Re: Concerns about SFrame viability for userspace stack walking

From: Indu Bhagat

Date: Thu Nov 06 2025 - 16:02:27 EST


On 11/5/25 11:51 PM, Florian Weimer wrote:
* 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?


(Yes, you did mention this before in another thread on Binutils.)

My thinking has been: some linker emulations default to lazy (I guess the reason is changing the default is difficult). So, users may end up continuing with lazy bindings unknowingly ?

But I guess not designing new toolchain features to support lazy binding seems reasonable.

Thanks