plugins: add helper functions for coverage plugins

Which provide information about:
- start_code.
- end_code.
- entry.
- path to the executable binary.

Signed-off-by: Ivanov Arkady <arkadiy.ivanov@ispras.ru>
Message-Id: <163491883461.304355.8210754161847179432.stgit@pc-System-Product-Name>
[AJB: reword title, better descriptions, defaults, rm export, fix include]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220204204335.1689602-22-alex.bennee@linaro.org>

include/qemu/qemu-plugin.h

@@ -590,4 +590,38 @@ void qemu_plugin_outs(const char *string);
  */
 bool qemu_plugin_bool_parse(const char *name, const char *val, bool *ret);
 
+/**
+ * qemu_plugin_path_to_binary() - path to binary file being executed
+ *
+ * Return a string representing the path to the binary. For user-mode
+ * this is the main executable. For system emulation we currently
+ * return NULL. The user should g_free() the string once no longer
+ * needed.
+ */
+const char *qemu_plugin_path_to_binary(void);
+
+/**
+ * qemu_plugin_start_code() - returns start of text segment
+ *
+ * Returns the nominal start address of the main text segment in
+ * user-mode. Currently returns 0 for system emulation.
+ */
+uint64_t qemu_plugin_start_code(void);
+
+/**
+ * qemu_plugin_end_code() - returns end of text segment
+ *
+ * Returns the nominal end address of the main text segment in
+ * user-mode. Currently returns 0 for system emulation.
+ */
+uint64_t qemu_plugin_end_code(void);
+
+/**
+ * qemu_plugin_entry_code() - returns start address for module
+ *
+ * Returns the nominal entry address of the main text segment in
+ * user-mode. Currently returns 0 for system emulation.
+ */
+uint64_t qemu_plugin_entry_code(void);
+
 #endif /* QEMU_PLUGIN_API_H */

plugins/api.c

@@ -44,6 +44,11 @@
 #ifndef CONFIG_USER_ONLY
 #include "qemu/plugin-memory.h"
 #include "hw/boards.h"
+#else
+#include "qemu.h"
+#ifdef CONFIG_LINUX
+#include "loader.h"
+#endif
 #endif
 
 /* Uninstall and Reset handlers */
@@ -391,3 +396,46 @@ bool qemu_plugin_bool_parse(const char *name, const char *value, bool *ret)
 {
     return name && value && qapi_bool_parse(name, value, ret, NULL);
 }
+
+/*
+ * Binary path, start and end locations
+ */
+const char *qemu_plugin_path_to_binary(void)
+{
+    char *path = NULL;
+#ifdef CONFIG_USER_ONLY
+    TaskState *ts = (TaskState *) current_cpu->opaque;
+    path = g_strdup(ts->bprm->filename);
+#endif
+    return path;
+}
+
+uint64_t qemu_plugin_start_code(void)
+{
+    uint64_t start = 0;
+#ifdef CONFIG_USER_ONLY
+    TaskState *ts = (TaskState *) current_cpu->opaque;
+    start = ts->info->start_code;
+#endif
+    return start;
+}
+
+uint64_t qemu_plugin_end_code(void)
+{
+    uint64_t end = 0;
+#ifdef CONFIG_USER_ONLY
+    TaskState *ts = (TaskState *) current_cpu->opaque;
+    end = ts->info->end_code;
+#endif
+    return end;
+}
+
+uint64_t qemu_plugin_entry_code(void)
+{
+    uint64_t entry = 0;
+#ifdef CONFIG_USER_ONLY
+    TaskState *ts = (TaskState *) current_cpu->opaque;
+    entry = ts->info->entry;
+#endif
+    return entry;
+}

plugins/qemu-plugins.symbols

@@ -1,5 +1,7 @@
 {
   qemu_plugin_bool_parse;
+  qemu_plugin_end_code;
+  qemu_plugin_entry_code;
   qemu_plugin_get_hwaddr;
   qemu_plugin_hwaddr_device_name;
   qemu_plugin_hwaddr_is_io;
@@ -17,6 +19,7 @@
   qemu_plugin_n_max_vcpus;
   qemu_plugin_n_vcpus;
   qemu_plugin_outs;
+  qemu_plugin_path_to_binary;
   qemu_plugin_register_atexit_cb;
   qemu_plugin_register_flush_cb;
   qemu_plugin_register_vcpu_exit_cb;
@@ -33,6 +36,7 @@
   qemu_plugin_register_vcpu_tb_exec_inline;
   qemu_plugin_register_vcpu_tb_trans_cb;
   qemu_plugin_reset;
+  qemu_plugin_start_code;
   qemu_plugin_tb_get_insn;
   qemu_plugin_tb_n_insns;
   qemu_plugin_tb_vaddr;