diff options
Diffstat (limited to 'hurd/hurdsig.c')
| -rw-r--r-- | hurd/hurdsig.c | 113 |
1 files changed, 86 insertions, 27 deletions
diff --git a/hurd/hurdsig.c b/hurd/hurdsig.c index 9620a00..c5ce050 100644 --- a/hurd/hurdsig.c +++ b/hurd/hurdsig.c @@ -667,9 +667,16 @@ _hurd_internal_post_signal (struct hurd_sigstate *ss, /* Nobody cares about this signal. */ break; + sigbomb: + /* We got a fault setting up the stack frame for the handler. + Nothing to do but die; BSD gets SIGILL in this case. */ + sigcode = signo; /* XXX ? */ + signo = SIGILL; + act = core; + /* FALLTHROUGH */ + case term: /* Time to die. */ case core: /* And leave a rotting corpse. */ - nirvana: /* Have the proc server stop all other threads in our task. */ err = __USEPORT (PROC, __proc_dostop (port, _hurd_msgport_thread)); assert_perror (err); @@ -693,7 +700,7 @@ _hurd_internal_post_signal (struct hurd_sigstate *ss, case handle: /* Call a handler for this signal. */ { - struct sigcontext *scp; + struct sigcontext *scp, ocontext; int wait_for_reply, state_changed; /* Stop the thread and abort its pending RPC operations. */ @@ -710,19 +717,64 @@ _hurd_internal_post_signal (struct hurd_sigstate *ss, thread_get_state is never kosher before thread_abort. */ abort_thread (ss, &thread_state, NULL, 0, 0); - wait_for_reply = (abort_rpcs (ss, signo, &thread_state, &state_changed, - &reply_port, reply_port_type, untraced) - != MACH_PORT_NULL); + if (ss->context) + { + /* We have a previous sigcontext that sigreturn was about + to restore when another signal arrived. */ + + mach_port_t *loc; - if (ss->critical_section) + if (_hurdsig_catch_fault (SIGSEGV)) + { + assert (_hurdsig_fault_sigcode >= (long int) ss->context && + _hurdsig_fault_sigcode < (long int) (ss->context + 1)); + /* We faulted reading the thread's stack. Forget that + context and pretend it wasn't there. It almost + certainly crash if this handler returns, but that's it's + problem. */ + ss->context = NULL; + } + else + { + /* Copy the context from the thread's stack before + we start diddling the stack to set up the handler. */ + ocontext = *ss->context; + ss->context = &ocontext; + } + _hurdsig_end_catch_fault (); + + if (! machine_get_basic_state (ss->thread, &thread_state)) + goto sigbomb; + loc = interrupted_reply_port_location (&thread_state); + if (loc && *loc != MACH_PORT_NULL) + /* This is the reply port for the context which called + sigreturn. Since we are abandoning that context entirely + and restoring SS->context instead, destroy this port. */ + __mach_port_destroy (__mach_task_self (), *loc); + + /* The thread was in sigreturn, not in any interruptible RPC. */ + wait_for_reply = 0; + + assert (! ss->critical_section); + } + else { - /* The thread is in a critical section. Mark the signal as - pending. When it finishes the critical section, it will - check for pending signals. */ - mark_pending (); - assert (! state_changed); - __thread_resume (ss->thread); - break; + wait_for_reply = (abort_rpcs (ss, signo, + &thread_state, &state_changed, + &reply_port, reply_port_type, + untraced) + != MACH_PORT_NULL); + + if (ss->critical_section) + { + /* The thread is in a critical section. Mark the signal as + pending. When it finishes the critical section, it will + check for pending signals. */ + mark_pending (); + assert (! state_changed); + __thread_resume (ss->thread); + break; + } } /* Call the machine-dependent function to set the thread up @@ -731,18 +783,10 @@ _hurd_internal_post_signal (struct hurd_sigstate *ss, signo, sigcode, wait_for_reply, &thread_state); if (scp == NULL) - { - /* We got a fault setting up the stack frame for the handler. - Nothing to do but die; BSD gets SIGILL in this case. */ - sigcode = signo; /* XXX ? */ - signo = SIGILL; - act = core; - goto nirvana; - } + goto sigbomb; /* Set the machine-independent parts of the signal context. */ - scp->sc_error = sigerror; { /* Fetch the thread variable for the MiG reply port, and set it to MACH_PORT_NULL. */ @@ -754,17 +798,32 @@ _hurd_internal_post_signal (struct hurd_sigstate *ss, } else scp->sc_reply_port = MACH_PORT_NULL; + + /* Save the intr_port in use by the interrupted code, + and clear the cell before running the trampoline. */ + scp->sc_intr_port = ss->intr_port; + ss->intr_port = MACH_PORT_NULL; + + if (ss->context) + { + /* After the handler runs we will restore to the state in + SS->context, not the state of the thread now. So restore + that context's reply port and intr port. */ + + scp->sc_reply_port = ss->context->sc_reply_port; + scp->sc_intr_port = ss->context->sc_intr_port; + + ss->context = NULL; + } } + /* Backdoor extra argument to signal handler. */ + scp->sc_error = sigerror; + /* Block SIGNO and requested signals while running the handler. */ scp->sc_mask = ss->blocked; ss->blocked |= __sigmask (signo) | ss->actions[signo].sa_mask; - /* Save the intr_port in use by the interrupted code, - and clear the cell before running the trampoline. */ - scp->sc_intr_port = ss->intr_port; - ss->intr_port = MACH_PORT_NULL; - /* Start the thread running the handler (or possibly waiting for an RPC reply before running the handler). */ err = __thread_set_state (ss->thread, MACHINE_THREAD_STATE_FLAVOR, |