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 14 static __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; 24 l_yes: 25 return true; 26 } 27 28 #endif /* __KERNEL__ */ 29 30 #ifdef CONFIG_X86_64 31 typedef u64 jump_label_t; 32 #else 33 typedef u32 jump_label_t; 34 #endif 35 36 struct jump_entry { 37 jump_label_t code; 38 jump_label_t target; 39 jump_label_t key; 40 }; 41 42 #endif 43