If so, should we put the call inside of vm_area_register_early?

Ah, we already do this. Sorry. My other questions remain.

Kind regards,
Daniel

Kind regards,
Daniel

quoted

quoted

 void __init kasan_init(void)
 {
 	kasan_init_shadow();

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 5310e217bd74..79d3895b0240 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h

@@ -49,6 +49,8 @@ extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
 int kasan_populate_early_shadow(const void *shadow_start,
 				const void *shadow_end);
 
+void kasan_populate_early_vm_area_shadow(void *start, unsigned long size);
+
 static inline void *kasan_mem_to_shadow(const void *addr)
 {
 	return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)

diff --git a/mm/kasan/init.c b/mm/kasan/init.c
index cc64ed6858c6..d39577d088a1 100644
--- a/mm/kasan/init.c
+++ b/mm/kasan/init.c

@@ -279,6 +279,11 @@ int __ref kasan_populate_early_shadow(const void *shadow_start,
 	return 0;
 }
 
+void __init __weak kasan_populate_early_vm_area_shadow(void *start,
+						       unsigned long size)
+{
+}

I'm just wondering if this could be a generic function, perhaps with an
appropriate IS_ENABLED() check of a generic Kconfig option
(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK ?) to short-circuit it, if it's
not only an arm64 problem.

But I haven't looked much further, so would appeal to you to either
confirm or reject this idea.

Thanks,
-- Marco