cregit-Linux how code gets into the kernel

Release 4.14 arch/arm64/kernel/crash_dump.c

/*
 * Routines for doing kexec-based kdump
 *
 * Copyright (C) 2017 Linaro Limited
 * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/crash_dump.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/memblock.h>
#include <linux/uaccess.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) { void *vaddr; if (!csize) return 0; vaddr = memremap(__pfn_to_phys(pfn), PAGE_SIZE, MEMREMAP_WB); 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); } memunmap(vaddr); return csize; }

Contributors

PersonTokensPropCommitsCommitProp
AKASHI Takahiro115100.00%1100.00%
Total115100.00%1100.00%

/** * elfcorehdr_read - read from ELF core header * @buf: buffer where the data is placed * @csize: number of bytes to read * @ppos: address in the memory * * This function reads @count bytes from elf core header which exists * on crash dump kernel's memory. */
ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) { memcpy(buf, phys_to_virt((phys_addr_t)*ppos), count); return count; }

Contributors

PersonTokensPropCommitsCommitProp
AKASHI Takahiro35100.00%1100.00%
Total35100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
AKASHI Takahiro171100.00%1100.00%
Total171100.00%1100.00%
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