[BUG] completely bonkers use of set_need_resched + VM_FAULT_NOPAGE
thellstrom at vmware.com
Fri Sep 13 01:39:50 PDT 2013
On 09/13/2013 10:32 AM, Daniel Vetter wrote:
> On Fri, Sep 13, 2013 at 10:23 AM, Thomas Hellstrom
> <thellstrom at vmware.com> wrote:
>> As previously mentioned, copy_from_user should return -EFAULT, since the
>> VMAs are marked with VM_IO. It should not recurse into fault(), so evil
>> user-space looses.
> I haven't put a printk in the code to prove this, but gem mmap also
> sets VM_IO in drm_gem_mmap_obj. And we can very much hit our own fault
> handler and deadlock ....
If this is indeed true, I guess I need to accept the fact that my
solution is bad.
(and worse I can't blame not having my morning coffee).
I'll take a deeper look.
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