From 90e636f60b76c590aded72964543945084d97c2f Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sat, 17 Feb 2024 00:59:44 +0100 Subject: arm64: mm: Make PUD folding check in set_pud() a runtime check When set_pud() is called on a 4-level paging build config that runs with 3 levels at runtime (which happens with 16k page size builds with support for LPA2), the updated entry is in fact a PGD in swapper_pg_dir[], and this is mapped read-only after boot. So in this case, the existing check needs to be performed as well, even though __PAGETABLE_PUD_FOLDED is not #define'd. So replace the #ifdef with a call to pgtable_l4_enabled(). Cc: Will Deacon Cc: Marc Zyngier Cc: Mark Rutland Cc: Ryan Roberts Signed-off-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20240216235944.3677178-2-ardb+git@google.com Reviewed-by: Itaru Kitayama Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/pgtable.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index b3c716fa8121..8bec85350865 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -699,14 +699,14 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd) #define pud_user(pud) pte_user(pud_pte(pud)) #define pud_user_exec(pud) pte_user_exec(pud_pte(pud)) +static inline bool pgtable_l4_enabled(void); + static inline void set_pud(pud_t *pudp, pud_t pud) { -#ifdef __PAGETABLE_PUD_FOLDED - if (in_swapper_pgdir(pudp)) { + if (!pgtable_l4_enabled() && in_swapper_pgdir(pudp)) { set_swapper_pgd((pgd_t *)pudp, __pgd(pud_val(pud))); return; } -#endif /* __PAGETABLE_PUD_FOLDED */ WRITE_ONCE(*pudp, pud); -- cgit v1.2.3