Perforce change 315103

Perforce change 315103

[p4admin]

[-- Attachment #1: Type: text/plain, Size: 2292 bytes --]

Change 315103 by devtools@devtools_gitimport on 2011/11/10 18:21:16

	commit 7bf07f3d4b4358aa6d99a26d7a0165f1e91c3fcc
	Author: Adam Litke <agl@us.ibm.com>
	Date:   Sat Sep 3 15:55:00 2005 -0700
	
	    [PATCH] hugetlb: move stale pte check into huge_pte_alloc()
	
	    Initial Post (Wed, 17 Aug 2005)
	
	    This patch moves the
	    	if (! pte_none(*pte))
	    		hugetlb_clean_stale_pgtable(pte);
	    logic into huge_pte_alloc() so all of its callers can be immune to the bug
	    described by Kenneth Chen at http://lkml.org/lkml/2004/6/16/246
	
	    > It turns out there is a bug in hugetlb_prefault(): with 3 level page table,
	    > huge_pte_alloc() might return a pmd that points to a PTE page. It happens
	    > if the virtual address for hugetlb mmap is recycled from previously used
	    > normal page mmap. free_pgtables() might not scrub the pmd entry on
	    > munmap and hugetlb_prefault skips on any pmd presence regardless what type
	    > it is.
	
	    Unless I am missing something, it seems more correct to place the check inside
	    huge_pte_alloc() to prevent a the same bug wherever a huge pte is allocated.
	    It also allows checking for this condition when lazily faulting huge pages
	    later in the series.
	
	    Signed-off-by: Adam Litke <agl@us.ibm.com>
	    Cc: <linux-mm@kvack.org>
	    Signed-off-by: Andrew Morton <akpm@osdl.org>
	    Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Affected files ...

... //sw/components_third_party/linux/git/master/.versions.submit#1694 edit
... //sw/components_third_party/linux/git/master/component/arch/i386/mm/hugetlbpage.c#4 edit
... //sw/components_third_party/linux/git/master/component/mm/hugetlb.c#4 edit

  http://serv30:8666/315103?ac=10


The information in this email is confidential. It is intended
solely for the addressee. Access to this email by anyone else
is unauthorised. If you are not the intended recipient, any
disclosure, copying, or distribution is prohibited and may be
unlawful. If you have received this email in error please delete
it immediately and contact commercial@sepura.com.

Sepura plc. Registered Office: Radio House, St Andrew’s Road, Cambridge, CB4 1GR, England. Registered in England and Wales. Registration Number 4353801
 

[-- Attachment #2: Type: text/html, Size: 3289 bytes --]