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Re: double fault -> PAGE_KERNEL flagged memory
- From: Roland McGrath <roland at redhat dot com>
- To: fche at redhat dot com (Frank Ch. Eigler)
- Cc: systemtap at sources dot redhat dot com
- Date: Wed, 23 Nov 2005 13:51:28 -0800 (PST)
- Subject: Re: double fault -> PAGE_KERNEL flagged memory
> Then this is analogous to the problem of calling printk from within an
> inconveniently placed kprobe. What can we do to eliminate this
> vulnerability? Can we somehow arrange to "fault in" all probe-related
> kernel-space vmalloc areas into new process' address spaces, so we don't
> encounter this unintentional and undesirable reentrancy?
What's the reason for using vmalloc then? Why not use kmalloc that doesn't
need page table changes?