From f1be77bb21120b5306b56d6854db1f8eb5c3678b Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 31 Jan 2011 11:30:04 +0100 Subject: [S390] pgtable_list corruption After page_table_free_rcu removed a page from the pgtable_list page_table_free better not add it again. Otherwise a page_table_alloc can reuse a page table fragment that is still in the rcu process. Signed-off-by: Martin Schwidefsky --- arch/s390/mm/pgtable.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 0c719c6..e1850c2 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -336,7 +336,8 @@ void page_table_free(struct mm_struct *mm, unsigned long *table) page->flags ^= bits; if (page->flags & FRAG_MASK) { /* Page now has some free pgtable fragments. */ - list_move(&page->lru, &mm->context.pgtable_list); + if (!list_empty(&page->lru)) + list_move(&page->lru, &mm->context.pgtable_list); page = NULL; } else /* All fragments of the 4K page have been freed. */ -- cgit v1.1