon, 09 Sep 2019 11:12:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=Rg4d64JpnTaANXvX3uzyA9vcQSLPYA1Q9YCgAGVLAdE=; b=fWLhzckvBH61fecR7zB865Jg/3mFMNrYTLWAWSGeq+qWJtOfowYsPpUvq+bwuAW9P6 Z7LCFr1BVmxOwJUaO6i/9ZSlrZhuUcqGmWFWOeD/uUuJM8ydEkwk3ivrc1lX1b3hNVsI 6DCj0nb0JRGJZT18h7YflhWJE2k7q9W1HmDDXrGfOZ0SDf8q97x1rnWuJFB2BKLzTCS4 NImAULxu7GGCCiRFsYtpyVn6ijZglF0Iuhiup0xopLhz0Sg5ThcJxkS8CoKbCNGFuH6S ra2JD13gWjlkh3BXg2VAIuzQMCsPc0R75DpBdBNbyUvp01oSAI3Kne5Ef52+Ng+GtYDK Jo/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Rg4d64JpnTaANXvX3uzyA9vcQSLPYA1Q9YCgAGVLAdE=; b=gWiGFThHjaULnBCy4Bk3ZSBtBzD5+TtBhZ8DGzW6uLXU4j+PktXmP8Gm/J5ks8Tmew s1xEfljmuI5xQLDu2FmJik3TBviKGSYaDOl4NJj/qstv8+5ofqqcDzw034s9yasls4P9 ntgTXVK2JX4vt1v2Qyple+oPyJJuLQ/JzY7TckoGeJdLOApJaD0xq7kH79QB/2K7Bfm7 Fq5g2uCs5t4YoRPs36bVV/g+nH50nYikSbI9qHfamSs290S6NcLDH0vJEHOaz08s+KQk FdCD8mxKpTjtPpWZDn1r9VLixM5E9R80j78vI1L9NymIu/IHLwDuBRoWJV1Lf9c61lYZ TWRg== X-Gm-Message-State: APjAAAX3tQU3G2orUWQv3NH8gRgirCwGr9QIRvt0xg14UQ2+/XCbANTR SbKD1MaGXIIDFH33agchvfnq+Q== X-Google-Smtp-Source: APXvYqzBKILQWUrwZxLxdaMSqsJPQCxgxErrstUv9wanVZcERloJPtlkE4yx+Jd36p+uvRKFpIPi1w== X-Received: by 2002:a05:620a:14c:: with SMTP id e12mr24483007qkn.47.1568052757183; Mon, 09 Sep 2019 11:12:37 -0700 (PDT) Received: from localhost.localdomain (c-73-69-118-222.hsd1.nh.comcast.net. [73.69.118.222]) by smtp.gmail.com with ESMTPSA id q8sm5611310qtj.76.2019.09.09.11.12.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Sep 2019 11:12:36 -0700 (PDT) From: Pavel Tatashin To: pasha.tatashin@soleen.com, jmorris@namei.org, sashal@kernel.org, ebiederm@xmission.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, corbet@lwn.net, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, marc.zyngier@arm.com, james.morse@arm.com, vladimir.murzin@arm.com, matthias.bgg@gmail.com, bhsharma@redhat.com, linux-mm@kvack.org, mark.rutland@arm.com Subject: [PATCH v4 09/17] arm64: hibernate: move page handling function to new trans_pgd.c Date: Mon, 9 Sep 2019 14:12:13 -0400 Message-Id: <20190909181221.309510-10-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190909181221.309510-1-pasha.tatashin@soleen.com> References: <20190909181221.309510-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190909_111238_869472_88FD1922 X-CRM114-Status: GOOD ( 19.76 ) X-Spam-Score: -0.2 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-0.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [2607:f8b0:4864:20:0:0:0:744 listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Now, that we abstracted the required functions move them to a new home. Later, we will generalize these function in order to be useful outside of hibernation. Signed-off-by: Pavel Tatashin --- arch/arm64/Kconfig | 4 + arch/arm64/include/asm/trans_pgd.h | 20 +++ arch/arm64/kernel/hibernate.c | 199 +------------------------- arch/arm64/mm/Makefile | 1 + arch/arm64/mm/trans_pgd.c | 219 +++++++++++++++++++++++++++++ 5 files changed, 245 insertions(+), 198 deletions(-) create mode 100644 arch/arm64/include/asm/trans_pgd.h create mode 100644 arch/arm64/mm/trans_pgd.c diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 3adcec05b1f6..91a7416ffe4e 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -999,6 +999,10 @@ config CRASH_DUMP For more details see Documentation/admin-guide/kdump/kdump.rst +config TRANS_TABLE + def_bool y + depends on HIBERNATION || KEXEC_CORE + config XEN_DOM0 def_bool y depends on XEN diff --git a/arch/arm64/include/asm/trans_pgd.h b/arch/arm64/include/asm/trans_pgd.h new file mode 100644 index 000000000000..c7b5402b7d87 --- /dev/null +++ b/arch/arm64/include/asm/trans_pgd.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * Copyright (c) 2019, Microsoft Corporation. + * Pavel Tatashin + */ + +#ifndef _ASM_TRANS_TABLE_H +#define _ASM_TRANS_TABLE_H + +#include +#include + +int trans_pgd_create_copy(pgd_t **dst_pgdp, unsigned long start, + unsigned long end); + +int trans_pgd_map_page(pgd_t *trans_pgd, void *page, unsigned long dst_addr, + pgprot_t pgprot); + +#endif /* _ASM_TRANS_TABLE_H */ diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c index 178488a902c7..94ede33bd777 100644 --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -16,7 +16,6 @@ #define pr_fmt(x) "hibernate: " x #include #include -#include #include #include #include @@ -31,14 +30,12 @@ #include #include #include -#include -#include -#include #include #include #include #include #include +#include #include /* @@ -182,45 +179,6 @@ int arch_hibernation_header_restore(void *addr) } EXPORT_SYMBOL(arch_hibernation_header_restore); -int trans_pgd_map_page(pgd_t *trans_pgd, void *page, - unsigned long dst_addr, - pgprot_t pgprot) -{ - pgd_t *pgdp; - pud_t *pudp; - pmd_t *pmdp; - pte_t *ptep; - - pgdp = pgd_offset_raw(trans_pgd, dst_addr); - if (pgd_none(READ_ONCE(*pgdp))) { - pudp = (void *)get_safe_page(GFP_ATOMIC); - if (!pudp) - return -ENOMEM; - pgd_populate(&init_mm, pgdp, pudp); - } - - pudp = pud_offset(pgdp, dst_addr); - if (pud_none(READ_ONCE(*pudp))) { - pmdp = (void *)get_safe_page(GFP_ATOMIC); - if (!pmdp) - return -ENOMEM; - pud_populate(&init_mm, pudp, pmdp); - } - - pmdp = pmd_offset(pudp, dst_addr); - if (pmd_none(READ_ONCE(*pmdp))) { - ptep = (void *)get_safe_page(GFP_ATOMIC); - if (!ptep) - return -ENOMEM; - pmd_populate_kernel(&init_mm, pmdp, ptep); - } - - ptep = pte_offset_kernel(pmdp, dst_addr); - set_pte(ptep, pfn_pte(virt_to_pfn(page), PAGE_KERNEL_EXEC)); - - return 0; -} - /* * Copies length bytes, starting at src_start into an new page, * perform cache maintenance, then maps it at the specified address low @@ -339,161 +297,6 @@ int swsusp_arch_suspend(void) return ret; } -static void _copy_pte(pte_t *dst_ptep, pte_t *src_ptep, unsigned long addr) -{ - pte_t pte = READ_ONCE(*src_ptep); - - if (pte_valid(pte)) { - /* - * Resume will overwrite areas that may be marked - * read only (code, rodata). Clear the RDONLY bit from - * the temporary mappings we use during restore. - */ - set_pte(dst_ptep, pte_mkwrite(pte)); - } else if (debug_pagealloc_enabled() && !pte_none(pte)) { - /* - * debug_pagealloc will removed the PTE_VALID bit if - * the page isn't in use by the resume kernel. It may have - * been in use by the original kernel, in which case we need - * to put it back in our copy to do the restore. - * - * Before marking this entry valid, check the pfn should - * be mapped. - */ - BUG_ON(!pfn_valid(pte_pfn(pte))); - - set_pte(dst_ptep, pte_mkpresent(pte_mkwrite(pte))); - } -} - -static int copy_pte(pmd_t *dst_pmdp, pmd_t *src_pmdp, unsigned long start, - unsigned long end) -{ - pte_t *src_ptep; - pte_t *dst_ptep; - unsigned long addr = start; - - dst_ptep = (pte_t *)get_safe_page(GFP_ATOMIC); - if (!dst_ptep) - return -ENOMEM; - pmd_populate_kernel(&init_mm, dst_pmdp, dst_ptep); - dst_ptep = pte_offset_kernel(dst_pmdp, start); - - src_ptep = pte_offset_kernel(src_pmdp, start); - do { - _copy_pte(dst_ptep, src_ptep, addr); - } while (dst_ptep++, src_ptep++, addr += PAGE_SIZE, addr != end); - - return 0; -} - -static int copy_pmd(pud_t *dst_pudp, pud_t *src_pudp, unsigned long start, - unsigned long end) -{ - pmd_t *src_pmdp; - pmd_t *dst_pmdp; - unsigned long next; - unsigned long addr = start; - - if (pud_none(READ_ONCE(*dst_pudp))) { - dst_pmdp = (pmd_t *)get_safe_page(GFP_ATOMIC); - if (!dst_pmdp) - return -ENOMEM; - pud_populate(&init_mm, dst_pudp, dst_pmdp); - } - dst_pmdp = pmd_offset(dst_pudp, start); - - src_pmdp = pmd_offset(src_pudp, start); - do { - pmd_t pmd = READ_ONCE(*src_pmdp); - - next = pmd_addr_end(addr, end); - if (pmd_none(pmd)) - continue; - if (pmd_table(pmd)) { - if (copy_pte(dst_pmdp, src_pmdp, addr, next)) - return -ENOMEM; - } else { - set_pmd(dst_pmdp, - __pmd(pmd_val(pmd) & ~PMD_SECT_RDONLY)); - } - } while (dst_pmdp++, src_pmdp++, addr = next, addr != end); - - return 0; -} - -static int copy_pud(pgd_t *dst_pgdp, pgd_t *src_pgdp, unsigned long start, - unsigned long end) -{ - pud_t *dst_pudp; - pud_t *src_pudp; - unsigned long next; - unsigned long addr = start; - - if (pgd_none(READ_ONCE(*dst_pgdp))) { - dst_pudp = (pud_t *)get_safe_page(GFP_ATOMIC); - if (!dst_pudp) - return -ENOMEM; - pgd_populate(&init_mm, dst_pgdp, dst_pudp); - } - dst_pudp = pud_offset(dst_pgdp, start); - - src_pudp = pud_offset(src_pgdp, start); - do { - pud_t pud = READ_ONCE(*src_pudp); - - next = pud_addr_end(addr, end); - if (pud_none(pud)) - continue; - if (pud_table(pud)) { - if (copy_pmd(dst_pudp, src_pudp, addr, next)) - return -ENOMEM; - } else { - set_pud(dst_pudp, - __pud(pud_val(pud) & ~PUD_SECT_RDONLY)); - } - } while (dst_pudp++, src_pudp++, addr = next, addr != end); - - return 0; -} - -static int copy_page_tables(pgd_t *dst_pgdp, unsigned long start, - unsigned long end) -{ - unsigned long next; - unsigned long addr = start; - pgd_t *src_pgdp = pgd_offset_k(start); - - dst_pgdp = pgd_offset_raw(dst_pgdp, start); - do { - next = pgd_addr_end(addr, end); - if (pgd_none(READ_ONCE(*src_pgdp))) - continue; - if (copy_pud(dst_pgdp, src_pgdp, addr, next)) - return -ENOMEM; - } while (dst_pgdp++, src_pgdp++, addr = next, addr != end); - - return 0; -} - -int trans_pgd_create_copy(pgd_t **dst_pgdp, unsigned long start, - unsigned long end) -{ - int rc; - pgd_t *trans_pgd = (pgd_t *)get_safe_page(GFP_ATOMIC); - - if (!trans_pgd) { - pr_err("Failed to allocate memory for temporary page tables.\n"); - return -ENOMEM; - } - - rc = copy_page_tables(trans_pgd, start, end); - if (!rc) - *dst_pgdp = trans_pgd; - - return rc; -} - /* * Setup then Resume from the hibernate image using swsusp_arch_suspend_exit(). * diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile index 849c1df3d214..f3002f1d0e61 100644 --- a/arch/arm64/mm/Makefile +++ b/arch/arm64/mm/Makefile @@ -6,6 +6,7 @@ obj-y := dma-mapping.o extable.o fault.o init.o \ obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o obj-$(CONFIG_ARM64_PTDUMP_CORE) += dump.o obj-$(CONFIG_ARM64_PTDUMP_DEBUGFS) += ptdump_debugfs.o +obj-$(CONFIG_TRANS_TABLE) += trans_pgd.o obj-$(CONFIG_NUMA) += numa.o obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o KASAN_SANITIZE_physaddr.o += n diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c new file mode 100644 index 000000000000..5ac712b92439 --- /dev/null +++ b/arch/arm64/mm/trans_pgd.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Transitional page tables for kexec and hibernate + * + * This file derived from: arch/arm64/kernel/hibernate.c + * + * Copyright (c) 2019, Microsoft Corporation. + * Pavel Tatashin + * + */ + +/* + * Transitional tables are used during system transferring from one world to + * another: such as during hibernate restore, and kexec reboots. During these + * phases one cannot rely on page table not being overwritten. This is because + * hibernate and kexec can overwrite the current page tables during transition. + */ + +#include +#include +#include +#include +#include +#include +#include + +static void _copy_pte(pte_t *dst_ptep, pte_t *src_ptep, unsigned long addr) +{ + pte_t pte = READ_ONCE(*src_ptep); + + if (pte_valid(pte)) { + /* + * Resume will overwrite areas that may be marked + * read only (code, rodata). Clear the RDONLY bit from + * the temporary mappings we use during restore. + */ + set_pte(dst_ptep, pte_mkwrite(pte)); + } else if (debug_pagealloc_enabled() && !pte_none(pte)) { + /* + * debug_pagealloc will removed the PTE_VALID bit if + * the page isn't in use by the resume kernel. It may have + * been in use by the original kernel, in which case we need + * to put it back in our copy to do the restore. + * + * Before marking this entry valid, check the pfn should + * be mapped. + */ + BUG_ON(!pfn_valid(pte_pfn(pte))); + + set_pte(dst_ptep, pte_mkpresent(pte_mkwrite(pte))); + } +} + +static int copy_pte(pmd_t *dst_pmdp, pmd_t *src_pmdp, unsigned long start, + unsigned long end) +{ + pte_t *src_ptep; + pte_t *dst_ptep; + unsigned long addr = start; + + dst_ptep = (pte_t *)get_safe_page(GFP_ATOMIC); + if (!dst_ptep) + return -ENOMEM; + pmd_populate_kernel(&init_mm, dst_pmdp, dst_ptep); + dst_ptep = pte_offset_kernel(dst_pmdp, start); + + src_ptep = pte_offset_kernel(src_pmdp, start); + do { + _copy_pte(dst_ptep, src_ptep, addr); + } while (dst_ptep++, src_ptep++, addr += PAGE_SIZE, addr != end); + + return 0; +} + +static int copy_pmd(pud_t *dst_pudp, pud_t *src_pudp, unsigned long start, + unsigned long end) +{ + pmd_t *src_pmdp; + pmd_t *dst_pmdp; + unsigned long next; + unsigned long addr = start; + + if (pud_none(READ_ONCE(*dst_pudp))) { + dst_pmdp = (pmd_t *)get_safe_page(GFP_ATOMIC); + if (!dst_pmdp) + return -ENOMEM; + pud_populate(&init_mm, dst_pudp, dst_pmdp); + } + dst_pmdp = pmd_offset(dst_pudp, start); + + src_pmdp = pmd_offset(src_pudp, start); + do { + pmd_t pmd = READ_ONCE(*src_pmdp); + + next = pmd_addr_end(addr, end); + if (pmd_none(pmd)) + continue; + if (pmd_table(pmd)) { + if (copy_pte(dst_pmdp, src_pmdp, addr, next)) + return -ENOMEM; + } else { + set_pmd(dst_pmdp, + __pmd(pmd_val(pmd) & ~PMD_SECT_RDONLY)); + } + } while (dst_pmdp++, src_pmdp++, addr = next, addr != end); + + return 0; +} + +static int copy_pud(pgd_t *dst_pgdp, pgd_t *src_pgdp, unsigned long start, + unsigned long end) +{ + pud_t *dst_pudp; + pud_t *src_pudp; + unsigned long next; + unsigned long addr = start; + + if (pgd_none(READ_ONCE(*dst_pgdp))) { + dst_pudp = (pud_t *)get_safe_page(GFP_ATOMIC); + if (!dst_pudp) + return -ENOMEM; + pgd_populate(&init_mm, dst_pgdp, dst_pudp); + } + dst_pudp = pud_offset(dst_pgdp, start); + + src_pudp = pud_offset(src_pgdp, start); + do { + pud_t pud = READ_ONCE(*src_pudp); + + next = pud_addr_end(addr, end); + if (pud_none(pud)) + continue; + if (pud_table(pud)) { + if (copy_pmd(dst_pudp, src_pudp, addr, next)) + return -ENOMEM; + } else { + set_pud(dst_pudp, + __pud(pud_val(pud) & ~PUD_SECT_RDONLY)); + } + } while (dst_pudp++, src_pudp++, addr = next, addr != end); + + return 0; +} + +static int copy_page_tables(pgd_t *dst_pgdp, unsigned long start, + unsigned long end) +{ + unsigned long next; + unsigned long addr = start; + pgd_t *src_pgdp = pgd_offset_k(start); + + dst_pgdp = pgd_offset_raw(dst_pgdp, start); + do { + next = pgd_addr_end(addr, end); + if (pgd_none(READ_ONCE(*src_pgdp))) + continue; + if (copy_pud(dst_pgdp, src_pgdp, addr, next)) + return -ENOMEM; + } while (dst_pgdp++, src_pgdp++, addr = next, addr != end); + + return 0; +} + +int trans_pgd_create_copy(pgd_t **dst_pgdp, unsigned long start, + unsigned long end) +{ + int rc; + pgd_t *trans_pgd = (pgd_t *)get_safe_page(GFP_ATOMIC); + + if (!trans_pgd) { + pr_err("Failed to allocate memory for temporary page tables.\n"); + return -ENOMEM; + } + + rc = copy_page_tables(trans_pgd, start, end); + if (!rc) + *dst_pgdp = trans_pgd; + + return rc; +} + +int trans_pgd_map_page(pgd_t *trans_pgd, void *page, unsigned long dst_addr, + pgprot_t pgprot) +{ + pgd_t *pgdp; + pud_t *pudp; + pmd_t *pmdp; + pte_t *ptep; + + pgdp = pgd_offset_raw(trans_pgd, dst_addr); + if (pgd_none(READ_ONCE(*pgdp))) { + pudp = (void *)get_safe_page(GFP_ATOMIC); + if (!pudp) + return -ENOMEM; + pgd_populate(&init_mm, pgdp, pudp); + } + + pudp = pud_offset(pgdp, dst_addr); + if (pud_none(READ_ONCE(*pudp))) { + pmdp = (void *)get_safe_page(GFP_ATOMIC); + if (!pmdp) + return -ENOMEM; + pud_populate(&init_mm, pudp, pmdp); + } + + pmdp = pmd_offset(pudp, dst_addr); + if (pmd_none(READ_ONCE(*pmdp))) { + ptep = (void *)get_safe_page(GFP_ATOMIC); + if (!ptep) + return -ENOMEM; + pmd_populate_kernel(&init_mm, pmdp, ptep); + } + + ptep = pte_offset_kernel(pmdp, dst_addr); + set_pte(ptep, pfn_pte(virt_to_pfn(page), PAGE_KERNEL_EXEC)); + + return 0; +}