add new API uc_query() to query internal status of emulator at runtime

include/uc_priv.h

@@ -32,6 +32,8 @@ typedef struct ModuleEntry {
 
 typedef QTAILQ_HEAD(, ModuleEntry) ModuleTypeList;
 
+typedef uc_err (*query_t)(struct uc_struct *uc, uc_query_type type, size_t *result);
+
 // return 0 on success, -1 on failure
 typedef int (*reg_read_t)(struct uc_struct *uc, unsigned int regid, void *value);
 typedef int (*reg_write_t)(struct uc_struct *uc, unsigned int regid, const void *value);
@@ -93,6 +95,7 @@ struct uc_struct {
     struct CPUTailQ cpus;   // qemu/cpu-exec.c
     uc_err errnum;  // qemu/cpu-exec.c
     AddressSpace as;
+    query_t query;
     reg_read_t reg_read;
     reg_write_t reg_write;
     reg_reset_t reg_reset;

include/unicorn/unicorn.h

@@ -255,6 +255,12 @@ typedef struct uc_mem_region {
     uint32_t perms; // memory permissions of the region
 } uc_mem_region;
 
+// All type of queries for uc_query() API.
+typedef enum uc_query_type {
+    // Query current hardware mode for ARM. Return 1 for Thumb, 0 for ARM
+    UC_QUERY_ARM_MODE = 1,
+} uc_query_type;
+
 /*
  Return combined API version & major and minor version numbers.
 
@@ -315,6 +321,18 @@ uc_err uc_open(uc_arch arch, uc_mode mode, uc_engine **uc);
 UNICORN_EXPORT
 uc_err uc_close(uc_engine *uc);
 
+/*
+ Query internal status of engine.
+
+ @uc: handle returned by uc_open()
+ @type: query type
+ @result: status retrieved
+
+ @return: error code of uc_err enum type (UC_ERR_*, see above)
+*/
+UNICORN_EXPORT
+uc_err uc_query(uc_engine *uc, uc_query_type type, size_t *result);
+
 /*
  Report the last error number when some API function fail.
  Like glibc's errno, uc_errno might not retain its old value once accessed.

qemu/target-arm/unicorn_arm.c

@@ -108,6 +108,19 @@ static bool arm_stop_interrupt(int intno)
     }
 }
 
+static uc_err arm_query(struct uc_struct *uc, uc_query_type type, size_t *result)
+{
+    CPUState *mycpu = first_cpu;
+
+    switch(type) {
+        case UC_QUERY_ARM_MODE:
+            *result = (ARM_CPU(uc, mycpu)->env.thumb != 0);
+            return UC_ERR_OK;
+        default:
+            return UC_ERR_ARG;
+    }
+}
+
 void arm_uc_init(struct uc_struct* uc)
 {
     register_accel_types(uc);
@@ -118,5 +131,6 @@ void arm_uc_init(struct uc_struct* uc)
     uc->reg_reset = arm_reg_reset;
     uc->set_pc = arm_set_pc;
     uc->stop_interrupt = arm_stop_interrupt;
+    uc->query = arm_query;
     uc_common_init(uc);
 }

uc.c

@@ -1190,3 +1190,15 @@ uint32_t uc_mem_regions(uc_engine *uc, uc_mem_region **regions, uint32_t *count)
     return UC_ERR_OK;
 }
 
+UNICORN_EXPORT
+uc_err uc_query(uc_engine *uc, uc_query_type type, size_t *result)
+{
+    switch(uc->arch) {
+        case UC_ARCH_ARM:
+            return uc->query(uc, type, result);
+        default:
+            return UC_ERR_ARG;
+    }
+
+    return UC_ERR_OK;
+}