[PATCH] ARM: select HAVE_POSIX_CPU_TIMERS_TASK_WORK

[Sebastian Andrzej Siewior]

On 2026-07-18 23:45:15 [+0200], Karl Mehltretter wrote:
> Commit c6e61c06d606 ("ARM: 9463/1: Allow to enable RT") enabled PREEMPT_RT
> on ARM but did not select HAVE_POSIX_CPU_TIMERS_TASK_WORK. This leaves
> CONFIG_POSIX_CPU_TIMERS_TASK_WORK disabled, so CPU timers expire in hard
> IRQ context.
…
> Fixes: c6e61c06d606 ("ARM: 9463/1: Allow to enable RT")
> Assisted-by: Claude:claude-fable-5
> Signed-off-by: Karl Mehltretter <kmehltretter at gmail.com>

Reviewed-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>

> Found with a self-hosted syzkaller instance patched to fuzz kernels on
> QEMU's versatilepb machine (ARM926EJ-S, ARMv5TE). Runtime-tested before
> and after the change on that setup, and compile-tested mps2_defconfig
> with PREEMPT_RT (NOMMU, CPU_V7M).

I obviously got the rules confused while dropping the KVM patches.

Sebastian