import Unicorn2

qemu/accel/tcg/translator.c

@@ -0,0 +1,168 @@
+/*
+ * Generic intermediate code generation.
+ *
+ * Copyright (C) 2016-2017 Lluís Vilanova <vilanova@ac.upc.edu>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "tcg/tcg.h"
+#include "tcg/tcg-op.h"
+#include "exec/exec-all.h"
+#include "exec/gen-icount.h"
+#include "exec/translator.h"
+
+#include <uc_priv.h>
+
+/* Pairs with tcg_clear_temp_count.
+   To be called by #TranslatorOps.{translate_insn,tb_stop} if
+   (1) the target is sufficiently clean to support reporting,
+   (2) as and when all temporaries are known to be consumed.
+   For most targets, (2) is at the end of translate_insn.  */
+void translator_loop_temp_check(DisasContextBase *db)
+{
+#if 0
+    if (tcg_check_temp_count()) {
+        qemu_log("warning: TCG temporary leaks before "
+                 TARGET_FMT_lx "\n", db->pc_next);
+    }
+#endif
+}
+
+void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
+                     CPUState *cpu, TranslationBlock *tb, int max_insns)
+{
+    int bp_insn = 0;
+    struct uc_struct *uc = (struct uc_struct *)cpu->uc;
+    TCGContext *tcg_ctx = uc->tcg_ctx;
+    TCGOp *prev_op = NULL;
+    bool block_hook = false;
+
+    /* Initialize DisasContext */
+    db->tb = tb;
+    db->pc_first = tb->pc;
+    db->pc_next = db->pc_first;
+    db->is_jmp = DISAS_NEXT;
+    db->num_insns = 0;
+    db->max_insns = max_insns;
+    db->singlestep_enabled = cpu->singlestep_enabled;
+
+    ops->init_disas_context(db, cpu);
+    tcg_debug_assert(db->is_jmp == DISAS_NEXT);  /* no early exit */
+
+    /* Reset the temp count so that we can identify leaks */
+    tcg_clear_temp_count();
+
+    /* Unicorn: early check to see if the address of this block is
+     * the "run until" address. */
+    if (tb->pc == cpu->uc->addr_end) {
+        // This should catch that instruction is at the end
+        // and generate appropriate halting code.
+        gen_tb_start(tcg_ctx, db->tb);
+        ops->tb_start(db, cpu);
+        db->num_insns++;
+        ops->insn_start(db, cpu);
+        ops->translate_insn(db, cpu);
+        goto _end_loop;
+    }
+
+    /* Unicorn: trace this block on request
+     * Only hook this block if it is not broken from previous translation due to
+     * full translation cache
+     */
+    if (HOOK_EXISTS_BOUNDED(uc, UC_HOOK_BLOCK, tb->pc)) {
+        prev_op = tcg_last_op(tcg_ctx);
+        block_hook = true;
+        gen_uc_tracecode(tcg_ctx, 0xf8f8f8f8, UC_HOOK_BLOCK_IDX, uc, db->pc_first);
+    }
+
+    // tcg_dump_ops(tcg_ctx, false, "translator loop");
+
+    /* Start translating.  */
+    gen_tb_start(tcg_ctx, db->tb);
+    // tcg_dump_ops(tcg_ctx, false, "tb start");
+
+    ops->tb_start(db, cpu);
+    // tcg_dump_ops(tcg_ctx, false, "tb start 2");
+
+    tcg_debug_assert(db->is_jmp == DISAS_NEXT);  /* no early exit */
+
+    while (true) {
+        db->num_insns++;
+
+        ops->insn_start(db, cpu);
+        tcg_debug_assert(db->is_jmp == DISAS_NEXT);  /* no early exit */
+
+        /* Pass breakpoint hits to target for further processing */
+        if (!db->singlestep_enabled
+            && unlikely(!QTAILQ_EMPTY(&cpu->breakpoints))) {
+            CPUBreakpoint *bp;
+            QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
+                if (bp->pc == db->pc_next) {
+                    if (ops->breakpoint_check(db, cpu, bp)) {
+                        bp_insn = 1;
+                        break;
+                    }
+                }
+            }
+            /* The breakpoint_check hook may use DISAS_TOO_MANY to indicate
+               that only one more instruction is to be executed.  Otherwise
+               it should use DISAS_NORETURN when generating an exception,
+               but may use a DISAS_TARGET_* value for Something Else.  */
+            if (db->is_jmp > DISAS_TOO_MANY) {
+                break;
+            }
+        }
+
+        /* Disassemble one instruction.  The translate_insn hook should
+           update db->pc_next and db->is_jmp to indicate what should be
+           done next -- either exiting this loop or locate the start of
+           the next instruction.  */
+        ops->translate_insn(db, cpu);
+        // tcg_dump_ops(tcg_ctx, false, "insn translate");
+
+        /* Stop translation if translate_insn so indicated.  */
+        if (db->is_jmp != DISAS_NEXT) {
+            break;
+        }
+
+        /* Stop translation if the output buffer is full,
+           or we have executed all of the allowed instructions.  */
+        if (tcg_op_buf_full(tcg_ctx) || db->num_insns >= db->max_insns) {
+            db->is_jmp = DISAS_TOO_MANY;
+            break;
+        }
+    }
+
+_end_loop:
+    /* Emit code to exit the TB, as indicated by db->is_jmp.  */
+    ops->tb_stop(db, cpu);
+    gen_tb_end(tcg_ctx, db->tb, db->num_insns - bp_insn);
+    // tcg_dump_ops(tcg_ctx, false, "tb end");
+
+    /* The disas_log hook may use these values rather than recompute.  */
+    db->tb->size = db->pc_next - db->pc_first;
+    db->tb->icount = db->num_insns;
+
+    if (block_hook) {
+        TCGOp *tcg_op;
+
+        // Unicorn: patch the callback to have the proper block size.
+        if (prev_op) {
+            // As explained further up in the function where prev_op is
+            // assigned, we move forward in the tail queue, so we're modifying the
+            // move instruction generated by gen_uc_tracecode() that contains
+            // the instruction size to assign the proper size (replacing 0xF1F1F1F1).
+            tcg_op = QTAILQ_NEXT(prev_op, link);
+        } else {
+            // this basic block is the first emulated code ever,
+            // so the basic block operand is the first operand
+            tcg_op = QTAILQ_FIRST(&tcg_ctx->ops);
+        }
+
+        tcg_op->args[1] = db->tb->size;
+    }
+}