From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bamako.nerim.net (bamako.nerim.net [62.4.17.28]) by ozlabs.org (Postfix) with ESMTP id B9C3BB7D0D for ; Fri, 29 Jan 2010 19:19:02 +1100 (EST) Date: Fri, 29 Jan 2010 09:18:57 +0100 From: Jean Delvare To: Christian Kujau , Benjamin Herrenschmidt Subject: Re: i2c_powermac: Kernel access of bad area Message-ID: <20100129091857.3b7228db@hyperion.delvare> In-Reply-To: <20100107171738.2c83b13e@hyperion.delvare> References: <1262079255.2173.216.camel@pasglop> <20100106173745.57207520@hyperion.delvare> <20100107171738.2c83b13e@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: linuxppc-dev@ozlabs.org, Michael Hanselmann , LKML , Stelian Pop List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Ben, Christian, On Thu, 7 Jan 2010 17:17:38 +0100, Jean Delvare wrote: > On Wed, 6 Jan 2010 19:41:05 -0800 (PST), Christian Kujau wrote: > > Hi Jean, > > > > On Wed, 6 Jan 2010 at 17:37, Jean Delvare wrote: > > > I think that sysfs files creation should be moved to the end of > > > probe_thermostat() and sysfs files removal should be moved to the > > > beginning of remove_thermostat(). Something like the totally untested > > > patch below (no ppc machine at hand): > > > > I applied your patch to 2.6.33-rc3, and was able to unload i2c-powermac and > > then reading the files left in /sys/devices/temperatures. I even tried to > > read the non-existant files (e.g. sensor1_fan_speed, etc...), but the > > kernel just wouldn't oops :) > > > > So the initial oops is gone - yeah! Ben, what about applying this patch of mine, as Christian reported it fixed his oops? > > However, the "Badness" remains when I try to modprobe i2c-powermac again: > > > > [ 442.148222] PowerMac i2c bus pmu 2 registered > > [ 442.148792] PowerMac i2c bus pmu 1 registered > > [ 442.149299] PowerMac i2c bus mac-io 0 registered > > [ 442.163573] adt746x: ADT7467 initializing > > [ 442.170072] adt746x: Lowering max temperatures from 73, 80, 109 to 67, 47, 67 > > [ 442.176559] PowerMac i2c bus uni-n 1 registered > > [ 442.227115] sysfs: cannot create duplicate filename '/devices/ams' > > [ 442.227697] ------------[ cut here ]------------ > > [ 442.228176] Badness at fs/sysfs/dir.c:487 > > [ 442.228642] NIP: c00eb71c LR: c00eb71c CTR: 00000000 > > [ 442.229117] REGS: eea0fa50 TRAP: 0700 Not tainted (2.6.33-rc3) > > [ 442.229592] MSR: 00029032 CR: 42008444 XER: 00000000 > > [ 442.230151] TASK = eea10000[2821] 'modprobe' THREAD: eea0e000 > > [ 442.230191] GPR00: c00eb71c eea0fb00 eea10000 0000004c 000064c6 ffffffff ffffffff 00000000 > > [ 442.230758] GPR08: efa71740 c03e0000 00000000 000064c6 44008428 10020390 100e0000 100df49c > > [ 442.231326] GPR16: 100b54c0 100df49c 100ddd20 1018fb08 100b5340 c03e674c c03e6720 c03ea044 > > [ 442.231902] GPR24: 00000000 24008422 ffffffea eea0fb58 ef0e9000 ef0e9000 ef0a9ea0 ffffffef > > [ 442.233187] NIP [c00eb71c] sysfs_add_one+0x94/0xc0 > > [ 442.233695] LR [c00eb71c] sysfs_add_one+0x94/0xc0 > > [ 442.234363] Call Trace: > > > > I've put the whole dmesg on: > > > > http://nerdbynature.de/bits/2.6.33-rc2/i2c_powermac/r1/ > > Hmm. Looks like a different but somewhat similar problem in the ams > driver: some code that is in ams_exit() (the module exit code) should > instead be called when the device (not module) is removed. It probably > doesn't make much of a difference in the PMU case, but in the I2C case > it does matter. > > The following, totally untested patch may fix it. I make no guarantee > that my code isn't racy though, I'm not familiar enough with the ams > driver code to tell for sure. > > --- > drivers/hwmon/ams/ams-core.c | 11 +++++++---- > drivers/hwmon/ams/ams-i2c.c | 2 ++ > drivers/hwmon/ams/ams-pmu.c | 2 ++ > drivers/hwmon/ams/ams.h | 1 + > 4 files changed, 12 insertions(+), 4 deletions(-) > > --- linux-2.6.33-rc3.orig/drivers/hwmon/ams/ams-core.c 2009-06-10 05:05:27.000000000 +0200 > +++ linux-2.6.33-rc3/drivers/hwmon/ams/ams-core.c 2010-01-07 17:14:25.000000000 +0100 > @@ -213,7 +213,7 @@ int __init ams_init(void) > return -ENODEV; > } > > -void ams_exit(void) > +void ams_sensor_detach(void) > { > /* Remove input device */ > ams_input_exit(); > @@ -221,9 +221,6 @@ void ams_exit(void) > /* Remove attributes */ > device_remove_file(&ams_info.of_dev->dev, &dev_attr_current); > > - /* Shut down implementation */ > - ams_info.exit(); > - > /* Flush interrupt worker > * > * We do this after ams_info.exit(), because an interrupt might > @@ -239,6 +236,12 @@ void ams_exit(void) > pmf_unregister_irq_client(&ams_freefall_client); > } > > +static void __exit ams_exit(void) > +{ > + /* Shut down implementation */ > + ams_info.exit(); > +} > + > MODULE_AUTHOR("Stelian Pop, Michael Hanselmann"); > MODULE_DESCRIPTION("Apple Motion Sensor driver"); > MODULE_LICENSE("GPL"); > --- linux-2.6.33-rc3.orig/drivers/hwmon/ams/ams-i2c.c 2009-06-10 05:05:27.000000000 +0200 > +++ linux-2.6.33-rc3/drivers/hwmon/ams/ams-i2c.c 2010-01-07 17:12:46.000000000 +0100 > @@ -238,6 +238,8 @@ static int ams_i2c_probe(struct i2c_clie > static int ams_i2c_remove(struct i2c_client *client) > { > if (ams_info.has_device) { > + ams_sensor_detach(); > + > /* Disable interrupts */ > ams_i2c_set_irq(AMS_IRQ_ALL, 0); > > --- linux-2.6.33-rc3.orig/drivers/hwmon/ams/ams-pmu.c 2009-06-10 05:05:27.000000000 +0200 > +++ linux-2.6.33-rc3/drivers/hwmon/ams/ams-pmu.c 2010-01-07 17:13:47.000000000 +0100 > @@ -133,6 +133,8 @@ static void ams_pmu_get_xyz(s8 *x, s8 *y > > static void ams_pmu_exit(void) > { > + ams_sensor_detach(); > + > /* Disable interrupts */ > ams_pmu_set_irq(AMS_IRQ_ALL, 0); > > --- linux-2.6.33-rc3.orig/drivers/hwmon/ams/ams.h 2009-06-10 05:05:27.000000000 +0200 > +++ linux-2.6.33-rc3/drivers/hwmon/ams/ams.h 2010-01-07 17:11:43.000000000 +0100 > @@ -61,6 +61,7 @@ extern struct ams ams_info; > > extern void ams_sensors(s8 *x, s8 *y, s8 *z); > extern int ams_sensor_attach(void); > +extern void ams_sensor_detach(void); > > extern int ams_pmu_init(struct device_node *np); > extern int ams_i2c_init(struct device_node *np); Christian, did you ever test this second patch of mine? If you did, what was the outcome? -- Jean Delvare