>From c92522f6199055cd609ddd785dc9d8e85153e3b4 Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen Date: Tue, 6 Sep 2022 09:51:59 +0300 Subject: [PATCH] x86/fault: Simplify PFN calculation in handle_user_rmp_fault() Use functions in asm/pgtable.h to calculate the PFN for the address inside PTE's page directory. PG_LEVEL_4K PTE's obviously do not have a page directory but it is not an issue as: page_level_mask(PG_LEVEL_4K - 1) == page_level_mask(PG_LEVEL_NONE) == 0 Signed-off-by: Jarkko Sakkinen --- arch/x86/mm/fault.c | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 6404ef73eb56..28b3f80611a3 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1219,11 +1219,6 @@ do_kern_addr_fault(struct pt_regs *regs, unsigned long hw_error_code, } NOKPROBE_SYMBOL(do_kern_addr_fault); -static inline size_t pages_per_hpage(int level) -{ - return page_level_size(level) / PAGE_SIZE; -} - /* * Return 1 if the caller need to retry, 0 if it the address need to be split * in order to resolve the fault. @@ -1248,15 +1243,8 @@ static int handle_user_rmp_page_fault(struct pt_regs *regs, unsigned long error_ if (!pte || !pte_present(*pte)) return 1; - pfn = pte_pfn(*pte); - - /* If its large page then calculte the fault pfn */ - if (level > PG_LEVEL_4K) { - unsigned long mask; - - mask = pages_per_hpage(level) - pages_per_hpage(level - 1); - pfn |= (address >> PAGE_SHIFT) & mask; - } + /* Calculate PFN inside the page directory: */ + pfn = pte_pfn(*pte) | PFN_DOWN(address & page_level_mask(level - 1)); /* * If its a guest private page, then the fault cannot be resolved. -- 2.37.2