LXR linux/tools/perf/jvmti/libjvmti.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/compiler.h>
   3#include <linux/string.h>
   4#include <sys/types.h>
   5#include <stdio.h>
   6#include <string.h>
   7#include <stdlib.h>
   8#include <err.h>
   9#include <jvmti.h>
  10#ifdef HAVE_JVMTI_CMLR
  11#include <jvmticmlr.h>
  12#endif
  13#include <limits.h>
  14
  15#include "jvmti_agent.h"
  16
  17static int has_line_numbers;
  18void *jvmti_agent;
  19
  20static void print_error(jvmtiEnv *jvmti, const char *msg, jvmtiError ret)
  21{
  22        char *err_msg = NULL;
  23        jvmtiError err;
  24        err = (*jvmti)->GetErrorName(jvmti, ret, &err_msg);
  25        if (err == JVMTI_ERROR_NONE) {
  26                warnx("%s failed with %s", msg, err_msg);
  27                (*jvmti)->Deallocate(jvmti, (unsigned char *)err_msg);
  28        } else {
  29                warnx("%s failed with an unknown error %d", msg, ret);
  30        }
  31}
  32
  33#ifdef HAVE_JVMTI_CMLR
  34static jvmtiError
  35do_get_line_numbers(jvmtiEnv *jvmti, void *pc, jmethodID m, jint bci,
  36                    jvmti_line_info_t *tab, jint *nr)
  37{
  38        jint i, lines = 0;
  39        jint nr_lines = 0;
  40        jvmtiLineNumberEntry *loc_tab = NULL;
  41        jvmtiError ret;
  42
  43        ret = (*jvmti)->GetLineNumberTable(jvmti, m, &nr_lines, &loc_tab);
  44        if (ret != JVMTI_ERROR_NONE) {
  45                print_error(jvmti, "GetLineNumberTable", ret);
  46                return ret;
  47        }
  48
  49        for (i = 0; i < nr_lines; i++) {
  50                if (loc_tab[i].start_location < bci) {
  51                        tab[lines].pc = (unsigned long)pc;
  52                        tab[lines].line_number = loc_tab[i].line_number;
  53                        tab[lines].discrim = 0; /* not yet used */
  54                        tab[lines].methodID = m;
  55                        lines++;
  56                } else {
  57                        break;
  58                }
  59        }
  60        (*jvmti)->Deallocate(jvmti, (unsigned char *)loc_tab);
  61        *nr = lines;
  62        return JVMTI_ERROR_NONE;
  63}
  64
  65static jvmtiError
  66get_line_numbers(jvmtiEnv *jvmti, const void *compile_info, jvmti_line_info_t **tab, int *nr_lines)
  67{
  68        const jvmtiCompiledMethodLoadRecordHeader *hdr;
  69        jvmtiCompiledMethodLoadInlineRecord *rec;
  70        jvmtiLineNumberEntry *lne = NULL;
  71        PCStackInfo *c;
  72        jint nr, ret;
  73        int nr_total = 0;
  74        int i, lines_total = 0;
  75
  76        if (!(tab && nr_lines))
  77                return JVMTI_ERROR_NULL_POINTER;
  78
  79        /*
  80         * Phase 1 -- get the number of lines necessary
  81         */
  82        for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {
  83                if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {
  84                        rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;
  85                        for (i = 0; i < rec->numpcs; i++) {
  86                                c = rec->pcinfo + i;
  87                                nr = 0;
  88                                /*
  89                                 * unfortunately, need a tab to get the number of lines!
  90                                 */
  91                                ret = (*jvmti)->GetLineNumberTable(jvmti, c->methods[0], &nr, &lne);
  92                                if (ret == JVMTI_ERROR_NONE) {
  93                                        /* free what was allocated for nothing */
  94                                        (*jvmti)->Deallocate(jvmti, (unsigned char *)lne);
  95                                        nr_total += (int)nr;
  96                                } else {
  97                                        print_error(jvmti, "GetLineNumberTable", ret);
  98                                }
  99                        }
 100                }
 101        }
 102
 103        if (nr_total == 0)
 104                return JVMTI_ERROR_NOT_FOUND;
 105
 106        /*
 107         * Phase 2 -- allocate big enough line table
 108         */
 109        *tab = malloc(nr_total * sizeof(**tab));
 110        if (!*tab)
 111                return JVMTI_ERROR_OUT_OF_MEMORY;
 112
 113        for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {
 114                if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {
 115                        rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;
 116                        for (i = 0; i < rec->numpcs; i++) {
 117                                c = rec->pcinfo + i;
 118                                nr = 0;
 119                                ret = do_get_line_numbers(jvmti, c->pc,
 120                                                          c->methods[0],
 121                                                          c->bcis[0],
 122                                                          *tab + lines_total,
 123                                                          &nr);
 124                                if (ret == JVMTI_ERROR_NONE)
 125                                        lines_total += nr;
 126                        }
 127                }
 128        }
 129        *nr_lines = lines_total;
 130        return JVMTI_ERROR_NONE;
 131}
 132#else /* HAVE_JVMTI_CMLR */
 133
 134static jvmtiError
 135get_line_numbers(jvmtiEnv *jvmti __maybe_unused, const void *compile_info __maybe_unused,
 136                 jvmti_line_info_t **tab __maybe_unused, int *nr_lines __maybe_unused)
 137{
 138        return JVMTI_ERROR_NONE;
 139}
 140#endif /* HAVE_JVMTI_CMLR */
 141
 142static void
 143copy_class_filename(const char * class_sign, const char * file_name, char * result, size_t max_length)
 144{
 145        /*
 146        * Assume path name is class hierarchy, this is a common practice with Java programs
 147        */
 148        if (*class_sign == 'L') {
 149                int j, i = 0;
 150                char *p = strrchr(class_sign, '/');
 151                if (p) {
 152                        /* drop the 'L' prefix and copy up to the final '/' */
 153                        for (i = 0; i < (p - class_sign); i++)
 154                                result[i] = class_sign[i+1];
 155                }
 156                /*
 157                * append file name, we use loops and not string ops to avoid modifying
 158                * class_sign which is used later for the symbol name
 159                */
 160                for (j = 0; i < (max_length - 1) && file_name && j < strlen(file_name); j++, i++)
 161                        result[i] = file_name[j];
 162
 163                result[i] = '\0';
 164        } else {
 165                /* fallback case */
 166                strlcpy(result, file_name, max_length);
 167        }
 168}
 169
 170static jvmtiError
 171get_source_filename(jvmtiEnv *jvmti, jmethodID methodID, char ** buffer)
 172{
 173        jvmtiError ret;
 174        jclass decl_class;
 175        char *file_name = NULL;
 176        char *class_sign = NULL;
 177        char fn[PATH_MAX];
 178        size_t len;
 179
 180        ret = (*jvmti)->GetMethodDeclaringClass(jvmti, methodID, &decl_class);
 181        if (ret != JVMTI_ERROR_NONE) {
 182                print_error(jvmti, "GetMethodDeclaringClass", ret);
 183                return ret;
 184        }
 185
 186        ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name);
 187        if (ret != JVMTI_ERROR_NONE) {
 188                print_error(jvmti, "GetSourceFileName", ret);
 189                return ret;
 190        }
 191
 192        ret = (*jvmti)->GetClassSignature(jvmti, decl_class, &class_sign, NULL);
 193        if (ret != JVMTI_ERROR_NONE) {
 194                print_error(jvmti, "GetClassSignature", ret);
 195                goto free_file_name_error;
 196        }
 197
 198        copy_class_filename(class_sign, file_name, fn, PATH_MAX);
 199        len = strlen(fn);
 200        *buffer = malloc((len + 1) * sizeof(char));
 201        if (!*buffer) {
 202                print_error(jvmti, "GetClassSignature", ret);
 203                ret = JVMTI_ERROR_OUT_OF_MEMORY;
 204                goto free_class_sign_error;
 205        }
 206        strcpy(*buffer, fn);
 207        ret = JVMTI_ERROR_NONE;
 208
 209free_class_sign_error:
 210        (*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);
 211free_file_name_error:
 212        (*jvmti)->Deallocate(jvmti, (unsigned char *)file_name);
 213
 214        return ret;
 215}
 216
 217static jvmtiError
 218fill_source_filenames(jvmtiEnv *jvmti, int nr_lines,
 219                      const jvmti_line_info_t * line_tab,
 220                      char ** file_names)
 221{
 222        int index;
 223        jvmtiError ret;
 224
 225        for (index = 0; index < nr_lines; ++index) {
 226                ret = get_source_filename(jvmti, line_tab[index].methodID, &(file_names[index]));
 227                if (ret != JVMTI_ERROR_NONE)
 228                        return ret;
 229        }
 230
 231        return JVMTI_ERROR_NONE;
 232}
 233
 234static void JNICALL
 235compiled_method_load_cb(jvmtiEnv *jvmti,
 236                        jmethodID method,
 237                        jint code_size,
 238                        void const *code_addr,
 239                        jint map_length,
 240                        jvmtiAddrLocationMap const *map,
 241                        const void *compile_info)
 242{
 243        jvmti_line_info_t *line_tab = NULL;
 244        char ** line_file_names = NULL;
 245        jclass decl_class;
 246        char *class_sign = NULL;
 247        char *func_name = NULL;
 248        char *func_sign = NULL;
 249        char *file_name = NULL;
 250        char fn[PATH_MAX];
 251        uint64_t addr = (uint64_t)(uintptr_t)code_addr;
 252        jvmtiError ret;
 253        int nr_lines = 0; /* in line_tab[] */
 254        size_t len;
 255        int output_debug_info = 0;
 256
 257        ret = (*jvmti)->GetMethodDeclaringClass(jvmti, method,
 258                                                &decl_class);
 259        if (ret != JVMTI_ERROR_NONE) {
 260                print_error(jvmti, "GetMethodDeclaringClass", ret);
 261                return;
 262        }
 263
 264        if (has_line_numbers && map && map_length) {
 265                ret = get_line_numbers(jvmti, compile_info, &line_tab, &nr_lines);
 266                if (ret != JVMTI_ERROR_NONE) {
 267                        warnx("jvmti: cannot get line table for method");
 268                        nr_lines = 0;
 269                } else if (nr_lines > 0) {
 270                        line_file_names = malloc(sizeof(char*) * nr_lines);
 271                        if (!line_file_names) {
 272                                warnx("jvmti: cannot allocate space for line table method names");
 273                        } else {
 274                                memset(line_file_names, 0, sizeof(char*) * nr_lines);
 275                                ret = fill_source_filenames(jvmti, nr_lines, line_tab, line_file_names);
 276                                if (ret != JVMTI_ERROR_NONE) {
 277                                        warnx("jvmti: fill_source_filenames failed");
 278                                } else {
 279                                        output_debug_info = 1;
 280                                }
 281                        }
 282                }
 283        }
 284
 285        ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name);
 286        if (ret != JVMTI_ERROR_NONE) {
 287                print_error(jvmti, "GetSourceFileName", ret);
 288                goto error;
 289        }
 290
 291        ret = (*jvmti)->GetClassSignature(jvmti, decl_class,
 292                                          &class_sign, NULL);
 293        if (ret != JVMTI_ERROR_NONE) {
 294                print_error(jvmti, "GetClassSignature", ret);
 295                goto error;
 296        }
 297
 298        ret = (*jvmti)->GetMethodName(jvmti, method, &func_name,
 299                                      &func_sign, NULL);
 300        if (ret != JVMTI_ERROR_NONE) {
 301                print_error(jvmti, "GetMethodName", ret);
 302                goto error;
 303        }
 304
 305        copy_class_filename(class_sign, file_name, fn, PATH_MAX);
 306
 307        /*
 308         * write source line info record if we have it
 309         */
 310        if (output_debug_info)
 311                if (jvmti_write_debug_info(jvmti_agent, addr, nr_lines, line_tab, (const char * const *) line_file_names))
 312                        warnx("jvmti: write_debug_info() failed");
 313
 314        len = strlen(func_name) + strlen(class_sign) + strlen(func_sign) + 2;
 315        {
 316                char str[len];
 317                snprintf(str, len, "%s%s%s", class_sign, func_name, func_sign);
 318
 319                if (jvmti_write_code(jvmti_agent, str, addr, code_addr, code_size))
 320                        warnx("jvmti: write_code() failed");
 321        }
 322error:
 323        (*jvmti)->Deallocate(jvmti, (unsigned char *)func_name);
 324        (*jvmti)->Deallocate(jvmti, (unsigned char *)func_sign);
 325        (*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);
 326        (*jvmti)->Deallocate(jvmti, (unsigned char *)file_name);
 327        free(line_tab);
 328        while (line_file_names && (nr_lines > 0)) {
 329            if (line_file_names[nr_lines - 1]) {
 330                free(line_file_names[nr_lines - 1]);
 331            }
 332            nr_lines -= 1;
 333        }
 334        free(line_file_names);
 335}
 336
 337static void JNICALL
 338code_generated_cb(jvmtiEnv *jvmti,
 339                  char const *name,
 340                  void const *code_addr,
 341                  jint code_size)
 342{
 343        uint64_t addr = (uint64_t)(unsigned long)code_addr;
 344        int ret;
 345
 346        ret = jvmti_write_code(jvmti_agent, name, addr, code_addr, code_size);
 347        if (ret)
 348                warnx("jvmti: write_code() failed for code_generated");
 349}
 350
 351JNIEXPORT jint JNICALL
 352Agent_OnLoad(JavaVM *jvm, char *options, void *reserved __maybe_unused)
 353{
 354        jvmtiEventCallbacks cb;
 355        jvmtiCapabilities caps1;
 356        jvmtiJlocationFormat format;
 357        jvmtiEnv *jvmti = NULL;
 358        jint ret;
 359
 360        jvmti_agent = jvmti_open();
 361        if (!jvmti_agent) {
 362                warnx("jvmti: open_agent failed");
 363                return -1;
 364        }
 365
 366        /*
 367         * Request a JVMTI interface version 1 environment
 368         */
 369        ret = (*jvm)->GetEnv(jvm, (void *)&jvmti, JVMTI_VERSION_1);
 370        if (ret != JNI_OK) {
 371                warnx("jvmti: jvmti version 1 not supported");
 372                return -1;
 373        }
 374
 375        /*
 376         * acquire method_load capability, we require it
 377         * request line numbers (optional)
 378         */
 379        memset(&caps1, 0, sizeof(caps1));
 380        caps1.can_generate_compiled_method_load_events = 1;
 381
 382        ret = (*jvmti)->AddCapabilities(jvmti, &caps1);
 383        if (ret != JVMTI_ERROR_NONE) {
 384                print_error(jvmti, "AddCapabilities", ret);
 385                return -1;
 386        }
 387        ret = (*jvmti)->GetJLocationFormat(jvmti, &format);
 388        if (ret == JVMTI_ERROR_NONE && format == JVMTI_JLOCATION_JVMBCI) {
 389                memset(&caps1, 0, sizeof(caps1));
 390                caps1.can_get_line_numbers = 1;
 391                caps1.can_get_source_file_name = 1;
 392                ret = (*jvmti)->AddCapabilities(jvmti, &caps1);
 393                if (ret == JVMTI_ERROR_NONE)
 394                        has_line_numbers = 1;
 395        } else if (ret != JVMTI_ERROR_NONE)
 396                print_error(jvmti, "GetJLocationFormat", ret);
 397
 398
 399        memset(&cb, 0, sizeof(cb));
 400
 401        cb.CompiledMethodLoad   = compiled_method_load_cb;
 402        cb.DynamicCodeGenerated = code_generated_cb;
 403
 404        ret = (*jvmti)->SetEventCallbacks(jvmti, &cb, sizeof(cb));
 405        if (ret != JVMTI_ERROR_NONE) {
 406                print_error(jvmti, "SetEventCallbacks", ret);
 407                return -1;
 408        }
 409
 410        ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
 411                        JVMTI_EVENT_COMPILED_METHOD_LOAD, NULL);
 412        if (ret != JVMTI_ERROR_NONE) {
 413                print_error(jvmti, "SetEventNotificationMode(METHOD_LOAD)", ret);
 414                return -1;
 415        }
 416
 417        ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
 418                        JVMTI_EVENT_DYNAMIC_CODE_GENERATED, NULL);
 419        if (ret != JVMTI_ERROR_NONE) {
 420                print_error(jvmti, "SetEventNotificationMode(CODE_GENERATED)", ret);
 421                return -1;
 422        }
 423        return 0;
 424}
 425
 426JNIEXPORT void JNICALL
 427Agent_OnUnload(JavaVM *jvm __maybe_unused)
 428{
 429        int ret;
 430
 431        ret = jvmti_close(jvmti_agent);
 432        if (ret)
 433                errx(1, "Error: op_close_agent()");
 434}
 435