76 lines
1.7 KiB
C
76 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#include <linux/module.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/smp.h>
|
|
#include <asm/text-patching.h>
|
|
#include <asm/alternative.h>
|
|
#include <asm/facility.h>
|
|
#include <asm/nospec-branch.h>
|
|
|
|
static int __initdata_or_module alt_instr_disabled;
|
|
|
|
static int __init disable_alternative_instructions(char *str)
|
|
{
|
|
alt_instr_disabled = 1;
|
|
return 0;
|
|
}
|
|
|
|
early_param("noaltinstr", disable_alternative_instructions);
|
|
|
|
static void __init_or_module __apply_alternatives(struct alt_instr *start,
|
|
struct alt_instr *end)
|
|
{
|
|
struct alt_instr *a;
|
|
u8 *instr, *replacement;
|
|
|
|
/*
|
|
* The scan order should be from start to end. A later scanned
|
|
* alternative code can overwrite previously scanned alternative code.
|
|
*/
|
|
for (a = start; a < end; a++) {
|
|
instr = (u8 *)&a->instr_offset + a->instr_offset;
|
|
replacement = (u8 *)&a->repl_offset + a->repl_offset;
|
|
|
|
if (!__test_facility(a->facility, alt_stfle_fac_list))
|
|
continue;
|
|
|
|
if (unlikely(a->instrlen % 2)) {
|
|
WARN_ONCE(1, "cpu alternatives instructions length is "
|
|
"odd, skipping patching\n");
|
|
continue;
|
|
}
|
|
|
|
s390_kernel_write(instr, replacement, a->instrlen);
|
|
}
|
|
}
|
|
|
|
void __init_or_module apply_alternatives(struct alt_instr *start,
|
|
struct alt_instr *end)
|
|
{
|
|
if (!alt_instr_disabled)
|
|
__apply_alternatives(start, end);
|
|
}
|
|
|
|
extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
|
|
void __init apply_alternative_instructions(void)
|
|
{
|
|
apply_alternatives(__alt_instructions, __alt_instructions_end);
|
|
}
|
|
|
|
static void do_sync_core(void *info)
|
|
{
|
|
sync_core();
|
|
}
|
|
|
|
void text_poke_sync(void)
|
|
{
|
|
on_each_cpu(do_sync_core, NULL, 1);
|
|
}
|
|
|
|
void text_poke_sync_lock(void)
|
|
{
|
|
cpus_read_lock();
|
|
text_poke_sync();
|
|
cpus_read_unlock();
|
|
}
|