x86/alternatives: Add and use text_gen_insn() helper (63f62add) · Commits · 戴 / test

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

+2 −0

Original line number	Diff line number	Diff line
		@@ -49,6 +49,8 @@ extern void text_poke_bp(void addr, const void opcode, size_t len, const void
		extern void text_poke_queue(void addr, const void opcode, size_t len, const void *emulate);
		extern void text_poke_finish(void);

		extern void text_gen_insn(u8 opcode, const void addr, const void *dest);

		extern int after_bootmem;
		extern __ro_after_init struct mm_struct *poking_mm;
		extern __ro_after_init unsigned long poking_addr;

arch/x86/kernel/alternative.c

+36 −0

Original line number	Diff line number	Diff line
		@@ -1237,3 +1237,39 @@ void text_poke_bp(void addr, const void opcode, size_t len, const void *emulat
		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 = 0;

		lockdep_assert_held(&text_mutex);

		insn.opcode = opcode;

		#define __CASE(insn) \
		case insn##_INSN_OPCODE: size = insn##_INSN_SIZE; break

		switch(opcode) {
		__CASE(INT3);
		__CASE(CALL);
		__CASE(JMP32);
		__CASE(JMP8);
		}

		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/jump_label.c

+11 −20

Original line number	Diff line number	Diff line
		@@ -16,15 +16,7 @@
		#include <asm/alternative.h>
		#include <asm/text-patching.h>

		union jump_code_union {
		char code[JUMP_LABEL_NOP_SIZE];
		struct {
		char jump;
		int offset;
		} __attribute__((packed));
		};

		static void bug_at(unsigned char *ip, int line)
		static void bug_at(const void *ip, int line)
		{
		/*
		* The location is not an op that we were expecting.
		@@ -38,33 +30,32 @@ static void bug_at(unsigned char *ip, int line)
		static const void *
		__jump_label_set_jump_code(struct jump_entry *entry, enum jump_label_type type, int init)
		{
		static union jump_code_union code; /* relies on text_mutex */
		const unsigned char default_nop[] = { STATIC_KEY_INIT_NOP };
		const unsigned char *ideal_nop = ideal_nops[NOP_ATOMIC5];
		const void *expect;
		const void expect, code;
		const void addr, dest;
		int line;

		lockdep_assert_held(&text_mutex);
		addr = (void *)jump_entry_code(entry);
		dest = (void *)jump_entry_target(entry);

		code.jump = JMP32_INSN_OPCODE;
		code.offset = jump_entry_target(entry) -
		(jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE);
		code = text_gen_insn(JMP32_INSN_OPCODE, addr, dest);

		if (init) {
		expect = default_nop; line = __LINE__;
		} else if (type == JUMP_LABEL_JMP) {
		expect = ideal_nop; line = __LINE__;
		} else {
		expect = code.code; line = __LINE__;
		expect = code; line = __LINE__;
		}

		if (memcmp((void *)jump_entry_code(entry), expect, JUMP_LABEL_NOP_SIZE))
		bug_at((void *)jump_entry_code(entry), line);
		if (memcmp(addr, expect, JUMP_LABEL_NOP_SIZE))
		bug_at(addr, line);

		if (type == JUMP_LABEL_NOP)
		memcpy(&code, ideal_nop, JUMP_LABEL_NOP_SIZE);
		code = ideal_nop;

		return &code;
		return code;
		}

		static void inline __jump_label_transform(struct jump_entry *entry,

arch/x86/kernel/kprobes/opt.c

+1 −6

Original line number	Diff line number	Diff line
		@@ -447,18 +447,13 @@ void arch_optimize_kprobes(struct list_head *oplist)
		void arch_unoptimize_kprobe(struct optimized_kprobe *op)
		{
		u8 insn_buff[RELATIVEJUMP_SIZE];
		u8 emulate_buff[RELATIVEJUMP_SIZE];

		/* Set int3 to first byte for kprobes */
		insn_buff[0] = BREAKPOINT_INSTRUCTION;
		memcpy(insn_buff + 1, op->optinsn.copied_insn, RELATIVE_ADDR_SIZE);

		emulate_buff[0] = RELATIVEJUMP_OPCODE;
		(s32 )(&emulate_buff[1]) = (s32)((long)op->optinsn.insn -
		((long)op->kp.addr + RELATIVEJUMP_SIZE));

		text_poke_bp(op->kp.addr, insn_buff, RELATIVEJUMP_SIZE,
		emulate_buff);
		text_gen_insn(JMP32_INSN_OPCODE, op->kp.addr, op->optinsn.insn));
		}

		/*

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