[PATCH 2/2] arm64/mm: Update create_kpti_ng_temp_pgd() to handle pgtable_alloc failure

David Hildenbrand david at redhat.com
Tue Aug 19 00:41:40 PDT 2025


On 13.08.25 16:56, Chaitanya S Prakash wrote:
> create_kpti_ng_temp_pgd() was created as an alias for void returning
> __create_pgd_mapping_locked() and relied on pgtable_alloc() to BUG_ON()
> if an allocation failure occurred. But as __create_pgd_mapping_locked()
> has been updated as a part of the error propagation patch to return a
> non-void value, update create_kpti_ng_temp_pgd() to act as a wrapper
> around __create_pgd_mapping_locked() and BUG_ON() on ret being a non
> zero value.

If  my memory serves me right, panic() is preferred in such unexpected 
early-boot scenarios (BUG_ON is frowned upon), where you can actually 
print what is going wrong.


Which raises the question: could create_kpti_ng_temp_pgd() be __init? 
__kpti_install_ng_mappings(), the only caller, seems to be.

-- 
Cheers

David / dhildenb




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