--- zzzz-none-000/linux-3.10.107/arch/s390/include/asm/jump_label.h 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/arch/s390/include/asm/jump_label.h 2021-02-04 17:41:59.000000000 +0000 @@ -1,26 +1,40 @@ #ifndef _ASM_S390_JUMP_LABEL_H #define _ASM_S390_JUMP_LABEL_H +#ifndef __ASSEMBLY__ + #include #define JUMP_LABEL_NOP_SIZE 6 +#define JUMP_LABEL_NOP_OFFSET 2 -#ifdef CONFIG_64BIT -#define ASM_PTR ".quad" -#define ASM_ALIGN ".balign 8" -#else -#define ASM_PTR ".long" -#define ASM_ALIGN ".balign 4" -#endif +/* + * We use a brcl 0,2 instruction for jump labels at compile time so it + * can be easily distinguished from a hotpatch generated instruction. + */ +static __always_inline bool arch_static_branch(struct static_key *key, bool branch) +{ + asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n" + ".pushsection __jump_table, \"aw\"\n" + ".balign 8\n" + ".quad 0b, %l[label], %0\n" + ".popsection\n" + : : "X" (&((char *)key)[branch]) : : label); -static __always_inline bool arch_static_branch(struct static_key *key) + return false; +label: + return true; +} + +static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) { - asm_volatile_goto("0: brcl 0,0\n" + asm_volatile_goto("0: brcl 15, %l[label]\n" ".pushsection __jump_table, \"aw\"\n" - ASM_ALIGN "\n" - ASM_PTR " 0b, %l[label], %0\n" + ".balign 8\n" + ".quad 0b, %l[label], %0\n" ".popsection\n" - : : "X" (key) : : label); + : : "X" (&((char *)key)[branch]) : : label); + return false; label: return true; @@ -34,4 +48,5 @@ jump_label_t key; }; +#endif /* __ASSEMBLY__ */ #endif