| From aaacf4bb51b243875b203e6ff73b5047636b4efa Mon Sep 17 00:00:00 2001 |
| From: Wolfgang Ocker <weo@reccoware.de> |
| Date: Mon, 1 Dec 2008 13:13:52 -0800 |
| Subject: spi: avoid spidev crash when device is removed |
| |
| From: Wolfgang Ocker <weo@reccoware.de> |
| |
| commit aaacf4bb51b243875b203e6ff73b5047636b4efa upstream. |
| |
| I saw a kernel oops in spidev_remove() when a spidev device was registered |
| and I unloaded the SPI master driver: |
| |
| Unable to handle kernel paging request for data at address 0x00000004 |
| Faulting instruction address: 0xc01c0c50 |
| Oops: Kernel access of bad area, sig: 11 [#1] |
| CDSPR |
| Modules linked in: spi_ppc4xx(-) |
| NIP: c01c0c50 LR: c01bf9e4 CTR: c01c0c34 |
| REGS: cec89c30 TRAP: 0300 Not tainted (2.6.27.3izt) |
| MSR: 00021000 <ME> CR: 24000228 XER: 20000007 |
| DEAR: 00000004, ESR: 00800000 |
| TASK = cf889040[2070] 'rmmod' THREAD: cec88000 |
| GPR00: 00000000 cec89ce0 cf889040 cec8e000 00000004 cec8e000 ffffffff 00000000 |
| GPR08: 0000001c c0336380 00000000 c01c0c34 00000001 1001a338 100e0000 100df49c |
| GPR16: 100b54c0 100df49c 100ddd20 100f05a8 100b5340 100efd68 00000000 00000000 |
| GPR24: 100ec008 100f0428 c0327788 c0327794 cec8e0ac cec8e000 c0336380 00000000 |
| NIP [c01c0c50] spidev_remove+0x1c/0xe4 |
| LR [c01bf9e4] spi_drv_remove+0x2c/0x3c |
| Call Trace: |
| [cec89d00] [c01bf9e4] spi_drv_remove+0x2c/0x3c |
| [cec89d10] [c01859a0] __device_release_driver+0x78/0xb4 |
| [cec89d20] [c0185ab0] device_release_driver+0x28/0x44 |
| [cec89d40] [c0184be8] bus_remove_device+0xac/0xd8 |
| [cec89d60] [c0183094] device_del+0x100/0x194 |
| [cec89d80] [c0183140] device_unregister+0x18/0x30 |
| [cec89da0] [c01bf30c] __unregister+0x20/0x34 |
| [cec89db0] [c0182778] device_for_each_child+0x38/0x74 |
| [cec89de0] [c01bf2d0] spi_unregister_master+0x28/0x44 |
| [cec89e00] [c01bfeac] spi_bitbang_stop+0x1c/0x58 |
| [cec89e20] [d908a5e0] spi_ppc4xx_of_remove+0x24/0x7c [spi_ppc4xx] |
| [...] |
| |
| IMHO a call to spi_set_drvdata() is missing in spidev_probe(). The patch |
| below helped. |
| |
| Signed-off-by: Wolfgang Ocker <weo@reccoware.de> |
| Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> |
| 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> |
| |
| --- |
| drivers/spi/spidev.c | 4 +++- |
| 1 file changed, 3 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/spi/spidev.c |
| +++ b/drivers/spi/spidev.c |
| @@ -598,7 +598,9 @@ static int spidev_probe(struct spi_devic |
| } |
| mutex_unlock(&device_list_lock); |
| |
| - if (status != 0) |
| + if (status == 0) |
| + spi_set_drvdata(spi, spidev); |
| + else |
| kfree(spidev); |
| |
| return status; |
