From aaacf4bb51b243875b203e6ff73b5047636b4efa Mon Sep 17 00:00:00 2001 From: Wolfgang Ocker Date: Mon, 1 Dec 2008 13:13:52 -0800 Subject: spi: avoid spidev crash when device is removed 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 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 Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/spi/spidev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/spi') diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c index 89a43755a453..5d869c4d3eb2 100644 --- a/drivers/spi/spidev.c +++ b/drivers/spi/spidev.c @@ -597,7 +597,9 @@ static int spidev_probe(struct spi_device *spi) } mutex_unlock(&device_list_lock); - if (status != 0) + if (status == 0) + spi_set_drvdata(spi, spidev); + else kfree(spidev); return status; -- cgit v1.2.3