mm/huge_memory: Fix vmf_insert_pfn_{pmd, pud}() crash, handle unaligned addresses
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Message ID 155741946350.372037.11148198430068238140.stgit@dwillia2-desk3.amr.corp.intel.com
State New
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Series
  • mm/huge_memory: Fix vmf_insert_pfn_{pmd, pud}() crash, handle unaligned addresses
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Commit Message

Dan Williams May 9, 2019, 4:31 p.m. UTC
Starting with commit 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

Cc: <stable@vger.kernel.org>
Fixes: c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()")
Reported-by: Piotr Balcer <piotr.balcer@intel.com>
Tested-by: Yan Ma <yan.ma@intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Chandan Rajendra <chandan@linux.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---

 drivers/dax/device.c    |    6 ++----
 fs/dax.c                |    6 ++----
 include/linux/huge_mm.h |    6 ++----
 mm/huge_memory.c        |   16 ++++++++++------
 4 files changed, 16 insertions(+), 18 deletions(-)

Comments

Matthew Wilcox May 9, 2019, 5:42 p.m. UTC | #1
On Thu, May 09, 2019 at 09:31:41AM -0700, Dan Williams wrote:
> diff --git a/drivers/dax/device.c b/drivers/dax/device.c
> index e428468ab661..996d68ff992a 100644
> --- a/drivers/dax/device.c
> +++ b/drivers/dax/device.c
> @@ -184,8 +184,7 @@ static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax,
> +	return vmf_insert_pfn_pmd(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);

I think we can ditch the third parameter too.  Going through the callers ...

> @@ -235,8 +234,7 @@ static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
> +	return vmf_insert_pfn_pud(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);

> @@ -1575,8 +1575,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
> +		result = vmf_insert_pfn_pmd(vmf, pfn, write);

This 'write' parameter came earlier from:

        bool write = vmf->flags & FAULT_FLAG_WRITE;

and it is not modified subsequently.

> @@ -1686,8 +1685,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t pfn, unsigned int order)
> +		ret = vmf_insert_pfn_pmd(vmf, pfn, FAULT_FLAG_WRITE);

If FAULT_FLAG_WRITE is not set in a mkwrite handler, I don't know
what's gone wrong with the world.

Even without these changes,

Reviewed-by: Matthew Wilcox <willy@infradead.org>
Jan Kara May 9, 2019, 7:32 p.m. UTC | #2
On Thu 09-05-19 09:31:41, Dan Williams wrote:
> Starting with commit 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
> 
> Cc: <stable@vger.kernel.org>
> Fixes: c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()")
> Reported-by: Piotr Balcer <piotr.balcer@intel.com>
> Tested-by: Yan Ma <yan.ma@intel.com>
> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> Cc: Chandan Rajendra <chandan@linux.ibm.com>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Matthew Wilcox <willy@infradead.org>
> Cc: Souptick Joarder <jrdr.linux@gmail.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
> 
>  drivers/dax/device.c    |    6 ++----
>  fs/dax.c                |    6 ++----
>  include/linux/huge_mm.h |    6 ++----
>  mm/huge_memory.c        |   16 ++++++++++------
>  4 files changed, 16 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/dax/device.c b/drivers/dax/device.c
> index e428468ab661..996d68ff992a 100644
> --- a/drivers/dax/device.c
> +++ b/drivers/dax/device.c
> @@ -184,8 +184,7 @@ 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
> @@ -235,8 +234,7 @@ 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,
> diff --git a/fs/dax.c b/fs/dax.c
> index e5e54da1715f..83009875308c 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1575,8 +1575,7 @@ 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:
> @@ -1686,8 +1685,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t pfn, unsigned int order)
>  		ret = vmf_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn);
>  #ifdef CONFIG_FS_DAX_PMD
>  	else if (order == PMD_ORDER)
> -		ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
> -			pfn, true);
> +		ret = vmf_insert_pfn_pmd(vmf, pfn, FAULT_FLAG_WRITE);
>  #endif
>  	else
>  		ret = VM_FAULT_FALLBACK;
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 381e872bfde0..7cd5c150c21d 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -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,
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 165ea46bf149..4310c6e9e5a3 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -793,11 +793,13 @@ 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
> @@ -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 @@ 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
> @@ -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);
>
Pankaj Gupta May 10, 2019, 5:42 a.m. UTC | #3
> 
> Starting with commit 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
> 
> Cc: vger.kernel.org>
> Fixes: c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by
> insert_pfn_pmd()")
> Reported-by: Piotr Balcer <piotr.balcer@intel.com>
> Tested-by: Yan Ma <yan.ma@intel.com>
> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> Cc: Chandan Rajendra <chandan@linux.ibm.com>
> Cc: Jan Kara suse.cz>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Matthew Wilcox infradead.org>
> Cc: Souptick Joarder <jrdr.linux@gmail.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
> 
>  drivers/dax/device.c    |    6 ++----
>  fs/dax.c                |    6 ++----
>  include/linux/huge_mm.h |    6 ++----
>  mm/huge_memory.c        |   16 ++++++++++------
>  4 files changed, 16 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/dax/device.c b/drivers/dax/device.c
> index e428468ab661..996d68ff992a 100644
> --- a/drivers/dax/device.c
> +++ b/drivers/dax/device.c
> @@ -184,8 +184,7 @@ 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
> @@ -235,8 +234,7 @@ 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,
> diff --git a/fs/dax.c b/fs/dax.c
> index e5e54da1715f..83009875308c 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1575,8 +1575,7 @@ 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:
> @@ -1686,8 +1685,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t pfn,
> unsigned int order)
>                  ret = vmf_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn);
>  #ifdef CONFIG_FS_DAX_PMD
>          else if (order == PMD_ORDER)
> -                ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
> -                        pfn, true);
> +                ret = vmf_insert_pfn_pmd(vmf, pfn, FAULT_FLAG_WRITE);
>  #endif
>          else
>                  ret = VM_FAULT_FALLBACK;
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 381e872bfde0..7cd5c150c21d 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -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,
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 165ea46bf149..4310c6e9e5a3 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -793,11 +793,13 @@ 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
> @@ -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 @@ 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
> @@ -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);
> 

Thanks for the patch. 
This patch solves the issue faced while testing virtio pmem.

Tested-by: Pankaj Gupta <pagupta@redhat.com>

>
Aneesh Kumar K.V May 10, 2019, 9:02 p.m. UTC | #4
Dan Williams <dan.j.williams@intel.com> writes:

> Starting with commit 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
>

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>

> Cc: <stable@vger.kernel.org>
> Fixes: c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()")
> Reported-by: Piotr Balcer <piotr.balcer@intel.com>
> Tested-by: Yan Ma <yan.ma@intel.com>
> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> Cc: Chandan Rajendra <chandan@linux.ibm.com>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Matthew Wilcox <willy@infradead.org>
> Cc: Souptick Joarder <jrdr.linux@gmail.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>
>  drivers/dax/device.c    |    6 ++----
>  fs/dax.c                |    6 ++----
>  include/linux/huge_mm.h |    6 ++----
>  mm/huge_memory.c        |   16 ++++++++++------
>  4 files changed, 16 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/dax/device.c b/drivers/dax/device.c
> index e428468ab661..996d68ff992a 100644
> --- a/drivers/dax/device.c
> +++ b/drivers/dax/device.c
> @@ -184,8 +184,7 @@ 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
> @@ -235,8 +234,7 @@ 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,
> diff --git a/fs/dax.c b/fs/dax.c
> index e5e54da1715f..83009875308c 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1575,8 +1575,7 @@ 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:
> @@ -1686,8 +1685,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t pfn, unsigned int order)
>  		ret = vmf_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn);
>  #ifdef CONFIG_FS_DAX_PMD
>  	else if (order == PMD_ORDER)
> -		ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
> -			pfn, true);
> +		ret = vmf_insert_pfn_pmd(vmf, pfn, FAULT_FLAG_WRITE);
>  #endif
>  	else
>  		ret = VM_FAULT_FALLBACK;
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 381e872bfde0..7cd5c150c21d 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -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,
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 165ea46bf149..4310c6e9e5a3 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -793,11 +793,13 @@ 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
> @@ -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 @@ 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
> @@ -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);

Patch
diff mbox series

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index e428468ab661..996d68ff992a 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -184,8 +184,7 @@  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
@@ -235,8 +234,7 @@  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,
diff --git a/fs/dax.c b/fs/dax.c
index e5e54da1715f..83009875308c 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1575,8 +1575,7 @@  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:
@@ -1686,8 +1685,7 @@  dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t pfn, unsigned int order)
 		ret = vmf_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn);
 #ifdef CONFIG_FS_DAX_PMD
 	else if (order == PMD_ORDER)
-		ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
-			pfn, true);
+		ret = vmf_insert_pfn_pmd(vmf, pfn, FAULT_FLAG_WRITE);
 #endif
 	else
 		ret = VM_FAULT_FALLBACK;
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 381e872bfde0..7cd5c150c21d 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -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,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 165ea46bf149..4310c6e9e5a3 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -793,11 +793,13 @@  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
@@ -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 @@  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
@@ -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);