forked from luck/tmp_suning_uos_patched
f75b1b1bed
UML needs it's own probe_kernel_read() to handle kernel mode faults correctly. The implementation uses mincore() on the host side to detect whether a page is owned by the UML kernel process. This fixes also a possible crash when sysrq-t is used. Starting with 3.10 sysrq-t calls probe_kernel_read() to read details from the kernel workers. As kernel worker are completely async pointers may turn NULL while reading them. Cc: <stian@nixia.no> Cc: <tj@kernel.org> Cc: <stable@vger.kernel.org> # 3.10.x Signed-off-by: Richard Weinberger <richard@nod.at>
25 lines
638 B
C
25 lines
638 B
C
/*
|
|
* Copyright (C) 2013 Richard Weinberger <richrd@nod.at>
|
|
*
|
|
* 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/uaccess.h>
|
|
#include <linux/kernel.h>
|
|
#include <os.h>
|
|
|
|
long probe_kernel_read(void *dst, const void *src, size_t size)
|
|
{
|
|
void *psrc = (void *)rounddown((unsigned long)src, PAGE_SIZE);
|
|
|
|
if ((unsigned long)src < PAGE_SIZE || size <= 0)
|
|
return -EFAULT;
|
|
|
|
if (os_mincore(psrc, size + src - psrc) <= 0)
|
|
return -EFAULT;
|
|
|
|
return __probe_kernel_read(dst, src, size);
|
|
}
|