diff options
| -rw-r--r-- | hurd/hurdsig.c | 15 | ||||
| -rw-r--r-- | hurd/intr-msg.c | 1 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/mig-reply.c | 25 |
3 files changed, 20 insertions, 21 deletions
diff --git a/hurd/hurdsig.c b/hurd/hurdsig.c index b3808f9..78ea59d 100644 --- a/hurd/hurdsig.c +++ b/hurd/hurdsig.c @@ -477,9 +477,18 @@ _hurdsig_abort_rpcs (struct hurd_sigstate *ss, int signo, int sigthread, if (reply) { /* The interrupt didn't work. - Destroy the receive right the thread is blocked on. */ - __mach_port_destroy (__mach_task_self (), *reply); - *reply = MACH_PORT_NULL; + Destroy the receive right the thread is blocked on, and + replace it with a dead name to keep the name from reuse until + the therad is done with it. To do this atomically, first + insert a send right, and then destroy the receive right, + turning the send right into a dead name. */ + err = __mach_port_insert_right (__mach_task_self (), + *reply, *reply, + MACH_MSG_TYPE_MAKE_SEND); + assert_perror (err); + err = __mach_port_mod_refs (__mach_task_self (), *reply, + MACH_PORT_RIGHT_RECEIVE, -1); + assert_perror (err); } /* The system call return value register now contains diff --git a/hurd/intr-msg.c b/hurd/intr-msg.c index 1a086b5..716d87a 100644 --- a/hurd/intr-msg.c +++ b/hurd/intr-msg.c @@ -305,6 +305,7 @@ _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg, { /* Make sure we have a valid reply port. The one we were using may have been destroyed by interruption. */ + __mig_dealloc_reply_port (rcv_name); m->header.msgh_local_port = rcv_name = __mig_get_reply_port (); m->header.msgh_bits = msgh_bits; option = user_option; diff --git a/sysdeps/mach/hurd/mig-reply.c b/sysdeps/mach/hurd/mig-reply.c index 3fdee80..7ea001d 100644 --- a/sysdeps/mach/hurd/mig-reply.c +++ b/sysdeps/mach/hurd/mig-reply.c @@ -69,29 +69,18 @@ __mig_dealloc_reply_port (mach_port_t arg) mach_port_t port = get_reply_port (); set_reply_port (MACH_PORT_NULL); /* So the mod_refs RPC won't use it. */ - - /* Normally, ARG should be the same as PORT that we store. However, if a - signal has interrupted the RPC, the stored PORT has been deallocated and - reset to MACH_PORT_NULL (or possibly MACH_PORT_DEAD). In this case the - MIG routine still has the old name, which it passes to us here. We must - not deallocate (or otherwise touch) it, since it may be already allocated - to another port right. Fortunately MIG itself doesn't do anything with - the reply port on errors either, other than immediately calling this - function. - - And so: - 1. Assert that things are sane, i.e. and PORT is either invalid or same - as ARG. - 2. Only deallocate the name if our stored PORT still names it. In that - case we're sure the right has not been deallocated / the name reused. - */ - + assert (port == arg); if (!MACH_PORT_VALID (port)) return; - assert (port == arg); err = __mach_port_mod_refs (__mach_task_self (), port, MACH_PORT_RIGHT_RECEIVE, -1); + if (err == KERN_INVALID_RIGHT) + /* It could be that during signal handling, the receive right had been + replaced with a dead name. */ + err = __mach_port_mod_refs (__mach_task_self (), port, + MACH_PORT_RIGHT_DEAD_NAME, -1); + assert_perror (err); } weak_alias (__mig_dealloc_reply_port, mig_dealloc_reply_port) |