diff options
Diffstat (limited to 'arch/x86/include/asm/jump_label.h')
| -rw-r--r-- | arch/x86/include/asm/jump_label.h | 80 |
1 files changed, 18 insertions, 62 deletions
diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index 8c0de4282659..a5fb34fe56a4 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -2,19 +2,6 @@ #ifndef _ASM_X86_JUMP_LABEL_H #define _ASM_X86_JUMP_LABEL_H -#ifndef HAVE_JUMP_LABEL -/* - * For better or for worse, if jump labels (the gcc extension) are missing, - * then the entire static branch patching infrastructure is compiled out. - * If that happens, the code in here will malfunction. Raise a compiler - * error instead. - * - * In theory, jump labels and the static branch patching infrastructure - * could be decoupled to fix this. - */ -#error asm/jump_label.h included on a non-jump-label kernel -#endif - #define JUMP_LABEL_NOP_SIZE 5 #ifdef CONFIG_X86_64 @@ -33,14 +20,9 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { - asm_volatile_goto("1:" - ".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t" - ".pushsection __jump_table, \"aw\" \n\t" - _ASM_ALIGN "\n\t" - _ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t" - ".popsection \n\t" - : : "i" (key), "i" (branch) : : l_yes); - + asm_volatile_goto("STATIC_BRANCH_NOP l_yes=\"%l[l_yes]\" key=\"%c0\" " + "branch=\"%c1\"" + : : "i" (key), "i" (branch) : : l_yes); return false; l_yes: return true; @@ -48,13 +30,8 @@ l_yes: static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) { - asm_volatile_goto("1:" - ".byte 0xe9\n\t .long %l[l_yes] - 2f\n\t" - "2:\n\t" - ".pushsection __jump_table, \"aw\" \n\t" - _ASM_ALIGN "\n\t" - _ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t" - ".popsection \n\t" + asm_volatile_goto("STATIC_BRANCH_JMP l_yes=\"%l[l_yes]\" key=\"%c0\" " + "branch=\"%c1\"" : : "i" (key), "i" (branch) : : l_yes); return false; @@ -62,49 +39,28 @@ l_yes: return true; } -#ifdef CONFIG_X86_64 -typedef u64 jump_label_t; -#else -typedef u32 jump_label_t; -#endif - -struct jump_entry { - jump_label_t code; - jump_label_t target; - jump_label_t key; -}; - #else /* __ASSEMBLY__ */ -.macro STATIC_JUMP_IF_TRUE target, key, def -.Lstatic_jump_\@: - .if \def - /* Equivalent to "jmp.d32 \target" */ - .byte 0xe9 - .long \target - .Lstatic_jump_after_\@ -.Lstatic_jump_after_\@: - .else - .byte STATIC_KEY_INIT_NOP - .endif +.macro STATIC_BRANCH_NOP l_yes:req key:req branch:req +.Lstatic_branch_nop_\@: + .byte STATIC_KEY_INIT_NOP +.Lstatic_branch_no_after_\@: .pushsection __jump_table, "aw" _ASM_ALIGN - _ASM_PTR .Lstatic_jump_\@, \target, \key + .long .Lstatic_branch_nop_\@ - ., \l_yes - . + _ASM_PTR \key + \branch - . .popsection .endm -.macro STATIC_JUMP_IF_FALSE target, key, def -.Lstatic_jump_\@: - .if \def - .byte STATIC_KEY_INIT_NOP - .else - /* Equivalent to "jmp.d32 \target" */ - .byte 0xe9 - .long \target - .Lstatic_jump_after_\@ -.Lstatic_jump_after_\@: - .endif +.macro STATIC_BRANCH_JMP l_yes:req key:req branch:req +.Lstatic_branch_jmp_\@: + .byte 0xe9 + .long \l_yes - .Lstatic_branch_jmp_after_\@ +.Lstatic_branch_jmp_after_\@: .pushsection __jump_table, "aw" _ASM_ALIGN - _ASM_PTR .Lstatic_jump_\@, \target, \key + 1 + .long .Lstatic_branch_jmp_\@ - ., \l_yes - . + _ASM_PTR \key + \branch - . .popsection .endm |