From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 23 Apr 2020 13:22:10 +0200
Subject: objtool: Rework allocating stack_ops on decode
Git-commit: 7d989fcadd6e225a61d6490dd15bdbdfc8a53d5c
Patch-mainline: v5.8-rc1
References: bsc#1202396
Wrap each stack_op in a macro that allocates and adds it to the list.
This simplifies trying to figure out what to do with the pre-allocated
stack_op at the end.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200428191659.736151601@infradead.org
Acked-by: Miroslav Benes <mbenes@suse.cz>
---
tools/objtool/arch/x86/decode.c | 237 +++++++++++++++++++++++-----------------
1 file changed, 139 insertions(+), 98 deletions(-)
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -78,6 +78,11 @@ bool arch_callee_saved_reg(unsigned char
}
}
+#define ADD_OP(op) \
+ if (!(op = calloc(1, sizeof(*op)))) \
+ return -1; \
+ else for (list_add_tail(&op->list, ops_list); op; op = NULL)
+
int arch_decode_instruction(struct elf *elf, struct section *sec,
unsigned long offset, unsigned int maxlen,
unsigned int *len, enum insn_type *type,
@@ -89,7 +94,7 @@ int arch_decode_instruction(struct elf *
unsigned char op1, op2, rex = 0, rex_b = 0, rex_r = 0, rex_w = 0,
rex_x = 0, modrm = 0, modrm_mod = 0, modrm_rm = 0,
modrm_reg = 0, sib = 0;
- struct stack_op *op;
+ struct stack_op *op = NULL;
x86_64 = is_x86_64(elf);
if (x86_64 == -1)
@@ -130,10 +135,6 @@ int arch_decode_instruction(struct elf *
if (insn.sib.nbytes)
sib = insn.sib.bytes[0];
- op = calloc(1, sizeof(*op));
- if (!op)
- return -1;
-
switch (op1) {
case 0x1:
@@ -142,10 +143,12 @@ int arch_decode_instruction(struct elf *
/* add/sub reg, %rsp */
*type = INSN_STACK;
- op->src.type = OP_SRC_ADD;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
}
break;
@@ -153,9 +156,11 @@ int arch_decode_instruction(struct elf *
/* push reg */
*type = INSN_STACK;
- op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
- op->dest.type = OP_DEST_PUSH;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
+ op->dest.type = OP_DEST_PUSH;
+ }
break;
@@ -163,9 +168,11 @@ int arch_decode_instruction(struct elf *
/* pop reg */
*type = INSN_STACK;
- op->src.type = OP_SRC_POP;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
+ ADD_OP(op) {
+ op->src.type = OP_SRC_POP;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
+ }
break;
@@ -173,8 +180,10 @@ int arch_decode_instruction(struct elf *
case 0x6a:
/* push immediate */
*type = INSN_STACK;
- op->src.type = OP_SRC_CONST;
- op->dest.type = OP_DEST_PUSH;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_CONST;
+ op->dest.type = OP_DEST_PUSH;
+ }
break;
case 0x70 ... 0x7f:
@@ -189,11 +198,13 @@ int arch_decode_instruction(struct elf *
if (modrm == 0xe4) {
/* and imm, %rsp */
*type = INSN_STACK;
- op->src.type = OP_SRC_AND;
- op->src.reg = CFI_SP;
- op->src.offset = insn.immediate.value;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_AND;
+ op->src.reg = CFI_SP;
+ op->src.offset = insn.immediate.value;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
break;
}
@@ -206,11 +217,13 @@ int arch_decode_instruction(struct elf *
/* add/sub imm, %rsp */
*type = INSN_STACK;
- op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_SP;
- op->src.offset = insn.immediate.value * sign;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = CFI_SP;
+ op->src.offset = insn.immediate.value * sign;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
break;
case 0x89:
@@ -218,10 +231,12 @@ int arch_decode_instruction(struct elf *
/* mov %rsp, reg */
*type = INSN_STACK;
- op->src.type = OP_SRC_REG;
- op->src.reg = CFI_SP;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b];
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = CFI_SP;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b];
+ }
break;
}
@@ -229,10 +244,12 @@ int arch_decode_instruction(struct elf *
/* mov reg, %rsp */
*type = INSN_STACK;
- op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
break;
}
@@ -243,21 +260,25 @@ int arch_decode_instruction(struct elf *
/* mov reg, disp(%rbp) */
*type = INSN_STACK;
- op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
- op->dest.type = OP_DEST_REG_INDIRECT;
- op->dest.reg = CFI_BP;
- op->dest.offset = insn.displacement.value;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->dest.type = OP_DEST_REG_INDIRECT;
+ op->dest.reg = CFI_BP;
+ op->dest.offset = insn.displacement.value;
+ }
} else if (rex_w && !rex_b && modrm_rm == 4 && sib == 0x24) {
/* mov reg, disp(%rsp) */
*type = INSN_STACK;
- op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
- op->dest.type = OP_DEST_REG_INDIRECT;
- op->dest.reg = CFI_SP;
- op->dest.offset = insn.displacement.value;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->dest.type = OP_DEST_REG_INDIRECT;
+ op->dest.reg = CFI_SP;
+ op->dest.offset = insn.displacement.value;
+ }
}
break;
@@ -267,22 +288,26 @@ int arch_decode_instruction(struct elf *
/* mov disp(%rbp), reg */
*type = INSN_STACK;
- op->src.type = OP_SRC_REG_INDIRECT;
- op->src.reg = CFI_BP;
- op->src.offset = insn.displacement.value;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG_INDIRECT;
+ op->src.reg = CFI_BP;
+ op->src.offset = insn.displacement.value;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ }
} else if (rex_w && !rex_b && sib == 0x24 &&
modrm_mod != 3 && modrm_rm == 4) {
/* mov disp(%rsp), reg */
*type = INSN_STACK;
- op->src.type = OP_SRC_REG_INDIRECT;
- op->src.reg = CFI_SP;
- op->src.offset = insn.displacement.value;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG_INDIRECT;
+ op->src.reg = CFI_SP;
+ op->src.offset = insn.displacement.value;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ }
}
break;
@@ -291,27 +316,31 @@ int arch_decode_instruction(struct elf *
if (sib == 0x24 && rex_w && !rex_b && !rex_x) {
*type = INSN_STACK;
- if (!insn.displacement.value) {
- /* lea (%rsp), reg */
- op->src.type = OP_SRC_REG;
- } else {
- /* lea disp(%rsp), reg */
- op->src.type = OP_SRC_ADD;
- op->src.offset = insn.displacement.value;
+ ADD_OP(op) {
+ if (!insn.displacement.value) {
+ /* lea (%rsp), reg */
+ op->src.type = OP_SRC_REG;
+ } else {
+ /* lea disp(%rsp), reg */
+ op->src.type = OP_SRC_ADD;
+ op->src.offset = insn.displacement.value;
+ }
+ op->src.reg = CFI_SP;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
}
- op->src.reg = CFI_SP;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
} else if (rex == 0x48 && modrm == 0x65) {
/* lea disp(%rbp), %rsp */
*type = INSN_STACK;
- op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_BP;
- op->src.offset = insn.displacement.value;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = CFI_BP;
+ op->src.offset = insn.displacement.value;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
} else if (rex == 0x49 && modrm == 0x62 &&
insn.displacement.value == -8) {
@@ -323,11 +352,13 @@ int arch_decode_instruction(struct elf *
* stack realignment.
*/
*type = INSN_STACK;
- op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_R10;
- op->src.offset = -8;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = CFI_R10;
+ op->src.offset = -8;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
} else if (rex == 0x49 && modrm == 0x65 &&
insn.displacement.value == -16) {
@@ -339,11 +370,13 @@ int arch_decode_instruction(struct elf *
* stack realignment.
*/
*type = INSN_STACK;
- op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_R13;
- op->src.offset = -16;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = CFI_R13;
+ op->src.offset = -16;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
}
break;
@@ -351,8 +384,10 @@ int arch_decode_instruction(struct elf *
case 0x8f:
/* pop to mem */
*type = INSN_STACK;
- op->src.type = OP_SRC_POP;
- op->dest.type = OP_DEST_MEM;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_POP;
+ op->dest.type = OP_DEST_MEM;
+ }
break;
case 0x90:
@@ -362,15 +397,19 @@ int arch_decode_instruction(struct elf *
case 0x9c:
/* pushf */
*type = INSN_STACK;
- op->src.type = OP_SRC_CONST;
- op->dest.type = OP_DEST_PUSH;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_CONST;
+ op->dest.type = OP_DEST_PUSH;
+ }
break;
case 0x9d:
/* popf */
*type = INSN_STACK;
- op->src.type = OP_SRC_POP;
- op->dest.type = OP_DEST_MEM;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_POP;
+ op->dest.type = OP_DEST_MEM;
+ }
break;
case 0x0f:
@@ -399,15 +438,19 @@ int arch_decode_instruction(struct elf *
/* push fs/gs */
*type = INSN_STACK;
- op->src.type = OP_SRC_CONST;
- op->dest.type = OP_DEST_PUSH;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_CONST;
+ op->dest.type = OP_DEST_PUSH;
+ }
} else if (op2 == 0xa1 || op2 == 0xa9) {
/* pop fs/gs */
*type = INSN_STACK;
- op->src.type = OP_SRC_POP;
- op->dest.type = OP_DEST_MEM;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_POP;
+ op->dest.type = OP_DEST_MEM;
+ }
}
break;
@@ -421,7 +464,8 @@ int arch_decode_instruction(struct elf *
* pop bp
*/
*type = INSN_STACK;
- op->dest.type = OP_DEST_LEAVE;
+ ADD_OP(op)
+ op->dest.type = OP_DEST_LEAVE;
break;
@@ -468,8 +512,10 @@ int arch_decode_instruction(struct elf *
/* push from mem */
*type = INSN_STACK;
- op->src.type = OP_SRC_CONST;
- op->dest.type = OP_DEST_PUSH;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_CONST;
+ op->dest.type = OP_DEST_PUSH;
+ }
}
break;
@@ -480,11 +526,6 @@ int arch_decode_instruction(struct elf *
*immediate = insn.immediate.nbytes ? insn.immediate.value : 0;
- if (*type == INSN_STACK)
- list_add_tail(&op->list, ops_list);
- else
- free(op);
-
return 0;
}