[PATCH v2] ARM: enable interrupts when unhandled user faults are triggered

[Sebastian Andrzej Siewior]

On 2026-06-29 20:33:49 [+0800], Xie Yuanbin wrote:
> PREEMPT_RT requires interrupts to be enabled when sending signals.
> 
> When do_DataAbort()/do_PrefetchAbort() triggers unhandled user faults,
> that is `inf->fn()` return a non-zero value, and the interrupts are not
> enabled within the hook function, force_sig_fault() will be called
> with interrupts disabled.
> 
> This can be triggered by user programs executing the bkpt instruction,
> with kernel config CONFIG_PERF_EVENTS=n.
> 
> Enable interrupts in do_DataAbort()/do_PrefetchAbort() when unhandled
> user faults are triggered to fix the issue.
> 
> Fixes: c6e61c06d606 ("ARM: 9463/1: Allow to enable RT")
> 
> Suggested-by: Russell King <linux at armlinux.org.uk>
> Suggested-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
> Signed-off-by: Xie Yuanbin <xieyuanbin1 at huawei.com>

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

This fixes the issue that can be easily triggered.

Sebastian