Date: Tue, 31 Mar 1998 13:10:02 -0800 (PST) From: Peter Jeremy <Peter.Jeremy@alcatel.com.au> To: freebsd-bugs Subject: Re: kern/6099: LPIP to slow machine causes hang Message-ID: <199803312110.NAA22216@hub.freebsd.org>
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The following reply was made to PR kern/6099; it has been noted by GNATS.
From: Peter Jeremy <Peter.Jeremy@alcatel.com.au>
To: freebsd-gnats-submit@freebsd.org
Cc: dag-erli@ifi.uio.no, dmlb@ragnet.demon.co.uk, regnauld@deepo.prosa.dk
Subject: Re: kern/6099: LPIP to slow machine causes hang
Date: Wed, 01 Apr 1998 07:02:21 +1000 (EST)
This problem appears to be identical to PRs kern/1271 and i386/5698.
The problem with LPIP is that enabling an lpt port for LPIP does not
update net_imask. This means that LPIP interrupts can break splimp()
critical regions - which includes all mbuf handling.
The following patches correct the problem in 2.2.5R. The problem also
exists in older versions of 2.2, -stable and -current. The same patches
will presumably correct similar bugs in those versions.
--- /home3/jeremyp/fbsd.225/src/sys/i386/isa/lpt.c Tue Nov 12 20:08:38 1996
+++ /tmp/lpt.c Fri Mar 27 19:08:19 1998
@@ -214,9 +214,9 @@
#define LP_AUTOLF 0x40 /* tell printer to do an automatic lf */
#define LP_BYPASS 0x80 /* bypass printer ready checks */
struct buf *sc_inbuf;
+ char *sc_cp ;
short sc_xfercnt ;
char sc_primed;
- char *sc_cp ;
u_char sc_irq ; /* IRQ status of port */
#define LP_HAS_IRQ 0x01 /* we have an irq available */
#define LP_USE_IRQ 0x02 /* we are using our irq */
@@ -224,6 +224,7 @@
u_char sc_backoff ; /* time to call lptout() again */
#ifdef INET
+ u_short sc_irqmask; /* hardware interrupt mask */
struct ifnet sc_if;
u_char *sc_ifbuf;
int sc_iferrs;
@@ -445,6 +446,7 @@
sc->sc_irq = LP_HAS_IRQ | LP_USE_IRQ | LP_ENABLE_IRQ;
printf("lpt%d: Interrupt-driven port\n", unit);
#ifdef INET
+ sc->sc_irqmask = isdp->id_irq;
lpattach(sc, unit);
#endif
} else {
@@ -933,7 +935,7 @@
struct ifaddr *ifa = (struct ifaddr *)data;
struct ifreq *ifr = (struct ifreq *)data;
u_char *ptr;
-
+ int x;
switch (cmd) {
case SIOCSIFDSTADDR:
@@ -941,6 +943,9 @@
case SIOCSIFADDR:
if (ifa->ifa_addr->sa_family != AF_INET)
return EAFNOSUPPORT;
+ x = splhigh();
+ net_imask |= sc->sc_irqmask;
+ splx(x);
ifp->if_flags |= IFF_UP;
/* FALLTHROUGH */
case SIOCSIFFLAGS:
--
Peter Jeremy (VK2PJ) peter.jeremy@alcatel.com.au
Alcatel Australia Limited
41 Mandible St Phone: +61 2 9690 5019
ALEXANDRIA NSW 2015 Fax: +61 2 9690 5247
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