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Commit 58db3813 authored by Dan Williams's avatar Dan Williams Committed by Greg Kroah-Hartman
Browse files

mm/huge_memory: fix vmf_insert_pfn_{pmd, pud}() crash, handle unaligned addresses 

commit fce86ff5802bac3a7b19db171aa1949ef9caac31 upstream.

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: default avatarDan Williams <dan.j.williams@intel.com>
Reported-by: default avatarPiotr Balcer <piotr.balcer@intel.com>
Tested-by: default avatarYan Ma <yan.ma@intel.com>
Tested-by: default avatarPankaj Gupta <pagupta@redhat.com>
Reviewed-by: default avatarMatthew Wilcox <willy@infradead.org>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Chandan Rajendra <chandan@linux.ibm.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f580a54b

drivers/dax/device.c

+2 −4
Original line number Diff line number Diff line
@@ -325,8 +325,7 @@ static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax, 


	*pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);



	return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, *pfn,

			vmf->flags & FAULT_FLAG_WRITE);

	return vmf_insert_pfn_pmd(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);

}



#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
@@ -376,8 +375,7 @@ static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax, 


	*pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);



	return vmf_insert_pfn_pud(vmf->vma, vmf->address, vmf->pud, *pfn,

			vmf->flags & FAULT_FLAG_WRITE);

	return vmf_insert_pfn_pud(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);

}

#else

static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,

fs/dax.c

+2 −4
Original line number Diff line number Diff line
@@ -1660,8 +1660,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, 
		}



		trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);

		result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn,

					    write);

		result = vmf_insert_pfn_pmd(vmf, pfn, write);

		break;

	case IOMAP_UNWRITTEN:

	case IOMAP_HOLE:
@@ -1775,8 +1774,7 @@ static vm_fault_t dax_insert_pfn_mkwrite(struct vm_fault *vmf, 
		break;

#ifdef CONFIG_FS_DAX_PMD

	case PE_SIZE_PMD:

		ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,

			pfn, true);

		ret = vmf_insert_pfn_pmd(vmf, pfn, FAULT_FLAG_WRITE);

		break;

#endif

	default:

include/linux/huge_mm.h

+2 −4
Original line number Diff line number Diff line
@@ -47,10 +47,8 @@ extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, 
extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,

			unsigned long addr, pgprot_t newprot,

			int prot_numa);

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_pud(struct vm_area_struct *vma, unsigned long addr,

			pud_t *pud, pfn_t pfn, bool write);

vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write);

vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write);

enum transparent_hugepage_flag {

	TRANSPARENT_HUGEPAGE_FLAG,

	TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,

mm/huge_memory.c

+10 −6
Original line number Diff line number Diff line
@@ -772,11 +772,13 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, 
		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
@@ -799,7 +801,7 @@ 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);
@@ -848,10 +850,12 @@ static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, 
	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
@@ -868,7 +872,7 @@ 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);