tree d007605a8ecdbbbdb436e53cde63349f67ca142b
parent a7904a3dc0448b839069bdb6270d2c7485a4330a
author Josh Poimboeuf <jpoimboe@kernel.org> 1726498337 +0200
committer Josh Poimboeuf <jpoimboe@kernel.org> 1734989465 -0800

unwind: Add deferred user space unwinding API

Add unwind_user_deferred() which allows callers to schedule task work to
unwind the user space stack before returning to user space.  This solves
several problems for its callers:

  - Ensure the unwind happens in task context even if the caller may be
    running in interrupt context.

  - Only do the unwind once, even if called multiple times either by the
    same caller or multiple callers.

  - Create a "context cookie" which allows trace post-processing to
    correlate kernel unwinds/traces with the user unwind.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>