Commit 96268889 authored Oct 31, 2006 by Hugh Dickins Committed by Paul Mackerras Nov 01, 2006

[POWERPC] Make high hugepage areas preempt safe



Checking source for other get_paca()->field preemption dangers found that
open_high_hpage_areas does a structure copy into its paca while preemption
is enabled: unsafe however gcc accomplishes it.  Just remove that copy:
it's done safely afterwards by on_each_cpu, as in open_low_hpage_areas.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

parent 5fe8e8b8

arch/powerpc/mm/hugetlbpage.c

+0 −3

Original line number	Original line	Diff line number	Diff line
	@@ -480,9 +480,6 @@ static int open_high_hpage_areas(struct mm_struct *mm, u16 newareas)

	mm->context.high_htlb_areas \|= newareas;		mm->context.high_htlb_areas \|= newareas;

	/* update the paca copy of the context struct */
	get_paca()->context = mm->context;

	/* the context change must make it to memory before the flush,		/* the context change must make it to memory before the flush,
	* so that further SLB misses do the right thing. */		* so that further SLB misses do the right thing. */
	mb();		mb();