Issue #2313 has been updated by Nicolas Thery.
Hello, I've observed both behaviors too. The hang is a deadlock between the father process (truss) and the child being exec'ed (e.g. ls). The father waits for the child to stop in procfs_ioctl (PIOCWAIT). The child waits in PSTALL() in exec_new_vmspace() for the father to PRELE() its reference to the child. This deadlocks because of pfs_find() which PHOLD()'s the child at the beginning of procfs_ioctl() and keeps the reference while sleeping. One possible fix would be to keep track of the number of procfs_ioctl(PIOCWAIT) sleepers and adjust the expected lock count passed to PSTALL (there is already such an adjustment for the vfork() case). This requires adding a new field to struct proc though. I'm in the process of trying this. As an aside the tests for P_INEXEC in procfs_open() and procfs_ioctl() are suspicious. The flag could be set just after being tested. Cheers, Nicolas On 25 February 2012 17:24, Venkatesh Srinivas via Redmine <bugtracker-ad...@leaf.dragonflybsd.org> wrote: > > Issue #2313 has been reported by Venkatesh Srinivas. > > ---------------------------------------- > Bug #2313: truss doesn't work on 3.0/ -master > http://bugs.dragonflybsd.org/issues/2313 > > Author: Venkatesh Srinivas > Status: New > Priority: Normal > Assignee: > Category: > Target version: > > > truss on master stalls on 'exec1' or enters a loop of:: > > truss: PIOCWAIT top of loop: Inappropriate ioctl for device > truss: PIOCCONT: Inappropriate ioctl for device > > when tracing /bin/ls, among other programs. > > > -- > You have received this notification because you have either subscribed to it, > or are involved in it. > To change your notification preferences, please click here: > http://bugs.dragonflybsd.org/my/account ---------------------------------------- Bug #2313: truss doesn't work on 3.0/ -master http://bugs.dragonflybsd.org/issues/2313 Author: Venkatesh Srinivas Status: New Priority: Normal Assignee: Category: Target version: truss on master stalls on 'exec1' or enters a loop of:: truss: PIOCWAIT top of loop: Inappropriate ioctl for device truss: PIOCCONT: Inappropriate ioctl for device when tracing /bin/ls, among other programs. -- You have received this notification because you have either subscribed to it, or are involved in it. To change your notification preferences, please click here: http://bugs.dragonflybsd.org/my/account
