50 lines
1.0 KiB
C
50 lines
1.0 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Routines for doing kexec-based kdump
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*
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* Copyright (C) 2017 Linaro Limited
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* Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
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*/
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#include <linux/crash_dump.h>
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#include <linux/errno.h>
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#include <linux/io.h>
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#include <linux/uio.h>
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#include <asm/memory.h>
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ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
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size_t csize, unsigned long offset)
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{
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void *vaddr;
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if (!csize)
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return 0;
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vaddr = memremap(__pfn_to_phys(pfn), PAGE_SIZE, MEMREMAP_WB);
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if (!vaddr)
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return -ENOMEM;
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csize = copy_to_iter(vaddr + offset, csize, iter);
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memunmap(vaddr);
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return csize;
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}
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/**
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* elfcorehdr_read - read from ELF core header
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* @buf: buffer where the data is placed
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* @count: number of bytes to read
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* @ppos: address in the memory
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*
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* This function reads @count bytes from elf core header which exists
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* on crash dump kernel's memory.
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*/
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ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
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{
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memcpy(buf, phys_to_virt((phys_addr_t)*ppos), count);
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*ppos += count;
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return count;
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}
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