421 lines · c
1// SPDX-License-Identifier: GPL-2.02#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_CMLR11#include <jvmticmlr.h>12#endif13#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_CMLR34static jvmtiError35do_get_line_number(jvmtiEnv *jvmti, void *pc, jmethodID m, jint bci,36 jvmti_line_info_t *tab)37{38 jint i, nr_lines = 0;39 jvmtiLineNumberEntry *loc_tab = NULL;40 jvmtiError ret;41 jint src_line = -1;42 43 ret = (*jvmti)->GetLineNumberTable(jvmti, m, &nr_lines, &loc_tab);44 if (ret == JVMTI_ERROR_ABSENT_INFORMATION || ret == JVMTI_ERROR_NATIVE_METHOD) {45 /* No debug information for this method */46 return ret;47 } else if (ret != JVMTI_ERROR_NONE) {48 print_error(jvmti, "GetLineNumberTable", ret);49 return ret;50 }51 52 for (i = 0; i < nr_lines && loc_tab[i].start_location <= bci; i++) {53 src_line = i;54 }55 56 if (src_line != -1) {57 tab->pc = (unsigned long)pc;58 tab->line_number = loc_tab[src_line].line_number;59 tab->discrim = 0; /* not yet used */60 tab->methodID = m;61 62 ret = JVMTI_ERROR_NONE;63 } else {64 ret = JVMTI_ERROR_ABSENT_INFORMATION;65 }66 67 (*jvmti)->Deallocate(jvmti, (unsigned char *)loc_tab);68 69 return ret;70}71 72static jvmtiError73get_line_numbers(jvmtiEnv *jvmti, const void *compile_info, jvmti_line_info_t **tab, int *nr_lines)74{75 const jvmtiCompiledMethodLoadRecordHeader *hdr;76 jvmtiCompiledMethodLoadInlineRecord *rec;77 PCStackInfo *c;78 jint ret;79 int nr_total = 0;80 int i, lines_total = 0;81 82 if (!(tab && nr_lines))83 return JVMTI_ERROR_NULL_POINTER;84 85 /*86 * Phase 1 -- get the number of lines necessary87 */88 for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {89 if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {90 rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;91 nr_total += rec->numpcs;92 }93 }94 95 if (nr_total == 0)96 return JVMTI_ERROR_NOT_FOUND;97 98 /*99 * Phase 2 -- allocate big enough line table100 */101 *tab = malloc(nr_total * sizeof(**tab));102 if (!*tab)103 return JVMTI_ERROR_OUT_OF_MEMORY;104 105 for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {106 if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {107 rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;108 for (i = 0; i < rec->numpcs; i++) {109 c = rec->pcinfo + i;110 /*111 * c->methods is the stack of inlined method calls112 * at c->pc. [0] is the leaf method. Caller frames113 * are ignored at the moment.114 */115 ret = do_get_line_number(jvmti, c->pc,116 c->methods[0],117 c->bcis[0],118 *tab + lines_total);119 if (ret == JVMTI_ERROR_NONE)120 lines_total++;121 }122 }123 }124 *nr_lines = lines_total;125 return JVMTI_ERROR_NONE;126}127#else /* HAVE_JVMTI_CMLR */128 129static jvmtiError130get_line_numbers(jvmtiEnv *jvmti __maybe_unused, const void *compile_info __maybe_unused,131 jvmti_line_info_t **tab __maybe_unused, int *nr_lines __maybe_unused)132{133 return JVMTI_ERROR_NONE;134}135#endif /* HAVE_JVMTI_CMLR */136 137static void138copy_class_filename(const char * class_sign, const char * file_name, char * result, size_t max_length)139{140 /*141 * Assume path name is class hierarchy, this is a common practice with Java programs142 */143 if (*class_sign == 'L') {144 int j, i = 0;145 char *p = strrchr(class_sign, '/');146 if (p) {147 /* drop the 'L' prefix and copy up to the final '/' */148 for (i = 0; i < (p - class_sign); i++)149 result[i] = class_sign[i+1];150 }151 /*152 * append file name, we use loops and not string ops to avoid modifying153 * class_sign which is used later for the symbol name154 */155 for (j = 0; i < (max_length - 1) && file_name && j < strlen(file_name); j++, i++)156 result[i] = file_name[j];157 158 result[i] = '\0';159 } else {160 /* fallback case */161 strlcpy(result, file_name, max_length);162 }163}164 165static jvmtiError166get_source_filename(jvmtiEnv *jvmti, jmethodID methodID, char ** buffer)167{168 jvmtiError ret;169 jclass decl_class;170 char *file_name = NULL;171 char *class_sign = NULL;172 char fn[PATH_MAX];173 size_t len;174 175 ret = (*jvmti)->GetMethodDeclaringClass(jvmti, methodID, &decl_class);176 if (ret != JVMTI_ERROR_NONE) {177 print_error(jvmti, "GetMethodDeclaringClass", ret);178 return ret;179 }180 181 ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name);182 if (ret != JVMTI_ERROR_NONE) {183 print_error(jvmti, "GetSourceFileName", ret);184 return ret;185 }186 187 ret = (*jvmti)->GetClassSignature(jvmti, decl_class, &class_sign, NULL);188 if (ret != JVMTI_ERROR_NONE) {189 print_error(jvmti, "GetClassSignature", ret);190 goto free_file_name_error;191 }192 193 copy_class_filename(class_sign, file_name, fn, PATH_MAX);194 len = strlen(fn);195 *buffer = malloc((len + 1) * sizeof(char));196 if (!*buffer) {197 print_error(jvmti, "GetClassSignature", ret);198 ret = JVMTI_ERROR_OUT_OF_MEMORY;199 goto free_class_sign_error;200 }201 strcpy(*buffer, fn);202 ret = JVMTI_ERROR_NONE;203 204free_class_sign_error:205 (*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);206free_file_name_error:207 (*jvmti)->Deallocate(jvmti, (unsigned char *)file_name);208 209 return ret;210}211 212static jvmtiError213fill_source_filenames(jvmtiEnv *jvmti, int nr_lines,214 const jvmti_line_info_t * line_tab,215 char ** file_names)216{217 int index;218 jvmtiError ret;219 220 for (index = 0; index < nr_lines; ++index) {221 ret = get_source_filename(jvmti, line_tab[index].methodID, &(file_names[index]));222 if (ret != JVMTI_ERROR_NONE)223 return ret;224 }225 226 return JVMTI_ERROR_NONE;227}228 229static void JNICALL230compiled_method_load_cb(jvmtiEnv *jvmti,231 jmethodID method,232 jint code_size,233 void const *code_addr,234 jint map_length,235 jvmtiAddrLocationMap const *map,236 const void *compile_info)237{238 jvmti_line_info_t *line_tab = NULL;239 char ** line_file_names = NULL;240 jclass decl_class;241 char *class_sign = NULL;242 char *func_name = NULL;243 char *func_sign = NULL;244 uint64_t addr = (uint64_t)(uintptr_t)code_addr;245 jvmtiError ret;246 int nr_lines = 0; /* in line_tab[] */247 size_t len;248 int output_debug_info = 0;249 250 ret = (*jvmti)->GetMethodDeclaringClass(jvmti, method,251 &decl_class);252 if (ret != JVMTI_ERROR_NONE) {253 print_error(jvmti, "GetMethodDeclaringClass", ret);254 return;255 }256 257 if (has_line_numbers && map && map_length) {258 ret = get_line_numbers(jvmti, compile_info, &line_tab, &nr_lines);259 if (ret != JVMTI_ERROR_NONE) {260 if (ret != JVMTI_ERROR_NOT_FOUND) {261 warnx("jvmti: cannot get line table for method");262 }263 nr_lines = 0;264 } else if (nr_lines > 0) {265 line_file_names = malloc(sizeof(char*) * nr_lines);266 if (!line_file_names) {267 warnx("jvmti: cannot allocate space for line table method names");268 } else {269 memset(line_file_names, 0, sizeof(char*) * nr_lines);270 ret = fill_source_filenames(jvmti, nr_lines, line_tab, line_file_names);271 if (ret != JVMTI_ERROR_NONE) {272 warnx("jvmti: fill_source_filenames failed");273 } else {274 output_debug_info = 1;275 }276 }277 }278 }279 280 ret = (*jvmti)->GetClassSignature(jvmti, decl_class,281 &class_sign, NULL);282 if (ret != JVMTI_ERROR_NONE) {283 print_error(jvmti, "GetClassSignature", ret);284 goto error;285 }286 287 ret = (*jvmti)->GetMethodName(jvmti, method, &func_name,288 &func_sign, NULL);289 if (ret != JVMTI_ERROR_NONE) {290 print_error(jvmti, "GetMethodName", ret);291 goto error;292 }293 294 /*295 * write source line info record if we have it296 */297 if (output_debug_info)298 if (jvmti_write_debug_info(jvmti_agent, addr, nr_lines, line_tab, (const char * const *) line_file_names))299 warnx("jvmti: write_debug_info() failed");300 301 len = strlen(func_name) + strlen(class_sign) + strlen(func_sign) + 2;302 {303 char str[len];304 snprintf(str, len, "%s%s%s", class_sign, func_name, func_sign);305 306 if (jvmti_write_code(jvmti_agent, str, addr, code_addr, code_size))307 warnx("jvmti: write_code() failed");308 }309error:310 (*jvmti)->Deallocate(jvmti, (unsigned char *)func_name);311 (*jvmti)->Deallocate(jvmti, (unsigned char *)func_sign);312 (*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);313 free(line_tab);314 while (line_file_names && (nr_lines > 0)) {315 if (line_file_names[nr_lines - 1]) {316 free(line_file_names[nr_lines - 1]);317 }318 nr_lines -= 1;319 }320 free(line_file_names);321}322 323static void JNICALL324code_generated_cb(jvmtiEnv *jvmti,325 char const *name,326 void const *code_addr,327 jint code_size)328{329 uint64_t addr = (uint64_t)(unsigned long)code_addr;330 int ret;331 332 ret = jvmti_write_code(jvmti_agent, name, addr, code_addr, code_size);333 if (ret)334 warnx("jvmti: write_code() failed for code_generated");335}336 337JNIEXPORT jint JNICALL338Agent_OnLoad(JavaVM *jvm, char *options, void *reserved __maybe_unused)339{340 jvmtiEventCallbacks cb;341 jvmtiCapabilities caps1;342 jvmtiJlocationFormat format;343 jvmtiEnv *jvmti = NULL;344 jint ret;345 346 jvmti_agent = jvmti_open();347 if (!jvmti_agent) {348 warnx("jvmti: open_agent failed");349 return -1;350 }351 352 /*353 * Request a JVMTI interface version 1 environment354 */355 ret = (*jvm)->GetEnv(jvm, (void *)&jvmti, JVMTI_VERSION_1);356 if (ret != JNI_OK) {357 warnx("jvmti: jvmti version 1 not supported");358 return -1;359 }360 361 /*362 * acquire method_load capability, we require it363 * request line numbers (optional)364 */365 memset(&caps1, 0, sizeof(caps1));366 caps1.can_generate_compiled_method_load_events = 1;367 368 ret = (*jvmti)->AddCapabilities(jvmti, &caps1);369 if (ret != JVMTI_ERROR_NONE) {370 print_error(jvmti, "AddCapabilities", ret);371 return -1;372 }373 ret = (*jvmti)->GetJLocationFormat(jvmti, &format);374 if (ret == JVMTI_ERROR_NONE && format == JVMTI_JLOCATION_JVMBCI) {375 memset(&caps1, 0, sizeof(caps1));376 caps1.can_get_line_numbers = 1;377 caps1.can_get_source_file_name = 1;378 ret = (*jvmti)->AddCapabilities(jvmti, &caps1);379 if (ret == JVMTI_ERROR_NONE)380 has_line_numbers = 1;381 } else if (ret != JVMTI_ERROR_NONE)382 print_error(jvmti, "GetJLocationFormat", ret);383 384 385 memset(&cb, 0, sizeof(cb));386 387 cb.CompiledMethodLoad = compiled_method_load_cb;388 cb.DynamicCodeGenerated = code_generated_cb;389 390 ret = (*jvmti)->SetEventCallbacks(jvmti, &cb, sizeof(cb));391 if (ret != JVMTI_ERROR_NONE) {392 print_error(jvmti, "SetEventCallbacks", ret);393 return -1;394 }395 396 ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,397 JVMTI_EVENT_COMPILED_METHOD_LOAD, NULL);398 if (ret != JVMTI_ERROR_NONE) {399 print_error(jvmti, "SetEventNotificationMode(METHOD_LOAD)", ret);400 return -1;401 }402 403 ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,404 JVMTI_EVENT_DYNAMIC_CODE_GENERATED, NULL);405 if (ret != JVMTI_ERROR_NONE) {406 print_error(jvmti, "SetEventNotificationMode(CODE_GENERATED)", ret);407 return -1;408 }409 return 0;410}411 412JNIEXPORT void JNICALL413Agent_OnUnload(JavaVM *jvm __maybe_unused)414{415 int ret;416 417 ret = jvmti_close(jvmti_agent);418 if (ret)419 errx(1, "Error: op_close_agent()");420}421