From dfb69f8e28ed3795eec20db127d6bfc0ef26e42f Mon Sep 17 00:00:00 2001
From: Gabriel Ionita <d9rect@pm.me>
Date: Sun, 26 Oct 2025 18:40:00 +0100
Subject: [PATCH] add support for passing arguments to target program

---
 src/tracer.cpp   | 14 ++++++++++++--
 src/tracer.hpp   |  4 +++-
 test_with_args.c | 23 +++++++++++++++++++++++
 3 files changed, 38 insertions(+), 3 deletions(-)
 create mode 100644 test_with_args.c

diff --git a/src/tracer.cpp b/src/tracer.cpp
index 5bec9ba..7a8938f 100644
--- a/src/tracer.cpp
+++ b/src/tracer.cpp
@@ -91,13 +91,23 @@ uint64_t Tracer::get_load_address(pid_t pid, const std::string &exec_path) {
   return 0;
 }
 
-void Tracer::watch_variable(const std::string &exec_path, uint64_t address, size_t size) {
+void Tracer::watch_variable(const std::string &exec_path, uint64_t address, size_t size,
+                            const std::vector<std::string> &args) {
   pid_t pid = fork();
 
   if (pid == 0) {
     // Child process: execute the target binary
     ptrace(PTRACE_TRACEME, 0, 0, 0);
-    execl(exec_path.c_str(), exec_path.c_str(), nullptr);
+
+    // Build argv array for execv
+    std::vector<char*> argv_vec;
+    argv_vec.push_back(const_cast<char*>(exec_path.c_str()));
+    for (const auto& arg : args) {
+      argv_vec.push_back(const_cast<char*>(arg.c_str()));
+    }
+    argv_vec.push_back(nullptr);
+
+    execv(exec_path.c_str(), argv_vec.data());
     std::cerr << "Error: Failed to execute " << exec_path << std::endl;
     exit(1);
   } else if (pid > 0) {
diff --git a/src/tracer.hpp b/src/tracer.hpp
index c38e8c9..25313e2 100644
--- a/src/tracer.hpp
+++ b/src/tracer.hpp
@@ -3,10 +3,12 @@
 
 #include <cstdint>
 #include <string>
+#include <vector>
 
 class Tracer {
 public:
-  void watch_variable(const std::string &exec_path, uint64_t address, size_t size);
+  void watch_variable(const std::string &exec_path, uint64_t address, size_t size,
+                      const std::vector<std::string> &args = {});
 
 private:
   void setup_hardware_watchpoint(pid_t pid, uint64_t address, size_t size);
diff --git a/test_with_args.c b/test_with_args.c
new file mode 100644
index 0000000..7fa960d
--- /dev/null
+++ b/test_with_args.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+volatile int global_counter = 0;
+
+int main(int argc, char **argv) {
+    printf("Program started with %d arguments\n", argc - 1);
+
+    for (int i = 1; i < argc; i++) {
+        printf("  arg[%d]: %s\n", i, argv[i]);
+    }
+
+    global_counter = argc;
+    printf("Set global_counter to %d\n", global_counter);
+
+    if (argc > 1) {
+        int val = atoi(argv[1]);
+        global_counter += val;
+        printf("Added %d, global_counter now = %d\n", val, global_counter);
+    }
+
+    return 0;
+}