tools/perf/jvmti/libjvmti.c

   1 #include <linux/compiler.h>
   2 #include <sys/types.h>
   3 #include <stdio.h>
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include <err.h>
   7 #include <jvmti.h>
   8 #include <jvmticmlr.h>
   9 #include <limits.h>
  10
  11 #include "jvmti_agent.h"
  12
  13 static int has_line_numbers;
  14 void *jvmti_agent;
  15
  16 static void print_error(jvmtiEnv *jvmti, const char *msg, jvmtiError ret)
  17 {
  18         char *err_msg = NULL;
  19         jvmtiError err;
  20         err = (*jvmti)->GetErrorName(jvmti, ret, &err_msg);
  21         if (err == JVMTI_ERROR_NONE) {
  22                 warnx("%s failed with %s", msg, err_msg);
  23                 (*jvmti)->Deallocate(jvmti, (unsigned char *)err_msg);
  24         } else {
  25                 warnx("%s failed with an unknown error %d", msg, ret);
  26         }
  27 }
  28
  29 static jvmtiError
  30 do_get_line_numbers(jvmtiEnv *jvmti, void *pc, jmethodID m, jint bci,
  31                     jvmti_line_info_t *tab, jint *nr)
  32 {
  33         jint i, lines = 0;
  34         jint nr_lines = 0;
  35         jvmtiLineNumberEntry *loc_tab = NULL;
  36         jvmtiError ret;
  37
  38         ret = (*jvmti)->GetLineNumberTable(jvmti, m, &nr_lines, &loc_tab);
  39         if (ret != JVMTI_ERROR_NONE) {
  40                 print_error(jvmti, "GetLineNumberTable", ret);
  41                 return ret;
  42         }
  43
  44         for (i = 0; i < nr_lines; i++) {
  45                 if (loc_tab[i].start_location < bci) {
  46                         tab[lines].pc = (unsigned long)pc;
  47                         tab[lines].line_number = loc_tab[i].line_number;
  48                         tab[lines].discrim = 0; /* not yet used */
  49                         lines++;
  50                 } else {
  51                         break;
  52                 }
  53         }
  54         (*jvmti)->Deallocate(jvmti, (unsigned char *)loc_tab);
  55         *nr = lines;
  56         return JVMTI_ERROR_NONE;
  57 }
  58
  59 static jvmtiError
  60 get_line_numbers(jvmtiEnv *jvmti, const void *compile_info, jvmti_line_info_t **tab, int *nr_lines)
  61 {
  62         const jvmtiCompiledMethodLoadRecordHeader *hdr;
  63         jvmtiCompiledMethodLoadInlineRecord *rec;
  64         jvmtiLineNumberEntry *lne = NULL;
  65         PCStackInfo *c;
  66         jint nr, ret;
  67         int nr_total = 0;
  68         int i, lines_total = 0;
  69
  70         if (!(tab && nr_lines))
  71                 return JVMTI_ERROR_NULL_POINTER;
  72
  73         /*
  74          * Phase 1 -- get the number of lines necessary
  75          */
  76         for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {
  77                 if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {
  78                         rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;
  79                         for (i = 0; i < rec->numpcs; i++) {
  80                                 c = rec->pcinfo + i;
  81                                 nr = 0;
  82                                 /*
  83                                  * unfortunately, need a tab to get the number of lines!
  84                                  */
  85                                 ret = (*jvmti)->GetLineNumberTable(jvmti, c->methods[0], &nr, &lne);
  86                                 if (ret == JVMTI_ERROR_NONE) {
  87                                         /* free what was allocated for nothing */
  88                                         (*jvmti)->Deallocate(jvmti, (unsigned char *)lne);
  89                                         nr_total += (int)nr;
  90                                 } else {
  91                                         print_error(jvmti, "GetLineNumberTable", ret);
  92                                 }
  93                         }
  94                 }
  95         }
  96
  97         if (nr_total == 0)
  98                 return JVMTI_ERROR_NOT_FOUND;
  99
 100         /*
 101          * Phase 2 -- allocate big enough line table
 102          */
 103         *tab = malloc(nr_total * sizeof(**tab));
 104         if (!*tab)
 105                 return JVMTI_ERROR_OUT_OF_MEMORY;
 106
 107         for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {
 108                 if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {
 109                         rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;
 110                         for (i = 0; i < rec->numpcs; i++) {
 111                                 c = rec->pcinfo + i;
 112                                 nr = 0;
 113                                 ret = do_get_line_numbers(jvmti, c->pc,
 114                                                           c->methods[0],
 115                                                           c->bcis[0],
 116                                                           *tab + lines_total,
 117                                                           &nr);
 118                                 if (ret == JVMTI_ERROR_NONE)
 119                                         lines_total += nr;
 120                         }
 121                 }
 122         }
 123         *nr_lines = lines_total;
 124         return JVMTI_ERROR_NONE;
 125 }
 126
 127 static void JNICALL
 128 compiled_method_load_cb(jvmtiEnv *jvmti,
 129                         jmethodID method,
 130                         jint code_size,
 131                         void const *code_addr,
 132                         jint map_length,
 133                         jvmtiAddrLocationMap const *map,
 134                         const void *compile_info)
 135 {
 136         jvmti_line_info_t *line_tab = NULL;
 137         jclass decl_class;
 138         char *class_sign = NULL;
 139         char *func_name = NULL;
 140         char *func_sign = NULL;
 141         char *file_name= NULL;
 142         char fn[PATH_MAX];
 143         uint64_t addr = (uint64_t)(uintptr_t)code_addr;
 144         jvmtiError ret;
 145         int nr_lines = 0; /* in line_tab[] */
 146         size_t len;
 147
 148         ret = (*jvmti)->GetMethodDeclaringClass(jvmti, method,
 149                                                 &decl_class);
 150         if (ret != JVMTI_ERROR_NONE) {
 151                 print_error(jvmti, "GetMethodDeclaringClass", ret);
 152                 return;
 153         }
 154
 155         if (has_line_numbers && map && map_length) {
 156                 ret = get_line_numbers(jvmti, compile_info, &line_tab, &nr_lines);
 157                 if (ret != JVMTI_ERROR_NONE) {
 158                         warnx("jvmti: cannot get line table for method");
 159                         nr_lines = 0;
 160                 }
 161         }
 162
 163         ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name);
 164         if (ret != JVMTI_ERROR_NONE) {
 165                 print_error(jvmti, "GetSourceFileName", ret);
 166                 goto error;
 167         }
 168
 169         ret = (*jvmti)->GetClassSignature(jvmti, decl_class,
 170                                           &class_sign, NULL);
 171         if (ret != JVMTI_ERROR_NONE) {
 172                 print_error(jvmti, "GetClassSignature", ret);
 173                 goto error;
 174         }
 175
 176         ret = (*jvmti)->GetMethodName(jvmti, method, &func_name,
 177                                       &func_sign, NULL);
 178         if (ret != JVMTI_ERROR_NONE) {
 179                 print_error(jvmti, "GetMethodName", ret);
 180                 goto error;
 181         }
 182
 183         /*
 184          * Assume path name is class hierarchy, this is a common practice with Java programs
 185          */
 186         if (*class_sign == 'L') {
 187                 int j, i = 0;
 188                 char *p = strrchr(class_sign, '/');
 189                 if (p) {
 190                         /* drop the 'L' prefix and copy up to the final '/' */
 191                         for (i = 0; i < (p - class_sign); i++)
 192                                 fn[i] = class_sign[i+1];
 193                 }
 194                 /*
 195                  * append file name, we use loops and not string ops to avoid modifying
 196                  * class_sign which is used later for the symbol name
 197                  */
 198                 for (j = 0; i < (PATH_MAX - 1) && file_name && j < strlen(file_name); j++, i++)
 199                         fn[i] = file_name[j];
 200                 fn[i] = '\0';
 201         } else {
 202                 /* fallback case */
 203                 strcpy(fn, file_name);
 204         }
 205         /*
 206          * write source line info record if we have it
 207          */
 208         if (jvmti_write_debug_info(jvmti_agent, addr, fn, line_tab, nr_lines))
 209                 warnx("jvmti: write_debug_info() failed");
 210
 211         len = strlen(func_name) + strlen(class_sign) + strlen(func_sign) + 2;
 212         {
 213                 char str[len];
 214                 snprintf(str, len, "%s%s%s", class_sign, func_name, func_sign);
 215
 216                 if (jvmti_write_code(jvmti_agent, str, addr, code_addr, code_size))
 217                         warnx("jvmti: write_code() failed");
 218         }
 219 error:
 220         (*jvmti)->Deallocate(jvmti, (unsigned char *)func_name);
 221         (*jvmti)->Deallocate(jvmti, (unsigned char *)func_sign);
 222         (*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);
 223         (*jvmti)->Deallocate(jvmti, (unsigned char *)file_name);
 224         free(line_tab);
 225 }
 226
 227 static void JNICALL
 228 code_generated_cb(jvmtiEnv *jvmti,
 229                   char const *name,
 230                   void const *code_addr,
 231                   jint code_size)
 232 {
 233         uint64_t addr = (uint64_t)(unsigned long)code_addr;
 234         int ret;
 235
 236         ret = jvmti_write_code(jvmti_agent, name, addr, code_addr, code_size);
 237         if (ret)
 238                 warnx("jvmti: write_code() failed for code_generated");
 239 }
 240
 241 JNIEXPORT jint JNICALL
 242 Agent_OnLoad(JavaVM *jvm, char *options, void *reserved __maybe_unused)
 243 {
 244         jvmtiEventCallbacks cb;
 245         jvmtiCapabilities caps1;
 246         jvmtiJlocationFormat format;
 247         jvmtiEnv *jvmti = NULL;
 248         jint ret;
 249
 250         jvmti_agent = jvmti_open();
 251         if (!jvmti_agent) {
 252                 warnx("jvmti: open_agent failed");
 253                 return -1;
 254         }
 255
 256         /*
 257          * Request a JVMTI interface version 1 environment
 258          */
 259         ret = (*jvm)->GetEnv(jvm, (void *)&jvmti, JVMTI_VERSION_1);
 260         if (ret != JNI_OK) {
 261                 warnx("jvmti: jvmti version 1 not supported");
 262                 return -1;
 263         }
 264
 265         /*
 266          * acquire method_load capability, we require it
 267          * request line numbers (optional)
 268          */
 269         memset(&caps1, 0, sizeof(caps1));
 270         caps1.can_generate_compiled_method_load_events = 1;
 271
 272         ret = (*jvmti)->AddCapabilities(jvmti, &caps1);
 273         if (ret != JVMTI_ERROR_NONE) {
 274                 print_error(jvmti, "AddCapabilities", ret);
 275                 return -1;
 276         }
 277         ret = (*jvmti)->GetJLocationFormat(jvmti, &format);
 278         if (ret == JVMTI_ERROR_NONE && format == JVMTI_JLOCATION_JVMBCI) {
 279                 memset(&caps1, 0, sizeof(caps1));
 280                 caps1.can_get_line_numbers = 1;
 281                 caps1.can_get_source_file_name = 1;
 282                 ret = (*jvmti)->AddCapabilities(jvmti, &caps1);
 283                 if (ret == JVMTI_ERROR_NONE)
 284                         has_line_numbers = 1;
 285         } else if (ret != JVMTI_ERROR_NONE)
 286                 print_error(jvmti, "GetJLocationFormat", ret);
 287
 288
 289         memset(&cb, 0, sizeof(cb));
 290
 291         cb.CompiledMethodLoad   = compiled_method_load_cb;
 292         cb.DynamicCodeGenerated = code_generated_cb;
 293
 294         ret = (*jvmti)->SetEventCallbacks(jvmti, &cb, sizeof(cb));
 295         if (ret != JVMTI_ERROR_NONE) {
 296                 print_error(jvmti, "SetEventCallbacks", ret);
 297                 return -1;
 298         }
 299
 300         ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
 301                         JVMTI_EVENT_COMPILED_METHOD_LOAD, NULL);
 302         if (ret != JVMTI_ERROR_NONE) {
 303                 print_error(jvmti, "SetEventNotificationMode(METHOD_LOAD)", ret);
 304                 return -1;
 305         }
 306
 307         ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
 308                         JVMTI_EVENT_DYNAMIC_CODE_GENERATED, NULL);
 309         if (ret != JVMTI_ERROR_NONE) {
 310                 print_error(jvmti, "SetEventNotificationMode(CODE_GENERATED)", ret);
 311                 return -1;
 312         }
 313         return 0;
 314 }
 315
 316 JNIEXPORT void JNICALL
 317 Agent_OnUnload(JavaVM *jvm __maybe_unused)
 318 {
 319         int ret;
 320
 321         ret = jvmti_close(jvmti_agent);
 322         if (ret)
 323                 errx(1, "Error: op_close_agent()");
 324 }