MerijnandClaude Opus 5.5 3cd2ff9140 fix(libkernel): take a redirected delivery from rsp and the live registers ...

A thread suspended inside a system call returns through sysret, which
overwrites rcx and r11, so the delivery address passed in rcx was
garbage when the redirected thread resumed. PPSA12544 crashed that way
on its SaveDataProcessQueue thread, blocked in a host wait when Unity's
GC raised SIGUSR1. The redirected rip is now an entry stub that takes
the delivery from its fixed place above rsp. It also stores the live
general registers into the delivery's context first: the snapshot taken
while the thread was in the system call still holds the call number in
rax instead of its result, which the restore would have handed back to
the wait.

The guest test raises at a thread blocked on a host mutex in 20 rounds
and expects each delivery once the wait returns; it fails without this
change.

AI-assisted: yes

Co-Authored-By: Claude Opus 5.5 <[email protected]>

2026-10-06 15:41:25 +02:00

..

src

fix(libkernel): take a redirected delivery from rsp and the live registers

2026-10-06 15:41:25 +02:00