---
- branch: MAIN
  date: Sun Apr 14 12:51:17 UTC 2024
  files:
  - new: '1.15'
    old: '1.14'
    path: src/sys/arch/aarch64/aarch64/cpu_machdep.c
    pathrev: src/sys/arch/aarch64/aarch64/cpu_machdep.c@1.15
    type: modified
  - new: '1.9'
    old: '1.8'
    path: src/sys/arch/aarch64/aarch64/sig_machdep.c
    pathrev: src/sys/arch/aarch64/aarch64/sig_machdep.c@1.9
    type: modified
  id: 20240414T125117Z.978f87c1f4fa4c5b5fd91e995a7545ce2c7c399b
  log: |
    kern/58149: aarch64: Cannot return from a signal handler if SP was misaligned when the signal arrived

    Apply the kernel diff from the PR

    1. sendsig_siginfo() previously assumed that user SP was always aligned to
       16 bytes and could call signal handlers with SP misaligned. This is a
       wrong assumption because aarch64 demands that SP is aligned *only while*
       it's being used to access memory. Now it properly aligns it before
       pusing anything on the stack.

    2. cpu_mcontext_validate() used to check if _REG_SP was aligned and
       considered the ucontext invalid otherwise. This meant if a signal was
       sent to a process whose SP was misaligned, the signal handler would fail
       to return because the ucontext passed from the kernel was an invalid
       one. Now setcontext(2) doesn't complain about misaligned SP.
  module: src
  subject: 'CVS commit: src/sys/arch/aarch64/aarch64'
  unixtime: '1713099077'
  user: skrll