From nobody Mon Jun 22 19:21:09 2026 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 EF450C433EF for ; Fri, 18 Mar 2022 09:37:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234531AbiCRJiv (ORCPT ); Fri, 18 Mar 2022 05:38:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232006AbiCRJit (ORCPT ); Fri, 18 Mar 2022 05:38:49 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 61E732EA92E for ; Fri, 18 Mar 2022 02:37:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647596248; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N68VYWZC9sV47zXSAfLRMPeBevEjaUPkamR26hvVk8E=; b=DiCTrfrkBgaCCI6bPJ2Z47Vk64jue8AMCqyrYW+lIs64v+XEuaBpjS/mjTDwtTk7YQdj8g 7v0dScadJToD3jW47DrXFNe5OvxabvdFml3FGXE3Hgorw6MrMkW3s/T0vr64MBDhqhzOwB i9m6MqPrPFXYbwnhGaqb499mRxacn+Q= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-656-ksdvGkt8M0uIfzLmWYtObg-1; Fri, 18 Mar 2022 05:37:23 -0400 X-MC-Unique: ksdvGkt8M0uIfzLmWYtObg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id BBAD6100B8C8; Fri, 18 Mar 2022 09:37:22 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-13-174.pek2.redhat.com [10.72.13.174]) by smtp.corp.redhat.com (Postfix) with ESMTP id DE43E112C256; Fri, 18 Mar 2022 09:37:17 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: willy@infradead.org, bhe@redhat.com, kexec@lists.infradead.org, yangtiezhu@loongson.cn, amit.kachhap@arm.com, hch@lst.de, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk Subject: [PATCH v4 1/4] vmcore: Convert copy_oldmem_page() to take an iov_iter Date: Fri, 18 Mar 2022 17:37:03 +0800 Message-Id: <20220318093706.161534-2-bhe@redhat.com> In-Reply-To: <20220318093706.161534-1-bhe@redhat.com> References: <20220318093706.161534-1-bhe@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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) Reviewed-by: Christoph Hellwig Acked-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 =20 -/** - * 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 pointe= d by - * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of by= tes - * 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; =20 @@ -40,14 +28,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; =20 - if (userbuf) { - if (copy_to_user(buf, vaddr + offset, csize)) { - iounmap(vaddr); - return -EFAULT; - } - } else { - memcpy(buf, vaddr + offset, csize); - } + csize =3D copy_to_iter(vaddr + offset, csize, iter); =20 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 =20 -/** - * 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 pointe= d by - * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of by= tes - * 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; =20 @@ -38,14 +24,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; =20 - if (userbuf) { - if (copy_to_user((char __user *)buf, vaddr + offset, csize)) { - memunmap(vaddr); - return -EFAULT; - } - } else { - memcpy(buf, vaddr + offset, csize); - } + csize =3D copy_to_iter(vaddr + offset, csize, iter); =20 memunmap(vaddr); =20 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 =20 -/** - * 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; =20 if (!csize) return 0; vaddr =3D __va(pfn< #include +#include =20 -/** - * 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; =20 @@ -24,14 +12,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, return 0; =20 vaddr =3D kmap_local_pfn(pfn); - - if (!userbuf) { - memcpy(buf, vaddr + offset, csize); - } else { - if (copy_to_user(buf, vaddr + offset, csize)) - csize =3D -EFAULT; - } - + csize =3D copy_to_iter(vaddr + offset, csize, iter); kunmap_local(vaddr); =20 return csize; diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_d= ump.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 =20 @@ -68,33 +68,8 @@ void __init setup_kdump_trampoline(void) } #endif /* CONFIG_NONSTATIC_KERNEL */ =20 -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, =20 if (memblock_is_region_memory(paddr, csize)) { vaddr =3D __va(paddr); - csize =3D copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); + csize =3D copy_to_iter(vaddr + offset, csize, iter); } else { vaddr =3D ioremap_cache(paddr, PAGE_SIZE); - csize =3D copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); + csize =3D copy_to_iter(vaddr + offset, csize, iter); iounmap(vaddr); } =20 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 @@ =20 #include #include +#include =20 -/** - * 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 pointe= d by - * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of by= tes - * 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; =20 @@ -33,13 +21,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; =20 - if (userbuf) { - if (copy_to_user((char __user *)buf, vaddr + offset, csize)) { - memunmap(vaddr); - return -EFAULT; - } - } else - memcpy(buf, vaddr + offset, csize); + csize =3D copy_to_iter(vaddr + offset, csize, iter); =20 memunmap(vaddr); return csize; diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c index af8202121642..8a613a22671b 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 @@ -214,8 +215,8 @@ static int copy_oldmem_user(void __user *dst, void *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) { void *src; int rc; @@ -223,10 +224,12 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf= , size_t csize, if (!csize) return 0; src =3D (void *) (pfn << PAGE_SHIFT) + offset; - if (userbuf) - rc =3D 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 =3D copy_oldmem_user(iter->iov->iov_base, src, csize); else - rc =3D copy_oldmem_kernel((void *) buf, src, csize); + rc =3D copy_oldmem_kernel(iter->kvec->iov_base, src, csize); return rc; } =20 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 =20 -/** - * 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 use= rbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void __iomem *vaddr; =20 @@ -32,15 +20,8 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, return 0; =20 vaddr =3D 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 =3D 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_3= 2.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 =20 static inline bool is_crashed_pfn_valid(unsigned long pfn) { @@ -29,21 +28,8 @@ static inline bool is_crashed_pfn_valid(unsigned long pf= n) #endif } =20 -/** - * 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; =20 @@ -54,14 +40,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, s= ize_t csize, return -EFAULT; =20 vaddr =3D kmap_local_pfn(pfn); - - if (!userbuf) { - memcpy(buf, vaddr + offset, csize); - } else { - if (copy_to_user(buf, vaddr + offset, csize)) - csize =3D -EFAULT; - } - + csize =3D copy_to_iter(vaddr + offset, csize, iter); kunmap_local(vaddr); =20 return csize; diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_6= 4.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 @@ =20 #include #include -#include +#include #include #include =20 -static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csi= ze, - 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, ch= ar *buf, size_t csize, if (!vaddr) return -ENOMEM; =20 - 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 =3D copy_to_iter(vaddr + offset, csize, iter); =20 set_iounmap_nonlazy(); iounmap((void __iomem *)vaddr); return csize; } =20 -/** - * 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_atomi= c. - */ -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); } =20 -/** +/* * copy_oldmem_page_encrypted - same as copy_oldmem_page() above but iorem= ap 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 cs= ize, - unsigned long offset, int userbuf) +ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pf= n, + 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); } =20 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 702754dd1daf..7e7252e162c2 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include "internal.h" @@ -126,9 +127,8 @@ static int open_vmcore(struct inode *inode, struct file= *file) } =20 /* 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; @@ -149,29 +149,23 @@ ssize_t read_from_oldmem(char *buf, size_t count, =20 /* If pfn is not ram, return zeros for sparse dump files */ if (!pfn_is_ram(pfn)) { - tmp =3D 0; - if (!userbuf) - memset(buf, 0, nr_bytes); - else if (clear_user(buf, nr_bytes)) - tmp =3D -EFAULT; + tmp =3D iov_iter_zero(nr_bytes, iter); } else { if (encrypted) - tmp =3D copy_oldmem_page_encrypted(pfn, buf, + tmp =3D copy_oldmem_page_encrypted(iter, pfn, nr_bytes, - offset, - userbuf); + offset); else - tmp =3D copy_oldmem_page(pfn, buf, nr_bytes, - offset, userbuf); + tmp =3D copy_oldmem_page(iter, pfn, nr_bytes, + offset); } - if (tmp < 0) { + if (tmp < nr_bytes) { up_read(&vmcore_cb_rwsem); - return tmp; + return -EFAULT; } =20 *ppos +=3D nr_bytes; count -=3D nr_bytes; - buf +=3D nr_bytes; read +=3D nr_bytes; ++pfn; offset =3D 0; @@ -181,6 +175,27 @@ ssize_t read_from_oldmem(char *buf, size_t count, return read; } =20 +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 =3D (__force void __user *)buf; + iov.iov_len =3D count; + iov_iter_init(&iter, READ, &iov, 1, count); + } else { + kvec.iov_base =3D buf; + kvec.iov_len =3D 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 */ @@ -225,11 +240,10 @@ int __weak remap_oldmem_pfn_range(struct vm_area_stru= ct *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); } =20 /* 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); =20 -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 csi= ze, + unsigned long offset); +ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pf= n, + size_t csize, unsigned long offset); =20 void vmcore_cleanup(void); =20 --=20 2.34.1 From nobody Mon Jun 22 19:21:09 2026 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 89A72C433EF for ; Fri, 18 Mar 2022 09:37:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234553AbiCRJi5 (ORCPT ); Fri, 18 Mar 2022 05:38:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234526AbiCRJiu (ORCPT ); Fri, 18 Mar 2022 05:38:50 -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 472E72EB57C for ; Fri, 18 Mar 2022 02:37:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647596251; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eQqq3tAm+IryJ8cAH+qgKU1zkyNnMxOLjwIL6dRIXvw=; b=NwmNzmyTa1ykFu+SwcrbMJJIs94bvjDo09KBpji2GaEGLObP8B2DSixrH5Ege/naOkF9NN x8zSGWTK8zTRgHcGmLfJAMd8EdZnqIN3z9GuPlO3K6A/Z+jk8t/KsKbsMpQ8rawGXS6zWE RFMdqk5jLCFtv8eKyyBRyLcLIouIYEY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-665-G4iKGDoQONK-N6PQuvQUtg-1; Fri, 18 Mar 2022 05:37:28 -0400 X-MC-Unique: G4iKGDoQONK-N6PQuvQUtg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B8D9B8002BF; Fri, 18 Mar 2022 09:37:27 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-13-174.pek2.redhat.com [10.72.13.174]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5F344112C08E; Fri, 18 Mar 2022 09:37:23 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: willy@infradead.org, bhe@redhat.com, kexec@lists.infradead.org, yangtiezhu@loongson.cn, amit.kachhap@arm.com, hch@lst.de, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk Subject: [PATCH v4 2/4] vmcore: Convert __read_vmcore to use an iov_iter Date: Fri, 18 Mar 2022 17:37:04 +0800 Message-Id: <20220318093706.161534-3-bhe@redhat.com> In-Reply-To: <20220318093706.161534-1-bhe@redhat.com> References: <20220318093706.161534-1-bhe@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "Matthew Wilcox (Oracle)" This gets rid of copy_to() and let us use proc_read_iter() instead of proc_read(). Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Acked-by: Baoquan He --- fs/proc/vmcore.c | 81 +++++++++++++++++------------------------------- 1 file changed, 29 insertions(+), 52 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 7e7252e162c2..cebf49160ea5 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -246,22 +246,8 @@ ssize_t __weak copy_oldmem_page_encrypted(struct iov_i= ter *iter, return copy_oldmem_page(iter, pfn, csize, offset); } =20 -/* - * Copy to either kernel or user space - */ -static int copy_to(void *target, void *src, size_t size, int userbuf) -{ - if (userbuf) { - if (copy_to_user((char __user *) target, src, size)) - return -EFAULT; - } else { - memcpy(target, src, size); - } - return 0; -} - #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP -static int vmcoredd_copy_dumps(void *dst, u64 start, size_t size, int user= buf) +static int vmcoredd_copy_dumps(struct iov_iter *iter, u64 start, size_t si= ze) { struct vmcoredd_node *dump; u64 offset =3D 0; @@ -274,14 +260,13 @@ static int vmcoredd_copy_dumps(void *dst, u64 start, = size_t size, int userbuf) if (start < offset + dump->size) { tsz =3D min(offset + (u64)dump->size - start, (u64)size); buf =3D dump->buf + start - offset; - if (copy_to(dst, buf, tsz, userbuf)) { + if (copy_to_iter(buf, tsz, iter) < tsz) { ret =3D -EFAULT; goto out_unlock; } =20 size -=3D tsz; start +=3D tsz; - dst +=3D tsz; =20 /* Leave now if buffer filled already */ if (!size) @@ -337,33 +322,28 @@ static int vmcoredd_mmap_dumps(struct vm_area_struct = *vma, unsigned long dst, /* Read from the ELF header and then the crash dump. On error, negative va= lue is * returned otherwise number of bytes read are returned. */ -static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos, - int userbuf) +static ssize_t __read_vmcore(struct iov_iter *iter, loff_t *fpos) { ssize_t acc =3D 0, tmp; size_t tsz; u64 start; struct vmcore *m =3D NULL; =20 - if (buflen =3D=3D 0 || *fpos >=3D vmcore_size) + if (iter->count =3D=3D 0 || *fpos >=3D vmcore_size) return 0; =20 - /* trim buflen to not go beyond EOF */ - if (buflen > vmcore_size - *fpos) - buflen =3D vmcore_size - *fpos; + iov_iter_truncate(iter, vmcore_size - *fpos); =20 /* Read ELF core header */ if (*fpos < elfcorebuf_sz) { - tsz =3D min(elfcorebuf_sz - (size_t)*fpos, buflen); - if (copy_to(buffer, elfcorebuf + *fpos, tsz, userbuf)) + tsz =3D min(elfcorebuf_sz - (size_t)*fpos, iter->count); + if (copy_to_iter(elfcorebuf + *fpos, tsz, iter) < tsz) return -EFAULT; - buflen -=3D tsz; *fpos +=3D tsz; - buffer +=3D tsz; acc +=3D tsz; =20 /* leave now if filled buffer already */ - if (buflen =3D=3D 0) + if (iter->count =3D=3D 0) return acc; } =20 @@ -384,35 +364,31 @@ static ssize_t __read_vmcore(char *buffer, size_t buf= len, loff_t *fpos, /* Read device dumps */ if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) { tsz =3D min(elfcorebuf_sz + vmcoredd_orig_sz - - (size_t)*fpos, buflen); + (size_t)*fpos, iter->count); start =3D *fpos - elfcorebuf_sz; - if (vmcoredd_copy_dumps(buffer, start, tsz, userbuf)) + if (vmcoredd_copy_dumps(iter, start, tsz)) return -EFAULT; =20 - buflen -=3D tsz; *fpos +=3D tsz; - buffer +=3D tsz; acc +=3D tsz; =20 /* leave now if filled buffer already */ - if (!buflen) + if (!iter->count) return acc; } #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ =20 /* Read remaining elf notes */ - tsz =3D min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen); + tsz =3D min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, iter->count); kaddr =3D elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz; - if (copy_to(buffer, kaddr, tsz, userbuf)) + if (copy_to_iter(kaddr, tsz, iter) < tsz) return -EFAULT; =20 - buflen -=3D tsz; *fpos +=3D tsz; - buffer +=3D tsz; acc +=3D tsz; =20 /* leave now if filled buffer already */ - if (buflen =3D=3D 0) + if (iter->count =3D=3D 0) return acc; } =20 @@ -420,19 +396,17 @@ static ssize_t __read_vmcore(char *buffer, size_t buf= len, loff_t *fpos, if (*fpos < m->offset + m->size) { tsz =3D (size_t)min_t(unsigned long long, m->offset + m->size - *fpos, - buflen); + iter->count); start =3D m->paddr + *fpos - m->offset; - tmp =3D read_from_oldmem(buffer, tsz, &start, - userbuf, cc_platform_has(CC_ATTR_MEM_ENCRYPT)); + tmp =3D read_from_oldmem_iter(iter, tsz, &start, + cc_platform_has(CC_ATTR_MEM_ENCRYPT)); if (tmp < 0) return tmp; - buflen -=3D tsz; *fpos +=3D tsz; - buffer +=3D tsz; acc +=3D tsz; =20 /* leave now if filled buffer already */ - if (buflen =3D=3D 0) + if (iter->count =3D=3D 0) return acc; } } @@ -440,15 +414,14 @@ static ssize_t __read_vmcore(char *buffer, size_t buf= len, loff_t *fpos, return acc; } =20 -static ssize_t read_vmcore(struct file *file, char __user *buffer, - size_t buflen, loff_t *fpos) +static ssize_t read_vmcore(struct kiocb *iocb, struct iov_iter *iter) { - return __read_vmcore((__force char *) buffer, buflen, fpos, 1); + return __read_vmcore(iter, &iocb->ki_pos); } =20 /* * The vmcore fault handler uses the page cache and fills data using the - * standard __vmcore_read() function. + * standard __read_vmcore() function. * * On s390 the fault handler is used for memory regions that can't be mapp= ed * directly with remap_pfn_range(). @@ -458,9 +431,10 @@ static vm_fault_t mmap_vmcore_fault(struct vm_fault *v= mf) #ifdef CONFIG_S390 struct address_space *mapping =3D vmf->vma->vm_file->f_mapping; pgoff_t index =3D vmf->pgoff; + struct iov_iter iter; + struct kvec kvec; struct page *page; loff_t offset; - char *buf; int rc; =20 page =3D find_or_create_page(mapping, index, GFP_KERNEL); @@ -468,8 +442,11 @@ static vm_fault_t mmap_vmcore_fault(struct vm_fault *v= mf) return VM_FAULT_OOM; if (!PageUptodate(page)) { offset =3D (loff_t) index << PAGE_SHIFT; - buf =3D __va((page_to_pfn(page) << PAGE_SHIFT)); - rc =3D __read_vmcore(buf, PAGE_SIZE, &offset, 0); + kvec.iov_base =3D page_address(page); + kvec.iov_len =3D PAGE_SIZE; + iov_iter_kvec(&iter, READ, &kvec, 1, PAGE_SIZE); + + rc =3D __read_vmcore(&iter, &offset); if (rc < 0) { unlock_page(page); put_page(page); @@ -719,7 +696,7 @@ static int mmap_vmcore(struct file *file, struct vm_are= a_struct *vma) =20 static const struct proc_ops vmcore_proc_ops =3D { .proc_open =3D open_vmcore, - .proc_read =3D read_vmcore, + .proc_read_iter =3D read_vmcore, .proc_lseek =3D default_llseek, .proc_mmap =3D mmap_vmcore, }; --=20 2.34.1 From nobody Mon Jun 22 19:21:09 2026 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 9EE99C433EF for ; Fri, 18 Mar 2022 09:37:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233098AbiCRJjG (ORCPT ); Fri, 18 Mar 2022 05:39:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234526AbiCRJi7 (ORCPT ); Fri, 18 Mar 2022 05:38:59 -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 8FD642EA92E for ; Fri, 18 Mar 2022 02:37:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647596256; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/b2o0BdzcwY9Tmgob1KBIWJnoOrpkLRZ+Jjx3XbgB9Y=; b=Vf1YULD3D7ATSMbTmDLoIDoM/gmNlSA+0ck+66ZEPZhqzr9+qg8xUyXP2RpE53Pg2mYUER WEF+Uk7xNhYEMJD2JV17uIlzVS938fK2QyuEiV7JaFB6vuMHvfyu02wuKB4ngnUHWXQsEc q0zyX9zj6M6Ft1oGmrnEW4eyPOaUEPI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-37-ZMOOYaNnOam9cYaTNjBFbA-1; Fri, 18 Mar 2022 05:37:33 -0400 X-MC-Unique: ZMOOYaNnOam9cYaTNjBFbA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id BD8FD811E76; Fri, 18 Mar 2022 09:37:32 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-13-174.pek2.redhat.com [10.72.13.174]) by smtp.corp.redhat.com (Postfix) with ESMTP id 70C55112C08E; Fri, 18 Mar 2022 09:37:28 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: willy@infradead.org, bhe@redhat.com, kexec@lists.infradead.org, yangtiezhu@loongson.cn, amit.kachhap@arm.com, hch@lst.de, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk Subject: [PATCH v4 3/4] vmcore: Convert read_from_oldmem() to take an iov_iter Date: Fri, 18 Mar 2022 17:37:05 +0800 Message-Id: <20220318093706.161534-4-bhe@redhat.com> In-Reply-To: <20220318093706.161534-1-bhe@redhat.com> References: <20220318093706.161534-1-bhe@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "Matthew Wilcox (Oracle)" Remove the read_from_oldmem() wrapper introduced earlier and convert all the remaining callers to pass an iov_iter. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Acked-by: Baoquan He --- arch/x86/kernel/crash_dump_64.c | 7 +++++- fs/proc/vmcore.c | 40 +++++++++++++-------------------- include/linux/crash_dump.h | 10 ++++----- 3 files changed, 25 insertions(+), 32 deletions(-) diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_6= 4.c index f922d51c9d1f..0fa87648e55c 100644 --- a/arch/x86/kernel/crash_dump_64.c +++ b/arch/x86/kernel/crash_dump_64.c @@ -55,6 +55,11 @@ ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter= , unsigned long pfn, =20 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) { - return read_from_oldmem(buf, count, ppos, 0, + struct kvec kvec =3D { .iov_base =3D buf, .iov_len =3D count }; + struct iov_iter iter; + + iov_iter_kvec(&iter, READ, &kvec, 1, count); + + return read_from_oldmem(&iter, count, ppos, cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)); } diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index cebf49160ea5..4cbb8db7c507 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -127,7 +127,7 @@ static int open_vmcore(struct inode *inode, struct file= *file) } =20 /* Reads a page from the oldmem device from given offset. */ -static ssize_t read_from_oldmem_iter(struct iov_iter *iter, size_t count, +ssize_t read_from_oldmem(struct iov_iter *iter, size_t count, u64 *ppos, bool encrypted) { unsigned long pfn, offset; @@ -175,27 +175,6 @@ static ssize_t read_from_oldmem_iter(struct iov_iter *= iter, size_t count, return read; } =20 -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 =3D (__force void __user *)buf; - iov.iov_len =3D count; - iov_iter_init(&iter, READ, &iov, 1, count); - } else { - kvec.iov_base =3D buf; - kvec.iov_len =3D 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 */ @@ -215,7 +194,12 @@ void __weak elfcorehdr_free(unsigned long long addr) */ ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos) { - return read_from_oldmem(buf, count, ppos, 0, false); + struct kvec kvec =3D { .iov_base =3D buf, .iov_len =3D count }; + struct iov_iter iter; + + iov_iter_kvec(&iter, READ, &kvec, 1, count); + + return read_from_oldmem(&iter, count, ppos, false); } =20 /* @@ -223,7 +207,13 @@ ssize_t __weak elfcorehdr_read(char *buf, size_t count= , u64 *ppos) */ ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos) { - return read_from_oldmem(buf, count, ppos, 0, cc_platform_has(CC_ATTR_MEM_= ENCRYPT)); + struct kvec kvec =3D { .iov_base =3D buf, .iov_len =3D count }; + struct iov_iter iter; + + iov_iter_kvec(&iter, READ, &kvec, 1, count); + + return read_from_oldmem(&iter, count, ppos, + cc_platform_has(CC_ATTR_MEM_ENCRYPT)); } =20 /* @@ -398,7 +388,7 @@ static ssize_t __read_vmcore(struct iov_iter *iter, lof= f_t *fpos) m->offset + m->size - *fpos, iter->count); start =3D m->paddr + *fpos - m->offset; - tmp =3D read_from_oldmem_iter(iter, tsz, &start, + tmp =3D read_from_oldmem(iter, tsz, &start, cc_platform_has(CC_ATTR_MEM_ENCRYPT)); if (tmp < 0) return tmp; diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index a1cf7d5c03c7..0f3a656293b0 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -134,13 +134,11 @@ static inline int vmcore_add_device_dump(struct vmcor= edd_data *data) #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ =20 #ifdef CONFIG_PROC_VMCORE -ssize_t read_from_oldmem(char *buf, size_t count, - u64 *ppos, int userbuf, - bool encrypted); +ssize_t read_from_oldmem(struct iov_iter *iter, size_t count, + u64 *ppos, bool encrypted); #else -static inline ssize_t read_from_oldmem(char *buf, size_t count, - u64 *ppos, int userbuf, - bool encrypted) +static inline ssize_t read_from_oldmem(struct iov_iter *iter, size_t count, + u64 *ppos, bool encrypted) { return -EOPNOTSUPP; } --=20 2.34.1 From nobody Mon Jun 22 19:21:09 2026 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 0CA0EC433EF for ; Fri, 18 Mar 2022 09:38:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234557AbiCRJjU (ORCPT ); Fri, 18 Mar 2022 05:39:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233747AbiCRJjO (ORCPT ); Fri, 18 Mar 2022 05:39:14 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id DA7161C349A for ; Fri, 18 Mar 2022 02:37:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647596274; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uS5OLLy58zowFJOHUPh79D3XiQk55Uu9GC4n+ZxRfmM=; b=Id2EjwxWO+An1UpxsQkUzBFPag9IXKtrVLWSGpDgzOa0DqKoUVoQQdZEo3JX58UTIs4Njk 1C9lK2EqyIZ2F9CcWSfyGbI2wGv7dve/0YgFItB9sBVSDUx9iVcvK+fIG13z6Pklphc3ep f511b4LnbgrJautIf/lBgXkFUenPjlY= 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-654-RZHKyeUmPHygu5KFbrOKWA-1; Fri, 18 Mar 2022 05:37:42 -0400 X-MC-Unique: RZHKyeUmPHygu5KFbrOKWA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D89092A2AD40; Fri, 18 Mar 2022 09:37:41 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-13-174.pek2.redhat.com [10.72.13.174]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7429E112C08E; Fri, 18 Mar 2022 09:37:33 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: willy@infradead.org, bhe@redhat.com, kexec@lists.infradead.org, yangtiezhu@loongson.cn, amit.kachhap@arm.com, hch@lst.de, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk Subject: [PATCH v4 4/4] fs/proc/vmcore: Use iov_iter_count() Date: Fri, 18 Mar 2022 17:37:06 +0800 Message-Id: <20220318093706.161534-5-bhe@redhat.com> In-Reply-To: <20220318093706.161534-1-bhe@redhat.com> References: <20220318093706.161534-1-bhe@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" To replace open coded iter->count. This makes code cleaner. Signed-off-by: Baoquan He --- fs/proc/vmcore.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 4cbb8db7c507..ed58a7edc821 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -319,21 +319,21 @@ static ssize_t __read_vmcore(struct iov_iter *iter, l= off_t *fpos) u64 start; struct vmcore *m =3D NULL; =20 - if (iter->count =3D=3D 0 || *fpos >=3D vmcore_size) + if (!iov_iter_count(iter) || *fpos >=3D vmcore_size) return 0; =20 iov_iter_truncate(iter, vmcore_size - *fpos); =20 /* Read ELF core header */ if (*fpos < elfcorebuf_sz) { - tsz =3D min(elfcorebuf_sz - (size_t)*fpos, iter->count); + tsz =3D min(elfcorebuf_sz - (size_t)*fpos, iov_iter_count(iter)); if (copy_to_iter(elfcorebuf + *fpos, tsz, iter) < tsz) return -EFAULT; *fpos +=3D tsz; acc +=3D tsz; =20 /* leave now if filled buffer already */ - if (iter->count =3D=3D 0) + if (!iov_iter_count(iter)) return acc; } =20 @@ -354,7 +354,7 @@ static ssize_t __read_vmcore(struct iov_iter *iter, lof= f_t *fpos) /* Read device dumps */ if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) { tsz =3D min(elfcorebuf_sz + vmcoredd_orig_sz - - (size_t)*fpos, iter->count); + (size_t)*fpos, iov_iter_count(iter)); start =3D *fpos - elfcorebuf_sz; if (vmcoredd_copy_dumps(iter, start, tsz)) return -EFAULT; @@ -363,13 +363,14 @@ static ssize_t __read_vmcore(struct iov_iter *iter, l= off_t *fpos) acc +=3D tsz; =20 /* leave now if filled buffer already */ - if (!iter->count) + if (!iov_iter_count(iter)) return acc; } #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ =20 /* Read remaining elf notes */ - tsz =3D min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, iter->count); + tsz =3D min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, + iov_iter_count(iter)); kaddr =3D elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz; if (copy_to_iter(kaddr, tsz, iter) < tsz) return -EFAULT; @@ -378,7 +379,7 @@ static ssize_t __read_vmcore(struct iov_iter *iter, lof= f_t *fpos) acc +=3D tsz; =20 /* leave now if filled buffer already */ - if (iter->count =3D=3D 0) + if (!iov_iter_count(iter)) return acc; } =20 @@ -386,7 +387,7 @@ static ssize_t __read_vmcore(struct iov_iter *iter, lof= f_t *fpos) if (*fpos < m->offset + m->size) { tsz =3D (size_t)min_t(unsigned long long, m->offset + m->size - *fpos, - iter->count); + iov_iter_count(iter)); start =3D m->paddr + *fpos - m->offset; tmp =3D read_from_oldmem(iter, tsz, &start, cc_platform_has(CC_ATTR_MEM_ENCRYPT)); @@ -396,7 +397,7 @@ static ssize_t __read_vmcore(struct iov_iter *iter, lof= f_t *fpos) acc +=3D tsz; =20 /* leave now if filled buffer already */ - if (iter->count =3D=3D 0) + if (!iov_iter_count(iter)) return acc; } } --=20 2.34.1