From 50c25ee97cf6ab011542167ab590c17012cea4ed Mon Sep 17 00:00:00 2001 From: Thomas Bogendoerfer Date: Fri, 4 Jun 2021 20:01:08 -0700 Subject: Revert "MIPS: make userspace mapping young by default" This reverts commit f685a533a7fab35c5d069dcd663f59c8e4171a75. The MIPS cache flush logic needs to know whether the mapping was already established to decide how to flush caches. This is done by checking the valid bit in the PTE. The commit above breaks this logic by setting the valid in the PTE in new mappings, which causes kernel crashes. Link: https://lkml.kernel.org/r/20210526094335.92948-1-tsbogend@alpha.franken.de Fixes: f685a533a7f ("MIPS: make userspace mapping young by default") Reported-by: Zhou Yanjie Signed-off-by: Thomas Bogendoerfer Cc: Huang Pei Cc: Nicholas Piggin Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'mm/memory.c') diff --git a/mm/memory.c b/mm/memory.c index 730daa00952b..f3ffab9b9e39 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2939,6 +2939,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) } flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); entry = mk_pte(new_page, vma->vm_page_prot); + entry = pte_sw_mkyoung(entry); entry = maybe_mkwrite(pte_mkdirty(entry), vma); /* @@ -3602,6 +3603,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) __SetPageUptodate(page); entry = mk_pte(page, vma->vm_page_prot); + entry = pte_sw_mkyoung(entry); if (vma->vm_flags & VM_WRITE) entry = pte_mkwrite(pte_mkdirty(entry)); @@ -3786,6 +3788,8 @@ void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr) if (prefault && arch_wants_old_prefaulted_pte()) entry = pte_mkold(entry); + else + entry = pte_sw_mkyoung(entry); if (write) entry = maybe_mkwrite(pte_mkdirty(entry), vma); -- cgit