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From: Dave Jiang <dave.jiang@intel.com>
To: akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-nvdimm@lists.01.org, jack@suse.com
Subject: Re: [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
Date: Thu, 30 Aug 2018 13:15:52 -0700	[thread overview]
Message-ID: <6fac48b2-6285-c8b2-a3ef-00a70846bed9@intel.com> (raw)
In-Reply-To: <153565954666.35458.15832314745699968487.stgit@djiang5-desk3.ch.intel.com>

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

WARNING: multiple messages have this Message-ID (diff)
From: Dave Jiang <dave.jiang@intel.com>
To: akpm@linux-foundation.org
Cc: jack@suse.com, linux-mm@kvack.org, dan.j.williams@intel.com,
	linux-nvdimm@lists.01.org
Subject: Re: [PATCH] mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
Date: Thu, 30 Aug 2018 13:15:52 -0700	[thread overview]
Message-ID: <6fac48b2-6285-c8b2-a3ef-00a70846bed9@intel.com> (raw)
In-Reply-To: <153565954666.35458.15832314745699968487.stgit@djiang5-desk3.ch.intel.com>

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
> 

  reply	other threads:[~2018-08-30 20:16 UTC|newest]

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

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