objtool: Change arch_decode_instruction() signature

In preparation to changing struct instruction around a bit, avoid
passing it's members by pointer and instead pass the whole thing.

A cleanup in it's own right too.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org> # build only
Tested-by: Thomas Weißschuh <linux@weissschuh.net> # compile and run
Link: https://lore.kernel.org/r/20230208172245.291087549@infradead.org

4 files changed, 64 insertions, 71 deletions

diff --git a/tools/objtool/arch/powerpc/decode.c b/tools/objtool/arch/powerpc/decode.c
index 9c653805a08a..53b55690f320 100644
--- a/tools/objtool/arch/powerpc/decode.c
+++ b/tools/objtool/arch/powerpc/decode.c
@@ -41,38 +41,36 @@ const char *arch_ret_insn(int len)
 
 int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
 			    unsigned long offset, unsigned int maxlen,
-			    unsigned int *len, enum insn_type *type,
-			    unsigned long *immediate,
-			    struct list_head *ops_list)
+			    struct instruction *insn)
 {
 	unsigned int opcode;
 	enum insn_type typ;
 	unsigned long imm;
-	u32 insn;
+	u32 ins;
 
-	insn = bswap_if_needed(file->elf, *(u32 *)(sec->data->d_buf + offset));
-	opcode = insn >> 26;
+	ins = bswap_if_needed(file->elf, *(u32 *)(sec->data->d_buf + offset));
+	opcode = ins >> 26;
 	typ = INSN_OTHER;
 	imm = 0;
 
 	switch (opcode) {
 	case 18: /* b[l][a] */
-		if ((insn & 3) == 1) /* bl */
+		if ((ins & 3) == 1) /* bl */
 			typ = INSN_CALL;
 
-		imm = insn & 0x3fffffc;
+		imm = ins & 0x3fffffc;
 		if (imm & 0x2000000)
 			imm -= 0x4000000;
 		break;
 	}
 
 	if (opcode == 1)
-		*len = 8;
+		insn->len = 8;
 	else
-		*len = 4;
+		insn->len = 4;
 
-	*type = typ;
-	*immediate = imm;
+	insn->type = typ;
+	insn->immediate = imm;
 
 	return 0;
 }
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index e7b030f7e2a5..c5c49277cf1a 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -146,12 +146,11 @@ static bool has_notrack_prefix(struct insn *insn)
 
 int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
 			    unsigned long offset, unsigned int maxlen,
-			    unsigned int *len, enum insn_type *type,
-			    unsigned long *immediate,
-			    struct list_head *ops_list)
+			    struct instruction *insn)
 {
+	struct list_head *ops_list = &insn->stack_ops;
 	const struct elf *elf = file->elf;
-	struct insn insn;
+	struct insn ins;
 	int x86_64, ret;
 	unsigned char op1, op2, op3, prefix,
 		      rex = 0, rex_b = 0, rex_r = 0, rex_w = 0, rex_x = 0,
@@ -165,42 +164,42 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 	if (x86_64 == -1)
 		return -1;
 
-	ret = insn_decode(&insn, sec->data->d_buf + offset, maxlen,
+	ret = insn_decode(&ins, sec->data->d_buf + offset, maxlen,
 			  x86_64 ? INSN_MODE_64 : INSN_MODE_32);
 	if (ret < 0) {
 		WARN("can't decode instruction at %s:0x%lx", sec->name, offset);
 		return -1;
 	}
 
-	*len = insn.length;
-	*type = INSN_OTHER;
+	insn->len = ins.length;
+	insn->type = INSN_OTHER;
 
-	if (insn.vex_prefix.nbytes)
+	if (ins.vex_prefix.nbytes)
 		return 0;
 
-	prefix = insn.prefixes.bytes[0];
+	prefix = ins.prefixes.bytes[0];
 
-	op1 = insn.opcode.bytes[0];
-	op2 = insn.opcode.bytes[1];
-	op3 = insn.opcode.bytes[2];
+	op1 = ins.opcode.bytes[0];
+	op2 = ins.opcode.bytes[1];
+	op3 = ins.opcode.bytes[2];
 
-	if (insn.rex_prefix.nbytes) {
-		rex = insn.rex_prefix.bytes[0];
+	if (ins.rex_prefix.nbytes) {
+		rex = ins.rex_prefix.bytes[0];
 		rex_w = X86_REX_W(rex) >> 3;
 		rex_r = X86_REX_R(rex) >> 2;
 		rex_x = X86_REX_X(rex) >> 1;
 		rex_b = X86_REX_B(rex);
 	}
 
-	if (insn.modrm.nbytes) {
-		modrm = insn.modrm.bytes[0];
+	if (ins.modrm.nbytes) {
+		modrm = ins.modrm.bytes[0];
 		modrm_mod = X86_MODRM_MOD(modrm);
 		modrm_reg = X86_MODRM_REG(modrm) + 8*rex_r;
 		modrm_rm  = X86_MODRM_RM(modrm)  + 8*rex_b;
 	}
 
-	if (insn.sib.nbytes) {
-		sib = insn.sib.bytes[0];
+	if (ins.sib.nbytes) {
+		sib = ins.sib.bytes[0];
 		/* sib_scale = X86_SIB_SCALE(sib); */
 		sib_index = X86_SIB_INDEX(sib) + 8*rex_x;
 		sib_base  = X86_SIB_BASE(sib)  + 8*rex_b;
@@ -254,7 +253,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 		break;
 
 	case 0x70 ... 0x7f:
-		*type = INSN_JUMP_CONDITIONAL;
+		insn->type = INSN_JUMP_CONDITIONAL;
 		break;
 
 	case 0x80 ... 0x83:
@@ -278,7 +277,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 		if (!rm_is_reg(CFI_SP))
 			break;
 
-		imm = insn.immediate.value;
+		imm = ins.immediate.value;
 		if (op1 & 2) { /* sign extend */
 			if (op1 & 1) { /* imm32 */
 				imm <<= 32;
@@ -309,7 +308,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			ADD_OP(op) {
 				op->src.type = OP_SRC_AND;
 				op->src.reg = CFI_SP;
-				op->src.offset = insn.immediate.value;
+				op->src.offset = ins.immediate.value;
 				op->dest.type = OP_DEST_REG;
 				op->dest.reg = CFI_SP;
 			}
@@ -356,7 +355,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 					op->src.reg = CFI_SP;
 					op->dest.type = OP_DEST_REG_INDIRECT;
 					op->dest.reg = modrm_rm;
-					op->dest.offset = insn.displacement.value;
+					op->dest.offset = ins.displacement.value;
 				}
 				break;
 			}
@@ -389,7 +388,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 				op->src.reg = modrm_reg;
 				op->dest.type = OP_DEST_REG_INDIRECT;
 				op->dest.reg = CFI_BP;
-				op->dest.offset = insn.displacement.value;
+				op->dest.offset = ins.displacement.value;
 			}
 			break;
 		}
@@ -402,7 +401,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 				op->src.reg = modrm_reg;
 				op->dest.type = OP_DEST_REG_INDIRECT;
 				op->dest.reg = CFI_SP;
-				op->dest.offset = insn.displacement.value;
+				op->dest.offset = ins.displacement.value;
 			}
 			break;
 		}
@@ -419,7 +418,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			ADD_OP(op) {
 				op->src.type = OP_SRC_REG_INDIRECT;
 				op->src.reg = CFI_BP;
-				op->src.offset = insn.displacement.value;
+				op->src.offset = ins.displacement.value;
 				op->dest.type = OP_DEST_REG;
 				op->dest.reg = modrm_reg;
 			}
@@ -432,7 +431,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			ADD_OP(op) {
 				op->src.type = OP_SRC_REG_INDIRECT;
 				op->src.reg = CFI_SP;
-				op->src.offset = insn.displacement.value;
+				op->src.offset = ins.displacement.value;
 				op->dest.type = OP_DEST_REG;
 				op->dest.reg = modrm_reg;
 			}
@@ -464,7 +463,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 
 		/* lea disp(%src), %dst */
 		ADD_OP(op) {
-			op->src.offset = insn.displacement.value;
+			op->src.offset = ins.displacement.value;
 			if (!op->src.offset) {
 				/* lea (%src), %dst */
 				op->src.type = OP_SRC_REG;
@@ -487,7 +486,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 		break;
 
 	case 0x90:
-		*type = INSN_NOP;
+		insn->type = INSN_NOP;
 		break;
 
 	case 0x9c:
@@ -511,39 +510,39 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 		if (op2 == 0x01) {
 
 			if (modrm == 0xca)
-				*type = INSN_CLAC;
+				insn->type = INSN_CLAC;
 			else if (modrm == 0xcb)
-				*type = INSN_STAC;
+				insn->type = INSN_STAC;
 
 		} else if (op2 >= 0x80 && op2 <= 0x8f) {
 
-			*type = INSN_JUMP_CONDITIONAL;
+			insn->type = INSN_JUMP_CONDITIONAL;
 
 		} else if (op2 == 0x05 || op2 == 0x07 || op2 == 0x34 ||
 			   op2 == 0x35) {
 
 			/* sysenter, sysret */
-			*type = INSN_CONTEXT_SWITCH;
+			insn->type = INSN_CONTEXT_SWITCH;
 
 		} else if (op2 == 0x0b || op2 == 0xb9) {
 
 			/* ud2 */
-			*type = INSN_BUG;
+			insn->type = INSN_BUG;
 
 		} else if (op2 == 0x0d || op2 == 0x1f) {
 
 			/* nopl/nopw */
-			*type = INSN_NOP;
+			insn->type = INSN_NOP;
 
 		} else if (op2 == 0x1e) {
 
 			if (prefix == 0xf3 && (modrm == 0xfa || modrm == 0xfb))
-				*type = INSN_ENDBR;
+				insn->type = INSN_ENDBR;
 
 
 		} else if (op2 == 0x38 && op3 == 0xf8) {
-			if (insn.prefixes.nbytes == 1 &&
-			    insn.prefixes.bytes[0] == 0xf2) {
+			if (ins.prefixes.nbytes == 1 &&
+			    ins.prefixes.bytes[0] == 0xf2) {
 				/* ENQCMD cannot be used in the kernel. */
 				WARN("ENQCMD instruction at %s:%lx", sec->name,
 				     offset);
@@ -591,29 +590,29 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 
 	case 0xcc:
 		/* int3 */
-		*type = INSN_TRAP;
+		insn->type = INSN_TRAP;
 		break;
 
 	case 0xe3:
 		/* jecxz/jrcxz */
-		*type = INSN_JUMP_CONDITIONAL;
+		insn->type = INSN_JUMP_CONDITIONAL;
 		break;
 
 	case 0xe9:
 	case 0xeb:
-		*type = INSN_JUMP_UNCONDITIONAL;
+		insn->type = INSN_JUMP_UNCONDITIONAL;
 		break;
 
 	case 0xc2:
 	case 0xc3:
-		*type = INSN_RETURN;
+		insn->type = INSN_RETURN;
 		break;
 
 	case 0xc7: /* mov imm, r/m */
 		if (!opts.noinstr)
 			break;
 
-		if (insn.length == 3+4+4 && !strncmp(sec->name, ".init.text", 10)) {
+		if (ins.length == 3+4+4 && !strncmp(sec->name, ".init.text", 10)) {
 			struct reloc *immr, *disp;
 			struct symbol *func;
 			int idx;
@@ -661,17 +660,17 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 
 	case 0xca: /* retf */
 	case 0xcb: /* retf */
-		*type = INSN_CONTEXT_SWITCH;
+		insn->type = INSN_CONTEXT_SWITCH;
 		break;
 
 	case 0xe0: /* loopne */
 	case 0xe1: /* loope */
 	case 0xe2: /* loop */
-		*type = INSN_JUMP_CONDITIONAL;
+		insn->type = INSN_JUMP_CONDITIONAL;
 		break;
 
 	case 0xe8:
-		*type = INSN_CALL;
+		insn->type = INSN_CALL;
 		/*
 		 * For the impact on the stack, a CALL behaves like
 		 * a PUSH of an immediate value (the return address).
@@ -683,30 +682,30 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 		break;
 
 	case 0xfc:
-		*type = INSN_CLD;
+		insn->type = INSN_CLD;
 		break;
 
 	case 0xfd:
-		*type = INSN_STD;
+		insn->type = INSN_STD;
 		break;
 
 	case 0xff:
 		if (modrm_reg == 2 || modrm_reg == 3) {
 
-			*type = INSN_CALL_DYNAMIC;
-			if (has_notrack_prefix(&insn))
+			insn->type = INSN_CALL_DYNAMIC;
+			if (has_notrack_prefix(&ins))
 				WARN("notrack prefix found at %s:0x%lx", sec->name, offset);
 
 		} else if (modrm_reg == 4) {
 
-			*type = INSN_JUMP_DYNAMIC;
-			if (has_notrack_prefix(&insn))
+			insn->type = INSN_JUMP_DYNAMIC;
+			if (has_notrack_prefix(&ins))
 				WARN("notrack prefix found at %s:0x%lx", sec->name, offset);
 
 		} else if (modrm_reg == 5) {
 
 			/* jmpf */
-			*type = INSN_CONTEXT_SWITCH;
+			insn->type = INSN_CONTEXT_SWITCH;
 
 		} else if (modrm_reg == 6) {
 
@@ -723,7 +722,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 		break;
 	}
 
-	*immediate = insn.immediate.nbytes ? insn.immediate.value : 0;
+	insn->immediate = ins.immediate.nbytes ? ins.immediate.value : 0;
 
 	return 0;
 }
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index ba07a8ebaf73..b3b423d33cc2 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -406,9 +406,7 @@ static int decode_instructions(struct objtool_file *file)
 
 			ret = arch_decode_instruction(file, sec, offset,
 						      sec->sh.sh_size - offset,
-						      &insn->len, &insn->type,
-						      &insn->immediate,
-						      &insn->stack_ops);
+						      insn);
 			if (ret)
 				goto err;
 
diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h
index 4ecb480131c7..73149f8090fa 100644
--- a/tools/objtool/include/objtool/arch.h
+++ b/tools/objtool/include/objtool/arch.h
@@ -75,9 +75,7 @@ void arch_initial_func_cfi_state(struct cfi_init_state *state);
 
 int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
 			    unsigned long offset, unsigned int maxlen,
-			    unsigned int *len, enum insn_type *type,
-			    unsigned long *immediate,
-			    struct list_head *ops_list);
+			    struct instruction *insn);
 
 bool arch_callee_saved_reg(unsigned char reg);