Here follows the new kernel dumping infrastructure.

Caveats:

The new savecore program is not complete in the sense that it emulates
enough of the old savecores features to do the job, but implements none
of the options yet.

I would appreciate if a userland hacker could help me out getting savecore
to do what we want it to do from a users point of view, compression,
email-notification, space reservation etc etc.  (send me email if
you are interested).

Currently, savecore will scan all devices marked as "swap" or "dump" in
/etc/fstab _or_ any devices specified on the command-line.

All architectures but i386 lack an implementation of dumpsys(), but
looking at the i386 version it should be trivial for anybody familiar
with the platform(s) to provide this function.

Documentation is quite sparse at this time, more to come.

Details:

ATA and SCSI drivers should work as the dump formatting code has been
removed.  The IDA, TWE and AAC have not yet been converted.

Dumpon now opens the device and uses ioctl(DIOCGKERNELDUMP) to set
the device as dumpdev.  To implement the "off" argument, /dev/null
is used as the device.

Savecore will fail if handed any options since they are not (yet)
implemented.  All devices marked "dump" or "swap" in /etc/fstab
will be scanned and dumps found will be saved to diskfiles
named from the MD5 hash of the header record.  The header record
is dumped in readable format in the .info file.  The kernel
is not saved.  Only complete dumps will be saved.

All maintainer rights for this code are disclaimed: feel free to
improve and extend.

Sponsored by:   DARPA, NAI Labs

1 files changed, 30 insertions, 173 deletions

diff --git a/sys/kern/kern_shutdown.c b/sys/kern/kern_shutdown.c
index 80cb9e6..66f3911 100644
--- a/sys/kern/kern_shutdown.c
+++ b/sys/kern/kern_shutdown.c
@@ -64,7 +64,6 @@
 #include <sys/sysproto.h>
 #include <sys/vnode.h>
 
-#include <machine/pcb.h>
 #include <machine/md_var.h>
 #include <machine/smp.h>
 
@@ -116,11 +115,10 @@ watchdog_tickle_fn wdog_tickler = NULL;
  */
 const char *panicstr;
 
-int dumping;				 /* system is dumping */
-dev_t dumpdev = NODEV;
+int dumping;				/* system is dumping */
+static struct dumperinfo dumper;	/* our selected dumper */
 
 static void boot(int) __dead2;
-static void dumpsys(void);
 static void poweroff_wait(void *, int);
 static void shutdown_halt(void *junk, int howto);
 static void shutdown_panic(void *junk, int howto);
@@ -178,7 +176,6 @@ shutdown_nice(int howto)
 	return;
 }
 static int	waittime = -1;
-static struct pcb dumppcb;
 
 static void
 print_uptime(void)
@@ -334,8 +331,11 @@ boot(int howto)
 	 */
 	EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
 	splhigh();
-	if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold)
-		dumpsys();
+	if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP &&
+	    !cold && dumper.dumper != NULL && !dumping) {
+			dumping++;
+			dumpsys(&dumper);
+	}
 
 	/* Now that we're going to really halt the system... */
 	EVENTHANDLER_INVOKE(shutdown_final, howto);
@@ -412,172 +412,6 @@ shutdown_reset(void *junk, int howto)
 	/* NOTREACHED */ /* assuming reset worked */
 }
 
-/*
- * Magic number for savecore
- *
- * exported (symorder) and used at least by savecore(8)
- *
- */
-static u_long const	dumpmag = 0x8fca0101UL;	
-
-static int	dumpsize = 0;		/* also for savecore */
-
-static int	dodump = 1;
-
-SYSCTL_INT(_machdep, OID_AUTO, do_dump, CTLFLAG_RW, &dodump, 0,
-    "Try to perform coredump on kernel panic");
-
-static int
-setdumpdev(dev_t dev)
-{
-	int psize;
-	long newdumplo;
-
-	if (dev == NODEV) {
-		dumpdev = dev;
-		return (0);
-	}
-	if (devsw(dev) == NULL)
-		return (ENXIO);		/* XXX is this right? */
-	if (devsw(dev)->d_psize == NULL)
-		return (ENXIO);		/* XXX should be ENODEV ? */
-	psize = devsw(dev)->d_psize(dev);
-	if (psize == -1)
-		return (ENXIO);		/* XXX should be ENODEV ? */
-	/*
-	 * XXX should clean up checking in dumpsys() to be more like this.
-	 */
-	newdumplo = psize - Maxmem * (PAGE_SIZE / DEV_BSIZE);
-	if (newdumplo <= LABELSECTOR)
-		return (ENOSPC);
-	dumpdev = dev;
-	dumplo = newdumplo;
-	return (0);
-}
-
-
-/* ARGSUSED */
-static void
-dump_conf(void *dummy)
-{
-	char *path;
-	dev_t dev;
-
-	path = malloc(MNAMELEN, M_TEMP, M_WAITOK);
-	if (TUNABLE_STR_FETCH("dumpdev", path, MNAMELEN) != 0) {
-		dev = getdiskbyname(path);
-		if (dev != NODEV)
-			dumpdev = dev;
-	}
-	free(path, M_TEMP);
-	if (setdumpdev(dumpdev) != 0)
-		dumpdev = NODEV;
-}
-
-SYSINIT(dump_conf, SI_SUB_DUMP_CONF, SI_ORDER_FIRST, dump_conf, NULL)
-
-static int
-sysctl_kern_dumpdev(SYSCTL_HANDLER_ARGS)
-{
-	int error;
-	udev_t ndumpdev;
-
-	ndumpdev = dev2udev(dumpdev);
-	error = sysctl_handle_opaque(oidp, &ndumpdev, sizeof ndumpdev, req);
-	if (error == 0 && req->newptr != NULL)
-		error = setdumpdev(udev2dev(ndumpdev, 0));
-	return (error);
-}
-
-SYSCTL_PROC(_kern, KERN_DUMPDEV, dumpdev, CTLTYPE_OPAQUE|CTLFLAG_RW,
-	0, sizeof dumpdev, sysctl_kern_dumpdev, "T,dev_t", "");
-
-/*
- * Doadump comes here after turning off memory management and
- * getting on the dump stack, either when called above, or by
- * the auto-restart code.
- */
-static void
-dumpsys(void)
-{
-	int	error;
-
-	savectx(&dumppcb);
-	if (!dodump)
-		return;
-	if (dumpdev == NODEV)
-		return;
-	if (!(devsw(dumpdev)))
-		return;
-	if (!(devsw(dumpdev)->d_dump))
-		return;
-	if (dumping++) {
-		dumping--;
-		printf("Dump already in progress, bailing...\n");
-		return;
-	}
-	dumpsize = Maxmem;
-	printf("\ndumping to dev %s, offset %ld\n", devtoname(dumpdev), dumplo);
-	printf("dump ");
-	error = (*devsw(dumpdev)->d_dump)(dumpdev);
-	dumping--;
-	if (error == 0) {
-		printf("succeeded\n");
-		return;
-	}
-	printf("failed, reason: ");
-	switch (error) {
-	case ENODEV:
-		printf("device doesn't support a dump routine\n");
-		break;
-
-	case ENXIO:
-		printf("device bad\n");
-		break;
-
-	case EFAULT:
-		printf("device not ready\n");
-		break;
-
-	case EINVAL:
-		printf("area improper\n");
-		break;
-
-	case EIO:
-		printf("i/o error\n");
-		break;
-
-	case EINTR:
-		printf("aborted from console\n");
-		break;
-
-	default:
-		printf("unknown, error = %d\n", error);
-		break;
-	}
-}
-
-int
-dumpstatus(vm_offset_t addr, off_t count)
-{
-	int c;
-
-	if (addr % (1024 * 1024) == 0) {
-#ifdef HW_WDOG
-		if (wdog_tickler)
-			(*wdog_tickler)();
-#endif   
-		printf("%ld ", (long)(count / (1024 * 1024)));
-	}
-
-	if ((c = cncheckc()) == 0x03)
-		return -1;
-	else if (c != -1)
-		printf("[CTRL-C to abort] ");
-	
-	return 0;
-}
-
 #ifdef SMP
 static u_int panic_cpu = NOCPU;
 #endif
@@ -697,3 +531,26 @@ kproc_shutdown(void *arg, int howto)
 	else
 		printf("stopped\n");
 }
+
+/* Registration of dumpers */
+int
+set_dumper(struct dumperinfo *di)
+{
+	if (di == NULL) {
+		bzero(&dumper, sizeof dumper);
+		return (0);
+	}
+	if (dumper.dumper != NULL)
+		return (EBUSY);
+	dumper = *di;
+	return (0);
+}
+
+#ifndef __i386__
+void
+dumpsys(struct dumperinfo *di __unused)
+{
+
+	printf("Kernel dumps not implemented on this architecture\n");
+}
+#endif