diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/perf/jvmti/libjvmti.c | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/tools/perf/jvmti/libjvmti.c b/tools/perf/jvmti/libjvmti.c new file mode 100644 index 000000000..fcca275e5 --- /dev/null +++ b/tools/perf/jvmti/libjvmti.c @@ -0,0 +1,420 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/compiler.h> +#include <linux/string.h> +#include <sys/types.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <err.h> +#include <jvmti.h> +#ifdef HAVE_JVMTI_CMLR +#include <jvmticmlr.h> +#endif +#include <limits.h> + +#include "jvmti_agent.h" + +static int has_line_numbers; +void *jvmti_agent; + +static void print_error(jvmtiEnv *jvmti, const char *msg, jvmtiError ret) +{ + char *err_msg = NULL; + jvmtiError err; + err = (*jvmti)->GetErrorName(jvmti, ret, &err_msg); + if (err == JVMTI_ERROR_NONE) { + warnx("%s failed with %s", msg, err_msg); + (*jvmti)->Deallocate(jvmti, (unsigned char *)err_msg); + } else { + warnx("%s failed with an unknown error %d", msg, ret); + } +} + +#ifdef HAVE_JVMTI_CMLR +static jvmtiError +do_get_line_number(jvmtiEnv *jvmti, void *pc, jmethodID m, jint bci, + jvmti_line_info_t *tab) +{ + jint i, nr_lines = 0; + jvmtiLineNumberEntry *loc_tab = NULL; + jvmtiError ret; + jint src_line = -1; + + ret = (*jvmti)->GetLineNumberTable(jvmti, m, &nr_lines, &loc_tab); + if (ret == JVMTI_ERROR_ABSENT_INFORMATION || ret == JVMTI_ERROR_NATIVE_METHOD) { + /* No debug information for this method */ + return ret; + } else if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "GetLineNumberTable", ret); + return ret; + } + + for (i = 0; i < nr_lines && loc_tab[i].start_location <= bci; i++) { + src_line = i; + } + + if (src_line != -1) { + tab->pc = (unsigned long)pc; + tab->line_number = loc_tab[src_line].line_number; + tab->discrim = 0; /* not yet used */ + tab->methodID = m; + + ret = JVMTI_ERROR_NONE; + } else { + ret = JVMTI_ERROR_ABSENT_INFORMATION; + } + + (*jvmti)->Deallocate(jvmti, (unsigned char *)loc_tab); + + return ret; +} + +static jvmtiError +get_line_numbers(jvmtiEnv *jvmti, const void *compile_info, jvmti_line_info_t **tab, int *nr_lines) +{ + const jvmtiCompiledMethodLoadRecordHeader *hdr; + jvmtiCompiledMethodLoadInlineRecord *rec; + PCStackInfo *c; + jint ret; + int nr_total = 0; + int i, lines_total = 0; + + if (!(tab && nr_lines)) + return JVMTI_ERROR_NULL_POINTER; + + /* + * Phase 1 -- get the number of lines necessary + */ + for (hdr = compile_info; hdr != NULL; hdr = hdr->next) { + if (hdr->kind == JVMTI_CMLR_INLINE_INFO) { + rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr; + nr_total += rec->numpcs; + } + } + + if (nr_total == 0) + return JVMTI_ERROR_NOT_FOUND; + + /* + * Phase 2 -- allocate big enough line table + */ + *tab = malloc(nr_total * sizeof(**tab)); + if (!*tab) + return JVMTI_ERROR_OUT_OF_MEMORY; + + for (hdr = compile_info; hdr != NULL; hdr = hdr->next) { + if (hdr->kind == JVMTI_CMLR_INLINE_INFO) { + rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr; + for (i = 0; i < rec->numpcs; i++) { + c = rec->pcinfo + i; + /* + * c->methods is the stack of inlined method calls + * at c->pc. [0] is the leaf method. Caller frames + * are ignored at the moment. + */ + ret = do_get_line_number(jvmti, c->pc, + c->methods[0], + c->bcis[0], + *tab + lines_total); + if (ret == JVMTI_ERROR_NONE) + lines_total++; + } + } + } + *nr_lines = lines_total; + return JVMTI_ERROR_NONE; +} +#else /* HAVE_JVMTI_CMLR */ + +static jvmtiError +get_line_numbers(jvmtiEnv *jvmti __maybe_unused, const void *compile_info __maybe_unused, + jvmti_line_info_t **tab __maybe_unused, int *nr_lines __maybe_unused) +{ + return JVMTI_ERROR_NONE; +} +#endif /* HAVE_JVMTI_CMLR */ + +static void +copy_class_filename(const char * class_sign, const char * file_name, char * result, size_t max_length) +{ + /* + * Assume path name is class hierarchy, this is a common practice with Java programs + */ + if (*class_sign == 'L') { + int j, i = 0; + char *p = strrchr(class_sign, '/'); + if (p) { + /* drop the 'L' prefix and copy up to the final '/' */ + for (i = 0; i < (p - class_sign); i++) + result[i] = class_sign[i+1]; + } + /* + * append file name, we use loops and not string ops to avoid modifying + * class_sign which is used later for the symbol name + */ + for (j = 0; i < (max_length - 1) && file_name && j < strlen(file_name); j++, i++) + result[i] = file_name[j]; + + result[i] = '\0'; + } else { + /* fallback case */ + strlcpy(result, file_name, max_length); + } +} + +static jvmtiError +get_source_filename(jvmtiEnv *jvmti, jmethodID methodID, char ** buffer) +{ + jvmtiError ret; + jclass decl_class; + char *file_name = NULL; + char *class_sign = NULL; + char fn[PATH_MAX]; + size_t len; + + ret = (*jvmti)->GetMethodDeclaringClass(jvmti, methodID, &decl_class); + if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "GetMethodDeclaringClass", ret); + return ret; + } + + ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name); + if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "GetSourceFileName", ret); + return ret; + } + + ret = (*jvmti)->GetClassSignature(jvmti, decl_class, &class_sign, NULL); + if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "GetClassSignature", ret); + goto free_file_name_error; + } + + copy_class_filename(class_sign, file_name, fn, PATH_MAX); + len = strlen(fn); + *buffer = malloc((len + 1) * sizeof(char)); + if (!*buffer) { + print_error(jvmti, "GetClassSignature", ret); + ret = JVMTI_ERROR_OUT_OF_MEMORY; + goto free_class_sign_error; + } + strcpy(*buffer, fn); + ret = JVMTI_ERROR_NONE; + +free_class_sign_error: + (*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign); +free_file_name_error: + (*jvmti)->Deallocate(jvmti, (unsigned char *)file_name); + + return ret; +} + +static jvmtiError +fill_source_filenames(jvmtiEnv *jvmti, int nr_lines, + const jvmti_line_info_t * line_tab, + char ** file_names) +{ + int index; + jvmtiError ret; + + for (index = 0; index < nr_lines; ++index) { + ret = get_source_filename(jvmti, line_tab[index].methodID, &(file_names[index])); + if (ret != JVMTI_ERROR_NONE) + return ret; + } + + return JVMTI_ERROR_NONE; +} + +static void JNICALL +compiled_method_load_cb(jvmtiEnv *jvmti, + jmethodID method, + jint code_size, + void const *code_addr, + jint map_length, + jvmtiAddrLocationMap const *map, + const void *compile_info) +{ + jvmti_line_info_t *line_tab = NULL; + char ** line_file_names = NULL; + jclass decl_class; + char *class_sign = NULL; + char *func_name = NULL; + char *func_sign = NULL; + uint64_t addr = (uint64_t)(uintptr_t)code_addr; + jvmtiError ret; + int nr_lines = 0; /* in line_tab[] */ + size_t len; + int output_debug_info = 0; + + ret = (*jvmti)->GetMethodDeclaringClass(jvmti, method, + &decl_class); + if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "GetMethodDeclaringClass", ret); + return; + } + + if (has_line_numbers && map && map_length) { + ret = get_line_numbers(jvmti, compile_info, &line_tab, &nr_lines); + if (ret != JVMTI_ERROR_NONE) { + if (ret != JVMTI_ERROR_NOT_FOUND) { + warnx("jvmti: cannot get line table for method"); + } + nr_lines = 0; + } else if (nr_lines > 0) { + line_file_names = malloc(sizeof(char*) * nr_lines); + if (!line_file_names) { + warnx("jvmti: cannot allocate space for line table method names"); + } else { + memset(line_file_names, 0, sizeof(char*) * nr_lines); + ret = fill_source_filenames(jvmti, nr_lines, line_tab, line_file_names); + if (ret != JVMTI_ERROR_NONE) { + warnx("jvmti: fill_source_filenames failed"); + } else { + output_debug_info = 1; + } + } + } + } + + ret = (*jvmti)->GetClassSignature(jvmti, decl_class, + &class_sign, NULL); + if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "GetClassSignature", ret); + goto error; + } + + ret = (*jvmti)->GetMethodName(jvmti, method, &func_name, + &func_sign, NULL); + if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "GetMethodName", ret); + goto error; + } + + /* + * write source line info record if we have it + */ + if (output_debug_info) + if (jvmti_write_debug_info(jvmti_agent, addr, nr_lines, line_tab, (const char * const *) line_file_names)) + warnx("jvmti: write_debug_info() failed"); + + len = strlen(func_name) + strlen(class_sign) + strlen(func_sign) + 2; + { + char str[len]; + snprintf(str, len, "%s%s%s", class_sign, func_name, func_sign); + + if (jvmti_write_code(jvmti_agent, str, addr, code_addr, code_size)) + warnx("jvmti: write_code() failed"); + } +error: + (*jvmti)->Deallocate(jvmti, (unsigned char *)func_name); + (*jvmti)->Deallocate(jvmti, (unsigned char *)func_sign); + (*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign); + free(line_tab); + while (line_file_names && (nr_lines > 0)) { + if (line_file_names[nr_lines - 1]) { + free(line_file_names[nr_lines - 1]); + } + nr_lines -= 1; + } + free(line_file_names); +} + +static void JNICALL +code_generated_cb(jvmtiEnv *jvmti, + char const *name, + void const *code_addr, + jint code_size) +{ + uint64_t addr = (uint64_t)(unsigned long)code_addr; + int ret; + + ret = jvmti_write_code(jvmti_agent, name, addr, code_addr, code_size); + if (ret) + warnx("jvmti: write_code() failed for code_generated"); +} + +JNIEXPORT jint JNICALL +Agent_OnLoad(JavaVM *jvm, char *options, void *reserved __maybe_unused) +{ + jvmtiEventCallbacks cb; + jvmtiCapabilities caps1; + jvmtiJlocationFormat format; + jvmtiEnv *jvmti = NULL; + jint ret; + + jvmti_agent = jvmti_open(); + if (!jvmti_agent) { + warnx("jvmti: open_agent failed"); + return -1; + } + + /* + * Request a JVMTI interface version 1 environment + */ + ret = (*jvm)->GetEnv(jvm, (void *)&jvmti, JVMTI_VERSION_1); + if (ret != JNI_OK) { + warnx("jvmti: jvmti version 1 not supported"); + return -1; + } + + /* + * acquire method_load capability, we require it + * request line numbers (optional) + */ + memset(&caps1, 0, sizeof(caps1)); + caps1.can_generate_compiled_method_load_events = 1; + + ret = (*jvmti)->AddCapabilities(jvmti, &caps1); + if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "AddCapabilities", ret); + return -1; + } + ret = (*jvmti)->GetJLocationFormat(jvmti, &format); + if (ret == JVMTI_ERROR_NONE && format == JVMTI_JLOCATION_JVMBCI) { + memset(&caps1, 0, sizeof(caps1)); + caps1.can_get_line_numbers = 1; + caps1.can_get_source_file_name = 1; + ret = (*jvmti)->AddCapabilities(jvmti, &caps1); + if (ret == JVMTI_ERROR_NONE) + has_line_numbers = 1; + } else if (ret != JVMTI_ERROR_NONE) + print_error(jvmti, "GetJLocationFormat", ret); + + + memset(&cb, 0, sizeof(cb)); + + cb.CompiledMethodLoad = compiled_method_load_cb; + cb.DynamicCodeGenerated = code_generated_cb; + + ret = (*jvmti)->SetEventCallbacks(jvmti, &cb, sizeof(cb)); + if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "SetEventCallbacks", ret); + return -1; + } + + ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE, + JVMTI_EVENT_COMPILED_METHOD_LOAD, NULL); + if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "SetEventNotificationMode(METHOD_LOAD)", ret); + return -1; + } + + ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE, + JVMTI_EVENT_DYNAMIC_CODE_GENERATED, NULL); + if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "SetEventNotificationMode(CODE_GENERATED)", ret); + return -1; + } + return 0; +} + +JNIEXPORT void JNICALL +Agent_OnUnload(JavaVM *jvm __maybe_unused) +{ + int ret; + + ret = jvmti_close(jvmti_agent); + if (ret) + errx(1, "Error: op_close_agent()"); +} |