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authorMatthew Wilcox (Oracle) <willy@infradead.org>2022-04-30 00:37:59 +0300
committerakpm <akpm@linux-foundation.org>2022-04-30 00:37:59 +0300
commit5d8de293c224896a4da99763fce4f9794308caf4 (patch)
tree06554517aca8f686fdc890da04dd811c1254c995 /arch/arm64/kernel/crash_dump.c
parent04d168c6d42d1772d35372301a14bb20784c81c5 (diff)
downloadlinux-5d8de293c224896a4da99763fce4f9794308caf4.tar.xz
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) <willy@infradead.org> Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/arm64/kernel/crash_dump.c')
-rw-r--r--arch/arm64/kernel/crash_dump.c29
1 files changed, 4 insertions, 25 deletions
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 <linux/crash_dump.h>
#include <linux/errno.h>
#include <linux/io.h>
-#include <linux/memblock.h>
-#include <linux/uaccess.h>
+#include <linux/uio.h>
#include <asm/memory.h>
-/**
- * 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);