Re: [PATCH v2 0/6] unwind, arm64: add sframe unwinder for kernel

Steven Rostedt <[email protected]> Mon, 17 Nov 2025 18:42:23 -0500
Newsgroups org.kernel.vger.linux-toolchains,org.kernel.vger.linux-kernel,org.kernel.vger.live-patching
Message-ID <[email protected]>
On Mon, 17 Nov 2025 15:06:32 -0800
Josh Poimboeuf <[email protected]> wrote:

> The ORC unwinder marks the unwind "unreliable" if it has to fall back to
> frame pointers.
> 
> But that's not a problem for livepatch because it only[*] unwinds
> blocked/sleeping tasks, which shouldn't have BPF on their stack anyway.
> 
> [*] with one exception: the task calling into livepatch

It may be a problem with preempted tasks right? I believe with PREEMPT_LAZY
(and definitely with PREEMPT_RT) BPF programs can be preempted.

-- Steve