[RFC PATCH 03/36] arm64: hibernate: mask DAIF before restoring hibernated kernel

[Vladimir Murzin]

On 7/10/26 04:40, Liao, Chang wrote:
>> @@ -465,9 +466,21 @@ int __nocfi swsusp_arch_resume(void)
>>  	if (el2_reset_needed())
>>  		__hyp_set_vectors(el2_vectors);
>>  
>> +	/*
>> +	 * It is necessary to mask all DAIF exceptions here as:
>> +	 *
>> +	 * - The copy of swsusp_arch_suspend_exit() in the hibernation
>> +	 *   text cannot handle taking any exceptions.
>> +	 *
>> +	 * - The suspended kernel masked all DAIF exceptions in
>> +	 *   swsusp_arch_resume(), and expects to be re-entered in the
>> +	 *   same state : with all DAIF exceptions masked.
>> +	 */
>> +	flags = local_daif_save();
>>  	hibernate_exit(virt_to_phys(tmp_pg_dir), resume_hdr.ttbr1_el1,
>>  		       resume_hdr.reenter_kernel, restore_pblist,
>>  		       resume_hdr.__hyp_stub_vectors, virt_to_phys(zero_page));
>> +	local_daif_restore(flags);
> As Jinjie said, the resumed kernel never return from hibernate_exit(). If that's
> the case, it seems better to place unreachable() rather than local_daif_restore(),
> would you agree?

Cannot disagree :) I'll fix that in the next iteration.

Cheers
Vladimir