On 05/15/2013 09:11 PM, richard -rw- weinberger wrote: > On Wed, May 15, 2013 at 9:06 PM, Toralf Förster <toralf.foerster@xxxxxx> wrote: >> On 05/13/2013 09:12 AM, richard -rw- weinberger wrote: >>> This looks like another issue. >>> Are you testing process_vm_writev() with trinity? >>> Looks like it managed to overwrite the stub page of a process, which >>> is not good. >> nope, it is the mremap syscall. >> >> A command like >> >> $>trinity -c mremap -N 10 >> >> immediately after starting a 32 bit Gentoo linux guest with current kernel 3.10-rc1-... + >> strnlen + stub4 patch works, but later a >> >> $>trinity -c mremap -N 1000 >> >> yields into >> >> 2013-05-15T21:02:04.061+02:00 trinity kernel: Stub registers - >> 2013-05-15T21:02:04.061+02:00 trinity kernel: 0 - 100000 >> 2013-05-15T21:02:04.061+02:00 trinity kernel: 1 - 300000 >> 2013-05-15T21:02:04.061+02:00 trinity kernel: 2 - 0 >> 2013-05-15T21:02:04.061+02:00 trinity kernel: 3 - 0 >> 2013-05-15T21:02:04.061+02:00 trinity kernel: 4 - 0 >> 2013-05-15T21:02:04.061+02:00 trinity kernel: 5 - 0 >> 2013-05-15T21:02:04.061+02:00 trinity kernel: 6 - 0 >> 2013-05-15T21:02:04.061+02:00 trinity kernel: 7 - 7b >> 2013-05-15T21:02:04.061+02:00 trinity kernel: 8 - 7b >> 2013-05-15T21:02:04.065+02:00 trinity kernel: 9 - 0 >> 2013-05-15T21:02:04.065+02:00 trinity kernel: 10 - 33 >> 2013-05-15T21:02:04.065+02:00 trinity kernel: 11 - ffffffff >> 2013-05-15T21:02:04.065+02:00 trinity kernel: 12 - 1000c3 >> 2013-05-15T21:02:04.065+02:00 trinity kernel: 13 - 73 >> 2013-05-15T21:02:04.065+02:00 trinity kernel: 14 - 10206 >> 2013-05-15T21:02:04.065+02:00 trinity kernel: 15 - 101028 >> 2013-05-15T21:02:04.065+02:00 trinity kernel: 16 - 7b >> 2013-05-15T21:02:04.065+02:00 trinity kernel: wait_stub_done : failed to wait for SIGTRAP, pid = 15692, n = 15692, errno = 0, status = 0xb7f >> >> and now that process can't be killed - I had to stop the UML guest. > > Hmm, you've remapped the stub page and therefore the process broke. > I think it would make sense to kill the process in stead of writing > the "wait_stub_done ..." message. > Changing the stub page is as destructive than overwriting the stack. Unfortunately no trinity process can be killed as soon as that happen. Neither pgrep, pkill, nor "ps -efla" do return any result. Killing any of those processes by its pid won't work too. > Maybe we can teach triniy to no change the stub page. > I'm sure trinity has also a mechanism to not destroy the stack. @trinity Mailing list What do you think about that ? -- MfG/Sincerely Toralf Förster pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3 -- To unsubscribe from this list: send the line "unsubscribe trinity" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
