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

On 7/10/26 04:00, Jinjie Ruan wrote:

quoted

@ -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));

hibernate_exit() is a noreturn function, the following
local_daif_restore() will not be called.

Agree. I'll fix that in the next iteration.

Cheers
Vladimir