On Tue, 18 Mar 2025 16:54:51 GMT, Jiangli Zhou <jian...@openjdk.org> wrote:
>> Please review this fix that avoids `JvmtiAgent::convert_xrun_agent` from >> prematurely exiting VM if `lookup_On_Load_entry_point` cannot load the agent >> using `JVM_OnLoad` symbol. Thanks >> >> `lookup_On_Load_entry_point` first tries to load the builtin agent from the >> executable by checking the requested symbol (`JVM_OnLoad`). If no builtin >> agent is found, it then tries to load the agent shared library (e.g. >> `libjdwp.so`) by calling `load_library`. The issue is that `load_library` is >> called with `vm_exit_on_error` set to `true`, which causes the VM to exit >> immediately if the agent shared library is not loaded. Therefore, >> `JvmtiAgent::convert_xrun_agent` has no chance to try loading the agent >> using `Agent_OnLoad` symbol >> (https://github.com/openjdk/jdk/blob/19154f7af34bf6f13d61d7a9f05d6277964845d8/src/hotspot/share/prims/jvmtiAgent.cpp#L352). >> This is a hidden issue on regular JDK, since the `load_library` can >> successfully find the agent shared library when >> `JvmtiAgent::convert_xrun_agent` first tries to load the agent using >> `JVM_OnLoad` symbol. The issue is noticed on static JDK as there is no >> `libjdwp.so` in static JDK. It can be reproduced with jtreg >> `runtime/6294277/So urceDebugExtension.java` test. >> >> As part of the fix, I cleaned up following in `invoke_JVM_OnLoad` and >> `invoke_Agent_OnLoad`. If there's an error, the VM should already have >> exited during `lookup_<JVM|Agent>_OnLoad_entry_point` in those cases. >> >> >> if (on_load_entry == nullptr) { >> vm_exit_during_initialization("Could not find ... function in -Xrun >> library", agent->name()); >> } > > Jiangli Zhou has updated the pull request incrementally with two additional > commits since the last revision: > > - Apply @dholmes-ora's edit suggestion. > > Co-authored-by: David Holmes > <62092539+dholmes-...@users.noreply.github.com> > - Apply @dholmes-ora's suggestion to use single line. > > Co-authored-by: David Holmes > <62092539+dholmes-...@users.noreply.github.com> I had a look yesterday and it looked good, and your latest changes look good also. ------------- Marked as reviewed by cjplummer (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/24086#pullrequestreview-2695605225
