Messages in this thread | | | Date | Tue, 20 Oct 2015 20:01:20 -0700 | Subject | Re: [PATCH v3 0/3] pstore: add pstore unregister | From | Kees Cook <> |
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On Tue, Oct 20, 2015 at 7:52 PM, Geliang Tang <geliangtang@163.com> wrote: > On Tue, Oct 20, 2015 at 10:19:09AM -0700, Kees Cook wrote: >> On Tue, Oct 20, 2015 at 12:39 AM, Geliang Tang <geliangtang@163.com> wrote: >> > On Mon, Oct 19, 2015 at 10:56:54PM +0000, Luck, Tony wrote: >> >> Thanks for looking to close out this TODO item. >> >> >> >> The thing that scared me about unloading pstore was what happens to >> >> a process that is in the middle of reading some /sys/fs/pstore/file-name-here >> >> Were you able to verify that this reading-while-rmmod case works correctly? >> >> -Kees > > $ sudo insmod zlib_deflate.ko > $ sudo insmod pstore.ko > $ lsmod > Module Size Used by > pstore 11225 0 > zlib_deflate 18292 1 pstore > > $ sudo mount -t pstore pstore /sys/fs/pstore > $ lsmod > Module Size Used by > pstore 11225 1 > zlib_deflate 18292 1 pstore > > $ sudo insmod reed_solomon.ko > $ sudo insmod ramoops.ko mem_address=0x40000000 mem_size=0x400000 > $ lsmod > Module Size Used by > ramoops 9638 0 > reed_solomon 5150 1 ramoops > pstore 11225 2 ramoops > zlib_deflate 18292 1 pstore > > $ tail -f /sys/fs/pstore/console-ramoops-0 & > [1] 3483 > $ lsmod > Module Size Used by > ramoops 9638 0 > reed_solomon 5150 1 ramoops > pstore 11225 3 ramoops > zlib_deflate 18292 1 pstore > > $ kill -9 3483 > $ lsmod > Module Size Used by > ramoops 9638 0 > reed_solomon 5150 1 ramoops > pstore 11225 2 ramoops > zlib_deflate 18292 1 pstore > > $ sudo rmmod ramoops > $ lsmod > Module Size Used by > reed_solomon 5150 0 > pstore 11225 1 > zlib_deflate 18292 1 pstore
What happens if you leave the tail running and try to rmmod ramoops? (I assume it'll just refuse.)
Nice!
Acked-by: Kees Cook <keescook@chromium.org>
-Kees
> > $ sudo umount /sys/fs/pstore/ > $ lsmod > Module Size Used by > reed_solomon 5150 0 > pstore 11225 0 > zlib_deflate 18292 1 pstore > > $ sudo rmmod pstore > $ lsmod > Module Size Used by > reed_solomon 5150 0 > zlib_deflate 18292 0 > > Thanks. > Geliang Tang >
-- Kees Cook Chrome OS Security
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