On Wed, 20 May 2026 00:17:02 GMT, Yasumasa Suenaga <[email protected]> wrote:

>> After [JDK-8377946](https://bugs.openjdk.org/browse/JDK-8377946), we can see 
>> test failure on ClhsdbPstack.java. But the failure was happened before 
>> [JDK-8377946](https://bugs.openjdk.org/browse/JDK-8377946) - test is passed, 
>> but we can see the exception and the function symbol was not been resolved. 
>> (You can see .jtr files in JBS)
>> 
>> `DwarfParser` should scan `.eh_frame` first. but `.debug_frame` should be 
>> scanned as fallback if target PC was not found in `.eh_frame`.
>> 
>> According to [System V ABI for 
>> AMD64](https://refspecs.linuxbase.org/elf/x86_64-abi-0.99.pdf), frame 
>> information should be included in .eh_frame (See 6.3 Unwinding Through 
>> Assembler Code)
>> 
>> In musl C, I found out the discussion for .eh_frame vs .debug_frame: 
>> https://www.openwall.com/lists/musl/2021/07/17/13
>> musl C does not seem to want to support `.eh_frame` - they seem to want to 
>> use `.debug_frame` for stack unwinding in debugging. But it could be 
>> different from ABI spec in above.
>> 
>> This PR is not small, but commit history might help to review.
>> 
>> - [Use lib->base 
>> directly](https://github.com/openjdk/jdk/commit/319e1b85d278bad90caeb5b13c41a0f4ca81cb00)
>>  - remove unnecessary field from `eh_frame_info`.
>> - [Move debuginfo related code to salibelf from 
>> symtab](https://github.com/openjdk/jdk/commit/0682a312f8202592e2ad6bc2210b27f5190c4ce0)
>>  - as a preparation for `.debug_frame`, debuginfo related code is needed for 
>> this PR, but it is written in symtab.c. So moved it to another file 
>> (salibelf.c).
>> - [Rename "eh_frame_info" to 
>> "frame_info"](https://github.com/openjdk/jdk/commit/662b373f316eeb920dc7b6a0df155a5b7c852ef1)
>>  - frame information in SA is no longer for `.eh_frame`, so renamed.
>> - [Use .debug_frame if DWARF parser could not find PC from 
>> .eh_frame](https://github.com/openjdk/jdk/commit/0e4477ac9bc95026283c1ad085c1bbb43b399ef0)
>>  - implement DWARF parser for `.debug_frame`.
>> - [Validate sender SP before to return sender frame in 
>> LinuxAMD64CFrame.java](https://github.com/openjdk/jdk/commit/ec4a08d3d4457c1bb70bb1a73e9978fd018eab1a)
>>  -
>> current `LinuxAMD64CFrame` might enter infinity loop not to find out bottom 
>> frame (I saw this case on Alpine), thus add condition for frame validation 
>> with stack pointer.
>> - [Re-enable mixed jstack tests on musl 
>> C](https://github.com/openjdk/jdk/commit/de27835d7ae58bc7547f25fefe1613af47757c82)
>>  - as stated in the commit message.
>> - [Update copyright 
>> year](https://github.com/openjdk/jdk/commit/2dc4f1dfa101f511a0305ede04aed027eb87c1f0)
>>  - as sta...
>
> Yasumasa Suenaga has updated the pull request with a new target base due to a 
> merge or a rebase. The pull request now contains eight commits:
> 
>  - Merge remote-tracking branch 'origin/master' into sa-debug_frame-v2
>  - Update copyright year
>  - Re-enable mixed jstack tests on musl C
>  - Validate sender SP before to return sender frame in LinuxAMD64CFrame.java
>  - Use .debug_frame if DWARF parser could not find PC from .eh_frame
>  - Rename "eh_frame_info" to "frame_info"
>  - Move debuginfo related code to salibelf from symtab
>  - Use lib->base directly

I hope this PR will be reviewed...

-------------

PR Comment: https://git.openjdk.org/jdk/pull/30815#issuecomment-4727230231

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