Messages in this thread | | | Date | Tue, 21 Sep 2010 14:13:10 +0800 | From | Kenneth <> | Subject | Re: Problem with debugfs |
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Hello, Mr. Greg,
I'm sorry I had not checked the git before sending my last mail.
For the problem I mention, consider this scenarios:
1. mm/hwpoinson-inject.c create a debugfs file with debugfs_create_u64("corrupt-filter-flags-mask", ..., &hwpoison_filter_flags_mask) 2. hwpoison_filter_flags_mask is supposed to be protected by filp->priv->mutex of this file when it is accessed from user space. 3. but when it is accessed from mm/memory-failure.c:hwpoison_filter_flags, there is no way for the function to protect the operation (so it simply ignore it). This may create a competition problem.
It should be a problem.
I'm sorry from my poor English skill.
Best Regards Kenneth Lee
On Tue, Sep 21, 2010 at 10:21:12AM +0800, kenny wrote: > Hi, there, > > I do not know who is the maintainer for debugfs now. But I think there is > problem with its API: It uses filp->priv->mutex to protect the read/write (to > the file) for the value of its attribute, but the mutex is not exported to the > API user. Therefore, there is no way to protect its value when you directly > use the value in your module. > > Is my understanding correct? > > Thanks > > > Best Regards > Kenneth Lee
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