[PATCH 0/2] fixes for omap2 nand driver

[PATCH 0/2] fixes for omap2 nand driver

[Andreas Bießmann]

These two patches fixes the omap_nand_remove function to release all resources
properly and be able to re-load the driver later on.

Andreas Bießmann (2):
  mtd/nand/omap2: fix omap_nand_remove segfault
  mtd/nand/omap2: fix module loading

 drivers/mtd/nand/omap2.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

-- 
1.7.10.4

[PATCH 1/2] mtd/nand/omap2: fix omap_nand_remove segfault

[Andreas Bießmann]

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 kfree()ed 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@biessmann.de>
cc: linux-mtd@lists.infradead.org
---
 drivers/mtd/nand/omap2.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index ac4fd75..4cd7ac0 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1387,7 +1387,7 @@ 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;
 }
 
-- 
1.7.10.4

Re: [PATCH 1/2] mtd/nand/omap2: fix omap_nand_remove segfault

[Artem Bityutskiy]

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On Fri, 2012-08-31 at 13:35 +0200, Andreas Bießmann wrote:
> 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 kfree()ed before.
> 
> This patch fixes following error when unloading the omap2 module:

Added "Cc: stable@vger.kernel.org" to both patches and pushed to
l2-mtd.git, thanks!

-- 
Best Regards,
Artem Bityutskiy

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[PATCH 2/2] mtd/nand/omap2: fix module loading

[Andreas Bießmann]

Unloading the omap2 nand driver missed to release the memory region which will
result in not being able to request it again if one want to load the driver
later on.

This patch fixes following error when loading omap2 module after unloading:
---8<---
~ $ rmmod omap2
~ $ modprobe omap2
[   37.420928] omap2-nand: probe of omap2-nand.0 failed with error -16
~ $
--->8---

This error was introduced in 67ce04bf2746f8a1f8c2a104b313d20c63f68378 which
was the first commit of this driver.

Signed-off-by: Andreas Bießmann <andreas@biessmann.de>
cc: linux-mtd@lists.infradead.org
---
 drivers/mtd/nand/omap2.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 4cd7ac0..48f1d4e 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1387,6 +1387,7 @@ 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);
+	release_mem_region(info->phys_base, NAND_IO_SIZE);
 	kfree(info);
 	return 0;
 }
-- 
1.7.10.4