From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: [PATCH] BUG_ON() bad input to request_irq Date: Thu, 24 Jan 2008 09:15:10 +1100 Message-ID: <200801240915.11216.rusty@rustcorp.com.au> References: <200801171757.59026.rusty@rustcorp.com.au> <200801171759.59029.rusty@rustcorp.com.au> <20080123140414.e1ff2263.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: jeff@garzik.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Andrew Morton Return-path: Received: from ozlabs.org ([203.10.76.45]:48204 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751623AbYAWWQB (ORCPT ); Wed, 23 Jan 2008 17:16:01 -0500 In-Reply-To: <20080123140414.e1ff2263.akpm@linux-foundation.org> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: On Thursday 24 January 2008 09:04:14 Andrew Morton wrote: > > On Thu, 17 Jan 2008 17:59:58 +1100 Rusty Russell > If no driver is passing in args which will trigger this BUG, we presumably > don't need the patch. You're only thinking of current code. The BUG catches future changes, too. > If some driver _is_ passing in args which will trigger these BUGs then it is > presumably working OK anyway. Taking a working system and making it go BUG > is likely to upset people. That's why I did the audit. See patch below which preceeded it, which Jeff hasn't responded to. Breaking his drivers might make him notice :) > IOW: WARN_ON, please. At end of cycles, sure, but not for 2.6.25: they're even more invisible than deprecated warnings :( Rusty. === request_irq() always returns -EINVAL with a NULL handler. I assume that these ancient network drivers were trying to find out if an irq is available. eepro.c expecting +EBUSY was doubly wrong. Request_irq should BUG() on bad input, and these would have been found earlier. Signed-off-by: Rusty Russell --- drivers/net/3c503.c | 2 +- drivers/net/e2100.c | 2 +- drivers/net/eepro.c | 2 +- drivers/net/hp.c | 2 +- kernel/irq/manage.c | 1 + 5 files changed, 5 insertions(+), 4 deletions(-) diff -r 0b7e4fbb6238 drivers/net/3c503.c --- a/drivers/net/3c503.c Thu Jan 17 15:49:34 2008 +1100 +++ b/drivers/net/3c503.c Thu Jan 17 16:40:28 2008 +1100 @@ -379,7 +379,7 @@ el2_open(struct net_device *dev) outb(EGACFR_NORM, E33G_GACFR); /* Enable RAM and interrupts. */ do { - if (request_irq (*irqp, NULL, 0, "bogus", dev) != -EBUSY) { + if (can_request_irq(*irqp, 0)) { /* Twinkle the interrupt, and check if it's seen. */ unsigned long cookie = probe_irq_on(); outb_p(0x04 << ((*irqp == 9) ? 2 : *irqp), E33G_IDCFR); diff -r 0b7e4fbb6238 drivers/net/e2100.c --- a/drivers/net/e2100.c Thu Jan 17 15:49:34 2008 +1100 +++ b/drivers/net/e2100.c Thu Jan 17 16:40:28 2008 +1100 @@ -202,7 +202,7 @@ static int __init e21_probe1(struct net_ if (dev->irq < 2) { int irqlist[] = {15,11,10,12,5,9,3,4}, i; for (i = 0; i < 8; i++) - if (request_irq (irqlist[i], NULL, 0, "bogus", NULL) != -EBUSY) { + if (can_request_irq(irqlist[i], 0)) { dev->irq = irqlist[i]; break; } diff -r 0b7e4fbb6238 drivers/net/eepro.c --- a/drivers/net/eepro.c Thu Jan 17 15:49:34 2008 +1100 +++ b/drivers/net/eepro.c Thu Jan 17 16:40:28 2008 +1100 @@ -914,7 +914,7 @@ static int eepro_grab_irq(struct net_dev eepro_sw2bank0(ioaddr); /* Switch back to Bank 0 */ - if (request_irq (*irqp, NULL, IRQF_SHARED, "bogus", dev) != EBUSY) { + if (can_request_irq(*irqp, IRQF_SHARED)) { unsigned long irq_mask; /* Twinkle the interrupt, and check if it's seen */ irq_mask = probe_irq_on(); diff -r 0b7e4fbb6238 drivers/net/hp.c --- a/drivers/net/hp.c Thu Jan 17 15:49:34 2008 +1100 +++ b/drivers/net/hp.c Thu Jan 17 16:40:28 2008 +1100 @@ -170,7 +170,7 @@ static int __init hp_probe1(struct net_d int *irqp = wordmode ? irq_16list : irq_8list; do { int irq = *irqp; - if (request_irq (irq, NULL, 0, "bogus", NULL) != -EBUSY) { + if (can_request_irq(irq, 0)) { unsigned long cookie = probe_irq_on(); /* Twinkle the interrupt, and check if it's seen. */ outb_p(irqmap[irq] | HP_RUN, ioaddr + HP_CONFIGURE); diff -r 0b7e4fbb6238 kernel/irq/manage.c --- a/kernel/irq/manage.c Thu Jan 17 15:49:34 2008 +1100 +++ b/kernel/irq/manage.c Thu Jan 17 16:40:28 2008 +1100 @@ -252,6 +252,7 @@ int can_request_irq(unsigned int irq, un return !action; } +EXPORT_SYMBOL(can_request_irq); void compat_irq_chip_set_default_handler(struct irq_desc *desc) {