mm: Preserve _PAGE_DEVMAP across mprotect() calls
diff mbox series

Message ID 20181009101917.32497-1-jack@suse.cz
State New
Headers show
Series
  • mm: Preserve _PAGE_DEVMAP across mprotect() calls
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Commit Message

Jan Kara Oct. 9, 2018, 10:19 a.m. UTC
Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a
result we will see warnings such as:

BUG: Bad page map in process JobWrk0013  pte:800001803875ea25 pmd:7624381067
addr:00007f0930720000 vm_flags:280000f9 anon_vma:          (null) mapping:ffff97f2384056f0 index:0
file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage:          (null)
CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G        W          4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased)
Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018
Call Trace:
 dump_stack+0x5a/0x75
 print_bad_pte+0x217/0x2c0
 ? enqueue_task_fair+0x76/0x9f0
 _vm_normal_page+0xe5/0x100
 zap_pte_range+0x148/0x740
 unmap_page_range+0x39a/0x4b0
 unmap_vmas+0x42/0x90
 unmap_region+0x99/0xf0
 ? vma_gap_callbacks_rotate+0x1a/0x20
 do_munmap+0x255/0x3a0
 vm_munmap+0x54/0x80
 SyS_munmap+0x1d/0x30
 do_syscall_64+0x74/0x150
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
...

when mprotect(2) gets used on DAX mappings. Also there is a wide variety
of other failures that can result from the missing _PAGE_DEVMAP flag
when the area gets used by get_user_pages() later.

Fix the problem by including _PAGE_DEVMAP in a set of flags that get
preserved by mprotect(2).

Fixes: 69660fd797c3 ("x86, mm: introduce _PAGE_DEVMAP")
Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
---
 arch/powerpc/include/asm/book3s/64/pgtable.h | 4 ++--
 arch/x86/include/asm/pgtable_types.h         | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

Comments

Michal Hocko Oct. 9, 2018, 1:07 p.m. UTC | #1
On Tue 09-10-18 12:19:17, Jan Kara wrote:
> Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a
> result we will see warnings such as:
> 
> BUG: Bad page map in process JobWrk0013  pte:800001803875ea25 pmd:7624381067
> addr:00007f0930720000 vm_flags:280000f9 anon_vma:          (null) mapping:ffff97f2384056f0 index:0
> file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage:          (null)
> CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G        W          4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased)
> Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018
> Call Trace:
>  dump_stack+0x5a/0x75
>  print_bad_pte+0x217/0x2c0
>  ? enqueue_task_fair+0x76/0x9f0
>  _vm_normal_page+0xe5/0x100
>  zap_pte_range+0x148/0x740
>  unmap_page_range+0x39a/0x4b0
>  unmap_vmas+0x42/0x90
>  unmap_region+0x99/0xf0
>  ? vma_gap_callbacks_rotate+0x1a/0x20
>  do_munmap+0x255/0x3a0
>  vm_munmap+0x54/0x80
>  SyS_munmap+0x1d/0x30
>  do_syscall_64+0x74/0x150
>  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
> ...
> 
> when mprotect(2) gets used on DAX mappings. Also there is a wide variety
> of other failures that can result from the missing _PAGE_DEVMAP flag
> when the area gets used by get_user_pages() later.
> 
> Fix the problem by including _PAGE_DEVMAP in a set of flags that get
> preserved by mprotect(2).
> 
> Fixes: 69660fd797c3 ("x86, mm: introduce _PAGE_DEVMAP")
> Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64")
> CC: stable@vger.kernel.org
> Signed-off-by: Jan Kara <jack@suse.cz>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  arch/powerpc/include/asm/book3s/64/pgtable.h | 4 ++--
>  arch/x86/include/asm/pgtable_types.h         | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
> index 2fdc865ca374..2a2486526d1f 100644
> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
> @@ -114,7 +114,7 @@
>   */
>  #define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
>  			 _PAGE_ACCESSED | H_PAGE_THP_HUGE | _PAGE_PTE | \
> -			 _PAGE_SOFT_DIRTY)
> +			 _PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
>  /*
>   * user access blocked by key
>   */
> @@ -132,7 +132,7 @@
>   */
>  #define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
>  			 _PAGE_ACCESSED | _PAGE_SPECIAL | _PAGE_PTE |	\
> -			 _PAGE_SOFT_DIRTY)
> +			 _PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
>  
>  #define H_PTE_PKEY  (H_PTE_PKEY_BIT0 | H_PTE_PKEY_BIT1 | H_PTE_PKEY_BIT2 | \
>  		     H_PTE_PKEY_BIT3 | H_PTE_PKEY_BIT4)
> diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
> index b64acb08a62b..106b7d0e2dae 100644
> --- a/arch/x86/include/asm/pgtable_types.h
> +++ b/arch/x86/include/asm/pgtable_types.h
> @@ -124,7 +124,7 @@
>   */
>  #define _PAGE_CHG_MASK	(PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT |		\
>  			 _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY |	\
> -			 _PAGE_SOFT_DIRTY)
> +			 _PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
>  #define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE)
>  
>  /*
> -- 
> 2.16.4
Dan Williams Oct. 9, 2018, 5:55 p.m. UTC | #2
On Tue, Oct 9, 2018 at 3:19 AM Jan Kara <jack@suse.cz> wrote:
>
> Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a
> result we will see warnings such as:
>
> BUG: Bad page map in process JobWrk0013  pte:800001803875ea25 pmd:7624381067
> addr:00007f0930720000 vm_flags:280000f9 anon_vma:          (null) mapping:ffff97f2384056f0 index:0
> file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage:          (null)
> CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G        W          4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased)
> Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018
> Call Trace:
>  dump_stack+0x5a/0x75
>  print_bad_pte+0x217/0x2c0
>  ? enqueue_task_fair+0x76/0x9f0
>  _vm_normal_page+0xe5/0x100
>  zap_pte_range+0x148/0x740
>  unmap_page_range+0x39a/0x4b0
>  unmap_vmas+0x42/0x90
>  unmap_region+0x99/0xf0
>  ? vma_gap_callbacks_rotate+0x1a/0x20
>  do_munmap+0x255/0x3a0
>  vm_munmap+0x54/0x80
>  SyS_munmap+0x1d/0x30
>  do_syscall_64+0x74/0x150
>  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
> ...
>
> when mprotect(2) gets used on DAX mappings. Also there is a wide variety
> of other failures that can result from the missing _PAGE_DEVMAP flag
> when the area gets used by get_user_pages() later.
>
> Fix the problem by including _PAGE_DEVMAP in a set of flags that get
> preserved by mprotect(2).
>
> Fixes: 69660fd797c3 ("x86, mm: introduce _PAGE_DEVMAP")
> Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64")
> CC: stable@vger.kernel.org
> Signed-off-by: Jan Kara <jack@suse.cz>

Looks good, do you want me to take this upstream along with the livelock fix?
Johannes Thumshirn Oct. 9, 2018, 6:38 p.m. UTC | #3
Looks good,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Jan Kara Oct. 10, 2018, 7:45 a.m. UTC | #4
On Tue 09-10-18 10:55:14, Dan Williams wrote:
> On Tue, Oct 9, 2018 at 3:19 AM Jan Kara <jack@suse.cz> wrote:
> >
> > Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a
> > result we will see warnings such as:
> >
> > BUG: Bad page map in process JobWrk0013  pte:800001803875ea25 pmd:7624381067
> > addr:00007f0930720000 vm_flags:280000f9 anon_vma:          (null) mapping:ffff97f2384056f0 index:0
> > file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage:          (null)
> > CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G        W          4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased)
> > Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018
> > Call Trace:
> >  dump_stack+0x5a/0x75
> >  print_bad_pte+0x217/0x2c0
> >  ? enqueue_task_fair+0x76/0x9f0
> >  _vm_normal_page+0xe5/0x100
> >  zap_pte_range+0x148/0x740
> >  unmap_page_range+0x39a/0x4b0
> >  unmap_vmas+0x42/0x90
> >  unmap_region+0x99/0xf0
> >  ? vma_gap_callbacks_rotate+0x1a/0x20
> >  do_munmap+0x255/0x3a0
> >  vm_munmap+0x54/0x80
> >  SyS_munmap+0x1d/0x30
> >  do_syscall_64+0x74/0x150
> >  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
> > ...
> >
> > when mprotect(2) gets used on DAX mappings. Also there is a wide variety
> > of other failures that can result from the missing _PAGE_DEVMAP flag
> > when the area gets used by get_user_pages() later.
> >
> > Fix the problem by including _PAGE_DEVMAP in a set of flags that get
> > preserved by mprotect(2).
> >
> > Fixes: 69660fd797c3 ("x86, mm: introduce _PAGE_DEVMAP")
> > Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64")
> > CC: stable@vger.kernel.org
> > Signed-off-by: Jan Kara <jack@suse.cz>
> 
> Looks good, do you want me to take this upstream along with the livelock fix?

Yes, I think that would be best. Thanks!

								Honza

Patch
diff mbox series

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 2fdc865ca374..2a2486526d1f 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -114,7 +114,7 @@ 
  */
 #define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
 			 _PAGE_ACCESSED | H_PAGE_THP_HUGE | _PAGE_PTE | \
-			 _PAGE_SOFT_DIRTY)
+			 _PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
 /*
  * user access blocked by key
  */
@@ -132,7 +132,7 @@ 
  */
 #define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
 			 _PAGE_ACCESSED | _PAGE_SPECIAL | _PAGE_PTE |	\
-			 _PAGE_SOFT_DIRTY)
+			 _PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
 
 #define H_PTE_PKEY  (H_PTE_PKEY_BIT0 | H_PTE_PKEY_BIT1 | H_PTE_PKEY_BIT2 | \
 		     H_PTE_PKEY_BIT3 | H_PTE_PKEY_BIT4)
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index b64acb08a62b..106b7d0e2dae 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -124,7 +124,7 @@ 
  */
 #define _PAGE_CHG_MASK	(PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT |		\
 			 _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY |	\
-			 _PAGE_SOFT_DIRTY)
+			 _PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
 #define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE)
 
 /*