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[Qemu-riscv] [PULL 26/32] disas/riscv: Disassemble reserved compressed e
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From: |
Palmer Dabbelt |
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Subject: |
[Qemu-riscv] [PULL 26/32] disas/riscv: Disassemble reserved compressed encodings as illegal |
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Date: |
Wed, 3 Jul 2019 01:40:42 -0700 |
From: Michael Clark <address@hidden>
Due to the design of the disassembler, the immediate is not
known during decoding of the opcode; so to handle compressed
encodings with reserved immediate values (non-zero), we need
to add an additional check during decompression to match
reserved encodings with zero immediates and translate them
into the illegal instruction.
The following compressed opcodes have reserved encodings with
zero immediates: c.addi4spn, c.addi, c.lui, c.addi16sp, c.srli,
c.srai, c.andi and c.slli
Signed-off-by: Michael Clark <address@hidden>
Signed-off-by: Alistair Francis <address@hidden>
[Palmer: Broke long lines]
Reviewed-by: Palmer Dabbelt <address@hidden>
Signed-off-by: Palmer Dabbelt <address@hidden>
---
disas/riscv.c | 62 +++++++++++++++++++++++++++++++++++++--------------
1 file changed, 45 insertions(+), 17 deletions(-)
diff --git a/disas/riscv.c b/disas/riscv.c
index 59a9b0437a5f..d37312705516 100644
--- a/disas/riscv.c
+++ b/disas/riscv.c
@@ -504,14 +504,19 @@ typedef struct {
const rvc_constraint *constraints;
} rv_comp_data;
+enum {
+ rvcd_imm_nz = 0x1
+};
+
typedef struct {
const char * const name;
const rv_codec codec;
const char * const format;
const rv_comp_data *pseudo;
- const int decomp_rv32;
- const int decomp_rv64;
- const int decomp_rv128;
+ const short decomp_rv32;
+ const short decomp_rv64;
+ const short decomp_rv128;
+ const short decomp_data;
} rv_opcode_data;
/* register names */
@@ -1011,7 +1016,8 @@ const rv_opcode_data opcode_data[] = {
{ "fcvt.q.lu", rv_codec_r_m, rv_fmt_rm_frd_rs1, NULL, 0, 0, 0 },
{ "fmv.x.q", rv_codec_r, rv_fmt_rd_frs1, NULL, 0, 0, 0 },
{ "fmv.q.x", rv_codec_r, rv_fmt_frd_rs1, NULL, 0, 0, 0 },
- { "c.addi4spn", rv_codec_ciw_4spn, rv_fmt_rd_rs1_imm, NULL, rv_op_addi,
rv_op_addi, rv_op_addi },
+ { "c.addi4spn", rv_codec_ciw_4spn, rv_fmt_rd_rs1_imm, NULL, rv_op_addi,
+ rv_op_addi, rv_op_addi, rvcd_imm_nz },
{ "c.fld", rv_codec_cl_ld, rv_fmt_frd_offset_rs1, NULL, rv_op_fld,
rv_op_fld, 0 },
{ "c.lw", rv_codec_cl_lw, rv_fmt_rd_offset_rs1, NULL, rv_op_lw, rv_op_lw,
rv_op_lw },
{ "c.flw", rv_codec_cl_lw, rv_fmt_frd_offset_rs1, NULL, rv_op_flw, 0, 0 },
@@ -1019,14 +1025,20 @@ const rv_opcode_data opcode_data[] = {
{ "c.sw", rv_codec_cs_sw, rv_fmt_rs2_offset_rs1, NULL, rv_op_sw, rv_op_sw,
rv_op_sw },
{ "c.fsw", rv_codec_cs_sw, rv_fmt_frs2_offset_rs1, NULL, rv_op_fsw, 0, 0 },
{ "c.nop", rv_codec_ci_none, rv_fmt_none, NULL, rv_op_addi, rv_op_addi,
rv_op_addi },
- { "c.addi", rv_codec_ci, rv_fmt_rd_rs1_imm, NULL, rv_op_addi, rv_op_addi,
rv_op_addi },
+ { "c.addi", rv_codec_ci, rv_fmt_rd_rs1_imm, NULL, rv_op_addi, rv_op_addi,
+ rv_op_addi, rvcd_imm_nz },
{ "c.jal", rv_codec_cj_jal, rv_fmt_rd_offset, NULL, rv_op_jal, 0, 0 },
{ "c.li", rv_codec_ci_li, rv_fmt_rd_rs1_imm, NULL, rv_op_addi, rv_op_addi,
rv_op_addi },
- { "c.addi16sp", rv_codec_ci_16sp, rv_fmt_rd_rs1_imm, NULL, rv_op_addi,
rv_op_addi, rv_op_addi },
- { "c.lui", rv_codec_ci_lui, rv_fmt_rd_imm, NULL, rv_op_lui, rv_op_lui,
rv_op_lui },
- { "c.srli", rv_codec_cb_sh6, rv_fmt_rd_rs1_imm, NULL, rv_op_srli,
rv_op_srli, rv_op_srli },
- { "c.srai", rv_codec_cb_sh6, rv_fmt_rd_rs1_imm, NULL, rv_op_srai,
rv_op_srai, rv_op_srai },
- { "c.andi", rv_codec_cb_imm, rv_fmt_rd_rs1_imm, NULL, rv_op_andi,
rv_op_andi, rv_op_andi },
+ { "c.addi16sp", rv_codec_ci_16sp, rv_fmt_rd_rs1_imm, NULL, rv_op_addi,
+ rv_op_addi, rv_op_addi, rvcd_imm_nz },
+ { "c.lui", rv_codec_ci_lui, rv_fmt_rd_imm, NULL, rv_op_lui, rv_op_lui,
+ rv_op_lui, rvcd_imm_nz },
+ { "c.srli", rv_codec_cb_sh6, rv_fmt_rd_rs1_imm, NULL, rv_op_srli,
+ rv_op_srli, rv_op_srli, rvcd_imm_nz },
+ { "c.srai", rv_codec_cb_sh6, rv_fmt_rd_rs1_imm, NULL, rv_op_srai,
+ rv_op_srai, rv_op_srai, rvcd_imm_nz },
+ { "c.andi", rv_codec_cb_imm, rv_fmt_rd_rs1_imm, NULL, rv_op_andi,
+ rv_op_andi, rv_op_andi, rvcd_imm_nz },
{ "c.sub", rv_codec_cs, rv_fmt_rd_rs1_rs2, NULL, rv_op_sub, rv_op_sub,
rv_op_sub },
{ "c.xor", rv_codec_cs, rv_fmt_rd_rs1_rs2, NULL, rv_op_xor, rv_op_xor,
rv_op_xor },
{ "c.or", rv_codec_cs, rv_fmt_rd_rs1_rs2, NULL, rv_op_or, rv_op_or,
rv_op_or },
@@ -1036,7 +1048,8 @@ const rv_opcode_data opcode_data[] = {
{ "c.j", rv_codec_cj, rv_fmt_rd_offset, NULL, rv_op_jal, rv_op_jal,
rv_op_jal },
{ "c.beqz", rv_codec_cb, rv_fmt_rs1_rs2_offset, NULL, rv_op_beq,
rv_op_beq, rv_op_beq },
{ "c.bnez", rv_codec_cb, rv_fmt_rs1_rs2_offset, NULL, rv_op_bne,
rv_op_bne, rv_op_bne },
- { "c.slli", rv_codec_ci_sh6, rv_fmt_rd_rs1_imm, NULL, rv_op_slli,
rv_op_slli, rv_op_slli },
+ { "c.slli", rv_codec_ci_sh6, rv_fmt_rd_rs1_imm, NULL, rv_op_slli,
+ rv_op_slli, rv_op_slli, rvcd_imm_nz },
{ "c.fldsp", rv_codec_ci_ldsp, rv_fmt_frd_offset_rs1, NULL, rv_op_fld,
rv_op_fld, rv_op_fld },
{ "c.lwsp", rv_codec_ci_lwsp, rv_fmt_rd_offset_rs1, NULL, rv_op_lw,
rv_op_lw, rv_op_lw },
{ "c.flwsp", rv_codec_ci_lwsp, rv_fmt_frd_offset_rs1, NULL, rv_op_flw, 0,
0 },
@@ -2795,8 +2808,13 @@ static void decode_inst_decompress_rv32(rv_decode *dec)
{
int decomp_op = opcode_data[dec->op].decomp_rv32;
if (decomp_op != rv_op_illegal) {
- dec->op = decomp_op;
- dec->codec = opcode_data[decomp_op].codec;
+ if ((opcode_data[dec->op].decomp_data & rvcd_imm_nz)
+ && dec->imm == 0) {
+ dec->op = rv_op_illegal;
+ } else {
+ dec->op = decomp_op;
+ dec->codec = opcode_data[decomp_op].codec;
+ }
}
}
@@ -2804,8 +2822,13 @@ static void decode_inst_decompress_rv64(rv_decode *dec)
{
int decomp_op = opcode_data[dec->op].decomp_rv64;
if (decomp_op != rv_op_illegal) {
- dec->op = decomp_op;
- dec->codec = opcode_data[decomp_op].codec;
+ if ((opcode_data[dec->op].decomp_data & rvcd_imm_nz)
+ && dec->imm == 0) {
+ dec->op = rv_op_illegal;
+ } else {
+ dec->op = decomp_op;
+ dec->codec = opcode_data[decomp_op].codec;
+ }
}
}
@@ -2813,8 +2836,13 @@ static void decode_inst_decompress_rv128(rv_decode *dec)
{
int decomp_op = opcode_data[dec->op].decomp_rv128;
if (decomp_op != rv_op_illegal) {
- dec->op = decomp_op;
- dec->codec = opcode_data[decomp_op].codec;
+ if ((opcode_data[dec->op].decomp_data & rvcd_imm_nz)
+ && dec->imm == 0) {
+ dec->op = rv_op_illegal;
+ } else {
+ dec->op = decomp_op;
+ dec->codec = opcode_data[decomp_op].codec;
+ }
}
}
--
2.21.0
- [Qemu-riscv] [PULL 15/32] target/riscv: Add the mcountinhibit CSR, (continued)
- [Qemu-riscv] [PULL 15/32] target/riscv: Add the mcountinhibit CSR, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 16/32] target/riscv: Set privledge spec 1.11.0 as default, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 18/32] target/riscv: Require either I or E base extension, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 20/32] target/riscv: Add support for disabling/enabling Counters, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 24/32] RISC-V: Update syscall list for 32-bit support., Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 19/32] target/riscv: Remove user version information, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 21/32] RISC-V: Add support for the Zifencei extension, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 23/32] RISC-V: Clear load reservations on context switch and SC, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 28/32] riscv: sifive_u: Do not create hard-coded phandles in DT, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 32/32] hw/riscv: Extend the kernel loading support, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 26/32] disas/riscv: Disassemble reserved compressed encodings as illegal,
Palmer Dabbelt <=
- [Qemu-riscv] [PULL 31/32] hw/riscv: Add support for loading a firmware, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 25/32] riscv: virt: Add cpu-topology DT node., Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 29/32] riscv: sifive_u: Update the plic hart config to support multicore, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 27/32] disas/riscv: Fix `rdinstreth` constraint, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 30/32] hw/riscv: Split out the boot functions, Palmer Dabbelt, 2019/07/03
- [Qemu-riscv] [PULL 22/32] RISC-V: Add support for the Zicsr extension, Palmer Dabbelt, 2019/07/03
- Re: [Qemu-riscv] [PULL] RISC-V Patches for the 4.1 Soft Freeze, Part 2 v3, Peter Maydell, 2019/07/04