8347143: [aix] Fix strdup use in os::dll_load

Reviewed-by: mdoerr, clanger, kbarrett

Author: Joachim Kern

src/hotspot/os/aix/os_aix.cpp

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012, 2024 SAP SE. All rights reserved.
+ * Copyright (c) 2012, 2025 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1068,21 +1068,24 @@ static void* dll_load_library(const char *filename, int *eno, char *ebuf, int eb
 // If filename matches <name>.so, and loading fails, repeat with <name>.a.
 void *os::dll_load(const char *filename, char *ebuf, int ebuflen) {
   void* result = nullptr;
-  char* const file_path = strdup(filename);
-  char* const pointer_to_dot = strrchr(file_path, '.');
   const char old_extension[] = ".so";
   const char new_extension[] = ".a";
-  STATIC_ASSERT(sizeof(old_extension) >= sizeof(new_extension));
   // First try to load the existing file.
-  int eno=0;
+  int eno = 0;
   result = dll_load_library(filename, &eno, ebuf, ebuflen);
-  // If the load fails,we try to reload by changing the extension to .a for .so files only.
+  // If the load fails, we try to reload by changing the extension to .a for .so files only.
   // Shared object in .so format dont have braces, hence they get removed for archives with members.
-  if (result == nullptr && eno == ENOENT && pointer_to_dot != nullptr && strcmp(pointer_to_dot, old_extension) == 0) {
-    snprintf(pointer_to_dot, sizeof(old_extension), "%s", new_extension);
-    result = dll_load_library(file_path, &eno, ebuf, ebuflen);
+  if (result == nullptr && eno == ENOENT) {
+    const char* pointer_to_dot = strrchr(filename, '.');
+    if (pointer_to_dot != nullptr && strcmp(pointer_to_dot, old_extension) == 0) {
+      STATIC_ASSERT(sizeof(old_extension) >= sizeof(new_extension));
+      char* tmp_path = os::strdup(filename);
+      size_t prefix_size = pointer_delta(pointer_to_dot, filename, 1);
+      os::snprintf(tmp_path + prefix_size, sizeof(old_extension), "%s", new_extension);
+      result = dll_load_library(tmp_path, &eno, ebuf, ebuflen);
+      os::free(tmp_path);
+    }
   }
-  FREE_C_HEAP_ARRAY(char, file_path);
   return result;
 }