diff options
| author | Hugh Dickins | 2005-10-30 02:16:38 +0100 |
|---|---|---|
| committer | Linus Torvalds | 2005-10-30 05:40:42 +0100 |
| commit | 8f5cd76c185a4c8aeb5fe1e560e3612bfc050c35 (patch) | |
| tree | 42f9fc842005eda8d898998850a20c6afb5ce7e6 /arch/um | |
| parent | [PATCH] mm: cris v32 mmu_context_lock (diff) | |
| download | kernel-qcow2-linux-8f5cd76c185a4c8aeb5fe1e560e3612bfc050c35.tar.gz kernel-qcow2-linux-8f5cd76c185a4c8aeb5fe1e560e3612bfc050c35.tar.xz kernel-qcow2-linux-8f5cd76c185a4c8aeb5fe1e560e3612bfc050c35.zip | |
[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>
Diffstat (limited to 'arch/um')
| -rw-r--r-- | arch/um/kernel/process_kern.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process_kern.c index 0d73ceeece72..34b54a3e2132 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) |