mtd: omap2: fix omap_nand_remove segfault

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=7d9b110269253b1d5858cfa57d68dfc7bf50dd77
Commit:     7d9b110269253b1d5858cfa57d68dfc7bf50dd77
Parent:     7be1f6b9a1ae3476a424380b52aad7c14c3273ab
Author:     Andreas Bießmann <andreas at biessmann.de>
AuthorDate: Fri Aug 31 13:35:41 2012 +0200
Committer:  David Woodhouse <David.Woodhouse at intel.com>
CommitDate: Sat Sep 29 15:29:18 2012 +0100

    mtd: omap2: fix omap_nand_remove segfault
    
    Do not kfree() the mtd_info; it is handled in the mtd subsystem and
    already freed by nand_release(). Instead kfree() the struct
    omap_nand_info allocated in omap_nand_probe which was not freed before.
    
    This patch fixes following error when unloading the omap2 module:
    
    ---8<---
    ~ $ rmmod omap2
    ------------[ cut here ]------------
    kernel BUG at mm/slab.c:3126!
    Internal error: Oops - BUG: 0 [#1] PREEMPT ARM
    Modules linked in: omap2(-)
    CPU: 0    Not tainted  (3.6.0-rc3-00230-g155e36d-dirty #3)
    PC is at cache_free_debugcheck+0x2d4/0x36c
    LR is at kfree+0xc8/0x2ac
    pc : [<c01125a0>]    lr : [<c0112efc>]    psr: 200d0193
    sp : c521fe08  ip : c0e8ef90  fp : c521fe5c
    r10: bf0001fc  r9 : c521e000  r8 : c0d99c8c
    r7 : c661ebc0  r6 : c065d5a4  r5 : c65c4060  r4 : c78005c0
    r3 : 00000000  r2 : 00001000  r1 : c65c4000  r0 : 00000001
    Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
    Control: 10c5387d  Table: 86694019  DAC: 00000015
    Process rmmod (pid: 549, stack limit = 0xc521e2f0)
    Stack: (0xc521fe08 to 0xc5220000)
    fe00:                   c008a874 c00bf44c c515c6d0 200d0193 c65c4860 c515c240
    fe20: c521fe3c c521fe30 c008a9c0 c008a854 c521fe5c c65c4860 c78005c0 bf0001fc
    fe40: c780ff40 a00d0113 c521e000 00000000 c521fe84 c521fe60 c0112efc c01122d8
    fe60: c65c4860 c0673778 c06737ac 00000000 00070013 00000000 c521fe9c c521fe88
    fe80: bf0001fc c0112e40 c0673778 bf001ca8 c521feac c521fea0 c02ca11c bf0001ac
    fea0: c521fec4 c521feb0 c02c82c4 c02ca100 c0673778 bf001ca8 c521fee4 c521fec8
    fec0: c02c8dd8 c02c8250 00000000 bf001ca8 bf001ca8 c0804ee0 c521ff04 c521fee8
    fee0: c02c804c c02c8d20 bf001924 00000000 bf001ca8 c521e000 c521ff1c c521ff08
    ff00: c02c950c c02c7fbc bf001d48 00000000 c521ff2c c521ff20 c02ca3a4 c02c94b8
    ff20: c521ff3c c521ff30 bf001938 c02ca394 c521ffa4 c521ff40 c009beb4 bf001930
    ff40: c521ff6c 70616d6f b6fe0032 c0014f84 70616d6f b6fe0032 00000081 60070010
    ff60: c521ff84 c521ff70 c008e1f4 c00bf328 0001a004 70616d6f c521ff94 0021ff88
    ff80: c008e368 0001a004 70616d6f b6fe0032 00000081 c0015028 00000000 c521ffa8
    ffa0: c0014dc0 c009bcd0 0001a004 70616d6f bec2ab38 00000880 bec2ab38 00000880
    ffc0: 0001a004 70616d6f b6fe0032 00000081 00000319 00000000 b6fe1000 00000000
    ffe0: bec2ab30 bec2ab20 00019f00 b6f539c0 60070010 bec2ab38 aaaaaaaa aaaaaaaa
    Backtrace:
    [<c01122cc>] (cache_free_debugcheck+0x0/0x36c) from [<c0112efc>] (kfree+0xc8/0x2ac)
    [<c0112e34>] (kfree+0x0/0x2ac) from [<bf0001fc>] (omap_nand_remove+0x5c/0x64 [omap2])
    [<bf0001a0>] (omap_nand_remove+0x0/0x64 [omap2]) from [<c02ca11c>] (platform_drv_remove+0x28/0x2c)
     r5:bf001ca8 r4:c0673778
    [<c02ca0f4>] (platform_drv_remove+0x0/0x2c) from [<c02c82c4>] (__device_release_driver+0x80/0xdc)
    [<c02c8244>] (__device_release_driver+0x0/0xdc) from [<c02c8dd8>] (driver_detach+0xc4/0xc8)
     r5:bf001ca8 r4:c0673778
    [<c02c8d14>] (driver_detach+0x0/0xc8) from [<c02c804c>] (bus_remove_driver+0x9c/0x104)
     r6:c0804ee0 r5:bf001ca8 r4:bf001ca8 r3:00000000
    [<c02c7fb0>] (bus_remove_driver+0x0/0x104) from [<c02c950c>] (driver_unregister+0x60/0x80)
     r6:c521e000 r5:bf001ca8 r4:00000000 r3:bf001924
    [<c02c94ac>] (driver_unregister+0x0/0x80) from [<c02ca3a4>] (platform_driver_unregister+0x1c/0x20)
     r5:00000000 r4:bf001d48
    [<c02ca388>] (platform_driver_unregister+0x0/0x20) from [<bf001938>] (omap_nand_driver_exit+0x14/0x1c [omap2])
    [<bf001924>] (omap_nand_driver_exit+0x0/0x1c [omap2]) from [<c009beb4>] (sys_delete_module+0x1f0/0x2ec)
    [<c009bcc4>] (sys_delete_module+0x0/0x2ec) from [<c0014dc0>] (ret_fast_syscall+0x0/0x48)
     r8:c0015028 r7:00000081 r6:b6fe0032 r5:70616d6f r4:0001a004
    Code: e1a00005 eb0d9172 e7f001f2 e7f001f2 (e7f001f2)
    ---[ end trace 6a30b24d8c0cc2ee ]---
    Segmentation fault
    --->8---
    
    This error was introduced in 67ce04bf2746f8a1f8c2a104b313d20c63f68378 which
    was the first commit of this driver.
    
    Signed-off-by: Andreas Bießmann <andreas at biessmann.de>
    Cc: stable at vger.kernel.org
    Signed-off-by: Artem Bityutskiy <artem.bityutskiy at linux.intel.com>
    Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
---
 drivers/mtd/nand/omap2.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index f47c422..e604a45 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1364,7 +1364,7 @@ static int omap_nand_remove(struct platform_device *pdev)
 	/* Release NAND device, its internal structures and partitions */
 	nand_release(&info->mtd);
 	iounmap(info->nand.IO_ADDR_R);
-	kfree(&info->mtd);
+	kfree(info);
 	return 0;
 }