29 lines
757 B
C
29 lines
757 B
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
/*
|
|
* simple_ring_buffer is used by the pKVM hypervisor which does not have access
|
|
* to all kernel symbols. Whatever is undefined when compiling this file is
|
|
* compiler and tooling-generated symbols that can safely be ignored for
|
|
* simple_ring_buffer.
|
|
*/
|
|
|
|
#include <linux/atomic.h>
|
|
#include <linux/string.h>
|
|
#include <asm/page.h>
|
|
|
|
void undefsyms_base(void *p, int n);
|
|
|
|
static char page[PAGE_SIZE] __aligned(PAGE_SIZE);
|
|
|
|
void undefsyms_base(void *p, int n)
|
|
{
|
|
char buffer[256] = { 0 };
|
|
|
|
u32 u = 0;
|
|
memset((char * volatile)page, 8, PAGE_SIZE);
|
|
memset((char * volatile)buffer, 8, sizeof(buffer));
|
|
memcpy((void * volatile)p, buffer, sizeof(buffer));
|
|
cmpxchg((u32 * volatile)&u, 0, 8);
|
|
WARN_ON(n == 0xdeadbeef);
|
|
}
|