gpmc-nand broken since v4.12
Roger Quadros
rogerq at ti.com
Mon Oct 16 03:22:04 PDT 2017
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
On 13/10/17 23:29, Boris Brezillon wrote:
> On Fri, 13 Oct 2017 22:24:58 +0200
> Boris Brezillon <boris.brezillon at free-electrons.com> wrote:
>
>> On Fri, 13 Oct 2017 14:50:33 +0200
>> Boris Brezillon <boris.brezillon at free-electrons.com> wrote:
>>
>>> On Fri, 13 Oct 2017 14:57:29 +0300
>>> Roger Quadros <rogerq at ti.com> wrote:
>>>
>>>> Hi Boris,
>>>>
>>>> NAND on gpmc-omap breaks for me while doing a unmount of a ubi volume since v4.12
>>>>
>>>> Behaviour follows through in v4.13 and v4.14-rc as well.
>>>>
>>>> Do you have any idea about this?
>>
>> More info on what has changed in 4.12: we no longer allocate the
>> nand_buffer struct + its internal buffer using a single big kmalloc
>> call, which means the nand_buffer struct is now likely to be allocated
>> in a small object slab (sizeof(nand_buffers) = 12). If you have a
>> use-after-free bug somewhere in the kernel, it might corrupt the
Spot on. Problem starts from commit 4d5dea5725f3aa95b9b64e252540e435dd216dbc
"mtd: nand: allocate aligned buffers if NAND_OWN_BUFFERS is unset"
>
> I meant buffer-overflow, not use-after-free.
Your analysis seems correct.
>
>> nand_buffers object, which might explain the bug you see here.
>>
>>>
>>> Can you try with this patch [1] applied and paste me the values printed
>>> just before the crash?
>>>
>>> [1]http://code.bulix.org/lc8xk0-209746
== unmounting volume
[ 36.308792] nand: nand_write_subpage_hwecc:2575 ecc_calc = (null) oob_poi = ed096800
[ 36.317319] mtd_ooblayout_set_bytes:1330 dst = ed096802 src = (null)
[ 36.324162] Unable to handle kernel NULL pointer dereference at virtual address 00000000
Running the following patch
https://hastebin.com/ulogurutuz.php
shows
[ 37.260689] nand: nand_write_subpage_hwecc:2547:A ecc_calc = ed116e40 oob_poi = ed117800
[ 37.260772] nand: nand_write_subpage_hwecc:2556:A1:step 0, ecc_calc = ed116e40
[ 37.260779] nand: nand_write_subpage_hwecc:2562:A2:step 0, ecc_calc = ed116e40
[ 37.260834] nand: nand_write_subpage_hwecc:2556:A1:step 1, ecc_calc = ed116e40
[ 37.260840] nand: nand_write_subpage_hwecc:2567:A3-pre:step 1, ecc_calc = ed116e40
[ 37.260846] omap_calculate_ecc_bch
[ 37.260856] nand: nand_write_subpage_hwecc:2570:A3-post:step 1, ecc_calc = (null)
[ 37.260912] nand: nand_write_subpage_hwecc:2556:A1:step 2, ecc_calc = (null)
[ 37.260918] nand: nand_write_subpage_hwecc:2562:A2:step 2, ecc_calc = (null)
[ 37.260972] nand: nand_write_subpage_hwecc:2556:A1:step 3, ecc_calc = (null)
[ 37.260978] nand: nand_write_subpage_hwecc:2562:A2:step 3, ecc_calc = (null)
[ 37.260984] nand: nand_write_subpage_hwecc:2587:B ecc_calc = (null) oob_poi = ed117800
[ 37.260991] mtd_ooblayout_set_bytes:1330 dst = ed117802 src = (null)
which means omap_calculate_ecc_bch() it the culprit.
Looks like the function calculates and stores ECC for all sectors even if we just want ECC
for just one sector (sub-page).
Is my understanding correct
- We should not be hooking the multi-sector ECC calculator omap_calculate_ecc_bch() to ecc.calculate
- provide a new one sector ECC calculator function (for BCH4/8/16) for omap and hook it to ecc.calculate
OR
- override nand_read_subpage() and nand_write_subpage() using omap specific implementation (for BCH4/8/16).
>>>
>>>>
>>>> == unmounting volume
>>>> [ 30.128584] Unable to handle kernel NULL pointer dereference at virtual address 00000000
>>>> [ 30.137234] pgd = ed3d0000
>>>> [ 30.140079] [00000000] *pgd=fd67a835
>>>> [ 30.143843] Internal error: Oops: 17 [#1] SMP ARM
>>>> [ 30.148781] Modules linked in: snd_soc_davinci_mcasp xhci_plat_hcd snd_soc_edma xhci_hcd snd_soc_tlv320aic3x snd_soc_simple_card snd_soc_omap snd_soc_simple_card_utils snd_soc_core usbcoe
>>>> [ 30.193881] CPU: 1 PID: 2149 Comm: umount Not tainted 4.12.0-00001-g2c09531 #1440
>>>> [ 30.201734] Hardware name: Generic DRA74X (Flattened Device Tree)
>>>> [ 30.208130] task: ec870140 task.stack: ed406000
>>>> [ 30.212889] PC is at memcpy+0xe8/0x330
>>>> [ 30.216833] LR is at mtd_ooblayout_set_bytes+0x7c/0xa4
>>>> [ 30.222231] pc : [<c04abe68>] lr : [<c05d7490>] psr: 60000013
>>>> [ 30.222231] sp : ed407b74 ip : 00000002 fp : 00000200
>>>> [ 30.234276] r10: ed082800 r9 : 00000000 r8 : ed079010
>>>> [ 30.239761] r7 : c05d76d8 r6 : 00000000 r5 : 00000038 r4 : 00000038
>>>> [ 30.246614] r3 : 00000038 r2 : 00000034 r1 : 00000000 r0 : ed082802
>>>> [ 30.253468] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
>>>> [ 30.260957] Control: 10c5387d Table: ad3d006a DAC: 00000051
>>>> [ 30.266986] Process umount (pid: 2149, stack limit = 0xed406218)
>>>> [ 30.273296] Stack: (0xed407b74 to 0xed408000)
>>>> [ 30.277868] 7b60: ed082802 00000038 c05d7490
>>>> [ 30.286458] 7b80: c05d76d8 ed082600 0000ffff 00000000 00000002 00000038 00000004 ed082800
>>>> [ 30.295047] 7ba0: ed079010 00000000 00000000 ed082800 ed079010 c05d74fc 00000038 c05d76d8
>>>> [ 30.303635] 7bc0: ed0e8f6a c05e8388 00000038 00000000 c0dc60f0 00000001 00000010 0000000e
>>>> [ 30.312216] 7be0: 00000004 00000001 00000001 00000001 c05f2668 ed079010 00000200 00000200
>>>> [ 30.320806] 7c00: 000095c0 00000200 ed082000 ed312200 000095c0 c05e9658 ed082000 00000000
>>>> [ 30.329392] 7c20: 000095c0 00000002 00000200 00000000 ed082000 ed407c80 00000000 00000000
>>>> [ 30.337975] 7c40: 00000000 00000001 00000040 00000000 00000000 04ae0200 00000000 ed079010
>>>> [ 30.346563] 7c60: ed407c80 ed407d30 00000200 ed312200 ed312200 c05e9994 ed407c80 c0191f70
>>>> [ 30.355150] 7c80: 00000000 00000200 00000000 00000000 00000000 00000000 ed312200 00000000
>>>> [ 30.363738] 7ca0: 00a00000 00000000 00000200 00000000 0f600000 00000000 ed407d30 c05d9fbc
>>>> [ 30.372328] 7cc0: 00000200 ed407d30 ed312200 00000000 9188fed8 c05d9f7c 00000000 c05d6c7c
>>>> [ 30.380917] 7ce0: 00000200 ed407d30 ed312200 ed312200 040e0200 00000000 ed628000 00000200
>>>> [ 30.389509] 7d00: 00000200 00000207 00000000 c0604cd0 00000200 ed407d30 ed312200 60000013
>>>> [ 30.398097] 7d20: 00000200 00000000 ed208040 c019269c 00000000 00000004 ed628dd8 ed312200
>>>> [ 30.406676] 7d40: ed628000 00000207 ed312200 00000800 00000207 00000000 ffffffff c060536c
>>>> [ 30.415267] 7d60: 00000200 c0607fb8 ed18c800 ed628000 ed2a0800 00000008 00000000 c0601178
>>>> [ 30.423851] 7d80: ed312200 ed628550 00000000 ed628000 ed312200 ed18c800 ed2a0800 ed628000
>>>> [ 30.432437] 7da0: ed312200 00000008 00000004 ed18c800 ed2a0800 00001014 ed208040 c0601cf0
>>>> [ 30.441020] 7dc0: 00000000 00000800 00000000 ec870140 00000003 60000013 c1568e2c c060154c
>>>> [ 30.449605] 7de0: ed18c800 c019269c 00000000 00000002 ed628000 00000800 ed628000 00000000
>>>> [ 30.458191] 7e00: 00000008 ed18c800 00000000 00000088 ed18c800 c0600538 00000000 00000800
>>>> [ 30.466779] 7e20: ed18c800 ed770000 00000000 00000008 ed770000 c0426a90 00000800 00000000
>>>> [ 30.475366] 7e40: 00000088 00000000 00000800 000000a0 ed770000 c0430904 00000800 c08002e8
>>>> [ 30.483952] 7e60: 00000000 00000000 000000d8 00000000 00000000 00000000 00000000 00000000
>>>> [ 30.492545] 7e80: ed18c800 ed407eb4 00000001 ed770000 00000000 00000288 00000003 ed51b5d4
>>>> [ 30.501126] 7ea0: ed406000 00000000 00000000 c0431880 ed77014c 76ecb30e 5c265a59 ec870140
>>>> [ 30.509709] 7ec0: 00000003 60000013 c1568e2c c0431f38 00000000 c019269c ed77014c 00000002
>>>> [ 30.518301] 7ee0: ed51b5d4 ed77014c ed77014c ed770104 ed51b5d4 ed770000 ed406000 00000000
>>>> [ 30.526886] 7f00: ed77014c c08039c8 00000000 00000288 00000003 ed51b5d4 ed770000 c042201c
>>>> [ 30.535471] 7f20: ed1cb000 00000000 c0dcbbe0 00000534 ec870140 c02e6324 edf88a10 ed1cb000
>>>> [ 30.544056] 7f40: c0926528 c02afaf4 c0421714 00000015 c0d823cc c02afc40 ed770000 c0421720
>>>> [ 30.552643] 7f60: ed1cb000 c02b0288 ec870140 ed61a600 00000000 c02d0950 ec870634 c0159b34
>>>> [ 30.561220] 7f80: ed61a61c 00000000 ed407fb0 c0107ae4 00000034 c0107ae4 00000000 c010b09c
>>>> [ 30.569803] 7fa0: 00021cb8 0001e320 00021cb8 c0107968 00000000 00000000 00000000 00000000
>>>> [ 30.578392] 7fc0: 00021cb8 0001e320 00021cb8 00000034 00021ca8 00000000 00000000 00000000
>>>> [ 30.586973] 7fe0: 00021ce8 bec06600 b6e11dbc b6e11ddc 60000010 00021cb8 afffd861 afffdc61
>>>> [ 30.595558] [<c04abe68>] (memcpy) from [<c05d7490>] (mtd_ooblayout_set_bytes+0x7c/0xa4)
>>>> [ 30.603968] [<c05d7490>] (mtd_ooblayout_set_bytes) from [<c05d74fc>] (mtd_ooblayout_set_eccbytes+0x1c/0x28)
>>>> [ 30.614207] [<c05d74fc>] (mtd_ooblayout_set_eccbytes) from [<c05e8388>] (nand_write_subpage_hwecc+0x1a8/0x1d0)
>>>> [ 30.624707] [<c05e8388>] (nand_write_subpage_hwecc) from [<c05e9658>] (nand_do_write_ops+0x22c/0x50c)
>>>> [ 30.634397] [<c05e9658>] (nand_do_write_ops) from [<c05e9994>] (nand_write+0x5c/0x7c)
>>>> [ 30.642621] [<c05e9994>] (nand_write) from [<c05d9fbc>] (part_write+0x40/0x48)
>>>> [ 30.650211] [<c05d9fbc>] (part_write) from [<c05d6c7c>] (mtd_write+0x90/0xa8)
>>>> [ 30.657718] [<c05d6c7c>] (mtd_write) from [<c0604cd0>] (ubi_io_write+0x114/0x6b8)
>>>> [ 30.665573] [<c0604cd0>] (ubi_io_write) from [<c060536c>] (ubi_io_write_vid_hdr+0xf8/0x148)
>>>> [ 30.674342] [<c060536c>] (ubi_io_write_vid_hdr) from [<c0601178>] (try_write_vid_and_data+0x54/0x1a4)
>>>> [ 30.684030] [<c0601178>] (try_write_vid_and_data) from [<c0601cf0>] (ubi_eba_write_leb+0x1f8/0x7bc)
>>>> [ 30.693525] [<c0601cf0>] (ubi_eba_write_leb) from [<c0600538>] (ubi_leb_write+0xbc/0xdc)
>>>> [ 30.702021] [<c0600538>] (ubi_leb_write) from [<c0426a90>] (ubifs_leb_write+0x9c/0x11c)
>>>> [ 30.710426] [<c0426a90>] (ubifs_leb_write) from [<c0430904>] (ubifs_log_start_commit+0x27c/0x444)
>>>> [ 30.719743] [<c0430904>] (ubifs_log_start_commit) from [<c0431880>] (do_commit+0x1b8/0x7e8)
>>>> [ 30.728521] [<c0431880>] (do_commit) from [<c042201c>] (ubifs_sync_fs+0x8c/0xa0)
>>>> [ 30.736292] [<c042201c>] (ubifs_sync_fs) from [<c02e6324>] (sync_filesystem+0x88/0xac)
>>>> [ 30.744616] [<c02e6324>] (sync_filesystem) from [<c02afaf4>] (generic_shutdown_super+0x24/0xf8)
>>>> [ 30.753754] [<c02afaf4>] (generic_shutdown_super) from [<c02afc40>] (kill_anon_super+0xc/0x18)
>>>> [ 30.762807] [<c02afc40>] (kill_anon_super) from [<c0421720>] (kill_ubifs_super+0xc/0x18)
>>>> [ 30.771308] [<c0421720>] (kill_ubifs_super) from [<c02b0288>] (deactivate_locked_super+0x5c/0x80)
>>>> [ 30.780627] [<c02b0288>] (deactivate_locked_super) from [<c02d0950>] (cleanup_mnt+0x38/0x78)
>>>> [ 30.789492] [<c02d0950>] (cleanup_mnt) from [<c0159b34>] (task_work_run+0xc0/0xe8)
>>>> [ 30.797444] [<c0159b34>] (task_work_run) from [<c010b09c>] (do_work_pending+0xd4/0xd8)
>>>> [ 30.805759] [<c010b09c>] (do_work_pending) from [<c0107968>] (slow_work_pending+0xc/0x20)
>>>> [ 30.814345] Code: e8bd8011 e26cc004 e35c0002 c4d13001 (a4d14001)
>>>> [ 30.820843] ---[ end trace bc240a5a583e6e02 ]---
>>>>
>>>
>>>
>>> ______________________________________________________
>>> Linux MTD discussion mailing list
>>> http://lists.infradead.org/mailman/listinfo/linux-mtd/
>>
>
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--
cheers,
-roger
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