How to use uprobe to trace OpenJDK HotSpot source code?

问题

I try to follow the instructions from link

In this example,

Tracing func_abc() in my test program, and including user-level stacks:

# ./uprobe -s p:/root/func_abc:func_c
Tracing uprobe func_c (p:func_c /root/func_abc:0x4f4). Ctrl-C to end.
        func_abc-25394 [000] d... 19603250.054040: func_c: (0x4004f4)
        func_abc-25394 [000] d... 19603250.054056: <user stack trace>
 =>  <00000000004004f4>
 =>  <0000000000400527>
 =>  <0000000000400537>
 =>  <00007fca9f0e376d>
        func_abc-25394 [000] d... 19603251.054250: func_c: (0x4004f4)
        func_abc-25394 [000] d... 19603251.054266: <user stack trace>
 =>  <00000000004004f4>
 =>  <0000000000400527>
 =>  <0000000000400537>
 =>  <00007fca9f0e376d>
^C
Ending tracing...

I want to probe function minor_collection_begin but it shows ERROR: missing symbol.

root@wxf:/home/wxf/perf-tool/perf-tools/bin# ./uprobe -s p:/home/wxf/9dev/build/linux-x86_64-normal-server-slowdebug/jdk/bin/java:AdaptiveSizePolicy::minor_collection_begin
ERROR: missing symbol "minor_collection_begin" in /home/wxf/9dev/build/linux-x86_64-normal-server-slowdebug/jdk/bin/java
root@wxf:/home/wxf/perf-tool/perf-tools/bin# ./uprobe -s p:/home/wxf/9dev/build/linux-x86_64-normal-server-slowdebug/jdk/bin/java:minor_collection_begin
ERROR: missing symbol "minor_collection_begin" in /home/wxf/9dev/build/linux-x86_64-normal-server-slowdebug/jdk/bin/java

I search a lot and find it is related to libjvm.so. However, I don't know what to do next.

wxf@wxf:/home/wxf/adjustableMaxHeapSize_9jdk_prj/9dev$ find -name "libjvm.so"
./build/linux-x86_64-normal-server-slowdebug/support/modules_libs/java.base/server/libjvm.so
./build/linux-x86_64-normal-server-slowdebug/hotspot/variant-server/libjvm/gtest/libjvm.so
./build/linux-x86_64-normal-server-slowdebug/jdk/lib/server/libjvm.so

回答1:

C++ symbols are mangled in binary objects. You won't find minor_collection_begin. The mangled symbol name for void AdaptiveSizePolicy::minor_collection_begin() is

_ZN18AdaptiveSizePolicy22minor_collection_beginEv

来源：https://stackoverflow.com/questions/48535366/how-to-use-uprobe-to-trace-openjdk-hotspot-source-code

标签

java-8

OpenJDK

jvm-hotspot