rev 49200 : 8199010: attachListener.hpp: Fix potential null termination issue found by coverity scans

   1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
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  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
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  24 
  25 #ifndef SHARE_VM_SERVICES_ATTACHLISTENER_HPP
  26 #define SHARE_VM_SERVICES_ATTACHLISTENER_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "utilities/debug.hpp"
  30 #include "utilities/ostream.hpp"
  31 #include "utilities/macros.hpp"
  32 #include "utilities/globalDefinitions.hpp"
  33 
  34 // The AttachListener thread services a queue of operations that are enqueued
  35 // by client tools. Each operation is identified by a name and has up to 3
  36 // arguments. The operation name is mapped to a function which performs the
  37 // operation. The function is called with an outputStream which is can use to
  38 // write any result data (for examples the properties command serializes
  39 // properties names and values to the output stream). When the function
  40 // complets the result value and any result data is returned to the client
  41 // tool.
  42 
  43 class AttachOperation;
  44 
  45 typedef jint (*AttachOperationFunction)(AttachOperation* op, outputStream* out);
  46 
  47 struct AttachOperationFunctionInfo {
  48   const char* name;
  49   AttachOperationFunction func;
  50 };
  51 
  52 class AttachListener: AllStatic {
  53  public:
  54   static void vm_start() NOT_SERVICES_RETURN;
  55   static void init()  NOT_SERVICES_RETURN;
  56   static void abort() NOT_SERVICES_RETURN;
  57 
  58   // invoke to perform clean-up tasks when all clients detach
  59   static void detachall() NOT_SERVICES_RETURN;
  60 
  61   // indicates if the Attach Listener needs to be created at startup
  62   static bool init_at_startup() NOT_SERVICES_RETURN_(false);
  63 
  64   // indicates if we have a trigger to start the Attach Listener
  65   static bool is_init_trigger() NOT_SERVICES_RETURN_(false);
  66 
  67 #if !INCLUDE_SERVICES
  68   static bool is_attach_supported()             { return false; }
  69 #else
  70  private:
  71   static volatile bool _initialized;
  72 
  73  public:
  74   static bool is_initialized()                  { return _initialized; }
  75   static void set_initialized()                 { _initialized = true; }
  76 
  77   // indicates if this VM supports attach-on-demand
  78   static bool is_attach_supported()             { return !DisableAttachMechanism; }
  79 
  80   // platform specific initialization
  81   static int pd_init();
  82 
  83   // platform specific operation
  84   static AttachOperationFunctionInfo* pd_find_operation(const char* name);
  85 
  86   // platform specific flag change
  87   static jint pd_set_flag(AttachOperation* op, outputStream* out);
  88 
  89   // platform specific detachall
  90   static void pd_detachall();
  91 
  92   // platform specific data dump
  93   static void pd_data_dump();
  94 
  95   // dequeue the next operation
  96   static AttachOperation* dequeue();
  97 #endif // !INCLUDE_SERVICES
  98 
  99  private:
 100   static bool has_init_error(TRAPS);
 101 };
 102 
 103 #if INCLUDE_SERVICES
 104 class AttachOperation: public CHeapObj<mtInternal> {
 105  public:
 106   enum {
 107     name_length_max = 16,       // maximum length of  name
 108     arg_length_max = 1024,      // maximum length of argument
 109     arg_count_max = 3           // maximum number of arguments
 110   };
 111 
 112   // name of special operation that can be enqueued when all
 113   // clients detach
 114   static char* detachall_operation_name() { return (char*)"detachall"; }
 115 
 116  private:
 117   char _name[name_length_max+1];
 118   char _arg[arg_count_max][arg_length_max+1];
 119 
 120  public:
 121   const char* name() const                      { return _name; }
 122 
 123   // set the operation name
 124   void set_name(char* name) {
 125     size_t len = strlen(name);
 126     assert(len <= name_length_max, "exceeds maximum name length");
 127     memcpy(_name, name, MIN2(len + 1, (size_t)name_length_max));

 128   }
 129 
 130   // get an argument value
 131   const char* arg(int i) const {
 132     assert(i>=0 && i<arg_count_max, "invalid argument index");
 133     return _arg[i];
 134   }
 135 
 136   // set an argument value
 137   void set_arg(int i, char* arg) {
 138     assert(i>=0 && i<arg_count_max, "invalid argument index");
 139     if (arg == NULL) {
 140       _arg[i][0] = '\0';
 141     } else {
 142       size_t len = strlen(arg);
 143       assert(len <= arg_length_max, "exceeds maximum argument length");
 144       memcpy(_arg[i], arg, MIN2(len + 1, (size_t)arg_length_max));

 145     }
 146   }
 147 
 148   // create an operation of a given name
 149   AttachOperation(char* name) {
 150     set_name(name);
 151     for (int i=0; i<arg_count_max; i++) {
 152       set_arg(i, NULL);
 153     }
 154   }
 155 
 156   // complete operation by sending result code and any result data to the client
 157   virtual void complete(jint result, bufferedStream* result_stream) = 0;
 158 };
 159 #endif // INCLUDE_SERVICES
 160 
 161 #endif // SHARE_VM_SERVICES_ATTACHLISTENER_HPP
--- EOF ---