Re: bsd.upgrade uvm_fault

"Theo de Raadt" <[email protected]> writes:

> I have no idea how com_cd.cd_devs[DEVUNIT(dev)] became NULL.
>
>> com4 at puc0 port 0 apic 2 int 16: ns16550a, 16 byte fifo
>
> because the way the config works is that if that line is printed,
> the com_cd.cd_devs[] has been filled with pointer to a properly-over-sized
> struct device * useable as a device-specific softc.
>
> One ugly thing about console in some drivers, is that the *open function
> might not be called before the first *write call, but *open() is responsible
> for allocating the tty structure with a call to ttymalloc().

Some more debugging **without** puc and this diff:

diff --git a/sys/dev/ic/com.c b/sys/dev/ic/com.c
index c5ceb956a67..438d6df11fa 100644
--- a/sys/dev/ic/com.c
+++ b/sys/dev/ic/com.c
@@ -638,7 +638,11 @@ comread(dev_t dev, struct uio *uio, int flag)
 int
 comwrite(dev_t dev, struct uio *uio, int flag)
 {
+	extern	struct vnode *cn_devvp;
+	extern	struct tty *constty;
 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(dev)];
+	printf("dev %d sc %p constty %p cn_devvp %p\n",
+	    DEVUNIT(dev), sc, constty, cn_devvp);
 	struct tty *tp = sc->sc_tty;
 
 	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));


this prints:

root on rd0a swap on rd0b dump on rd0b
WARNING: CHECK AND RESET THE DATE!
dev 4 sc 0x0 constty 0x0 cn_devvp 0xfffffd811efe1870
uvm_fault(0xfffffd811efd35c0, 0x58, 0, 1) -> e
fatal page fault in supervisor mode


Full disclosure: I'm running with DDB enabled in RAMDISK_CD as I
couldn't get the stack traces otherwise. Here's the whole set of
modified files:

diff --git a/sys/dev/ic/com.c b/sys/dev/ic/com.c
index c5ceb956a67..438d6df11fa 100644
--- a/sys/dev/ic/com.c
+++ b/sys/dev/ic/com.c
@@ -638,7 +638,11 @@ comread(dev_t dev, struct uio *uio, int flag)
 int
 comwrite(dev_t dev, struct uio *uio, int flag)
 {
+	extern	struct vnode *cn_devvp;
+	extern	struct tty *constty;
 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(dev)];
+	printf("dev %d sc %p constty %p cn_devvp %p\n",
+	    DEVUNIT(dev), sc, constty, cn_devvp);
 	struct tty *tp = sc->sc_tty;
 
 	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index 2e5934be756..4e72fca814b 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -2524,7 +2524,7 @@ so_print(void *v,
 	(*pr)("so_qlimit: %i\n", so->so_qlimit);
 	(*pr)("so_timeo: %i\n", so->so_timeo);
 	(*pr)("so_obmark: %lu\n", so->so_oobmark);
-
+#ifdef SOCKET_SPLICE
 	(*pr)("so_sp: %p\n", so->so_sp);
 	if (so->so_sp != NULL) {
 		(*pr)("\tssp_socket: %p\n", so->so_sp->ssp_socket);
@@ -2537,7 +2537,7 @@ so_print(void *v,
 		    timeout_pending(&so->so_spliceidleto) ? "" : "not ",
 		    so->so_spliceidleto.to_time);
 	}
-
+#endif
 	(*pr)("so_rcv:\n");
 	sobuf_print(&so->so_rcv, pr);
 	(*pr)("so_snd:\n");
diff --git a/sys/uvm/uvm_meter.c b/sys/uvm/uvm_meter.c
index 890b6b227b0..b27dbda32ec 100644
--- a/sys/uvm/uvm_meter.c
+++ b/sys/uvm/uvm_meter.c
@@ -297,7 +297,11 @@ uvmexp_print(int (*pr)(const char *, ...))
 {
 	struct uvmexp uexp;
 
+#ifdef SMALL_KERNEL
+	memcpy(&uexp, &uvmexp, sizeof(uexp));
+#else
 	uvmexp_read(&uexp);
+#endif
 
 	(*pr)("Current UVM status:\n");
 	(*pr)("  pagesize=%d (0x%x), pagemask=0x%x, pageshift=%d\n",