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* [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
@ 2018-08-30 20:06 Dave Jiang
  2018-08-30 20:12 ` Jeff Moyer
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Dave Jiang @ 2018-08-30 20:06 UTC (permalink / raw)
  To: akpm; +Cc: linux-mm, jack, linux-nvdimm

It looks like I missed the PUD path when doing VM_MIXEDMAP removal.
This can be triggered by:
1. Boot with memmap=4G!8G
2. build ndctl with destructive flag on
3. make TESTS=device-dax check

[  +0.000675] kernel BUG at mm/huge_memory.c:824!

Applying the same change that was applied to vmf_insert_pfn_pmd() in the
original patch.

Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device dax")

Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 mm/huge_memory.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c3bc7e9c9a2a..533f9b00147d 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
 	 * but we need to be consistent with PTEs and architectures that
 	 * can't support a 'special' bit.
 	 */
-	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
+	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) &&
+			!pfn_t_devmap(pfn));
 	BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
 						(VM_PFNMAP|VM_MIXEDMAP));
 	BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
-	BUG_ON(!pfn_t_devmap(pfn));
 
 	if (addr < vma->vm_start || addr >= vma->vm_end)
 		return VM_FAULT_SIGBUS;

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^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
  2018-08-30 20:06 [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal Dave Jiang
@ 2018-08-30 20:12 ` Jeff Moyer
  2018-08-30 20:28 ` Verma, Vishal L
  2018-08-31 10:22 ` Jan Kara
  2 siblings, 0 replies; 6+ messages in thread
From: Jeff Moyer @ 2018-08-30 20:12 UTC (permalink / raw)
  To: Dave Jiang; +Cc: linux-mm, akpm, linux-nvdimm, jack

Dave Jiang <dave.jiang@intel.com> writes:

> It looks like I missed the PUD path when doing VM_MIXEDMAP removal.
> This can be triggered by:
> 1. Boot with memmap=4G!8G
> 2. build ndctl with destructive flag on
> 3. make TESTS=device-dax check
>
> [  +0.000675] kernel BUG at mm/huge_memory.c:824!
>
> Applying the same change that was applied to vmf_insert_pfn_pmd() in the
> original patch.
>
> Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device dax")
>
> Reported-by: Vishal Verma <vishal.l.verma@intel.com>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Acked-by: Jeff Moyer <jmoyer@redhat.com>


> ---
>  mm/huge_memory.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index c3bc7e9c9a2a..533f9b00147d 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
>  	 * but we need to be consistent with PTEs and architectures that
>  	 * can't support a 'special' bit.
>  	 */
> -	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
> +	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) &&
> +			!pfn_t_devmap(pfn));
>  	BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
>  						(VM_PFNMAP|VM_MIXEDMAP));
>  	BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
> -	BUG_ON(!pfn_t_devmap(pfn));
>  
>  	if (addr < vma->vm_start || addr >= vma->vm_end)
>  		return VM_FAULT_SIGBUS;
>
> _______________________________________________
> Linux-nvdimm mailing list
> Linux-nvdimm@lists.01.org
> https://lists.01.org/mailman/listinfo/linux-nvdimm
_______________________________________________
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Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
  2018-08-30 20:06 [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal Dave Jiang
  2018-08-30 20:12 ` Jeff Moyer
@ 2018-08-30 20:28 ` Verma, Vishal L
  2018-08-31 10:22 ` Jan Kara
  2 siblings, 0 replies; 6+ messages in thread
From: Verma, Vishal L @ 2018-08-30 20:28 UTC (permalink / raw)
  To: Jiang, Dave, akpm; +Cc: linux-mm, jack, linux-nvdimm


On Thu, 2018-08-30 at 13:06 -0700, Dave Jiang wrote:
> It looks like I missed the PUD path when doing VM_MIXEDMAP removal.
> This can be triggered by:
> 1. Boot with memmap=4G!8G
> 2. build ndctl with destructive flag on
> 3. make TESTS=device-dax check
> 
> [  +0.000675] kernel BUG at mm/huge_memory.c:824!
> 
> Applying the same change that was applied to vmf_insert_pfn_pmd() in
> the
> original patch.
> 
> Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device
> dax")
> 
> Reported-by: Vishal Verma <vishal.l.verma@intel.com>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  mm/huge_memory.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

This fixes the unit test failure, feel free to add:
Tested-by: Vishal Verma <vishal.l.verma@intel.com>

> 
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index c3bc7e9c9a2a..533f9b00147d 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct
> vm_area_struct *vma, unsigned long addr,
>  	 * but we need to be consistent with PTEs and architectures
> that
>  	 * can't support a 'special' bit.
>  	 */
> -	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
> +	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) &&
> +			!pfn_t_devmap(pfn));
>  	BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
>  						(VM_PFNMAP|VM_MIXEDM
> AP));
>  	BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma-
> >vm_flags));
> -	BUG_ON(!pfn_t_devmap(pfn));
>  
>  	if (addr < vma->vm_start || addr >= vma->vm_end)
>  		return VM_FAULT_SIGBUS;
> 
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Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
  2018-08-30 20:06 [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal Dave Jiang
  2018-08-30 20:12 ` Jeff Moyer
  2018-08-30 20:28 ` Verma, Vishal L
@ 2018-08-31 10:22 ` Jan Kara
  2 siblings, 0 replies; 6+ messages in thread
From: Jan Kara @ 2018-08-31 10:22 UTC (permalink / raw)
  To: Dave Jiang; +Cc: linux-nvdimm, linux-mm, jack, akpm

On Thu 30-08-18 13:06:13, Dave Jiang wrote:
> It looks like I missed the PUD path when doing VM_MIXEDMAP removal.
> This can be triggered by:
> 1. Boot with memmap=4G!8G
> 2. build ndctl with destructive flag on
> 3. make TESTS=device-dax check
> 
> [  +0.000675] kernel BUG at mm/huge_memory.c:824!
> 
> Applying the same change that was applied to vmf_insert_pfn_pmd() in the
> original patch.
> 
> Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device dax")
> 
> Reported-by: Vishal Verma <vishal.l.verma@intel.com>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Looks good. You can add:

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

								Honza

> ---
>  mm/huge_memory.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index c3bc7e9c9a2a..533f9b00147d 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
>  	 * but we need to be consistent with PTEs and architectures that
>  	 * can't support a 'special' bit.
>  	 */
> -	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
> +	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) &&
> +			!pfn_t_devmap(pfn));
>  	BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
>  						(VM_PFNMAP|VM_MIXEDMAP));
>  	BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
> -	BUG_ON(!pfn_t_devmap(pfn));
>  
>  	if (addr < vma->vm_start || addr >= vma->vm_end)
>  		return VM_FAULT_SIGBUS;
> 
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR
_______________________________________________
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Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
  2018-08-30 20:05 Dave Jiang
@ 2018-08-30 20:15 ` Dave Jiang
  0 siblings, 0 replies; 6+ messages in thread
From: Dave Jiang @ 2018-08-30 20:15 UTC (permalink / raw)
  To: akpm; +Cc: linux-mm, linux-nvdimm, jack

Please ignore this email. It had malformed mail header. I have resent a
non-broken one, which looks like has been ack'ed by Jeff.


On 08/30/2018 01:05 PM, Dave Jiang wrote:
> It looks like I missed the PUD path when doing VM_MIXEDMAP removal.
> This can be triggered by:
> 1. Boot with memmap=4G!8G
> 2. build ndctl with destructive flag on
> 3. make TESTS=device-dax check
> 
> [  +0.000675] kernel BUG at mm/huge_memory.c:824!
> 
> Applying the same change that was applied to vmf_insert_pfn_pmd() in the
> original patch.
> 
> Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device dax")
> 
> Reported-by: Vishal Verma <vishal.l.verma@intel.com>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  mm/huge_memory.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index c3bc7e9c9a2a..533f9b00147d 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
>  	 * but we need to be consistent with PTEs and architectures that
>  	 * can't support a 'special' bit.
>  	 */
> -	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
> +	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) &&
> +			!pfn_t_devmap(pfn));
>  	BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
>  						(VM_PFNMAP|VM_MIXEDMAP));
>  	BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
> -	BUG_ON(!pfn_t_devmap(pfn));
>  
>  	if (addr < vma->vm_start || addr >= vma->vm_end)
>  		return VM_FAULT_SIGBUS;
> 
> _______________________________________________
> Linux-nvdimm mailing list
> Linux-nvdimm@lists.01.org
> https://lists.01.org/mailman/listinfo/linux-nvdimm
> 
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

^ permalink raw reply	[flat|nested] 6+ messages in thread
* [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
@ 2018-08-30 20:05 Dave Jiang
  2018-08-30 20:15 ` Dave Jiang
  0 siblings, 1 reply; 6+ messages in thread
From: Dave Jiang @ 2018-08-30 20:05 UTC (permalink / raw)
  To: akpm; +Cc: jack, linux-mm, dan.j.williams, , linux-nvdimm

It looks like I missed the PUD path when doing VM_MIXEDMAP removal.
This can be triggered by:
1. Boot with memmap=4G!8G
2. build ndctl with destructive flag on
3. make TESTS=device-dax check

[  +0.000675] kernel BUG at mm/huge_memory.c:824!

Applying the same change that was applied to vmf_insert_pfn_pmd() in the
original patch.

Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device dax")

Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 mm/huge_memory.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c3bc7e9c9a2a..533f9b00147d 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
 	 * but we need to be consistent with PTEs and architectures that
 	 * can't support a 'special' bit.
 	 */
-	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
+	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) &&
+			!pfn_t_devmap(pfn));
 	BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
 						(VM_PFNMAP|VM_MIXEDMAP));
 	BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
-	BUG_ON(!pfn_t_devmap(pfn));
 
 	if (addr < vma->vm_start || addr >= vma->vm_end)
 		return VM_FAULT_SIGBUS;

_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-08-31 10:22 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-08-30 20:06 [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal Dave Jiang
2018-08-30 20:12 ` Jeff Moyer
2018-08-30 20:28 ` Verma, Vishal L
2018-08-31 10:22 ` Jan Kara
  -- strict thread matches above, loose matches on Subject: below --
2018-08-30 20:05 Dave Jiang
2018-08-30 20:15 ` Dave Jiang

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