From 5d8de293c224896a4da99763fce4f9794308caf4 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 29 Apr 2022 14:37:59 -0700 Subject: vmcore: convert copy_oldmem_page() to take an iov_iter Patch series "Convert vmcore to use an iov_iter", v5. For some reason several people have been sending bad patches to fix compiler warnings in vmcore recently. Here's how it should be done. Compile-tested only on x86. As noted in the first patch, s390 should take this conversion a bit further, but I'm not inclined to do that work myself. This patch (of 3): 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. Link: https://lkml.kernel.org/r/20220408090636.560886-1-bhe@redhat.com Link: https://lkml.kernel.org/r/20220408090636.560886-2-bhe@redhat.com Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Baoquan He Reviewed-by: Christoph Hellwig Cc: Heiko Carstens Signed-off-by: Andrew Morton --- arch/sh/kernel/crash_dump.c | 29 +++++------------------------ 1 file changed, 5 insertions(+), 24 deletions(-) (limited to 'arch/sh/kernel') 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; } -- cgit v1.2.3