x86/ftrace: Use text_gen_insn() (67c1d4a2) · Commits · 戴 / test

arch/x86/include/asm/text-patching.h

+29 −1

Original line number	Diff line number	Diff line
		@@ -80,7 +80,35 @@ static inline int text_opcode_size(u8 opcode)
		return size;
		}

		extern void text_gen_insn(u8 opcode, const void addr, const void *dest);
		union text_poke_insn {
		u8 text[POKE_MAX_OPCODE_SIZE];
		struct {
		u8 opcode;
		s32 disp;
		} __attribute__((packed));
		};

		static __always_inline
		void text_gen_insn(u8 opcode, const void addr, const void *dest)
		{
		static union text_poke_insn insn; /* per instance */
		int size = text_opcode_size(opcode);

		insn.opcode = opcode;

		if (size > 1) {
		insn.disp = (long)dest - (long)(addr + size);
		if (size == 2) {
		/*
		* Ensure that for JMP9 the displacement
		* actually fits the signed byte.
		*/
		BUG_ON((insn.disp >> 31) != (insn.disp >> 7));
		}
		}

		return &insn.text;
		}

		extern int after_bootmem;
		extern __ro_after_init struct mm_struct *poking_mm;

arch/x86/kernel/alternative.c

+0 −26

Original line number	Diff line number	Diff line
		@@ -1247,29 +1247,3 @@ void __ref text_poke_bp(void addr, const void opcode, size_t len, const void *
		text_poke_loc_init(&tp, addr, opcode, len, emulate);
		text_poke_bp_batch(&tp, 1);
		}

		union text_poke_insn {
		u8 text[POKE_MAX_OPCODE_SIZE];
		struct {
		u8 opcode;
		s32 disp;
		} __attribute__((packed));
		};

		void text_gen_insn(u8 opcode, const void addr, const void *dest)
		{
		static union text_poke_insn insn; /* text_mutex */
		int size = text_opcode_size(opcode);

		lockdep_assert_held(&text_mutex);

		insn.opcode = opcode;

		if (size > 1) {
		insn.disp = (long)dest - (long)(addr + size);
		if (size == 2)
		BUG_ON((insn.disp >> 31) != (insn.disp >> 7));
		}

		return &insn.text;
		}

arch/x86/kernel/ftrace.c

+7 −25

Original line number	Diff line number	Diff line
		@@ -63,24 +63,6 @@ int ftrace_arch_code_modify_post_process(void)
		return 0;
		}

		union ftrace_code_union {
		char code[MCOUNT_INSN_SIZE];
		struct {
		char op;
		int offset;
		} __attribute__((packed));
		};

		static const char *ftrace_text_replace(char op, unsigned long ip, unsigned long addr)
		{
		static union ftrace_code_union calc;

		calc.op = op;
		calc.offset = (int)(addr - (ip + MCOUNT_INSN_SIZE));

		return calc.code;
		}

		static const char *ftrace_nop_replace(void)
		{
		return ideal_nops[NOP_ATOMIC5];
		@@ -88,7 +70,7 @@ static const char *ftrace_nop_replace(void)

		static const char *ftrace_call_replace(unsigned long ip, unsigned long addr)
		{
		return ftrace_text_replace(CALL_INSN_OPCODE, ip, addr);
		return text_gen_insn(CALL_INSN_OPCODE, (void )ip, (void )addr);
		}

		static int ftrace_verify_code(unsigned long ip, const char *old_code)
		@@ -480,20 +462,20 @@ void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
		/* Return the address of the function the trampoline calls */
		static void addr_from_call(void ptr)
		{
		union ftrace_code_union calc;
		union text_poke_insn call;
		int ret;

		ret = probe_kernel_read(&calc, ptr, MCOUNT_INSN_SIZE);
		ret = probe_kernel_read(&call, ptr, CALL_INSN_SIZE);
		if (WARN_ON_ONCE(ret < 0))
		return NULL;

		/* Make sure this is a call */
		if (WARN_ON_ONCE(calc.op != 0xe8)) {
		pr_warn("Expected e8, got %x\n", calc.op);
		if (WARN_ON_ONCE(call.opcode != CALL_INSN_OPCODE)) {
		pr_warn("Expected E8, got %x\n", call.opcode);
		return NULL;
		}

		return ptr + MCOUNT_INSN_SIZE + calc.offset;
		return ptr + CALL_INSN_SIZE + call.disp;
		}

		void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
		@@ -562,7 +544,7 @@ extern void ftrace_graph_call(void);

		static const char *ftrace_jmp_replace(unsigned long ip, unsigned long addr)
		{
		return ftrace_text_replace(JMP32_INSN_OPCODE, ip, addr);
		return text_gen_insn(JMP32_INSN_OPCODE, (void )ip, (void )addr);
		}

		static int ftrace_mod_jmp(unsigned long ip, void *func)

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