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authorHugh Dickins <hugh@veritas.com>2005-10-29 18:16:38 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-10-29 21:40:42 -0700
commit8f5cd76c185a4c8aeb5fe1e560e3612bfc050c35 (patch)
tree42f9fc842005eda8d898998850a20c6afb5ce7e6
parenta7e4705b24e611574e5c23105005ffdff694fd58 (diff)
downloadlinux-2.6.34-ux500-8f5cd76c185a4c8aeb5fe1e560e3612bfc050c35.tar.gz
[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>
-rw-r--r--arch/um/kernel/process_kern.c8
1 files changed, 5 insertions, 3 deletions
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)