1 /*
   2  * Copyright (c) 2010, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  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
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  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
  21  * questions.
  22  */
  23 
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <stdlib.h>
  27 #include "jvmti.h"
  28 #include "agent_common.h"
  29 #include "JVMTITools.h"
  30 #include "jvmti_tools.h"
  31 #include "mlvmJvmtiUtils.h"
  32 
  33 void copyFromJString(JNIEnv * pEnv, jstring src, char ** dst) {
  34     const char * pStr;
  35         jsize len;
  36 
  37     if ( ! NSK_VERIFY((pStr = NSK_CPP_STUB3(GetStringUTFChars, pEnv, src, NULL)) != NULL) ) {
  38         return;
  39     }
  40 
  41     len = NSK_CPP_STUB2(GetStringUTFLength, pEnv, src) + 1;
  42     *dst = malloc(len);
  43     strncpy(*dst, pStr, len);
  44 
  45     NSK_CPP_STUB3(ReleaseStringUTFChars, pEnv, src, pStr);
  46 }
  47 
  48 struct MethodName * getMethodName(jvmtiEnv * pJvmtiEnv, jmethodID method) {
  49     char * szName;
  50     char * szSignature;
  51     jclass clazz;
  52     struct MethodName * mn;
  53 
  54     if ( ! NSK_JVMTI_VERIFY(NSK_CPP_STUB5(GetMethodName, pJvmtiEnv, method, &szName, NULL, NULL)) ) {
  55         return NULL;
  56     }
  57 
  58     if ( ! NSK_JVMTI_VERIFY(NSK_CPP_STUB3(GetMethodDeclaringClass, pJvmtiEnv, method, &clazz)) ) {
  59         NSK_JVMTI_VERIFY(NSK_CPP_STUB2(Deallocate, pJvmtiEnv, (void *) szName));
  60         return NULL;
  61     }
  62 
  63     if ( ! NSK_JVMTI_VERIFY(NSK_CPP_STUB4(GetClassSignature, pJvmtiEnv, clazz, &szSignature, NULL)) ) {
  64         NSK_JVMTI_VERIFY(NSK_CPP_STUB2(Deallocate, pJvmtiEnv, (void *) szName));
  65         return NULL;
  66     }
  67 
  68     mn = malloc(sizeof(MethodNameStruct));
  69     strncpy(mn->methodName, szName, sizeof(mn->methodName));
  70     strncpy(mn->classSig, szSignature, sizeof(mn->classSig));
  71 
  72     NSK_JVMTI_VERIFY(NSK_CPP_STUB2(Deallocate, pJvmtiEnv, (void *) szName));
  73     NSK_JVMTI_VERIFY(NSK_CPP_STUB2(Deallocate, pJvmtiEnv, (void *) szSignature));
  74     return mn;
  75 }
  76 
  77 char * locationToString(jvmtiEnv * pJvmtiEnv, jmethodID method, jlocation location) {
  78     struct MethodName * pMN;
  79     // gcc 7.3 claims that snprintf below can output between 6 and 531 bytes. Setting buffer size to 600.
  80     char r[600];
  81 
  82     pMN = getMethodName(pJvmtiEnv, method);
  83     if ( ! pMN )
  84         return strdup("NONE");
  85 
  86     snprintf(r, sizeof(r), "%s .%s :%lx", pMN->classSig, pMN->methodName, (long) location);
  87 
  88     free(pMN);
  89 
  90     return strdup(r);
  91 }
  92 
  93 void * getTLS(jvmtiEnv * pJvmtiEnv, jthread thread, jsize sizeToAllocate) {
  94     void * tls;
  95     if ( ! NSK_JVMTI_VERIFY(NSK_CPP_STUB3(GetThreadLocalStorage, pJvmtiEnv, thread, &tls)) )
  96         return NULL;
  97 
  98     if ( ! tls) {
  99         if ( ! NSK_VERIFY((tls = malloc(sizeToAllocate)) != NULL) )
 100             return NULL;
 101 
 102         memset(tls, 0, sizeToAllocate);
 103 
 104         if ( ! NSK_JVMTI_VERIFY(NSK_CPP_STUB3(SetThreadLocalStorage, pJvmtiEnv, thread, tls)) )
 105             return NULL;
 106     }
 107 
 108     return tls;
 109 }