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

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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: Dan Williams <dan.j.williams@intel.com>
Reported-by: Piotr Balcer <piotr.balcer@intel.com>
Tested-by: Yan Ma <yan.ma@intel.com>
Tested-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Aneesh 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dan Williams 2019-05-13 17:15:33 -07:00 committed by Greg Kroah-Hartman
parent f580a54bbd
commit 58db381368
4 changed files with 16 additions and 18 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
drivers/dax/device.c
View file

@ -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); *pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, *pfn, return vmf_insert_pfn_pmd(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);
vmf->flags & FAULT_FLAG_WRITE);
} }
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD #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); *pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
return vmf_insert_pfn_pud(vmf->vma, vmf->address, vmf->pud, *pfn, return vmf_insert_pfn_pud(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);
vmf->flags & FAULT_FLAG_WRITE);
} }
#else #else
static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax, static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,

6
fs/dax.c
View file

@ -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); trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);
result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn, result = vmf_insert_pfn_pmd(vmf, pfn, write);
write);
break; break;
case IOMAP_UNWRITTEN: case IOMAP_UNWRITTEN:
case IOMAP_HOLE: case IOMAP_HOLE:
@ -1775,8 +1774,7 @@ static vm_fault_t dax_insert_pfn_mkwrite(struct vm_fault *vmf,
break; break;
#ifdef CONFIG_FS_DAX_PMD #ifdef CONFIG_FS_DAX_PMD
case PE_SIZE_PMD: case PE_SIZE_PMD:
ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, ret = vmf_insert_pfn_pmd(vmf, pfn, FAULT_FLAG_WRITE);
pfn, true);
break; break;
#endif #endif
default: default:

6
include/linux/huge_mm.h
View file

@ -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, extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, pgprot_t newprot, unsigned long addr, pgprot_t newprot,
int prot_numa); int prot_numa);
vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write);
pmd_t *pmd, pfn_t pfn, bool write); vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, 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);
enum transparent_hugepage_flag { enum transparent_hugepage_flag {
TRANSPARENT_HUGEPAGE_FLAG, TRANSPARENT_HUGEPAGE_FLAG,
TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,

16
mm/huge_memory.c
View file

@ -772,11 +772,13 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
pte_free(mm, pgtable); pte_free(mm, pgtable);
} }
vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write)
pmd_t *pmd, 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; pgprot_t pgprot = vma->vm_page_prot;
pgtable_t pgtable = NULL; pgtable_t pgtable = NULL;
/* /*
* If we had pmd_special, we could avoid all these restrictions, * If we had pmd_special, we could avoid all these restrictions,
* but we need to be consistent with PTEs and architectures that * 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); 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; return VM_FAULT_NOPAGE;
} }
EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd); 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); spin_unlock(ptl);
} }
vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write)
pud_t *pud, 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; pgprot_t pgprot = vma->vm_page_prot;
/* /*
* If we had pud_special, we could avoid all these restrictions, * If we had pud_special, we could avoid all these restrictions,
* but we need to be consistent with PTEs and architectures that * 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); 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; return VM_FAULT_NOPAGE;
} }
EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud); EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud);