Re: Concerns about SFrame viability for userspace stack walking

Florian Weimer <[email protected]> Thu, 06 Nov 2025 08:51:22 +0100
Newsgroups org.kernel.vger.linux-toolchains,org.kernel.vger.linux-kernel,org.kernel.vger.linux-perf-users
Message-ID <[email protected]>
* Indu Bhagat:

> PLT stubs may use stack (push to stack). As per the document "A null
> frame (MODE = 8) is the simplest possible frame, with no allocated
> stack of either kind (hence no saved registers)".  So null frame can
> be used for PLT only if the functions invoking the PLT stub were using
> an RBP-based frame.  Isnt it ?

I think I said this before, but I don't think new toolchain features
need to support lazy binding.  Without lazy bindings, the PLT stubs do
not change the stack pointer or frame pointer and just make a tail call.

Do you see a need for continued support of lazy binding?

Thanks,
Florian