From fce86ff5802bac3a7b19db171aa1949ef9caac31 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 13 May 2019 17:15:33 -0700 Subject: mm/huge_memory: fix vmf_insert_pfn_{pmd, pud}() crash, handle unaligned addresses Starting with c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()") vmf_insert_pfn_pmd() internally calls pmdp_set_access_flags(). That helper enforces a pmd aligned @address argument via VM_BUG_ON() assertion. Update the implementation to take a 'struct vm_fault' argument directly and apply the address alignment fixup internally to fix crash signatures like: kernel BUG at arch/x86/mm/pgtable.c:515! invalid opcode: 0000 [#1] SMP NOPTI CPU: 51 PID: 43713 Comm: java Tainted: G OE 4.19.35 #1 [..] RIP: 0010:pmdp_set_access_flags+0x48/0x50 [..] Call Trace: vmf_insert_pfn_pmd+0x198/0x350 dax_iomap_fault+0xe82/0x1190 ext4_dax_huge_fault+0x103/0x1f0 ? __switch_to_asm+0x40/0x70 __handle_mm_fault+0x3f6/0x1370 ? __switch_to_asm+0x34/0x70 ? __switch_to_asm+0x40/0x70 handle_mm_fault+0xda/0x200 __do_page_fault+0x249/0x4f0 do_page_fault+0x32/0x110 ? page_fault+0x8/0x30 page_fault+0x1e/0x30 Link: http://lkml.kernel.org/r/155741946350.372037.11148198430068238140.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()") Signed-off-by: Dan Williams Reported-by: Piotr Balcer Tested-by: Yan Ma Tested-by: Pankaj Gupta Reviewed-by: Matthew Wilcox Reviewed-by: Jan Kara Reviewed-by: Aneesh Kumar K.V Cc: Chandan Rajendra Cc: Souptick Joarder Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'mm/huge_memory.c') diff --git a/mm/huge_memory.c b/mm/huge_memory.c index b6a34b32d8ac..c314a362c167 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -793,11 +793,13 @@ out_unlock: pte_free(mm, pgtable); } -vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, - pmd_t *pmd, pfn_t pfn, bool write) +vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write) { + unsigned long addr = vmf->address & PMD_MASK; + struct vm_area_struct *vma = vmf->vma; pgprot_t pgprot = vma->vm_page_prot; pgtable_t pgtable = NULL; + /* * If we had pmd_special, we could avoid all these restrictions, * but we need to be consistent with PTEs and architectures that @@ -820,7 +822,7 @@ vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, track_pfn_insert(vma, &pgprot, pfn); - insert_pfn_pmd(vma, addr, pmd, pfn, pgprot, write, pgtable); + insert_pfn_pmd(vma, addr, vmf->pmd, pfn, pgprot, write, pgtable); return VM_FAULT_NOPAGE; } EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd); @@ -869,10 +871,12 @@ out_unlock: spin_unlock(ptl); } -vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, - pud_t *pud, pfn_t pfn, bool write) +vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write) { + unsigned long addr = vmf->address & PUD_MASK; + struct vm_area_struct *vma = vmf->vma; pgprot_t pgprot = vma->vm_page_prot; + /* * If we had pud_special, we could avoid all these restrictions, * but we need to be consistent with PTEs and architectures that @@ -889,7 +893,7 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, track_pfn_insert(vma, &pgprot, pfn); - insert_pfn_pud(vma, addr, pud, pfn, pgprot, write); + insert_pfn_pud(vma, addr, vmf->pud, pfn, pgprot, write); return VM_FAULT_NOPAGE; } EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud); -- cgit v1.2.3-59-g8ed1b