P2 - Don't call block end callback on every translation block end

Cisco-Talos · Feb 18, 2018 · 8851454 · 8851454
1 parent 5dc6102
commit 8851454
Showing 1 changed file with 8 additions and 3 deletions.
diff --git a/qemu/target/i386/translate.c b/qemu/target/i386/translate.c
@@ -2184,7 +2184,7 @@ static inline void gen_goto_tb(DisasContext *s, int tb_num, target_ulong eip)
         }
         //Pyrebox: block_end
         //helper_qemu_block_end_callback(CPUState* cpu,TranslationBlock* next_tb, target_ulong from,target_ulong to)
-        if (is_block_end_callback_needed(s->pgd)){
+        if (s->saved_pc && is_block_end_callback_needed(s->pgd)){
             TCGv_ptr tcg_tb = tcg_const_ptr((tcg_target_ulong)s->tb);
             TCGv tcg_from = tcg_temp_new();
             tcg_gen_movi_tl(tcg_from, s->saved_pc);
@@ -2620,7 +2620,7 @@ do_gen_eob_worker(DisasContext *s, bool inhibit, bool recheck_tf, TCGv jr)
 
         //Pyrebox: block_end
         //helper_qemu_block_end_callback(CPUState* cpu,TranslationBlock* next_tb, target_ulong from)
-        if (is_block_end_callback_needed(s->pgd)){
+        if (s->saved_pc && is_block_end_callback_needed(s->pgd)){
             TCGv_ptr tcg_tb = tcg_const_ptr((tcg_target_ulong)s->tb);
             TCGv tcg_from = tcg_temp_new();
             tcg_gen_movi_tl(tcg_from, s->saved_pc);
@@ -2646,7 +2646,7 @@ do_gen_eob_worker(DisasContext *s, bool inhibit, bool recheck_tf, TCGv jr)
         }
         //Pyrebox: block_end
         //helper_qemu_block_end_callback(CPUState* cpu,TranslationBlock* next_tb, target_ulong from)
-        if (is_block_end_callback_needed(s->pgd)){
+        if (s->saved_pc && is_block_end_callback_needed(s->pgd)){
             TCGv_ptr tcg_tb = tcg_const_ptr((tcg_target_ulong)s->tb);
             TCGv tcg_from = tcg_temp_new();
             tcg_gen_movi_tl(tcg_from, s->saved_pc);
@@ -6788,6 +6788,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
             gen_pop_update(s, ot);
             set_cc_op(s, CC_OP_EFLAGS);
             /* abort translation because TF/AC flag may change */
+            s->saved_pc = 0;
             gen_jmp_im(s->pc - s->cs_base);
             gen_eob(s);
         }
@@ -7178,6 +7179,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
         break;
     case 0xfb: /* sti */
         if (s->vm86 ? s->iopl == 3 : s->cpl <= s->iopl) {
+            s->saved_pc = 0;
             gen_helper_sti(cpu_env);
             /* interruptions are enabled only the first insn after sti */
             gen_jmp_im(s->pc - s->cs_base);
@@ -7717,6 +7719,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
                 gen_exception(s, EXCP0D_GPF, pc_start - s->cs_base);
                 break;
             }
+            s->saved_pc = 0;
             gen_update_cc_op(s);
             gen_jmp_im(pc_start - s->cs_base);
             gen_lea_modrm(env, s, modrm);
@@ -8741,6 +8744,7 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb)
            change to be happen */
         if (dc->tf || dc->singlestep_enabled ||
             (flags & HF_INHIBIT_IRQ_MASK)) {
+            dc->saved_pc = 0;
             gen_jmp_im(pc_ptr - dc->cs_base);
             gen_eob(dc);
             break;
@@ -8764,6 +8768,7 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb)
             (pc_ptr - pc_start) >= (TARGET_PAGE_SIZE - 32) ||
             num_insns >= max_insns) {
             gen_jmp_im(pc_ptr - dc->cs_base);
+            dc->saved_pc = 0;
             gen_eob(dc);
             break;
         }