On Sun, 8 Mar 2026 02:31:41 GMT, Yasumasa Suenaga <[email protected]> wrote:
>> We saw the failure in serviceability/sa/TestJhsdbJstackMixedWithXComp.java >> on Valhalla repo. `jhsdb jstack --mixed` could not unwind continuation call >> frames as following: >> >> >> * LingeredAppWithVirtualThread.run() bci:15 line:69 >> (Interpreted frame) >> * java.lang.Thread.runWith(java.lang.Object, >> java.lang.Runnable) bci:5 line:1540 (Compiled frame [deoptimized]; >> information may be imprecise) >> * java.lang.VirtualThread.run(java.lang.Runnable) bci:62 >> line:472 (Compiled frame [deoptimized]; information may be imprecise) >> 0x00007fdad773cf98 <StubRoutines (continuation stubs)> >> 0xfefefefefefefefe ???????? >> >> >> I found that `frame::sender_for_compiled_frame()` in frame_x86.inline.hpp >> has a special case if sender PC has return barrier entry, but SA does not >> handle it. >> >> This is not only a problem on Valhalla. Same problem exists on JDK. So I >> want to fix on JDK. >> This PR passed serviceability/sa tests on Linux, and also >> TestJhsdbJstackMixedWithXComp.java on Valhalla passed 100 times. >> >> This PR is assembled by following commits: >> >> * Follows continuation-related code in HotSpot, and use it on AMD64 SA code >> * >> https://github.com/openjdk/jdk/pull/30107/changes/4af559ee0dbc0bb61e0bcd91bb17459a5abf50ad >> * Fix for AArch64 >> * >> https://github.com/openjdk/jdk/pull/30107/changes/2cff0fe40c52b88dd8d79ad1534e73b7b0f88f8d >> * Fix for RISC-V >> * >> https://github.com/openjdk/jdk/pull/30107/changes/fdef0384577bb71d34371f11bc5878494f276857 >> * Fix for PPC64 >> * >> https://github.com/openjdk/jdk/pull/30107/changes/5d9774d82c7e8c4d92eae8995ab014232ce9590e > > Yasumasa Suenaga has updated the pull request incrementally with one > additional commit since the last revision: > > Frame size of CodeBlob should be checked before calling > senderForCompiledFrame() src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/amd64/AMD64Frame.java line 276: > 274: // > 275: // frame::next_frame() creates RegisterMap instance with 4 arguments. > 276: // It sets RegisterMap::WalkContinuation::skip to final argument > (walk_count), Suggestion: // It sets RegisterMap::WalkContinuation::skip to final argument (walk_cont), src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/amd64/AMD64Frame.java line 277: > 275: // frame::next_frame() creates RegisterMap instance with 4 arguments. > 276: // It sets RegisterMap::WalkContinuation::skip to final argument > (walk_count), > 277: // then _chunk would not be initialized following code in c'tor of > RegisterMap. Suggestion: // therefore _chunk will not be initialized by the following code in c'tor of RegisterMap. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/30107#discussion_r2909034861 PR Review Comment: https://git.openjdk.org/jdk/pull/30107#discussion_r2909037790
