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

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