8286431: Do not use resource array in posix mmap_attach_shared()

Reviewed-by: dholmes, jsjolen

Author: iklam

src/hotspot/os/posix/perfMemory_posix.cpp

@@ -1006,7 +1006,7 @@ static int open_sharedmem_file(const char* filename, int oflags, TRAPS) {
   // check to see if the file is secure
   if (!is_file_secure(fd, filename)) {
     ::close(fd);
-    return -1;
+    return OS_ERR;
   }
 
   return fd;
@@ -1173,8 +1173,6 @@ static void mmap_attach_shared(int vmid, char** addr, size_t* sizep, TRAPS) {
   int mmap_prot = PROT_READ;
   int file_flags = O_RDONLY | O_NOFOLLOW;
 
-  ResourceMark rm;
-
   // for linux, determine if vmid is for a containerized process
   int nspid = LINUX_ONLY(os::Linux::get_namespace_pid(vmid)) NOT_LINUX(-1);
   const char* luser = get_user_name(vmid, &nspid, CHECK);
@@ -1196,29 +1194,18 @@ static void mmap_attach_shared(int vmid, char** addr, size_t* sizep, TRAPS) {
               "Process not found");
   }
 
+  // open the shared memory file for the give vmid
   char* filename = get_sharedmem_filename(dirname, vmid, nspid);
 
-  // copy heap memory to resource memory. the open_sharedmem_file
-  // method below need to use the filename, but could throw an
-  // exception. using a resource array prevents the leak that
-  // would otherwise occur.
-  char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1);
-  strcpy(rfilename, filename);
+  // We don't use CHECK as we need to free the strings even if an exception occurred.
+  int fd = open_sharedmem_file(filename, file_flags, THREAD);
 
   // free the c heap resources that are no longer needed
   FREE_C_HEAP_ARRAY(char, luser);
   FREE_C_HEAP_ARRAY(char, dirname);
   FREE_C_HEAP_ARRAY(char, filename);
 
-  // open the shared memory file for the give vmid
-  int fd = open_sharedmem_file(rfilename, file_flags, THREAD);
-
-  if (fd == OS_ERR) {
-    return;
-  }
-
-  if (HAS_PENDING_EXCEPTION) {
-    ::close(fd);
+  if (fd == OS_ERR || HAS_PENDING_EXCEPTION) {
     return;
   }