diff options
Diffstat (limited to 'arch/x86/include/asm/text-patching.h')
| -rw-r--r-- | arch/x86/include/asm/text-patching.h | 112 |
1 files changed, 80 insertions, 32 deletions
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h index b7421780e4e9..f2d142a0a862 100644 --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -6,27 +6,17 @@ #include <linux/stddef.h> #include <asm/ptrace.h> -struct paravirt_patch_site; -#ifdef CONFIG_PARAVIRT -void apply_paravirt(struct paravirt_patch_site *start, - struct paravirt_patch_site *end); -#else -static inline void apply_paravirt(struct paravirt_patch_site *start, - struct paravirt_patch_site *end) -{} -#define __parainstructions NULL -#define __parainstructions_end NULL -#endif - /* * Currently, the max observed size in the kernel code is * JUMP_LABEL_NOP_SIZE/RELATIVEJUMP_SIZE, which are 5. * Raise it if needed. */ -#define POKE_MAX_OPCODE_SIZE 5 +#define TEXT_POKE_MAX_OPCODE_SIZE 5 extern void text_poke_early(void *addr, const void *opcode, size_t len); +extern void text_poke_apply_relocation(u8 *buf, const u8 * const instr, size_t instrlen, u8 *repl, size_t repl_len); + /* * Clear and restore the kernel write-protection flag on the local CPU. * Allows the kernel to edit read-only pages. @@ -42,13 +32,17 @@ extern void text_poke_early(void *addr, const void *opcode, size_t len); * an inconsistent instruction while you patch. */ extern void *text_poke(void *addr, const void *opcode, size_t len); -extern void text_poke_sync(void); +extern void smp_text_poke_sync_each_cpu(void); extern void *text_poke_kgdb(void *addr, const void *opcode, size_t len); -extern int poke_int3_handler(struct pt_regs *regs); -extern void text_poke_bp(void *addr, const void *opcode, size_t len, const void *emulate); +extern void *text_poke_copy(void *addr, const void *opcode, size_t len); +#define text_poke_copy text_poke_copy +extern void *text_poke_copy_locked(void *addr, const void *opcode, size_t len, bool core_ok); +extern void *text_poke_set(void *addr, int c, size_t len); +extern int smp_text_poke_int3_handler(struct pt_regs *regs); +extern void smp_text_poke_single(void *addr, const void *opcode, size_t len, const void *emulate); -extern void text_poke_queue(void *addr, const void *opcode, size_t len, const void *emulate); -extern void text_poke_finish(void); +extern void smp_text_poke_batch_add(void *addr, const void *opcode, size_t len, const void *emulate); +extern void smp_text_poke_batch_finish(void); #define INT3_INSN_SIZE 1 #define INT3_INSN_OPCODE 0xCC @@ -88,7 +82,7 @@ static __always_inline int text_opcode_size(u8 opcode) } union text_poke_insn { - u8 text[POKE_MAX_OPCODE_SIZE]; + u8 text[TEXT_POKE_MAX_OPCODE_SIZE]; struct { u8 opcode; s32 disp; @@ -96,30 +90,46 @@ union text_poke_insn { }; static __always_inline -void *text_gen_insn(u8 opcode, const void *addr, const void *dest) +void __text_gen_insn(void *buf, u8 opcode, const void *addr, const void *dest, int size) { - static union text_poke_insn insn; /* per instance */ - int size = text_opcode_size(opcode); + union text_poke_insn *insn = buf; - insn.opcode = opcode; + BUG_ON(size < text_opcode_size(opcode)); + + /* + * Hide the addresses to avoid the compiler folding in constants when + * referencing code, these can mess up annotations like + * ANNOTATE_NOENDBR. + */ + OPTIMIZER_HIDE_VAR(insn); + OPTIMIZER_HIDE_VAR(addr); + OPTIMIZER_HIDE_VAR(dest); + + insn->opcode = opcode; if (size > 1) { - insn.disp = (long)dest - (long)(addr + size); + insn->disp = (long)dest - (long)(addr + size); if (size == 2) { /* - * Ensure that for JMP9 the displacement + * Ensure that for JMP8 the displacement * actually fits the signed byte. */ - BUG_ON((insn.disp >> 31) != (insn.disp >> 7)); + BUG_ON((insn->disp >> 31) != (insn->disp >> 7)); } } +} +static __always_inline +void *text_gen_insn(u8 opcode, const void *addr, const void *dest) +{ + static union text_poke_insn insn; /* per instance */ + __text_gen_insn(&insn, opcode, addr, dest, text_opcode_size(opcode)); return &insn.text; } extern int after_bootmem; -extern __ro_after_init struct mm_struct *poking_mm; -extern __ro_after_init unsigned long poking_addr; +extern __ro_after_init struct mm_struct *text_poke_mm; +extern __ro_after_init unsigned long text_poke_mm_addr; #ifndef CONFIG_UML_X86 static __always_inline @@ -132,13 +142,14 @@ static __always_inline void int3_emulate_push(struct pt_regs *regs, unsigned long val) { /* - * The int3 handler in entry_64.S adds a gap between the + * The INT3 handler in entry_64.S adds a gap between the * stack where the break point happened, and the saving of * pt_regs. We can extend the original stack because of - * this gap. See the idtentry macro's create_gap option. + * this gap. See the idtentry macro's X86_TRAP_BP logic. * - * Similarly entry_32.S will have a gap on the stack for (any) hardware - * exception and pt_regs; see FIXUP_FRAME. + * Similarly, entry_32.S will have a gap on the stack for + * (any) hardware exception and pt_regs; see the + * FIXUP_FRAME macro. */ regs->sp -= sizeof(unsigned long); *(unsigned long *)regs->sp = val; @@ -165,6 +176,43 @@ void int3_emulate_ret(struct pt_regs *regs) unsigned long ip = int3_emulate_pop(regs); int3_emulate_jmp(regs, ip); } + +static __always_inline +bool __emulate_cc(unsigned long flags, u8 cc) +{ + static const unsigned long cc_mask[6] = { + [0] = X86_EFLAGS_OF, + [1] = X86_EFLAGS_CF, + [2] = X86_EFLAGS_ZF, + [3] = X86_EFLAGS_CF | X86_EFLAGS_ZF, + [4] = X86_EFLAGS_SF, + [5] = X86_EFLAGS_PF, + }; + + bool invert = cc & 1; + bool match; + + if (cc < 0xc) { + match = flags & cc_mask[cc >> 1]; + } else { + match = ((flags & X86_EFLAGS_SF) >> X86_EFLAGS_SF_BIT) ^ + ((flags & X86_EFLAGS_OF) >> X86_EFLAGS_OF_BIT); + if (cc >= 0xe) + match = match || (flags & X86_EFLAGS_ZF); + } + + return (match && !invert) || (!match && invert); +} + +static __always_inline +void int3_emulate_jcc(struct pt_regs *regs, u8 cc, unsigned long ip, unsigned long disp) +{ + if (__emulate_cc(regs->flags, cc)) + ip += disp; + + int3_emulate_jmp(regs, ip); +} + #endif /* !CONFIG_UML_X86 */ #endif /* _ASM_X86_TEXT_PATCHING_H */ |