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| author | Dan Carpenter <error27@gmail.com> | 2010-05-24 14:33:49 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-07-05 11:10:48 -0700 |
| commit | a2d9ed72377e51ab0df783ee766beebe5bf51a77 (patch) | |
| tree | 94948b0d7ccedda565196ddd0d0e7cd24725a38a /drivers/rtc | |
| parent | 748ba59b943ea9f259866b3e703eec790cf48846 (diff) | |
| download | lwn-a2d9ed72377e51ab0df783ee766beebe5bf51a77.tar.gz lwn-a2d9ed72377e51ab0df783ee766beebe5bf51a77.zip | |
rtc-cmos: do dev_set_drvdata() earlier in the initialization
commit 6ba8bcd457d9fc793ac9435aa2e4138f571d4ec5 upstream.
The bug is an oops when dev_get_drvdata() returned null in
cmos_update_irq_enable(). The call tree looks like this:
rtc_dev_ioctl()
=> rtc_update_irq_enable()
=> cmos_update_irq_enable()
It's caused by a race condition in the module initialization. It is
rtc_device_register() which makes the ioctl operations live so I moved
the call to dev_set_drvdata() before the call to rtc_device_register().
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=15963
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Dan Carpenter <error27@gmail.com>
Tested-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Cc: Malte Schroder <maltesch@gmx.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-cmos.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index 473e5f25e3dd..66c2d6a6d360 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -723,6 +723,9 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) } } + cmos_rtc.dev = dev; + dev_set_drvdata(dev, &cmos_rtc); + cmos_rtc.rtc = rtc_device_register(driver_name, dev, &cmos_rtc_ops, THIS_MODULE); if (IS_ERR(cmos_rtc.rtc)) { @@ -730,8 +733,6 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) goto cleanup0; } - cmos_rtc.dev = dev; - dev_set_drvdata(dev, &cmos_rtc); rename_region(ports, dev_name(&cmos_rtc.rtc->dev)); spin_lock_irq(&rtc_lock); |