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// 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();
}
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