Messages in this thread Patch in this message | | | From | Julien Thierry <> | Subject | [RFC v5 22/57] objtool: arm64: Decode add/sub immediate instructions | Date | Thu, 9 Jan 2020 16:02:25 +0000 |
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Decode instruction adding immediates to registers. Create stack operation for instructions interacting with the stack pointer or the frame pointer.
Suggested-by: Raphael Gault <raphael.gault@arm.com> Signed-off-by: Julien Thierry <jthierry@redhat.com> --- tools/objtool/arch/arm64/decode.c | 84 +++++++++++++++++++ .../objtool/arch/arm64/include/insn_decode.h | 7 ++ 2 files changed, 91 insertions(+)
diff --git a/tools/objtool/arch/arm64/decode.c b/tools/objtool/arch/arm64/decode.c index 6c8db9335fc9..d240f29a2390 100644 --- a/tools/objtool/arch/arm64/decode.c +++ b/tools/objtool/arch/arm64/decode.c @@ -13,6 +13,11 @@ #include "../../elf.h" #include "../../warn.h" +static bool stack_related_reg(int reg) +{ + return reg == CFI_SP || reg == CFI_BP; +} + bool arch_callee_saved_reg(unsigned char reg) { switch (reg) { @@ -153,6 +158,8 @@ int arm_decode_unknown(u32 instr, enum insn_type *type, static arm_decode_class aarch64_insn_dp_imm_decode_table[NR_DP_IMM_SUBCLASS] = { [0 ... INSN_PCREL] = arm_decode_pcrel, + [INSN_ADD_SUB] = arm_decode_add_sub, + [INSN_ADD_TAG] = arm_decode_add_sub_tags, [INSN_MOVE_WIDE] = arm_decode_move_wide, [INSN_BITFIELD] = arm_decode_bitfield, [INSN_EXTRACT] = arm_decode_extract, @@ -189,6 +196,83 @@ int arm_decode_pcrel(u32 instr, enum insn_type *type, return 0; } +int arm_decode_add_sub(u32 instr, enum insn_type *type, + unsigned long *immediate, struct list_head *ops_list) +{ + unsigned long imm12 = 0, imm = 0; + unsigned char sf = 0, sh = 0, S = 0, op_bit = 0; + unsigned char rn = 0, rd = 0; + + S = EXTRACT_BIT(instr, 29); + op_bit = EXTRACT_BIT(instr, 30); + sf = EXTRACT_BIT(instr, 31); + sh = EXTRACT_BIT(instr, 22); + rd = instr & ONES(5); + rn = (instr >> 5) & ONES(5); + imm12 = (instr >> 10) & ONES(12); + imm = ZERO_EXTEND(imm12 << (sh * 12), (sf + 1) * 32); + + *type = INSN_OTHER; + + if (rd == CFI_BP || (!S && rd == CFI_SP) || stack_related_reg(rn)) { + struct stack_op *op; + + *type = INSN_STACK; + + op = calloc(1, sizeof(*op)); + list_add_tail(&op->list, ops_list); + + op->dest.type = OP_DEST_REG; + op->dest.offset = 0; + op->dest.reg = rd; + op->src.type = OP_SRC_ADD; + op->src.offset = op_bit ? -1 * imm : imm; + op->src.reg = rn; + } + return 0; +} + +int arm_decode_add_sub_tags(u32 instr, enum insn_type *type, + unsigned long *immediate, + struct list_head *ops_list) +{ + unsigned char decode_field = 0, rn = 0, rd = 0, uimm6 = 0; + + decode_field = (instr >> 29) & ONES(3); + rd = instr & ONES(5); + rn = (instr >> 5) & ONES(5); + uimm6 = (instr >> 16) & ONES(6); + + *immediate = uimm6; + *type = INSN_OTHER; + +#define ADDG_DECODE 4 +#define SUBG_DECODE 5 + if (decode_field != ADDG_DECODE && decode_field != SUBG_DECODE) + return arm_decode_unknown(instr, type, immediate, ops_list); + +#undef ADDG_DECODE +#undef SUBG_DECODE + + if (stack_related_reg(rd)) { + struct stack_op *op; + + *type = INSN_STACK; + + op = calloc(1, sizeof(*op)); + list_add_tail(&op->list, ops_list); + + op->dest.type = OP_DEST_REG; + op->dest.offset = 0; + op->dest.reg = rd; + op->src.type = OP_SRC_ADD; + op->src.offset = 0; + op->src.reg = rn; + } + + return 0; +} + int arm_decode_move_wide(u32 instr, enum insn_type *type, unsigned long *immediate, struct list_head *ops_list) { diff --git a/tools/objtool/arch/arm64/include/insn_decode.h b/tools/objtool/arch/arm64/include/insn_decode.h index 06235d81300c..65e60b293a07 100644 --- a/tools/objtool/arch/arm64/include/insn_decode.h +++ b/tools/objtool/arch/arm64/include/insn_decode.h @@ -14,6 +14,8 @@ #define INSN_CLASS(opcode) (((opcode) >> 25) & (NR_INSN_CLASS - 1)) #define INSN_PCREL 0b001 //0b00x +#define INSN_ADD_SUB 0b010 +#define INSN_ADD_TAG 0b011 #define INSN_MOVE_WIDE 0b101 #define INSN_BITFIELD 0b110 #define INSN_EXTRACT 0b111 @@ -31,6 +33,11 @@ int arm_decode_unknown(u32 instr, enum insn_type *type, /* arm64 data processing -- immediate subclasses */ int arm_decode_pcrel(u32 instr, enum insn_type *type, unsigned long *immediate, struct list_head *ops_list); +int arm_decode_add_sub(u32 instr, enum insn_type *type, + unsigned long *immediate, struct list_head *ops_list); +int arm_decode_add_sub_tags(u32 instr, enum insn_type *type, + unsigned long *immediate, + struct list_head *ops_list); int arm_decode_move_wide(u32 instr, enum insn_type *type, unsigned long *immediate, struct list_head *ops_list); int arm_decode_bitfield(u32 instr, enum insn_type *type, -- 2.21.0
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