Contributors: 13
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Peter Zijlstra |
125 |
25.93% |
5 |
25.00% |
| Daniel Bristot de Oliveira |
109 |
22.61% |
2 |
10.00% |
| Steven Rostedt |
68 |
14.11% |
3 |
15.00% |
| Jason Baron |
61 |
12.66% |
1 |
5.00% |
| Jeremy Fitzhardinge |
49 |
10.17% |
1 |
5.00% |
| Ard Biesheuvel |
38 |
7.88% |
1 |
5.00% |
| Jiri Kosina |
16 |
3.32% |
1 |
5.00% |
| Nadav Amit |
7 |
1.45% |
1 |
5.00% |
| Andrew Lutomirski |
3 |
0.62% |
1 |
5.00% |
| Andy Shevchenko |
2 |
0.41% |
1 |
5.00% |
| Pavel Tatashin |
2 |
0.41% |
1 |
5.00% |
| Greg Kroah-Hartman |
1 |
0.21% |
1 |
5.00% |
| Randy Dunlap |
1 |
0.21% |
1 |
5.00% |
| Total |
482 |
|
20 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* jump label x86 support
*
* Copyright (C) 2009 Jason Baron <jbaron@redhat.com>
*
*/
#include <linux/jump_label.h>
#include <linux/memory.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/jhash.h>
#include <linux/cpu.h>
#include <asm/kprobes.h>
#include <asm/alternative.h>
#include <asm/text-patching.h>
static void bug_at(const void *ip, int line)
{
/*
* The location is not an op that we were expecting.
* Something went wrong. Crash the box, as something could be
* corrupting the kernel.
*/
pr_crit("jump_label: Fatal kernel bug, unexpected op at %pS [%p] (%5ph) %d\n", ip, ip, ip, line);
BUG();
}
static const void *
__jump_label_set_jump_code(struct jump_entry *entry, enum jump_label_type type)
{
const void *expect, *code;
const void *addr, *dest;
int line;
addr = (void *)jump_entry_code(entry);
dest = (void *)jump_entry_target(entry);
code = text_gen_insn(JMP32_INSN_OPCODE, addr, dest);
if (type == JUMP_LABEL_JMP) {
expect = x86_nops[5]; line = __LINE__;
} else {
expect = code; line = __LINE__;
}
if (memcmp(addr, expect, JUMP_LABEL_NOP_SIZE))
bug_at(addr, line);
if (type == JUMP_LABEL_NOP)
code = x86_nops[5];
return code;
}
static inline void __jump_label_transform(struct jump_entry *entry,
enum jump_label_type type,
int init)
{
const void *opcode = __jump_label_set_jump_code(entry, type);
/*
* As long as only a single processor is running and the code is still
* not marked as RO, text_poke_early() can be used; Checking that
* system_state is SYSTEM_BOOTING guarantees it. It will be set to
* SYSTEM_SCHEDULING before other cores are awaken and before the
* code is write-protected.
*
* At the time the change is being done, just ignore whether we
* are doing nop -> jump or jump -> nop transition, and assume
* always nop being the 'currently valid' instruction
*/
if (init || system_state == SYSTEM_BOOTING) {
text_poke_early((void *)jump_entry_code(entry), opcode,
JUMP_LABEL_NOP_SIZE);
return;
}
text_poke_bp((void *)jump_entry_code(entry), opcode, JUMP_LABEL_NOP_SIZE, NULL);
}
static void __ref jump_label_transform(struct jump_entry *entry,
enum jump_label_type type,
int init)
{
mutex_lock(&text_mutex);
__jump_label_transform(entry, type, init);
mutex_unlock(&text_mutex);
}
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
jump_label_transform(entry, type, 0);
}
bool arch_jump_label_transform_queue(struct jump_entry *entry,
enum jump_label_type type)
{
const void *opcode;
if (system_state == SYSTEM_BOOTING) {
/*
* Fallback to the non-batching mode.
*/
arch_jump_label_transform(entry, type);
return true;
}
mutex_lock(&text_mutex);
opcode = __jump_label_set_jump_code(entry, type);
text_poke_queue((void *)jump_entry_code(entry),
opcode, JUMP_LABEL_NOP_SIZE, NULL);
mutex_unlock(&text_mutex);
return true;
}
void arch_jump_label_transform_apply(void)
{
mutex_lock(&text_mutex);
text_poke_finish();
mutex_unlock(&text_mutex);
}
static enum {
JL_STATE_START,
JL_STATE_NO_UPDATE,
JL_STATE_UPDATE,
} jlstate __initdata_or_module = JL_STATE_START;
__init_or_module void arch_jump_label_transform_static(struct jump_entry *entry,
enum jump_label_type type)
{
if (jlstate == JL_STATE_UPDATE)
jump_label_transform(entry, type, 1);
}