Messages in this thread | | | Date | Fri, 1 Jul 2011 09:47:05 -0400 | From | Christoph Hellwig <> | Subject | Re: [PATCH 00/10] Enhance /dev/mem to allow read/write of arbitrary physical addresses |
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On Fri, Jul 01, 2011 at 02:58:02PM +0200, Ingo Molnar wrote: > So what was not mentioned in your series, what is *your* motivation > and your usecase? Enabling closed-source userspace drivers? Enabling > the crash utility?
He stated it pretty clearly in the thread, it's the crash utility.
> > If the former then shame on you, if the latter then how do you > explain that distros appear to disable the RAM aspect of /dev/mem: > > $ grep DEVMEM $(rpm -ql kernel-2.6.38-0.rc7.git2.3.fc16.x86_64 | grep config-2.6 ) > CONFIG_STRICT_DEVMEM=y > > So the crash utility use-case does not work on unpatched, default > kernels, right?
Not if you have highmem. That's why Redhat or Fedora to quote your example patch in the /dev/crash driver, which totally defeats the CONFIG_STRICT_DEVMEM setting. But apparently it's good enough that no one either noticed or at least doesn't care.
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