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authorRoland McGrath <roland@gnu.org>1996-01-04 10:00:22 +0000
committerRoland McGrath <roland@gnu.org>1996-01-04 10:00:22 +0000
commitfb8e70d6dd3a9c3a0e0d2713b5be3cbc9d7a6409 (patch)
treed465aa6b6c500395145dc09bc4ea448392cf1a6a /hurd
parent67f27f3a02d623331a56cddee2a56c34b3b13bd9 (diff)
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Wed Jan 3 20:23:42 1996 Roland McGrath <roland@churchy.gnu.ai.mit.edu>cvs/libc-960104
* hurd/catch-signal.c: New file. * hurd/intr-msg.c: When restarting RPC, fetch a new reply port. * hurd/hurdsig.c: Use new hurdfault.h interface. (abort_all_rpcs): Mutate return value to EINTR in threads whose replies we will wait for. * hurd/hurdkill.c (_hurd_sig_post): When doing pgrp, make sure we do ourselves last. Wed Jan 3 19:17:10 1996 Miles Bader <miles@gnu.ai.mit.edu> * sysdeps/mach/hurd/access.c (__access): Put the uid/gid arguments to auth_makeauth() in the right order. Wed Jan 3 17:19:04 1996 Roland McGrath <roland@churchy.gnu.ai.mit.edu> * sysdeps/generic/strsep.c: Rewritten. * sysdeps/mach/hurd/fork.c: Use a different workaround for the suspended page fault deadlock kernel bug: thread_abort our signal thread first thing after proc_dostop. * sysdeps/mach/hurd/setgid.c: Rewrote gid frobnication to recognize rootness properly. * hurd/hurdsig.c: Use new signal preemption interface.
Diffstat (limited to 'hurd')
-rw-r--r--hurd/catch-signal.c87
-rw-r--r--hurd/hurdsig.c77
-rw-r--r--hurd/intr-msg.c24
3 files changed, 155 insertions, 33 deletions
diff --git a/hurd/catch-signal.c b/hurd/catch-signal.c
new file mode 100644
index 0000000..3e8ee6c
--- /dev/null
+++ b/hurd/catch-signal.c
@@ -0,0 +1,87 @@
+/* Convenience function to catch expected signals during an operation.
+Copyright (C) 1996 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+#include <hurd/signal.h>
+#include <hurd/sigpreempt.h>
+#include <string.h>
+#include <assert.h>
+
+error_t
+hurd_catch_signal (sigset_t sigset,
+ unsigned long int first, unsigned long int last,
+ error_t (*operate) (struct hurd_signal_preempter *),
+ sighandler_t handler)
+{
+ jmp_buf buf;
+ void throw (int signo, long int sigcode, struct sigcontext *scp)
+ { longjmp (buf, scp->sc_error ?: EGRATUITOUS); }
+
+ struct hurd_signal_preempter preempter =
+ {
+ sigset, first, last,
+ NULL, handler == SIG_ERR ? (sighandler_t) &throw : handler,
+ };
+
+ struct hurd_sigstate *const ss = _hurd_self_sigstate ();
+ error_t error;
+
+ if (handler == SIG_ERR)
+ /* Not our handler; don't bother saving state. */
+ error = 0;
+ else
+ /* This returns again with nonzero value when we preempt a signal. */
+ error = setjmp (buf);
+
+ if (error == 0)
+ {
+ /* Install a signal preempter for the thread. */
+ __spin_lock (&ss->lock);
+ preempter.next = ss->preempters;
+ ss->preempters = &preempter;
+ __spin_unlock (&ss->lock);
+
+ /* Try the operation that might crash. */
+ (*operate) (&preempter);
+ }
+
+ /* Either FUNCTION completed happily and ERROR is still zero, or it hit
+ an expected signal and `throw' made setjmp return the signal error
+ code in ERROR. Now we can remove the preempter and return. */
+
+ __spin_lock (&ss->lock);
+ assert (ss->preempters == &preempter);
+ ss->preempters = preempter.next;
+ __spin_unlock (&ss->lock);
+
+ return error;
+}
+
+
+error_t
+hurd_safe_memset (void *dest, int byte, size_t nbytes)
+{
+ error_t operate (struct hurd_signal_preempter *preempter)
+ {
+ memset (dest, byte, nbytes);
+ return 0;
+ }
+ return hurd_catch_signal (sigmask (SIGBUS) | sigmask (SIGSEGV),
+ (vm_address_t) dest, (vm_address_t) dest + nbytes,
+ &operate, SIG_ERR);
+}
diff --git a/hurd/hurdsig.c b/hurd/hurdsig.c
index 290dba8..6085ab1 100644
--- a/hurd/hurdsig.c
+++ b/hurd/hurdsig.c
@@ -121,8 +121,9 @@ _hurd_thread_sigstate (thread_t thread)
#include "thread_state.h"
#include <hurd/msg_server.h>
#include <hurd/msg_reply.h> /* For __msg_sig_post_reply. */
-#include <assert.h>
#include <hurd/interrupt.h>
+#include <assert.h>
+#include <unistd.h>
int _hurd_core_limit; /* XXX */
@@ -216,12 +217,9 @@ interrupted_reply_port_location (struct machine_thread_all_state *thread_state,
mach_port_t *portloc = (mach_port_t *) __hurd_threadvar_location_from_sp
(_HURD_THREADVAR_MIG_REPLY, (void *) thread_state->basic.SP);
- if (sigthread && _hurdsig_catch_fault (SIGSEGV))
- {
- assert (_hurdsig_fault_sigcode == (long int) portloc);
- /* Faulted trying to read the stack. */
- return NULL;
- }
+ if (sigthread && _hurdsig_catch_memory_fault (portloc))
+ /* Faulted trying to read the stack. */
+ return NULL;
/* Fault now if this pointer is bogus. */
*(volatile mach_port_t *) portloc = *portloc;
@@ -363,9 +361,9 @@ abort_all_rpcs (int signo, struct machine_thread_all_state *state, int live)
reply_ports = alloca (nthreads * sizeof *reply_ports);
nthreads = 0;
- for (ss = _hurd_sigstates; ss != NULL; ss = ss->next)
+ for (ss = _hurd_sigstates; ss != NULL; ss = ss->next, ++nthreads)
if (ss->thread == _hurd_msgport_thread)
- reply_ports[nthreads++] = MACH_PORT_NULL;
+ reply_ports[nthreads] = MACH_PORT_NULL;
else
{
int state_changed;
@@ -374,15 +372,26 @@ abort_all_rpcs (int signo, struct machine_thread_all_state *state, int live)
/* Abort any operation in progress with interrupt_operation.
Record the reply port the thread is waiting on.
We will wait for all the replies below. */
- reply_ports[nthreads++] = _hurdsig_abort_rpcs (ss, signo, 1,
- state, &state_changed,
- NULL);
- if (state_changed && live)
- /* Aborting the RPC needed to change this thread's state,
- and it might ever run again. So write back its state. */
- __thread_set_state (ss->thread, MACHINE_THREAD_STATE_FLAVOR,
- (natural_t *) &state->basic,
- MACHINE_THREAD_STATE_COUNT);
+ reply_ports[nthreads] = _hurdsig_abort_rpcs (ss, signo, 1,
+ state, &state_changed,
+ NULL);
+ if (live)
+ {
+ if (reply_ports[nthreads] != MACH_PORT_NULL)
+ {
+ /* We will wait for the reply to this RPC below, so the
+ thread must issue a new RPC rather than waiting for the
+ reply to the one it sent. */
+ state->basic.SYSRETURN = EINTR;
+ state_changed = 1;
+ }
+ if (state_changed)
+ /* Aborting the RPC needed to change this thread's state,
+ and it might ever run again. So write back its state. */
+ __thread_set_state (ss->thread, MACHINE_THREAD_STATE_FLAVOR,
+ (natural_t *) &state->basic,
+ MACHINE_THREAD_STATE_COUNT);
+ }
}
/* Wait for replies from all the successfully interrupted RPCs. */
@@ -744,10 +753,8 @@ _hurd_internal_post_signal (struct hurd_sigstate *ss,
mach_port_t *loc;
- if (_hurdsig_catch_fault (SIGSEGV))
+ if (_hurdsig_catch_memory_fault (ss->context))
{
- 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
@@ -1176,14 +1183,34 @@ text_set_element (_hurd_reauth_hook, reauth_proc);
const char *
_hurdsig_getenv (const char *variable)
{
- if (_hurdsig_catch_fault (SIGSEGV))
+ if (_hurdsig_catch_memory_fault (__environ))
/* We bombed in getenv. */
return NULL;
else
{
- const char *value = getenv (variable);
- /* Fault now if VALUE is a bogus string. */
- (void) strlen (value);
+ const size_t len = strlen (variable);
+ char *value = NULL;
+ char *volatile *ep = __environ;
+ while (*ep)
+ {
+ const char *p = *ep;
+ _hurdsig_fault_preempter.first = (long int) p;
+ _hurdsig_fault_preempter.last = VM_MAX_ADDRESS;
+ if (! strncmp (p, variable, len) && p[len] == '=')
+ {
+ char *value;
+ size_t valuelen;
+ p += len + 1;
+ valuelen = strlen (p);
+ _hurdsig_fault_preempter.last = (long int) (p + valuelen);
+ value = malloc (++valuelen);
+ if (value)
+ memcpy (value, p, valuelen);
+ break;
+ }
+ _hurdsig_fault_preempter.first = (long int) ++ep;
+ _hurdsig_fault_preempter.last = (long int) (ep + 1);
+ }
_hurdsig_end_catch_fault ();
return value;
}
diff --git a/hurd/intr-msg.c b/hurd/intr-msg.c
index 41f43e1..9362731 100644
--- a/hurd/intr-msg.c
+++ b/hurd/intr-msg.c
@@ -1,5 +1,5 @@
/* Replacement for mach_msg used in interruptible Hurd RPCs.
-Copyright (C) 1995 Free Software Foundation, Inc.
+Copyright (C) 1995, 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -19,6 +19,7 @@ Cambridge, MA 02139, USA. */
#include <mach.h>
#include <mach/mig_errors.h>
+#include <mach/mig_support.h>
#include <hurd/signal.h>
#include "intr-msg.h"
@@ -45,7 +46,7 @@ _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg,
return EINTR when some other thread gets a signal, in which case we
want to restart our call. */
ss->intr_port = msg->msgh_remote_port;
-
+
/* A signal may arrive here, after intr_port is set, but before
the mach_msg system call. The signal handler might do an
interruptible RPC, and clobber intr_port; then it would not be
@@ -58,12 +59,12 @@ _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg,
if (ss->cancel)
{
- err = EINTR;
ss->cancel = 0;
+ return EINTR;
}
- else
- err = INTR_MSG_TRAP (msg, option, send_size,
- rcv_size, rcv_name, timeout, notify);
+
+ err = INTR_MSG_TRAP (msg, option, send_size,
+ rcv_size, rcv_name, timeout, notify);
switch (err)
{
@@ -83,7 +84,14 @@ _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg,
signal thread will have cleared SS->intr_port.
Since it's not cleared, the signal was for another thread,
or SA_RESTART is set. Restart the interrupted call. */
- goto message;
+ {
+ restart:
+ if (rcv_name != MACH_PORT_NULL)
+ /* Make sure we have a valid reply port. The one we were using
+ may have been destroyed by interruption. */
+ msg->msgh_local_port = rcv_name = __mig_get_reply_port ();
+ goto message;
+ }
/* FALLTHROUGH */
case MACH_RCV_PORT_DIED:
@@ -139,7 +147,7 @@ _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg,
if (ss->intr_port != MACH_PORT_NULL)
/* Nope; repeat the RPC.
XXX Resources moved? */
- goto message;
+ goto restart;
else
/* The EINTR return indicates cancellation, so clear the
flag. */