On Wed, May 15, 2013 at 9:30 PM, Toralf Förster <toralf.foerster@xxxxxx> wrote: > 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. Hmm, not good. I need to create me a reproducer for that. I'm unsure what exactly is going on. -- Thanks, //richard -- 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
