From 8f5cd76c185a4c8aeb5fe1e560e3612bfc050c35 Mon Sep 17 00:00:00 2001
From: Hugh Dickins <hugh@veritas.com>
Date: Sat, 29 Oct 2005 18:16:38 -0700
Subject: [PATCH] mm: uml pte atomicity

There's usually a good reason when a pte is examined without the lock; but it
makes me nervous when the pointer is dereferenced more than once.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 arch/um/kernel/process_kern.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

(limited to 'arch/um')

diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process_kern.c
index 0d73ceeece7..34b54a3e213 100644
--- a/arch/um/kernel/process_kern.c
+++ b/arch/um/kernel/process_kern.c
@@ -222,6 +222,7 @@ void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte;
+	pte_t ptent;
 
 	if(task->mm == NULL) 
 		return(ERR_PTR(-EINVAL));
@@ -238,12 +239,13 @@ void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 		return(ERR_PTR(-EINVAL));
 
 	pte = pte_offset_kernel(pmd, addr);
-	if(!pte_present(*pte)) 
+	ptent = *pte;
+	if(!pte_present(ptent))
 		return(ERR_PTR(-EINVAL));
 
 	if(pte_out != NULL)
-		*pte_out = *pte;
-	return((void *) (pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
+		*pte_out = ptent;
+	return((void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK));
 }
 
 char *current_cmd(void)
-- 
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