From df912ea4ae7233d1504fbd861ee127bd7ee5781d Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 25 Sep 2007 11:50:00 -0700 Subject: [PATCH] xen: execve's error paths don't pin the mm before unpinning execve's error paths don't activate (and therefore pin) the mm before calling exit_mmap to free it up, so don't try to unpin unless it is actually pinned. This prevents a BUG_ON from triggering. Signed-off-by: Jeremy Fitzhardinge Cc: Christian Ostheimer Signed-off-by: Linus Torvalds --- arch/i386/xen/mmu.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/i386/xen/mmu.c b/arch/i386/xen/mmu.c index 4ae038aa6c24..874db0cd1d2a 100644 --- a/arch/i386/xen/mmu.c +++ b/arch/i386/xen/mmu.c @@ -559,6 +559,9 @@ void xen_exit_mmap(struct mm_struct *mm) put_cpu(); spin_lock(&mm->page_table_lock); - xen_pgd_unpin(mm->pgd); + + /* pgd may not be pinned in the error exit path of execve */ + if (PagePinned(virt_to_page(mm->pgd))) + xen_pgd_unpin(mm->pgd); spin_unlock(&mm->page_table_lock); } -- 2.39.5