Re: [PATCH] linux-user/arm: Reset CPSR_E when entering a signal handler

[Richard Henderson]

On 5/15/20 2:25 PM, Peter Maydell wrote:
>> You also need to call arm_rebuild_hflags() after modifying CPSR_E
>> otherwise the change doesn't take effect.
> 
> Hmm. I was expecting cpsr_write() to take care of that if we
> updated a cpsr flag that was in the hflags, but it looks like
> the rebuild_hflags() is in the HELPER() wrapper but not in
> cpsr_write() itself. Richard, does anything go wrong if
> cpsr_write() proper does the hflags rebuild ?

We wind up rebuilding hflags multiple times, is all.

Most of the time we call cpsr_write we also do something else that also
requires a rebuild.  So we do it once after all updates.

We could probably rearrange code such that the cpsr_write is last, and then
sink the rebuild.  But I don't know if that's clearer, hiding the side effect.


r~