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 0E283C433EF for ; Fri, 8 Apr 2022 09:07:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232546AbiDHJJR (ORCPT ); Fri, 8 Apr 2022 05:09:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232645AbiDHJJA (ORCPT ); Fri, 8 Apr 2022 05:09:00 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 22C7B100764 for ; Fri, 8 Apr 2022 02:06:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1649408816; 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=rh0Hpvt4uG7v7kaZ8wWJL2/QNlicmVUp2UwxJSuxITw=; b=L6i3l+naNyWh9wgoya4gkzw3U+EjfEcMOiaeHAftFxVs3+5oRpte5L4zsYca9TFD9+DbWK DkShYGeCWv1KXotHC8r1lzNAH12HIiLhR+SH6S0hZK0lAgc+zB6yr+iA9xmsCUYrPdRbvg M9ZeMzDubx5cQUbPA53PU/V5R3S8BDs= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-389-eNliwG11OqawML9My83IVg-1; Fri, 08 Apr 2022 05:06:50 -0400 X-MC-Unique: eNliwG11OqawML9My83IVg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4BF561C00BA1; Fri, 8 Apr 2022 09:06:50 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-12-202.pek2.redhat.com [10.72.12.202]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5CF7E40D2962; Fri, 8 Apr 2022 09:06:44 +0000 (UTC) From: Baoquan He To: akpm@linux-foundation.org, willy@infradead.org Cc: linux-kernel@vger.kernel.org, kexec@lists.infradead.org, hch@lst.de, yangtiezhu@loongson.cn, amit.kachhap@arm.com, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, bhe@redhat.com Subject: [PATCH v5 RESEND 1/3] vmcore: Convert copy_oldmem_page() to take an iov_iter Date: Fri, 8 Apr 2022 17:06:34 +0800 Message-Id: <20220408090636.560886-2-bhe@redhat.com> In-Reply-To: <20220408090636.560886-1-bhe@redhat.com> References: <20220408090636.560886-1-bhe@redhat.com> MIME-Version: 1.0 Content-type: text/plain Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Matthew Wilcox (Oracle)" Instead of passing in a 'buf' and 'userbuf' argument, pass in an iov_iter. s390 needs more work to pass the iov_iter down further, or refactor, but I'd be more comfortable if someone who can test on s390 did that work. It's more convenient to convert the whole of read_from_oldmem() to take an iov_iter at the same time, so rename it to read_from_oldmem_iter() and add a temporary read_from_oldmem() wrapper that creates an iov_iter. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Baoquan He --- arch/arm/kernel/crash_dump.c | 27 +++------------- arch/arm64/kernel/crash_dump.c | 29 +++-------------- arch/ia64/kernel/crash_dump.c | 32 +++---------------- arch/mips/kernel/crash_dump.c | 27 +++------------- arch/powerpc/kernel/crash_dump.c | 35 +++------------------ arch/riscv/kernel/crash_dump.c | 26 +++------------ arch/s390/kernel/crash_dump.c | 13 +++++--- arch/sh/kernel/crash_dump.c | 29 +++-------------- arch/x86/kernel/crash_dump_32.c | 29 +++-------------- arch/x86/kernel/crash_dump_64.c | 41 +++++++----------------- fs/proc/vmcore.c | 54 ++++++++++++++++++++------------ include/linux/crash_dump.h | 9 +++--- 12 files changed, 91 insertions(+), 260 deletions(-) diff --git a/arch/arm/kernel/crash_dump.c b/arch/arm/kernel/crash_dump.c index 53cb92435392..938bd932df9a 100644 --- a/arch/arm/kernel/crash_dump.c +++ b/arch/arm/kernel/crash_dump.c @@ -14,22 +14,10 @@ #include #include #include +#include -/** - * copy_oldmem_page() - copy one page from old kernel memory - * @pfn: page frame number to be copied - * @buf: buffer where the copied page is placed - * @csize: number of bytes to copy - * @offset: offset in bytes into the page - * @userbuf: if set, @buf is int he user address space - * - * This function copies one page from old kernel memory into buffer pointed by - * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes - * copied or negative error in case of failure. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, - int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; @@ -40,14 +28,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; - if (userbuf) { - if (copy_to_user(buf, vaddr + offset, csize)) { - iounmap(vaddr); - return -EFAULT; - } - } else { - memcpy(buf, vaddr + offset, csize); - } + csize = copy_to_iter(vaddr + offset, csize, iter); iounmap(vaddr); return csize; diff --git a/arch/arm64/kernel/crash_dump.c b/arch/arm64/kernel/crash_dump.c index 58303a9ec32c..670e4ce81822 100644 --- a/arch/arm64/kernel/crash_dump.c +++ b/arch/arm64/kernel/crash_dump.c @@ -9,25 +9,11 @@ #include #include #include -#include -#include +#include #include -/** - * copy_oldmem_page() - copy one page from old kernel memory - * @pfn: page frame number to be copied - * @buf: buffer where the copied page is placed - * @csize: number of bytes to copy - * @offset: offset in bytes into the page - * @userbuf: if set, @buf is in a user address space - * - * This function copies one page from old kernel memory into buffer pointed by - * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes - * copied or negative error in case of failure. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, - int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; @@ -38,14 +24,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; - if (userbuf) { - if (copy_to_user((char __user *)buf, vaddr + offset, csize)) { - memunmap(vaddr); - return -EFAULT; - } - } else { - memcpy(buf, vaddr + offset, csize); - } + csize = copy_to_iter(vaddr + offset, csize, iter); memunmap(vaddr); diff --git a/arch/ia64/kernel/crash_dump.c b/arch/ia64/kernel/crash_dump.c index 0ed3c3dee4cd..4ef68e2aa757 100644 --- a/arch/ia64/kernel/crash_dump.c +++ b/arch/ia64/kernel/crash_dump.c @@ -10,42 +10,18 @@ #include #include #include - +#include #include -#include -/** - * copy_oldmem_page - copy one page from "oldmem" - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from "oldmem". For this page, there is no pte mapped - * in the current kernel. We stitch up a pte, similar to kmap_atomic. - * - * Calling copy_to_user() in atomic context is not desirable. Hence first - * copying the data to a pre-allocated kernel page and then copying to user - * space in non-atomic context. - */ -ssize_t -copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; if (!csize) return 0; vaddr = __va(pfn< #include +#include -/** - * copy_oldmem_page - copy one page from "oldmem" - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from "oldmem". For this page, there is no pte mapped - * in the current kernel. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; @@ -24,14 +12,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, return 0; vaddr = kmap_local_pfn(pfn); - - if (!userbuf) { - memcpy(buf, vaddr + offset, csize); - } else { - if (copy_to_user(buf, vaddr + offset, csize)) - csize = -EFAULT; - } - + csize = copy_to_iter(vaddr + offset, csize, iter); kunmap_local(vaddr); return csize; diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c index 5693e1c67c2b..32b4a97f1b79 100644 --- a/arch/powerpc/kernel/crash_dump.c +++ b/arch/powerpc/kernel/crash_dump.c @@ -16,7 +16,7 @@ #include #include #include -#include +#include #include #include @@ -68,33 +68,8 @@ void __init setup_kdump_trampoline(void) } #endif /* CONFIG_NONSTATIC_KERNEL */ -static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize, - unsigned long offset, int userbuf) -{ - if (userbuf) { - if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) - return -EFAULT; - } else - memcpy(buf, (vaddr + offset), csize); - - return csize; -} - -/** - * copy_oldmem_page - copy one page from "oldmem" - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from "oldmem". For this page, there is no pte mapped - * in the current kernel. We stitch up a pte, similar to kmap_atomic. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; phys_addr_t paddr; @@ -107,10 +82,10 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (memblock_is_region_memory(paddr, csize)) { vaddr = __va(paddr); - csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); + csize = copy_to_iter(vaddr + offset, csize, iter); } else { vaddr = ioremap_cache(paddr, PAGE_SIZE); - csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); + csize = copy_to_iter(vaddr + offset, csize, iter); iounmap(vaddr); } diff --git a/arch/riscv/kernel/crash_dump.c b/arch/riscv/kernel/crash_dump.c index 86cc0ada5752..ea2158cee97b 100644 --- a/arch/riscv/kernel/crash_dump.c +++ b/arch/riscv/kernel/crash_dump.c @@ -7,22 +7,10 @@ #include #include +#include -/** - * copy_oldmem_page() - copy one page from old kernel memory - * @pfn: page frame number to be copied - * @buf: buffer where the copied page is placed - * @csize: number of bytes to copy - * @offset: offset in bytes into the page - * @userbuf: if set, @buf is in a user address space - * - * This function copies one page from old kernel memory into buffer pointed by - * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes - * copied or negative error in case of failure. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, - int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; @@ -33,13 +21,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; - if (userbuf) { - if (copy_to_user((char __user *)buf, vaddr + offset, csize)) { - memunmap(vaddr); - return -EFAULT; - } - } else - memcpy(buf, vaddr + offset, csize); + csize = copy_to_iter(vaddr + offset, csize, iter); memunmap(vaddr); return csize; diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c index 69819b765250..a2c1c55daec0 100644 --- a/arch/s390/kernel/crash_dump.c +++ b/arch/s390/kernel/crash_dump.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -212,8 +213,8 @@ static int copy_oldmem_user(void __user *dst, unsigned long src, size_t count) /* * Copy one page from "oldmem" */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, + unsigned long offset) { unsigned long src; int rc; @@ -221,10 +222,12 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, if (!csize) return 0; src = pfn_to_phys(pfn) + offset; - if (userbuf) - rc = copy_oldmem_user((void __force __user *) buf, src, csize); + + /* XXX: pass the iov_iter down to a common function */ + if (iter_is_iovec(iter)) + rc = copy_oldmem_user(iter->iov->iov_base, src, csize); else - rc = copy_oldmem_kernel((void *) buf, src, csize); + rc = copy_oldmem_kernel(iter->kvec->iov_base, src, csize); return rc; } diff --git a/arch/sh/kernel/crash_dump.c b/arch/sh/kernel/crash_dump.c index 5b41b59698c1..19ce6a950aac 100644 --- a/arch/sh/kernel/crash_dump.c +++ b/arch/sh/kernel/crash_dump.c @@ -8,23 +8,11 @@ #include #include #include +#include #include -/** - * copy_oldmem_page - copy one page from "oldmem" - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from "oldmem". For this page, there is no pte mapped - * in the current kernel. We stitch up a pte, similar to kmap_atomic. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void __iomem *vaddr; @@ -32,15 +20,8 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, return 0; vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE); - - if (userbuf) { - if (copy_to_user((void __user *)buf, (vaddr + offset), csize)) { - iounmap(vaddr); - return -EFAULT; - } - } else - memcpy(buf, (vaddr + offset), csize); - + csize = copy_to_iter(vaddr + offset, csize, iter); iounmap(vaddr); + return csize; } diff --git a/arch/x86/kernel/crash_dump_32.c b/arch/x86/kernel/crash_dump_32.c index 5fcac46aaf6b..5f4ae5476e19 100644 --- a/arch/x86/kernel/crash_dump_32.c +++ b/arch/x86/kernel/crash_dump_32.c @@ -10,8 +10,7 @@ #include #include #include - -#include +#include static inline bool is_crashed_pfn_valid(unsigned long pfn) { @@ -29,21 +28,8 @@ static inline bool is_crashed_pfn_valid(unsigned long pfn) #endif } -/** - * copy_oldmem_page - copy one page from "oldmem" - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from "oldmem". For this page, there might be no pte mapped - * in the current kernel. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, + unsigned long offset) { void *vaddr; @@ -54,14 +40,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, return -EFAULT; vaddr = kmap_local_pfn(pfn); - - if (!userbuf) { - memcpy(buf, vaddr + offset, csize); - } else { - if (copy_to_user(buf, vaddr + offset, csize)) - csize = -EFAULT; - } - + csize = copy_to_iter(vaddr + offset, csize, iter); kunmap_local(vaddr); return csize; diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c index a7f617a3981d..f922d51c9d1f 100644 --- a/arch/x86/kernel/crash_dump_64.c +++ b/arch/x86/kernel/crash_dump_64.c @@ -8,12 +8,12 @@ #include #include -#include +#include #include #include -static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf, +static ssize_t __copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset, bool encrypted) { void *vaddr; @@ -29,47 +29,28 @@ static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, if (!vaddr) return -ENOMEM; - if (userbuf) { - if (copy_to_user((void __user *)buf, vaddr + offset, csize)) { - iounmap((void __iomem *)vaddr); - return -EFAULT; - } - } else - memcpy(buf, vaddr + offset, csize); + csize = copy_to_iter(vaddr + offset, csize, iter); set_iounmap_nonlazy(); iounmap((void __iomem *)vaddr); return csize; } -/** - * copy_oldmem_page - copy one page of memory - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from the old kernel's memory. For this page, there is no pte - * mapped in the current kernel. We stitch up a pte, similar to kmap_atomic. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, + unsigned long offset) { - return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, false); + return __copy_oldmem_page(iter, pfn, csize, offset, false); } -/** +/* * copy_oldmem_page_encrypted - same as copy_oldmem_page() above but ioremap the * memory with the encryption mask set to accommodate kdump on SME-enabled * machines. */ -ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { - return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true); + return __copy_oldmem_page(iter, pfn, csize, offset, true); } ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 6f1b8ddc6f7a..54dda2e19ed1 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include "internal.h" @@ -128,9 +129,8 @@ static int open_vmcore(struct inode *inode, struct file *file) } /* Reads a page from the oldmem device from given offset. */ -ssize_t read_from_oldmem(char *buf, size_t count, - u64 *ppos, int userbuf, - bool encrypted) +static ssize_t read_from_oldmem_iter(struct iov_iter *iter, size_t count, + u64 *ppos, bool encrypted) { unsigned long pfn, offset; size_t nr_bytes; @@ -152,29 +152,23 @@ ssize_t read_from_oldmem(char *buf, size_t count, /* If pfn is not ram, return zeros for sparse dump files */ if (!pfn_is_ram(pfn)) { - tmp = 0; - if (!userbuf) - memset(buf, 0, nr_bytes); - else if (clear_user(buf, nr_bytes)) - tmp = -EFAULT; + tmp = iov_iter_zero(nr_bytes, iter); } else { if (encrypted) - tmp = copy_oldmem_page_encrypted(pfn, buf, + tmp = copy_oldmem_page_encrypted(iter, pfn, nr_bytes, - offset, - userbuf); + offset); else - tmp = copy_oldmem_page(pfn, buf, nr_bytes, - offset, userbuf); + tmp = copy_oldmem_page(iter, pfn, nr_bytes, + offset); } - if (tmp < 0) { + if (tmp < nr_bytes) { srcu_read_unlock(&vmcore_cb_srcu, idx); - return tmp; + return -EFAULT; } *ppos += nr_bytes; count -= nr_bytes; - buf += nr_bytes; read += nr_bytes; ++pfn; offset = 0; @@ -184,6 +178,27 @@ ssize_t read_from_oldmem(char *buf, size_t count, return read; } +ssize_t read_from_oldmem(char *buf, size_t count, + u64 *ppos, int userbuf, + bool encrypted) +{ + struct iov_iter iter; + struct iovec iov; + struct kvec kvec; + + if (userbuf) { + iov.iov_base = (__force void __user *)buf; + iov.iov_len = count; + iov_iter_init(&iter, READ, &iov, 1, count); + } else { + kvec.iov_base = buf; + kvec.iov_len = count; + iov_iter_kvec(&iter, READ, &kvec, 1, count); + } + + return read_from_oldmem_iter(&iter, count, ppos, encrypted); +} + /* * Architectures may override this function to allocate ELF header in 2nd kernel */ @@ -228,11 +243,10 @@ int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma, /* * Architectures which support memory encryption override this. */ -ssize_t __weak -copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +ssize_t __weak copy_oldmem_page_encrypted(struct iov_iter *iter, + unsigned long pfn, size_t csize, unsigned long offset) { - return copy_oldmem_page(pfn, buf, csize, offset, userbuf); + return copy_oldmem_page(iter, pfn, csize, offset); } /* diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index 620821549b23..a1cf7d5c03c7 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -24,11 +24,10 @@ extern int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot); -extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, - unsigned long, int); -extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, - int userbuf); +ssize_t copy_oldmem_page(struct iov_iter *i, unsigned long pfn, size_t csize, + unsigned long offset); +ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset); void vmcore_cleanup(void); -- 2.34.1 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baoquan He Date: Fri, 8 Apr 2022 17:06:34 +0800 Subject: [PATCH v5 RESEND 1/3] vmcore: Convert copy_oldmem_page() to take an iov_iter In-Reply-To: <20220408090636.560886-1-bhe@redhat.com> References: <20220408090636.560886-1-bhe@redhat.com> Message-ID: <20220408090636.560886-2-bhe@redhat.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kexec@lists.infradead.org From: "Matthew Wilcox (Oracle)" Instead of passing in a 'buf' and 'userbuf' argument, pass in an iov_iter. s390 needs more work to pass the iov_iter down further, or refactor, but I'd be more comfortable if someone who can test on s390 did that work. It's more convenient to convert the whole of read_from_oldmem() to take an iov_iter at the same time, so rename it to read_from_oldmem_iter() and add a temporary read_from_oldmem() wrapper that creates an iov_iter. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Baoquan He --- arch/arm/kernel/crash_dump.c | 27 +++------------- arch/arm64/kernel/crash_dump.c | 29 +++-------------- arch/ia64/kernel/crash_dump.c | 32 +++---------------- arch/mips/kernel/crash_dump.c | 27 +++------------- arch/powerpc/kernel/crash_dump.c | 35 +++------------------ arch/riscv/kernel/crash_dump.c | 26 +++------------ arch/s390/kernel/crash_dump.c | 13 +++++--- arch/sh/kernel/crash_dump.c | 29 +++-------------- arch/x86/kernel/crash_dump_32.c | 29 +++-------------- arch/x86/kernel/crash_dump_64.c | 41 +++++++----------------- fs/proc/vmcore.c | 54 ++++++++++++++++++++------------ include/linux/crash_dump.h | 9 +++--- 12 files changed, 91 insertions(+), 260 deletions(-) diff --git a/arch/arm/kernel/crash_dump.c b/arch/arm/kernel/crash_dump.c index 53cb92435392..938bd932df9a 100644 --- a/arch/arm/kernel/crash_dump.c +++ b/arch/arm/kernel/crash_dump.c @@ -14,22 +14,10 @@ #include #include #include +#include -/** - * copy_oldmem_page() - copy one page from old kernel memory - * @pfn: page frame number to be copied - * @buf: buffer where the copied page is placed - * @csize: number of bytes to copy - * @offset: offset in bytes into the page - * @userbuf: if set, @buf is int he user address space - * - * This function copies one page from old kernel memory into buffer pointed by - * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes - * copied or negative error in case of failure. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, - int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; @@ -40,14 +28,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; - if (userbuf) { - if (copy_to_user(buf, vaddr + offset, csize)) { - iounmap(vaddr); - return -EFAULT; - } - } else { - memcpy(buf, vaddr + offset, csize); - } + csize = copy_to_iter(vaddr + offset, csize, iter); iounmap(vaddr); return csize; diff --git a/arch/arm64/kernel/crash_dump.c b/arch/arm64/kernel/crash_dump.c index 58303a9ec32c..670e4ce81822 100644 --- a/arch/arm64/kernel/crash_dump.c +++ b/arch/arm64/kernel/crash_dump.c @@ -9,25 +9,11 @@ #include #include #include -#include -#include +#include #include -/** - * copy_oldmem_page() - copy one page from old kernel memory - * @pfn: page frame number to be copied - * @buf: buffer where the copied page is placed - * @csize: number of bytes to copy - * @offset: offset in bytes into the page - * @userbuf: if set, @buf is in a user address space - * - * This function copies one page from old kernel memory into buffer pointed by - * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes - * copied or negative error in case of failure. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, - int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; @@ -38,14 +24,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; - if (userbuf) { - if (copy_to_user((char __user *)buf, vaddr + offset, csize)) { - memunmap(vaddr); - return -EFAULT; - } - } else { - memcpy(buf, vaddr + offset, csize); - } + csize = copy_to_iter(vaddr + offset, csize, iter); memunmap(vaddr); diff --git a/arch/ia64/kernel/crash_dump.c b/arch/ia64/kernel/crash_dump.c index 0ed3c3dee4cd..4ef68e2aa757 100644 --- a/arch/ia64/kernel/crash_dump.c +++ b/arch/ia64/kernel/crash_dump.c @@ -10,42 +10,18 @@ #include #include #include - +#include #include -#include -/** - * copy_oldmem_page - copy one page from "oldmem" - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from "oldmem". For this page, there is no pte mapped - * in the current kernel. We stitch up a pte, similar to kmap_atomic. - * - * Calling copy_to_user() in atomic context is not desirable. Hence first - * copying the data to a pre-allocated kernel page and then copying to user - * space in non-atomic context. - */ -ssize_t -copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; if (!csize) return 0; vaddr = __va(pfn< #include +#include -/** - * copy_oldmem_page - copy one page from "oldmem" - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from "oldmem". For this page, there is no pte mapped - * in the current kernel. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; @@ -24,14 +12,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, return 0; vaddr = kmap_local_pfn(pfn); - - if (!userbuf) { - memcpy(buf, vaddr + offset, csize); - } else { - if (copy_to_user(buf, vaddr + offset, csize)) - csize = -EFAULT; - } - + csize = copy_to_iter(vaddr + offset, csize, iter); kunmap_local(vaddr); return csize; diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c index 5693e1c67c2b..32b4a97f1b79 100644 --- a/arch/powerpc/kernel/crash_dump.c +++ b/arch/powerpc/kernel/crash_dump.c @@ -16,7 +16,7 @@ #include #include #include -#include +#include #include #include @@ -68,33 +68,8 @@ void __init setup_kdump_trampoline(void) } #endif /* CONFIG_NONSTATIC_KERNEL */ -static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize, - unsigned long offset, int userbuf) -{ - if (userbuf) { - if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) - return -EFAULT; - } else - memcpy(buf, (vaddr + offset), csize); - - return csize; -} - -/** - * copy_oldmem_page - copy one page from "oldmem" - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from "oldmem". For this page, there is no pte mapped - * in the current kernel. We stitch up a pte, similar to kmap_atomic. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; phys_addr_t paddr; @@ -107,10 +82,10 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (memblock_is_region_memory(paddr, csize)) { vaddr = __va(paddr); - csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); + csize = copy_to_iter(vaddr + offset, csize, iter); } else { vaddr = ioremap_cache(paddr, PAGE_SIZE); - csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); + csize = copy_to_iter(vaddr + offset, csize, iter); iounmap(vaddr); } diff --git a/arch/riscv/kernel/crash_dump.c b/arch/riscv/kernel/crash_dump.c index 86cc0ada5752..ea2158cee97b 100644 --- a/arch/riscv/kernel/crash_dump.c +++ b/arch/riscv/kernel/crash_dump.c @@ -7,22 +7,10 @@ #include #include +#include -/** - * copy_oldmem_page() - copy one page from old kernel memory - * @pfn: page frame number to be copied - * @buf: buffer where the copied page is placed - * @csize: number of bytes to copy - * @offset: offset in bytes into the page - * @userbuf: if set, @buf is in a user address space - * - * This function copies one page from old kernel memory into buffer pointed by - * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes - * copied or negative error in case of failure. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, - int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; @@ -33,13 +21,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; - if (userbuf) { - if (copy_to_user((char __user *)buf, vaddr + offset, csize)) { - memunmap(vaddr); - return -EFAULT; - } - } else - memcpy(buf, vaddr + offset, csize); + csize = copy_to_iter(vaddr + offset, csize, iter); memunmap(vaddr); return csize; diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c index 69819b765250..a2c1c55daec0 100644 --- a/arch/s390/kernel/crash_dump.c +++ b/arch/s390/kernel/crash_dump.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -212,8 +213,8 @@ static int copy_oldmem_user(void __user *dst, unsigned long src, size_t count) /* * Copy one page from "oldmem" */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, + unsigned long offset) { unsigned long src; int rc; @@ -221,10 +222,12 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, if (!csize) return 0; src = pfn_to_phys(pfn) + offset; - if (userbuf) - rc = copy_oldmem_user((void __force __user *) buf, src, csize); + + /* XXX: pass the iov_iter down to a common function */ + if (iter_is_iovec(iter)) + rc = copy_oldmem_user(iter->iov->iov_base, src, csize); else - rc = copy_oldmem_kernel((void *) buf, src, csize); + rc = copy_oldmem_kernel(iter->kvec->iov_base, src, csize); return rc; } diff --git a/arch/sh/kernel/crash_dump.c b/arch/sh/kernel/crash_dump.c index 5b41b59698c1..19ce6a950aac 100644 --- a/arch/sh/kernel/crash_dump.c +++ b/arch/sh/kernel/crash_dump.c @@ -8,23 +8,11 @@ #include #include #include +#include #include -/** - * copy_oldmem_page - copy one page from "oldmem" - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from "oldmem". For this page, there is no pte mapped - * in the current kernel. We stitch up a pte, similar to kmap_atomic. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void __iomem *vaddr; @@ -32,15 +20,8 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, return 0; vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE); - - if (userbuf) { - if (copy_to_user((void __user *)buf, (vaddr + offset), csize)) { - iounmap(vaddr); - return -EFAULT; - } - } else - memcpy(buf, (vaddr + offset), csize); - + csize = copy_to_iter(vaddr + offset, csize, iter); iounmap(vaddr); + return csize; } diff --git a/arch/x86/kernel/crash_dump_32.c b/arch/x86/kernel/crash_dump_32.c index 5fcac46aaf6b..5f4ae5476e19 100644 --- a/arch/x86/kernel/crash_dump_32.c +++ b/arch/x86/kernel/crash_dump_32.c @@ -10,8 +10,7 @@ #include #include #include - -#include +#include static inline bool is_crashed_pfn_valid(unsigned long pfn) { @@ -29,21 +28,8 @@ static inline bool is_crashed_pfn_valid(unsigned long pfn) #endif } -/** - * copy_oldmem_page - copy one page from "oldmem" - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from "oldmem". For this page, there might be no pte mapped - * in the current kernel. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, + unsigned long offset) { void *vaddr; @@ -54,14 +40,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, return -EFAULT; vaddr = kmap_local_pfn(pfn); - - if (!userbuf) { - memcpy(buf, vaddr + offset, csize); - } else { - if (copy_to_user(buf, vaddr + offset, csize)) - csize = -EFAULT; - } - + csize = copy_to_iter(vaddr + offset, csize, iter); kunmap_local(vaddr); return csize; diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c index a7f617a3981d..f922d51c9d1f 100644 --- a/arch/x86/kernel/crash_dump_64.c +++ b/arch/x86/kernel/crash_dump_64.c @@ -8,12 +8,12 @@ #include #include -#include +#include #include #include -static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf, +static ssize_t __copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset, bool encrypted) { void *vaddr; @@ -29,47 +29,28 @@ static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, if (!vaddr) return -ENOMEM; - if (userbuf) { - if (copy_to_user((void __user *)buf, vaddr + offset, csize)) { - iounmap((void __iomem *)vaddr); - return -EFAULT; - } - } else - memcpy(buf, vaddr + offset, csize); + csize = copy_to_iter(vaddr + offset, csize, iter); set_iounmap_nonlazy(); iounmap((void __iomem *)vaddr); return csize; } -/** - * copy_oldmem_page - copy one page of memory - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from the old kernel's memory. For this page, there is no pte - * mapped in the current kernel. We stitch up a pte, similar to kmap_atomic. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, + unsigned long offset) { - return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, false); + return __copy_oldmem_page(iter, pfn, csize, offset, false); } -/** +/* * copy_oldmem_page_encrypted - same as copy_oldmem_page() above but ioremap the * memory with the encryption mask set to accommodate kdump on SME-enabled * machines. */ -ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { - return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true); + return __copy_oldmem_page(iter, pfn, csize, offset, true); } ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 6f1b8ddc6f7a..54dda2e19ed1 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include "internal.h" @@ -128,9 +129,8 @@ static int open_vmcore(struct inode *inode, struct file *file) } /* Reads a page from the oldmem device from given offset. */ -ssize_t read_from_oldmem(char *buf, size_t count, - u64 *ppos, int userbuf, - bool encrypted) +static ssize_t read_from_oldmem_iter(struct iov_iter *iter, size_t count, + u64 *ppos, bool encrypted) { unsigned long pfn, offset; size_t nr_bytes; @@ -152,29 +152,23 @@ ssize_t read_from_oldmem(char *buf, size_t count, /* If pfn is not ram, return zeros for sparse dump files */ if (!pfn_is_ram(pfn)) { - tmp = 0; - if (!userbuf) - memset(buf, 0, nr_bytes); - else if (clear_user(buf, nr_bytes)) - tmp = -EFAULT; + tmp = iov_iter_zero(nr_bytes, iter); } else { if (encrypted) - tmp = copy_oldmem_page_encrypted(pfn, buf, + tmp = copy_oldmem_page_encrypted(iter, pfn, nr_bytes, - offset, - userbuf); + offset); else - tmp = copy_oldmem_page(pfn, buf, nr_bytes, - offset, userbuf); + tmp = copy_oldmem_page(iter, pfn, nr_bytes, + offset); } - if (tmp < 0) { + if (tmp < nr_bytes) { srcu_read_unlock(&vmcore_cb_srcu, idx); - return tmp; + return -EFAULT; } *ppos += nr_bytes; count -= nr_bytes; - buf += nr_bytes; read += nr_bytes; ++pfn; offset = 0; @@ -184,6 +178,27 @@ ssize_t read_from_oldmem(char *buf, size_t count, return read; } +ssize_t read_from_oldmem(char *buf, size_t count, + u64 *ppos, int userbuf, + bool encrypted) +{ + struct iov_iter iter; + struct iovec iov; + struct kvec kvec; + + if (userbuf) { + iov.iov_base = (__force void __user *)buf; + iov.iov_len = count; + iov_iter_init(&iter, READ, &iov, 1, count); + } else { + kvec.iov_base = buf; + kvec.iov_len = count; + iov_iter_kvec(&iter, READ, &kvec, 1, count); + } + + return read_from_oldmem_iter(&iter, count, ppos, encrypted); +} + /* * Architectures may override this function to allocate ELF header in 2nd kernel */ @@ -228,11 +243,10 @@ int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma, /* * Architectures which support memory encryption override this. */ -ssize_t __weak -copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +ssize_t __weak copy_oldmem_page_encrypted(struct iov_iter *iter, + unsigned long pfn, size_t csize, unsigned long offset) { - return copy_oldmem_page(pfn, buf, csize, offset, userbuf); + return copy_oldmem_page(iter, pfn, csize, offset); } /* diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index 620821549b23..a1cf7d5c03c7 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -24,11 +24,10 @@ extern int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot); -extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, - unsigned long, int); -extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, - int userbuf); +ssize_t copy_oldmem_page(struct iov_iter *i, unsigned long pfn, size_t csize, + unsigned long offset); +ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset); void vmcore_cleanup(void); -- 2.34.1