On 18/04/16 17:30, Marek Vasut wrote: > The driver never calls platform_set_drvdata() , so platform_get_drvdata() > in .remove returns NULL and thus $indio_dev variable in .remove is NULL. > Then it's only a matter of dereferencing the indio_dev variable to make > the kernel blow as seen below. This patch adds the platform_set_drvdata() > call to fix the problem. > > root@armhf:~# rmmod at91-sama5d2_adc > > Unable to handle kernel NULL pointer dereference at virtual address 000001d4 > pgd = dd57c000 > [000001d4] *pgd=00000000 > Internal error: Oops: 5 [#1] ARM > Modules linked in: at91_sama5d2_adc(-) > CPU: 0 PID: 1334 Comm: rmmod Not tainted 4.6.0-rc3-next-20160418+ #3 > Hardware name: Atmel SAMA5 > task: dd4fcc40 ti: de910000 task.ti: de910000 > PC is at mutex_lock+0x4/0x24 > LR is at iio_device_unregister+0x14/0x6c > pc : [<c05f4624>] lr : [<c0471f74>] psr: a00d0013 > sp : de911f00 ip : 00000000 fp : be898bd8 > r10: 00000000 r9 : de910000 r8 : c0107724 > r7 : 00000081 r6 : bf001048 r5 : 000001d4 r4 : 00000000 > r3 : bf000000 r2 : 00000000 r1 : 00000004 r0 : 000001d4 > Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none > Control: 10c53c7d Table: 3d57c059 DAC: 00000051 > Process rmmod (pid: 1334, stack limit = 0xde910208) > Stack: (0xde911f00 to 0xde912000) > 1f00: bf000000 00000000 df5c7e10 bf000010 bf000000 df5c7e10 df5c7e10 c0351ca8 > 1f20: c0351c84 df5c7e10 bf001048 c0350734 bf001048 df5c7e10 df5c7e44 c035087c > 1f40: bf001048 7f62dd4c 00000800 c034fb30 bf0010c0 c0158ee8 de910000 31397461 > 1f60: 6d61735f 32643561 6364615f 00000000 de911f90 de910000 de910000 00000000 > 1f80: de911fb0 10c53c7d de911f9c c05f33d8 de911fa0 00910000 be898ecb 7f62dd10 > 1fa0: 00000000 c0107560 be898ecb 7f62dd10 7f62dd4c 00000800 6f844800 6f844800 > 1fc0: be898ecb 7f62dd10 00000000 00000081 00000000 7f62dd10 be898bd8 be898bd8 > 1fe0: b6eedab1 be898b6c 7f61056b b6eedab6 000d0030 7f62dd4c 00000000 00000000 > [<c05f4624>] (mutex_lock) from [<c0471f74>] (iio_device_unregister+0x14/0x6c) > [<c0471f74>] (iio_device_unregister) from [<bf000010>] (at91_adc_remove+0x10/0x3c [at91_sama5d2_adc]) > [<bf000010>] (at91_adc_remove [at91_sama5d2_adc]) from [<c0351ca8>] (platform_drv_remove+0x24/0x3c) > [<c0351ca8>] (platform_drv_remove) from [<c0350734>] (__device_release_driver+0x84/0x110) > [<c0350734>] (__device_release_driver) from [<c035087c>] (driver_detach+0x8c/0x90) > [<c035087c>] (driver_detach) from [<c034fb30>] (bus_remove_driver+0x4c/0xa0) > [<c034fb30>] (bus_remove_driver) from [<c0158ee8>] (SyS_delete_module+0x110/0x1d0) > [<c0158ee8>] (SyS_delete_module) from [<c0107560>] (ret_fast_syscall+0x0/0x3c) > Code: e3520001 1affffd5 eafffff4 f5d0f000 (e1902f9f) > ---[ end trace 86914d7ad3696fca ]--- > > Signed-off-by: Marek Vasut <marex@xxxxxxx> > Cc: Ludovic Desroches <ludovic.desroches@xxxxxxxxx> > Cc: Jonathan Cameron <jic23@xxxxxxxxxx> Applied to the fixes-togreg branch and marked for stable. Thanks and oops :) Who removes modules anyway? Jonathan > --- > drivers/iio/adc/at91-sama5d2_adc.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c > index 07adb10..e10dca3 100644 > --- a/drivers/iio/adc/at91-sama5d2_adc.c > +++ b/drivers/iio/adc/at91-sama5d2_adc.c > @@ -497,6 +497,8 @@ static int at91_adc_probe(struct platform_device *pdev) > if (ret) > goto vref_disable; > > + platform_set_drvdata(pdev, indio_dev); > + > ret = iio_device_register(indio_dev); > if (ret < 0) > goto per_clk_disable_unprepare; > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
