Re: [RFC PATCH v1 12/16] unwind_user/backchain: Introduce back chain user space unwinding

[Jens Remus <jremus@linux.ibm.com>]

On 8/1/2025 2:36 PM, Heiko Carstens wrote:
> On Thu, Jul 17, 2025 at 10:19:54PM -0700, Josh Poimboeuf wrote:
>> On Thu, Jul 17, 2025 at 02:20:12PM +0200, Jens Remus wrote:

>> I believe stack_trace_save_user() is only used by ftrace, and that will
>> no longer be needed once ftrace starts using unwind_user.
>>
>> Maybe Heiko knows if that backchain user stacktrace code has any users?
>>
>> If distros aren't building with -mbackchain, maybe backchain support can
>> be considered obsoleted by sframe, and we can get away with not
>> implementing it.
> 
> I guess that's a valid option. I know only of some special cases where
> users compile everything on their own with -mbackchain to make this
> work on a per-case basis. It shouldn't cause to much pain for them to
> switch to sframe, as soon as that is available.

Let me have another stab at a cleaner implementation.  Shouldn't be too
much effort.  We can then decide whether to leave it out or not.

Will be away from keyboard for a few weeks.

Regards,
Jens
-- 
Jens Remus
Linux on Z Development (D3303)
+49-7031-16-1128 Office
jremus@de.ibm.com

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