tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#ifndef _ASM_X86_JUMP_LABEL_H
2#define _ASM_X86_JUMP_LABEL_H
3
4#ifdef __KERNEL__
5
6#include <linux/types.h>
7#include <asm/nops.h>
8#include <asm/asm.h>
9
10#define JUMP_LABEL_NOP_SIZE 5
11
12#define STATIC_KEY_INITIAL_NOP ".byte 0xe9 \n\t .long 0\n\t"
13
14static __always_inline bool arch_static_branch(struct static_key *key)
15{
16 asm goto("1:"
17 STATIC_KEY_INITIAL_NOP
18 ".pushsection __jump_table, \"aw\" \n\t"
19 _ASM_ALIGN "\n\t"
20 _ASM_PTR "1b, %l[l_yes], %c0 \n\t"
21 ".popsection \n\t"
22 : : "i" (key) : : l_yes);
23 return false;
24l_yes:
25 return true;
26}
27
28#endif /* __KERNEL__ */
29
30#ifdef CONFIG_X86_64
31typedef u64 jump_label_t;
32#else
33typedef u32 jump_label_t;
34#endif
35
36struct jump_entry {
37 jump_label_t code;
38 jump_label_t target;
39 jump_label_t key;
40};
41
42#endif