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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/powerpc/kernel/crash_dump.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/powerpc/kernel/crash_dump.c')
-rw-r--r-- | arch/powerpc/kernel/crash_dump.c | 35 |
1 files changed, 5 insertions, 30 deletions
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 <asm/kdump.h> #include <asm/prom.h> #include <asm/firmware.h> -#include <linux/uaccess.h> +#include <linux/uio.h> #include <asm/rtas.h> #include <asm/inst.h> @@ -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); } |