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author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-04-29 14:37:59 -0700 |
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committer | akpm <akpm@linux-foundation.org> | 2022-04-29 14:37:59 -0700 |
commit | 5d8de293c224896a4da99763fce4f9794308caf4 (patch) | |
tree | 06554517aca8f686fdc890da04dd811c1254c995 /arch/x86/kernel/crash_dump_32.c | |
parent | 04d168c6d42d1772d35372301a14bb20784c81c5 (diff) | |
download | linux-stable-5d8de293c224896a4da99763fce4f9794308caf4.tar.gz linux-stable-5d8de293c224896a4da99763fce4f9794308caf4.tar.bz2 linux-stable-5d8de293c224896a4da99763fce4f9794308caf4.zip |
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/x86/kernel/crash_dump_32.c')
-rw-r--r-- | arch/x86/kernel/crash_dump_32.c | 29 |
1 files changed, 4 insertions, 25 deletions
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 <linux/errno.h> #include <linux/highmem.h> #include <linux/crash_dump.h> - -#include <linux/uaccess.h> +#include <linux/uio.h> 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; |