target/riscv: Fix target address to update badaddr

Compute the target address before storing it into badaddr
when mis-aligned exception is triggered.
Use a target_pc temp to store the target address to avoid
the confusing operation that udpate target address into
cpu_pc before misalign check, then update it into badaddr
and restore cpu_pc to current pc if exception is triggered.

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230526072124.298466-2-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/insn_trans/trans_rvi.c.inc

@@ -51,25 +51,30 @@ static bool trans_jal(DisasContext *ctx, arg_jal *a)
 static bool trans_jalr(DisasContext *ctx, arg_jalr *a)
 {
     TCGLabel *misaligned = NULL;
+    TCGv target_pc = tcg_temp_new();
 
-    tcg_gen_addi_tl(cpu_pc, get_gpr(ctx, a->rs1, EXT_NONE), a->imm);
-    tcg_gen_andi_tl(cpu_pc, cpu_pc, (target_ulong)-2);
+    tcg_gen_addi_tl(target_pc, get_gpr(ctx, a->rs1, EXT_NONE), a->imm);
+    tcg_gen_andi_tl(target_pc, target_pc, (target_ulong)-2);
+
+    if (get_xl(ctx) == MXL_RV32) {
+        tcg_gen_ext32s_tl(target_pc, target_pc);
+    }
 
-    gen_set_pc(ctx, cpu_pc);
     if (!has_ext(ctx, RVC) && !ctx->cfg_ptr->ext_zca) {
         TCGv t0 = tcg_temp_new();
 
         misaligned = gen_new_label();
-        tcg_gen_andi_tl(t0, cpu_pc, 0x2);
+        tcg_gen_andi_tl(t0, target_pc, 0x2);
         tcg_gen_brcondi_tl(TCG_COND_NE, t0, 0x0, misaligned);
     }
 
     gen_set_gpri(ctx, a->rd, ctx->pc_succ_insn);
+    tcg_gen_mov_tl(cpu_pc, target_pc);
     lookup_and_goto_ptr(ctx);
 
     if (misaligned) {
         gen_set_label(misaligned);
-        gen_exception_inst_addr_mis(ctx);
+        gen_exception_inst_addr_mis(ctx, target_pc);
     }
     ctx->base.is_jmp = DISAS_NORETURN;
 
@@ -153,6 +158,7 @@ static bool gen_branch(DisasContext *ctx, arg_b *a, TCGCond cond)
     TCGLabel *l = gen_new_label();
     TCGv src1 = get_gpr(ctx, a->rs1, EXT_SIGN);
     TCGv src2 = get_gpr(ctx, a->rs2, EXT_SIGN);
+    target_ulong next_pc;
 
     if (get_xl(ctx) == MXL_RV128) {
         TCGv src1h = get_gprh(ctx, a->rs1);
@@ -169,10 +175,13 @@ static bool gen_branch(DisasContext *ctx, arg_b *a, TCGCond cond)
 
     gen_set_label(l); /* branch taken */
 
+    next_pc = ctx->base.pc_next + a->imm;
     if (!has_ext(ctx, RVC) && !ctx->cfg_ptr->ext_zca &&
-        ((ctx->base.pc_next + a->imm) & 0x3)) {
+        (next_pc & 0x3)) {
         /* misaligned */
-        gen_exception_inst_addr_mis(ctx);
+        TCGv target_pc = tcg_temp_new();
+        gen_pc_plus_diff(target_pc, ctx, next_pc);
+        gen_exception_inst_addr_mis(ctx, target_pc);
     } else {
         gen_goto_tb(ctx, 0, ctx->base.pc_next + a->imm);
     }

target/riscv/insn_trans/trans_rvzce.c.inc

@@ -202,8 +202,8 @@ static bool gen_pop(DisasContext *ctx, arg_cmpp *a, bool ret, bool ret_val)
     }
 
     if (ret) {
-        TCGv ret_addr = get_gpr(ctx, xRA, EXT_NONE);
-        gen_set_pc(ctx, ret_addr);
+        TCGv ret_addr = get_gpr(ctx, xRA, EXT_SIGN);
+        tcg_gen_mov_tl(cpu_pc, ret_addr);
         tcg_gen_lookup_and_goto_ptr();
         ctx->base.is_jmp = DISAS_NORETURN;
     }

target/riscv/translate.c

@@ -224,21 +224,18 @@ static void decode_save_opc(DisasContext *ctx)
     ctx->insn_start = NULL;
 }
 
-static void gen_set_pc_imm(DisasContext *ctx, target_ulong dest)
+static void gen_pc_plus_diff(TCGv target, DisasContext *ctx,
+                             target_ulong dest)
 {
     if (get_xl(ctx) == MXL_RV32) {
         dest = (int32_t)dest;
     }
-    tcg_gen_movi_tl(cpu_pc, dest);
+    tcg_gen_movi_tl(target, dest);
 }
 
-static void gen_set_pc(DisasContext *ctx, TCGv dest)
+static void gen_set_pc_imm(DisasContext *ctx, target_ulong dest)
 {
-    if (get_xl(ctx) == MXL_RV32) {
-        tcg_gen_ext32s_tl(cpu_pc, dest);
-    } else {
-        tcg_gen_mov_tl(cpu_pc, dest);
-    }
+    gen_pc_plus_diff(cpu_pc, ctx, dest);
 }
 
 static void generate_exception(DisasContext *ctx, int excp)
@@ -259,9 +256,9 @@ static void gen_exception_illegal(DisasContext *ctx)
     }
 }
 
-static void gen_exception_inst_addr_mis(DisasContext *ctx)
+static void gen_exception_inst_addr_mis(DisasContext *ctx, TCGv target)
 {
-    tcg_gen_st_tl(cpu_pc, cpu_env, offsetof(CPURISCVState, badaddr));
+    tcg_gen_st_tl(target, cpu_env, offsetof(CPURISCVState, badaddr));
     generate_exception(ctx, RISCV_EXCP_INST_ADDR_MIS);
 }
 
@@ -553,7 +550,9 @@ static void gen_jal(DisasContext *ctx, int rd, target_ulong imm)
     next_pc = ctx->base.pc_next + imm;
     if (!has_ext(ctx, RVC) && !ctx->cfg_ptr->ext_zca) {
         if ((next_pc & 0x3) != 0) {
-            gen_exception_inst_addr_mis(ctx);
+            TCGv target_pc = tcg_temp_new();
+            gen_pc_plus_diff(target_pc, ctx, next_pc);
+            gen_exception_inst_addr_mis(ctx, target_pc);
             return;
         }
     }