Hello Oleg, On Thu, 2013-09-26 at 21:10 +0200, Oleg Nesterov wrote: > On 09/26, Oleg Nesterov wrote: > > > > Thanks Peter. > > > > Well. I'am afraid my testing was wrong, because Karel reports > > it fixes the problem... > > > > But. I applied this patch to my 3.11 tree (last commit is bff157b3a) > > which also has the additional patch (03e12617 "tty: disassociate_ctty() > > sends the extra SIGCONT"), and > > > > TET_CONFIG=CFG TET_ROOT=. ./T.tcflush 4 > > > > still fails... T.tcflush was compiled on another (Karel's) machine, > > perhaps there is something in libc, I do not know. > > > > So let me ask just in case, I assume the fix below doesn't depend on > > other changes I could miss? > > > > I'll retest after git-pull and report... > > Still fails under the Linus's tree + this patch. > > However!!! > > Tested-by: Oleg Nesterov <oleg@xxxxxxxxxx> > > > > > It turns out, T.tcflush doesn't expect it can start as a process group > leader. In this case setsid() fails, then tty_open() doesn't set > signal->tty, and thus this patch makes no difference: tty_check_change() > fails because tty doesn't match signal->tty. > > And indeed, this test passes if you run it under strace, or simply do > > $ TET_CONFIG=CFG TET_ROOT=. perl -e "system './T.tcflush 4'" > > And damn, the fact it doesn't fail under strace doesn't allow you to > see that setsid() fails ;) > > This is probably explains why Karel reported success, perhaps he > didn't run this test individually. This is true, I didn't execute this particular test directly but through the LSB test suite framework. > > Thanks again Peter. Perhaps my analysis was wrong (and I do not see > setsid() in the sources), I do not really care. but perhaps tcflush.c > should be updated. > > Oleg. > Karel -- Karel Srot Quality Engineer, QE BaseOS Security team Email: ksrot@xxxxxxxxxx Web: www.cz.redhat.com Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html