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Revision 0d777df5d8953293be090d9ab5a355db893e8357 authored by Naoya Horiguchi on 11 December 2015, 21:40:49 UTC, committed by Linus Torvalds on 12 December 2015, 18:15:34 UTC 
mm: hugetlb: call huge_pte_alloc() only if ptep is null
 
Currently at the beginning of hugetlb_fault(), we call huge_pte_offset()
and check whether the obtained *ptep is a migration/hwpoison entry or
not.  And if not, then we get to call huge_pte_alloc().  This is racy
because the *ptep could turn into migration/hwpoison entry after the
huge_pte_offset() check.  This race results in BUG_ON in
huge_pte_alloc().

We don't have to call huge_pte_alloc() when the huge_pte_offset()
returns non-NULL, so let's fix this bug with moving the code into else
block.

Note that the *ptep could turn into a migration/hwpoison entry after
this block, but that's not a problem because we have another
!pte_present check later (we never go into hugetlb_no_page() in that
case.)

Fixes: 290408d4a250 ("hugetlb: hugepage migration core")
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>	[2.6.36+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 86fffe4
Raw File
mkuboot.sh 
#!/bin/bash

#
# Build U-Boot image when `mkimage' tool is available.
#

MKIMAGE=$(type -path "${CROSS_COMPILE}mkimage")

if [ -z "${MKIMAGE}" ]; then
	MKIMAGE=$(type -path mkimage)
	if [ -z "${MKIMAGE}" ]; then
		# Doesn't exist
		echo '"mkimage" command not found - U-Boot images will not be built' >&2
		exit 1;
	fi
fi

# Call "mkimage" to create U-Boot image
${MKIMAGE} "$@"
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