* Dag-Erling Smorgrav <[EMAIL PROTECTED]> [020317 19:27] wrote: > > ...the process has no open files at all, because... > > (kgdb) p p->p_pid > $4 = 10099 > (kgdb) p p->p_comm > $5 = "wc\000oot", '\000' <repeats 13 times> > (kgdb) p p->p_stat > $6 = 3 > (kgdb) p/x p->p_flag > $7 = 0x6000 > > ...it's exiting, and fdfree() has already run. > > Solution: p->p_fd must be protected by p's proc lock; fdfree() must > set it to NULL immediately after freeing it; checkdirs() must lock > each process before examining its fd list. > > Other problem spotted while investigating this: fdfree() can fail > silently; fdfree() should panic if fdp->fd_refcnt is non-zero.
Please let me know if this works for you. Index: vfs_syscalls.c =================================================================== RCS file: /home/ncvs/src/sys/kern/vfs_syscalls.c,v retrieving revision 1.231 diff -u -r1.231 vfs_syscalls.c --- vfs_syscalls.c 12 Mar 2002 04:00:10 -0000 1.231 +++ vfs_syscalls.c 18 Mar 2002 06:23:41 -0000 @@ -451,10 +451,14 @@ return; sx_slock(&allproc_lock); LIST_FOREACH(p, &allproc, p_list) { + PROC_LOCK(p); fdp = p->p_fd; - if (fdp == NULL) + if (fdp == NULL) { + PROC_UNLOCK(p); continue; + } FILEDESC_LOCK(fdp); + PROC_UNLOCK(p); if (fdp->fd_cdir == olddp) { VREF(newdp); fdp->fd_cdir = newdp; Index: kern_descrip.c =================================================================== RCS file: /home/ncvs/src/sys/kern/kern_descrip.c,v retrieving revision 1.128 diff -u -r1.128 kern_descrip.c --- kern_descrip.c 15 Mar 2002 08:03:46 -0000 1.128 +++ kern_descrip.c 18 Mar 2002 06:23:39 -0000 @@ -1321,19 +1321,26 @@ fdfree(td) struct thread *td; { - register struct filedesc *fdp = td->td_proc->p_fd; + register struct filedesc *fdp; struct file **fpp; register int i; + PROC_LOCK(td); + fdp = td->td_proc->p_fd; /* Certain daemons might not have file descriptors. */ - if (fdp == NULL) + if (fdp == NULL) { + PROC_UNLOCK(td); return; + } FILEDESC_LOCK(fdp); if (--fdp->fd_refcnt > 0) { FILEDESC_UNLOCK(fdp); + PROC_UNLOCK(td); return; } + td->td_proc->p_fd = NULL; + PROC_UNLOCK(td); /* * we are the last reference to the structure, we can * safely assume it will not change out from under us. To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message