Fixing issues noticed during testing. (#69)

- Added json file creation to GDB script, so user does not need to create or modify Uncore json file, just needs to enter any command settings (like sysroot or solib-search-path setting) before running 'setup_session' command.
- Added Crash server/Uncore and GDB synchronization needed when Uncore takes longer time to be executed.
+ some smaller changes

Author: ppetrovic98

llvm-15.0.3/lldb/tools/lldb-crash-server/UncoreHandler.cpp

@@ -2,6 +2,9 @@
 #include <iostream>
 #include <memory>
 #include <regex>
+#include <fstream>
+#include <unistd.h>
+#include <fcntl.h>
 
 #include "UncoreHandler.h"
 
@@ -14,14 +17,36 @@ bool lldb::UncoreHandler::RunUncore() {
 
   int status = std::system(cmd.c_str());
 
-  if (status != 0) {
+  std::string loader_file_path = m_working_dir + "/outdir/loader.bin";
+
+  if (status != 0 && !llvm::sys::fs::exists(loader_file_path)) {
     llvm::errs() << "Uncore execution failed.\n";
     return false;
   }
 
   return true;
 }
 
+bool WriteToPipe(std::string working_dir) {
+  std::string pipe_path = working_dir + "/gdb_lldb_signal_pipe";
+  int fd = open(pipe_path.c_str(), O_WRONLY);
+  if (fd == -1) {
+    llvm::errs() << "Failed to open the FIFO pipe. \n";
+    return false;
+  }
+
+  std::string message = "Crash server is ready.";
+  if (write(fd, message.c_str(), message.size()) == -1) {
+    llvm::errs() << "Failed to write into the pipe. \n";
+    close(fd);
+    return false;
+  }
+
+  close(fd);
+  return true;
+}
+
+
 ::pid_t lldb::UncoreHandler::RunLoaderProcess() {
 
   ::pid_t pid = fork();
@@ -40,7 +65,14 @@ ::pid_t lldb::UncoreHandler::RunLoaderProcess() {
 
     llvm::errs() << "Failed to execute loader.bin process. \n";
   } else {
-    sleep(2);
+    // TODO: Some kind of synchronization should be implemented with loader.bin
+    // so this can be removed
+    sleep(20);
+
+    if (!WriteToPipe(m_working_dir)) {
+      return LLDB_INVALID_PROCESS_ID;
+    }
+
     return pid;
   }
 

llvm-15.0.3/lldb/tools/lldb-crash-server/UncoreHandler.h

@@ -24,7 +24,7 @@ class UncoreHandler {
                    << "\n";
       exit(1);
     }
-    m_working_dir = cwd.str().data();
+    m_working_dir = cwd.c_str();
   }
 
   bool RunUncore();

llvm-15.0.3/lldb/tools/lldb-crash-server/gdb-interop/gdb_session_setup.py

@@ -4,6 +4,7 @@
 import subprocess
 import socket
 import os
+import json
 from contextlib import closing
 from pty import STDERR_FILENO, STDOUT_FILENO
 
@@ -19,6 +20,9 @@
 core_registers = {}
 live_registers = {}
 
+# Current working directory
+cwd = os.getcwd()
+
 # Global variable to store Crash server path
 lldb_crash_server_path = None
 
@@ -41,12 +45,14 @@ def __init__(self):
         )
 
     def invoke(self, arg, from_tty):
-        global lldb_crash_server_path
+        global lldb_crash_server_path, cwd
 
         args = arg.split()
         if len(args) != 2:
             print("Usage: setup_session <binary> <corefile>")
             return
+        
+        gdb_settings = self.get_gdb_setting()
 
         binary, corefile = args
         gdb.execute(f"file {binary}")
@@ -64,12 +70,22 @@ def invoke(self, arg, from_tty):
         if lldb_crash_server_path is None:
             print("Crash server path is not set.")
             return
+        
+        # Create uncore json file
+        self.create_json_file(corefile, binary, gdb_settings)
+
+        # Create a named pipe
+        pipe_path = os.path.join(cwd, "gdb_lldb_signal_pipe")
+        self.create_pipe(pipe_path)
 
         # Start Crash server as a subprocess
         port = self.find_free_port()
         subprocess.Popen([lldb_crash_server_path, "g", f"localhost:{port}", binary,
                          "--uncore-json", "./uncore.json"], stdout=STDOUT_FILENO, stderr=STDERR_FILENO)
 
+        # Read from a named pipe (waiting for a signal from Crash server)
+        self.read_from_pipe(pipe_path)
+
         # Connect to remote target
         gdb.execute(f"target remote localhost:{port}")
 
@@ -98,6 +114,92 @@ def find_free_port(self):
             s.bind(('localhost', 0))
             return s.getsockname()[1]
 
+    def create_json_file(self, core_path, binary_path, gdb_settings):
+        global cwd
+
+        # Set the uncore output and json file path
+        output_path = os.path.join(cwd, "outdir")
+        json_path = os.path.join(cwd, "uncore.json")
+
+        data = {
+            "core": core_path,
+            "binos_root": "",
+            "entry_point": "main",
+            "prog": binary_path,
+            "pid": "",
+            "additional_resources": "",
+            "custom_o_file": [],
+            "output_directory": output_path,
+            "hot_patch": {
+            },
+            "gdbparse": {
+                "gdb": "gdb",
+                "args": [
+                    binary_path,
+                    core_path
+                ],
+                "kwargs": {
+                }
+            }
+        }
+
+        if len(gdb_settings) > 1:
+            # Create a gdb script with all commands from gdb_settings
+            script_path = os.path.join(cwd, "gdb_uncore.script")
+            with open(script_path, "w") as script_file:
+                for cmd in gdb_settings:
+                    script_file.write(cmd + "\n")
+            data["gdbparse"]["kwargs"]["-x"] = script_path
+        elif len(gdb_settings) == 1:
+            data["gdbparse"]["kwargs"]["-ex"] = gdb_settings[0]
+
+        # Convert the JSON data to a string
+        json_str = json.dumps(data, indent=4)
+
+        # Write the JSON string to a file in the current working directory
+        try:
+            with open(json_path, "w") as json_file:
+                json_file.write(json_str)
+            print(f"JSON file successfully created at: {json_path}")
+        except Exception as e:
+            print(f"Error: {e}")
+
+    # Get gdb session settings
+    def get_gdb_setting(self):
+        gdb_settings = []
+
+        # Retrieve the process sysroot setting
+        sysroot_setting = gdb.execute("show sysroot", to_string=True)
+        if sysroot_setting.startswith("The current system root is"):
+            sysroot_path = sysroot_setting.split('"')[1].strip()
+            if sysroot_path != "target:" and sysroot_path != "":
+                gdb_settings.append(f"set sysroot {sysroot_path}")
+
+        # Retrieve and process solib-search-path setting
+        solib_search_path_setting = gdb.execute("show solib-search-path", to_string=True)
+        if solib_search_path_setting.startswith("The search path for loading non-absolute shared library symbol files is"):
+            solib_search_path = solib_search_path_setting.split(' is ')[1].strip()
+            if solib_search_path != "." and solib_search_path != "":
+                gdb_settings.append(f"set solib-search-path {solib_search_path}")
+
+        return gdb_settings
+
+    # Create a named FIFO pipe
+    def create_pipe(self, pipe_path):
+        try:
+            os.mkfifo(pipe_path)
+        except OSError as e:
+            print(f"Error creating the pipe: {e}")
+
+    # Read from the named pipe
+    def read_from_pipe(self, pipe_path):
+        try:
+            with open(pipe_path, "r") as pipe:
+                message = pipe.read()
+                print(message)
+        except Exception as e:
+            print(f"Error reading from the pipe: {e}")
+
 
 class RestoreRegisters(gdb.Command):
     """Restore registers to saved values from either corefile or live process."""