diff options
| -rw-r--r-- | sys/kern/sys_pipe.c | 33 | ||||
| -rw-r--r-- | sys/sys/pipe.h | 7 |
2 files changed, 29 insertions, 11 deletions
diff --git a/sys/kern/sys_pipe.c b/sys/kern/sys_pipe.c index b58d3c64fa2d..22468e22622b 100644 --- a/sys/kern/sys_pipe.c +++ b/sys/kern/sys_pipe.c @@ -263,8 +263,8 @@ pipe_zone_ctor(void *mem, int size, void *arg, int flags) * one at a time. When both are free'd, then the whole pair * is released. */ - rpipe->pipe_present = 1; - wpipe->pipe_present = 1; + rpipe->pipe_present = PIPE_ACTIVE; + wpipe->pipe_present = PIPE_ACTIVE; /* * Eventually, the MAC Framework may initialize the label @@ -982,7 +982,8 @@ pipe_write(fp, uio, active_cred, flags, td) /* * detect loss of pipe read side, issue SIGPIPE if lost. */ - if ((!wpipe->pipe_present) || (wpipe->pipe_state & PIPE_EOF)) { + if (wpipe->pipe_present != PIPE_ACTIVE || + (wpipe->pipe_state & PIPE_EOF)) { pipeunlock(wpipe); PIPE_UNLOCK(rpipe); return (EPIPE); @@ -1341,13 +1342,14 @@ pipe_poll(fp, events, active_cred, td) revents |= events & (POLLIN | POLLRDNORM); if (events & (POLLOUT | POLLWRNORM)) - if (!wpipe->pipe_present || (wpipe->pipe_state & PIPE_EOF) || + if (wpipe->pipe_present != PIPE_ACTIVE || + (wpipe->pipe_state & PIPE_EOF) || (((wpipe->pipe_state & PIPE_DIRECTW) == 0) && (wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt) >= PIPE_BUF)) revents |= events & (POLLOUT | POLLWRNORM); if ((rpipe->pipe_state & PIPE_EOF) || - (!wpipe->pipe_present) || + wpipe->pipe_present != PIPE_ACTIVE || (wpipe->pipe_state & PIPE_EOF)) revents |= POLLHUP; @@ -1486,7 +1488,7 @@ pipeclose(cpipe) * Disconnect from peer, if any. */ ppipe = cpipe->pipe_peer; - if (ppipe->pipe_present != 0) { + if (ppipe->pipe_present == PIPE_ACTIVE) { pipeselwakeup(ppipe); ppipe->pipe_state |= PIPE_EOF; @@ -1503,16 +1505,23 @@ pipeclose(cpipe) PIPE_UNLOCK(cpipe); pipe_free_kmem(cpipe); PIPE_LOCK(cpipe); - cpipe->pipe_present = 0; + cpipe->pipe_present = PIPE_CLOSING; pipeunlock(cpipe); + + /* + * knlist_clear() may sleep dropping the PIPE_MTX. Set the + * PIPE_FINALIZED, that allows other end to free the + * pipe_pair, only after the knotes are completely dismantled. + */ knlist_clear(&cpipe->pipe_sel.si_note, 1); + cpipe->pipe_present = PIPE_FINALIZED; knlist_destroy(&cpipe->pipe_sel.si_note); /* * If both endpoints are now closed, release the memory for the * pipe pair. If not, unlock. */ - if (ppipe->pipe_present == 0) { + if (ppipe->pipe_present == PIPE_FINALIZED) { PIPE_UNLOCK(cpipe); #ifdef MAC mac_destroy_pipe(pp); @@ -1536,7 +1545,7 @@ pipe_kqfilter(struct file *fp, struct knote *kn) break; case EVFILT_WRITE: kn->kn_fop = &pipe_wfiltops; - if (!cpipe->pipe_peer->pipe_present) { + if (cpipe->pipe_peer->pipe_present != PIPE_ACTIVE) { /* other end of pipe has been closed */ PIPE_UNLOCK(cpipe); return (EPIPE); @@ -1579,7 +1588,8 @@ filt_piperead(struct knote *kn, long hint) kn->kn_data = rpipe->pipe_map.cnt; if ((rpipe->pipe_state & PIPE_EOF) || - (!wpipe->pipe_present) || (wpipe->pipe_state & PIPE_EOF)) { + wpipe->pipe_present != PIPE_ACTIVE || + (wpipe->pipe_state & PIPE_EOF)) { kn->kn_flags |= EV_EOF; PIPE_UNLOCK(rpipe); return (1); @@ -1597,7 +1607,8 @@ filt_pipewrite(struct knote *kn, long hint) struct pipe *wpipe = rpipe->pipe_peer; PIPE_LOCK(rpipe); - if ((!wpipe->pipe_present) || (wpipe->pipe_state & PIPE_EOF)) { + if (wpipe->pipe_present != PIPE_ACTIVE || + (wpipe->pipe_state & PIPE_EOF)) { kn->kn_data = 0; kn->kn_flags |= EV_EOF; PIPE_UNLOCK(rpipe); diff --git a/sys/sys/pipe.h b/sys/sys/pipe.h index 1d3729fc38c9..2371b2a4e96f 100644 --- a/sys/sys/pipe.h +++ b/sys/sys/pipe.h @@ -115,6 +115,13 @@ struct pipe { }; /* + * Values for the pipe_present. + */ +#define PIPE_ACTIVE 1 +#define PIPE_CLOSING 2 +#define PIPE_FINALIZED 3 + +/* * Container structure to hold the two pipe endpoints, mutex, and label * pointer. */ |