On Tue, Oct 20, 2015 at 7:52 PM, Geliang Tang <geliangt...@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 <geliangt...@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 <keesc...@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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
