Re: [PATCH v3 13/15] gas: Don't skip SFrame FDE if .cfi_register specifies SP register

[Indu Bhagat <indu.bhagat@oracle.com>]

On 4/23/24 01:15, Indu Bhagat wrote:
>> Btw., besides the RFC Linux Kernel perf patch series "[PATCH RFC 
>> 00/10] perf: user space sframe unwinding" [1] is there any reference 
>> implementation of a SFrame unwinder I could use as base for testing 
>> SFrame unwinding on s390x? Maybe a GDB Python script to do unwinding 
>> using SFrame (not sure how to access the .sframe section)?
>>
>> [1] [PATCH RFC 00/10] perf: user space sframe unwinding,
>> https://lore.kernel.org/all/cover.1699487758.git.jpoimboe@kernel.org/
>>
> 
> We did have an "SFrame unwinder library" patchset for binutils, which we 
> used for testing SFrame for x86 and aarch64 support.  It wasn't 
> upstreamed because a) it had open issues, b) in hindsight, it doesn't 
> belong to binutils-gdp repo in the current shape.
> 
> I will push it in a personal branch upstream and share some notes on its 
> status and open issues. At the least, it should be helpful in testing 
> your s390 enhancements to the SFrame format.

I have pushed a user branch users/ibhagat/sframe-stacktracer-testsuite 
upstream.

The testsuite is in libsframe/testsuite/libsframe.stacktrace.  The 
"SFrame stack tracer library" is now a non-installed, 
testsuite-purpose-only, test library (see 
libsframe/testsuite/libsframe.stacktrace/libsfrast). Hope that helps.

The stacktracer testsuite itself needs bit more grooming before it can 
be presented for inclusion into libsframe's testsuite upstream.  If you 
have patches for this branch over time, please feel free to push them to 
the branch :)

Thanks
Indu