mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 05:48:40 +00:00
![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 2 normalized pattern(s): 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 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 # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
68 lines
1.7 KiB
C
68 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Routines for doing kexec-based kdump
|
|
*
|
|
* Copyright (C) 2017 Linaro Limited
|
|
* Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
|
|
*/
|
|
|
|
#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;
|
|
}
|
|
|
|
/**
|
|
* elfcorehdr_read - read from ELF core header
|
|
* @buf: buffer where the data is placed
|
|
* @count: 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;
|
|
}
|