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#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <err.h>
#include <jvmti.h>
#include <limits.h>
#include "jvmti_agent.h"
static int has_line_numbers;
void *jvmti_agent;
static void JNICALL
compiled_method_load_cb(jvmtiEnv *jvmti,
jmethodID method,
jint code_size,
void const *code_addr,
jint map_length,
jvmtiAddrLocationMap const *map,
void const *compile_info __unused)
{
jvmtiLineNumberEntry *tab = NULL;
jclass decl_class;
char *class_sign = NULL;
char *func_name = NULL;
char *func_sign = NULL;
char *file_name= NULL;
char fn[PATH_MAX];
uint64_t addr = (uint64_t)(uintptr_t)code_addr;
jvmtiError ret;
jint nr_lines = 0;
size_t len;
ret = (*jvmti)->GetMethodDeclaringClass(jvmti, method,
&decl_class);
if (ret != JVMTI_ERROR_NONE) {
warnx("jvmti: cannot get declaring class");
return;
}
if (has_line_numbers && map && map_length) {
ret = (*jvmti)->GetLineNumberTable(jvmti, method, &nr_lines, &tab);
if (ret != JVMTI_ERROR_NONE) {
warnx("jvmti: cannot get line table for method");
} else {
ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name);
if (ret != JVMTI_ERROR_NONE) {
warnx("jvmti: cannot get source filename ret=%d", ret);
nr_lines = 0;
}
}
}
ret = (*jvmti)->GetClassSignature(jvmti, decl_class,
&class_sign, NULL);
if (ret != JVMTI_ERROR_NONE) {
warnx("jvmti: getclassignature failed");
goto error;
}
ret = (*jvmti)->GetMethodName(jvmti, method, &func_name,
&func_sign, NULL);
if (ret != JVMTI_ERROR_NONE) {
warnx("jvmti: failed getmethodname");
goto error;
}
/*
* 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++)
fn[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 < (PATH_MAX - 1) && file_name && j < strlen(file_name); j++, i++)
fn[i] = file_name[j];
fn[i] = '\0';
} else {
/* fallback case */
strcpy(fn, file_name);
}
/*
* write source line info record if we have it
*/
if (jvmti_write_debug_info(jvmti_agent, addr, fn, map, tab, nr_lines))
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);
(*jvmti)->Deallocate(jvmti, (unsigned char *)tab);
(*jvmti)->Deallocate(jvmti, (unsigned char *)file_name);
}
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 __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) {
warnx("jvmti: acquire compiled_method capability failed");
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;
}
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) {
warnx("jvmti: cannot set event callbacks");
return -1;
}
ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
JVMTI_EVENT_COMPILED_METHOD_LOAD, NULL);
if (ret != JVMTI_ERROR_NONE) {
warnx("jvmti: setnotification failed for method_load");
return -1;
}
ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
JVMTI_EVENT_DYNAMIC_CODE_GENERATED, NULL);
if (ret != JVMTI_ERROR_NONE) {
warnx("jvmti: setnotification failed on code_generated");
return -1;
}
return 0;
}
JNIEXPORT void JNICALL
Agent_OnUnload(JavaVM *jvm __unused)
{
int ret;
ret = jvmti_close(jvmti_agent);
if (ret)
errx(1, "Error: op_close_agent()");
}
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