diff mbox series

jffs2: Fix use of uninitialized delayed_work, lockdep breakage

Message ID 20181019083020.14335-1-daniel.santos@pobox.com
State Accepted
Delegated to: Boris Brezillon
Headers show
Series jffs2: Fix use of uninitialized delayed_work, lockdep breakage | expand

Commit Message

Daniel Santos Oct. 19, 2018, 8:30 a.m. UTC 
jffs2_sync_fs makes the assumption that if CONFIG_JFFS2_FS_WRITEBUFFER
is defined then a write buffer is available and has been initialized.
However, this does is not the case when the mtd device has no
out-of-band buffer:

int jffs2_nand_flash_setup(struct jffs2_sb_info *c)
{
        if (!c->mtd->oobsize)
                return 0;
...

The resulting call to cancel_delayed_work_sync passing a uninitialized
(but zeroed) delayed_work struct forces lockdep to become disabled.

[   90.050639] overlayfs: upper fs does not support tmpfile.
[   90.652264] INFO: trying to register non-static key.
[   90.662171] the code is fine but needs lockdep annotation.
[   90.673090] turning off the locking correctness validator.
[   90.684021] CPU: 0 PID: 1762 Comm: mount_root Not tainted 4.14.63 #0
[   90.696672] Stack : 00000000 00000000 80d8f6a2 00000038 805f0000 80444600 8fe364f4 805dfbe7
[   90.713349]         80563a30 000006e2 8068370c 00000001 00000000 00000001 8e2fdc48 ffffffff
[   90.730020]         00000000 00000000 80d90000 00000000 00000106 00000000 6465746e 312e3420
[   90.746690]         6b636f6c 03bf0000 f8000000 20676e69 00000000 80000000 00000000 8e2c2a90
[   90.763362]         80d90000 00000001 00000000 8e2c2a90 00000003 80260dc0 08052098 80680000
[   90.780033]         ...
[   90.784902] Call Trace:
[   90.789793] [<8000f0d8>] show_stack+0xb8/0x148
[   90.798659] [<8005a000>] register_lock_class+0x270/0x55c
[   90.809247] [<8005cb64>] __lock_acquire+0x13c/0xf7c
[   90.818964] [<8005e314>] lock_acquire+0x194/0x1dc
[   90.828345] [<8003f27c>] flush_work+0x200/0x24c
[   90.837374] [<80041dfc>] __cancel_work_timer+0x158/0x210
[   90.847958] [<801a8770>] jffs2_sync_fs+0x20/0x54
[   90.857173] [<80125cf4>] iterate_supers+0xf4/0x120
[   90.866729] [<80158fc4>] sys_sync+0x44/0x9c
[   90.875067] [<80014424>] syscall_common+0x34/0x58

Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
---
 fs/jffs2/super.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Hou Tao Oct. 22, 2018, 12:32 a.m. UTC | #1 
On 2018/10/19 16:30, Daniel Santos wrote:
> jffs2_sync_fs makes the assumption that if CONFIG_JFFS2_FS_WRITEBUFFER
> is defined then a write buffer is available and has been initialized.
> However, this does is not the case when the mtd device has no
> out-of-band buffer:
> 
> int jffs2_nand_flash_setup(struct jffs2_sb_info *c)
> {
>         if (!c->mtd->oobsize)
>                 return 0;
> ...
> 
> The resulting call to cancel_delayed_work_sync passing a uninitialized
> (but zeroed) delayed_work struct forces lockdep to become disabled.
> 
> [   90.050639] overlayfs: upper fs does not support tmpfile.
> [   90.652264] INFO: trying to register non-static key.
> [   90.662171] the code is fine but needs lockdep annotation.
> [   90.673090] turning off the locking correctness validator.
> [   90.684021] CPU: 0 PID: 1762 Comm: mount_root Not tainted 4.14.63 #0
> [   90.696672] Stack : 00000000 00000000 80d8f6a2 00000038 805f0000 80444600 8fe364f4 805dfbe7
> [   90.713349]         80563a30 000006e2 8068370c 00000001 00000000 00000001 8e2fdc48 ffffffff
> [   90.730020]         00000000 00000000 80d90000 00000000 00000106 00000000 6465746e 312e3420
> [   90.746690]         6b636f6c 03bf0000 f8000000 20676e69 00000000 80000000 00000000 8e2c2a90
> [   90.763362]         80d90000 00000001 00000000 8e2c2a90 00000003 80260dc0 08052098 80680000
> [   90.780033]         ...
> [   90.784902] Call Trace:
> [   90.789793] [<8000f0d8>] show_stack+0xb8/0x148
> [   90.798659] [<8005a000>] register_lock_class+0x270/0x55c
> [   90.809247] [<8005cb64>] __lock_acquire+0x13c/0xf7c
> [   90.818964] [<8005e314>] lock_acquire+0x194/0x1dc
> [   90.828345] [<8003f27c>] flush_work+0x200/0x24c
> [   90.837374] [<80041dfc>] __cancel_work_timer+0x158/0x210
> [   90.847958] [<801a8770>] jffs2_sync_fs+0x20/0x54
> [   90.857173] [<80125cf4>] iterate_supers+0xf4/0x120
> [   90.866729] [<80158fc4>] sys_sync+0x44/0x9c
> [   90.875067] [<80014424>] syscall_common+0x34/0x58
> 
> Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
> ---
>  fs/jffs2/super.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
> index 793ad30970ff..cae4ecda3c50 100644
> --- a/fs/jffs2/super.c
> +++ b/fs/jffs2/super.c
> @@ -101,7 +101,8 @@ static int jffs2_sync_fs(struct super_block *sb, int wait)
>  	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
>  
>  #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
> -	cancel_delayed_work_sync(&c->wbuf_dwork);
> +	if (jffs2_is_writebuffered(c))
> +		cancel_delayed_work_sync(&c->wbuf_dwork);
>  #endif
>  
>  	mutex_lock(&c->alloc_sem);
> 

Reviewed-by: Hou Tao <houtao1@huawei.com>

And I am curious that why is there NAND Flash without OOB area ? So for them
the ECC data must be saved in data area ?

Regards,

Tao
Daniel Santos Oct. 22, 2018, 4:56 a.m. UTC | #2 
On 10/21/2018 07:32 PM, Hou Tao wrote:
>
> On 2018/10/19 16:30, Daniel Santos wrote:
>> jffs2_sync_fs makes the assumption that if CONFIG_JFFS2_FS_WRITEBUFFER
>> is defined then a write buffer is available and has been initialized.
>> However, this does is not the case when the mtd device has no
>> out-of-band buffer:
>>
>> int jffs2_nand_flash_setup(struct jffs2_sb_info *c)
>> {
>>         if (!c->mtd->oobsize)
>>                 return 0;
>> ...
>>
>> The resulting call to cancel_delayed_work_sync passing a uninitialized
>> (but zeroed) delayed_work struct forces lockdep to become disabled.
>>
>> [   90.050639] overlayfs: upper fs does not support tmpfile.
>> [   90.652264] INFO: trying to register non-static key.
>> [   90.662171] the code is fine but needs lockdep annotation.
>> [   90.673090] turning off the locking correctness validator.
>> [   90.684021] CPU: 0 PID: 1762 Comm: mount_root Not tainted 4.14.63 #0
>> [   90.696672] Stack : 00000000 00000000 80d8f6a2 00000038 805f0000 80444600 8fe364f4 805dfbe7
>> [   90.713349]         80563a30 000006e2 8068370c 00000001 00000000 00000001 8e2fdc48 ffffffff
>> [   90.730020]         00000000 00000000 80d90000 00000000 00000106 00000000 6465746e 312e3420
>> [   90.746690]         6b636f6c 03bf0000 f8000000 20676e69 00000000 80000000 00000000 8e2c2a90
>> [   90.763362]         80d90000 00000001 00000000 8e2c2a90 00000003 80260dc0 08052098 80680000
>> [   90.780033]         ...
>> [   90.784902] Call Trace:
>> [   90.789793] [<8000f0d8>] show_stack+0xb8/0x148
>> [   90.798659] [<8005a000>] register_lock_class+0x270/0x55c
>> [   90.809247] [<8005cb64>] __lock_acquire+0x13c/0xf7c
>> [   90.818964] [<8005e314>] lock_acquire+0x194/0x1dc
>> [   90.828345] [<8003f27c>] flush_work+0x200/0x24c
>> [   90.837374] [<80041dfc>] __cancel_work_timer+0x158/0x210
>> [   90.847958] [<801a8770>] jffs2_sync_fs+0x20/0x54
>> [   90.857173] [<80125cf4>] iterate_supers+0xf4/0x120
>> [   90.866729] [<80158fc4>] sys_sync+0x44/0x9c
>> [   90.875067] [<80014424>] syscall_common+0x34/0x58
>>
>> Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
>> ---
>>  fs/jffs2/super.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
>> index 793ad30970ff..cae4ecda3c50 100644
>> --- a/fs/jffs2/super.c
>> +++ b/fs/jffs2/super.c
>> @@ -101,7 +101,8 @@ static int jffs2_sync_fs(struct super_block *sb, int wait)
>>  	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
>>  
>>  #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
>> -	cancel_delayed_work_sync(&c->wbuf_dwork);
>> +	if (jffs2_is_writebuffered(c))
>> +		cancel_delayed_work_sync(&c->wbuf_dwork);
>>  #endif
>>  
>>  	mutex_lock(&c->alloc_sem);
>>
> Reviewed-by: Hou Tao <houtao1@huawei.com>
>
> And I am curious that why is there NAND Flash without OOB area ? So for them
> the ECC data must be saved in data area ?
>
> Regards,
>
> Tao

Thank you.

I'm not intimately familiar with these, but it's an SPI NOR chip and I'm
pretty sure they that they don't have ECC.  Specifically a Winbond
w25q128fv using drivers/mtd/devices/m25p80.c.

Thanks,
Daniel
Daniel Santos Nov. 5, 2018, 9:38 p.m. UTC | #3 
Ping.

Daniel

On 10/21/2018 07:32 PM, Hou Tao wrote:
>
> On 2018/10/19 16:30, Daniel Santos wrote:
>> jffs2_sync_fs makes the assumption that if CONFIG_JFFS2_FS_WRITEBUFFER
>> is defined then a write buffer is available and has been initialized.
>> However, this does is not the case when the mtd device has no
>> out-of-band buffer:
>>
>> int jffs2_nand_flash_setup(struct jffs2_sb_info *c)
>> {
>>         if (!c->mtd->oobsize)
>>                 return 0;
>> ...
>>
>> The resulting call to cancel_delayed_work_sync passing a uninitialized
>> (but zeroed) delayed_work struct forces lockdep to become disabled.
>>
>> [   90.050639] overlayfs: upper fs does not support tmpfile.
>> [   90.652264] INFO: trying to register non-static key.
>> [   90.662171] the code is fine but needs lockdep annotation.
>> [   90.673090] turning off the locking correctness validator.
>> [   90.684021] CPU: 0 PID: 1762 Comm: mount_root Not tainted 4.14.63 #0
>> [   90.696672] Stack : 00000000 00000000 80d8f6a2 00000038 805f0000 80444600 8fe364f4 805dfbe7
>> [   90.713349]         80563a30 000006e2 8068370c 00000001 00000000 00000001 8e2fdc48 ffffffff
>> [   90.730020]         00000000 00000000 80d90000 00000000 00000106 00000000 6465746e 312e3420
>> [   90.746690]         6b636f6c 03bf0000 f8000000 20676e69 00000000 80000000 00000000 8e2c2a90
>> [   90.763362]         80d90000 00000001 00000000 8e2c2a90 00000003 80260dc0 08052098 80680000
>> [   90.780033]         ...
>> [   90.784902] Call Trace:
>> [   90.789793] [<8000f0d8>] show_stack+0xb8/0x148
>> [   90.798659] [<8005a000>] register_lock_class+0x270/0x55c
>> [   90.809247] [<8005cb64>] __lock_acquire+0x13c/0xf7c
>> [   90.818964] [<8005e314>] lock_acquire+0x194/0x1dc
>> [   90.828345] [<8003f27c>] flush_work+0x200/0x24c
>> [   90.837374] [<80041dfc>] __cancel_work_timer+0x158/0x210
>> [   90.847958] [<801a8770>] jffs2_sync_fs+0x20/0x54
>> [   90.857173] [<80125cf4>] iterate_supers+0xf4/0x120
>> [   90.866729] [<80158fc4>] sys_sync+0x44/0x9c
>> [   90.875067] [<80014424>] syscall_common+0x34/0x58
>>
>> Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
>> ---
>>  fs/jffs2/super.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
>> index 793ad30970ff..cae4ecda3c50 100644
>> --- a/fs/jffs2/super.c
>> +++ b/fs/jffs2/super.c
>> @@ -101,7 +101,8 @@ static int jffs2_sync_fs(struct super_block *sb, int wait)
>>  	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
>>  
>>  #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
>> -	cancel_delayed_work_sync(&c->wbuf_dwork);
>> +	if (jffs2_is_writebuffered(c))
>> +		cancel_delayed_work_sync(&c->wbuf_dwork);
>>  #endif
>>  
>>  	mutex_lock(&c->alloc_sem);
>>
> Reviewed-by: Hou Tao <houtao1@huawei.com>
>
> And I am curious that why is there NAND Flash without OOB area ? So for them
> the ECC data must be saved in data area ?
>
> Regards,
>
> Tao
>
>
>
Daniel Santos Nov. 24, 2018, 3:29 p.m. UTC | #4 
Ping 2!

On 11/05/2018 03:38 PM, Daniel Santos wrote:
> Ping.
>
> Daniel
>
> On 10/21/2018 07:32 PM, Hou Tao wrote:
>> On 2018/10/19 16:30, Daniel Santos wrote:
>>> jffs2_sync_fs makes the assumption that if CONFIG_JFFS2_FS_WRITEBUFFER
>>> is defined then a write buffer is available and has been initialized.
>>> However, this does is not the case when the mtd device has no
>>> out-of-band buffer:
>>>
>>> int jffs2_nand_flash_setup(struct jffs2_sb_info *c)
>>> {
>>>         if (!c->mtd->oobsize)
>>>                 return 0;
>>> ...
>>>
>>> The resulting call to cancel_delayed_work_sync passing a uninitialized
>>> (but zeroed) delayed_work struct forces lockdep to become disabled.
>>>
>>> [   90.050639] overlayfs: upper fs does not support tmpfile.
>>> [   90.652264] INFO: trying to register non-static key.
>>> [   90.662171] the code is fine but needs lockdep annotation.
>>> [   90.673090] turning off the locking correctness validator.
>>> [   90.684021] CPU: 0 PID: 1762 Comm: mount_root Not tainted 4.14.63 #0
>>> [   90.696672] Stack : 00000000 00000000 80d8f6a2 00000038 805f0000 80444600 8fe364f4 805dfbe7
>>> [   90.713349]         80563a30 000006e2 8068370c 00000001 00000000 00000001 8e2fdc48 ffffffff
>>> [   90.730020]         00000000 00000000 80d90000 00000000 00000106 00000000 6465746e 312e3420
>>> [   90.746690]         6b636f6c 03bf0000 f8000000 20676e69 00000000 80000000 00000000 8e2c2a90
>>> [   90.763362]         80d90000 00000001 00000000 8e2c2a90 00000003 80260dc0 08052098 80680000
>>> [   90.780033]         ...
>>> [   90.784902] Call Trace:
>>> [   90.789793] [<8000f0d8>] show_stack+0xb8/0x148
>>> [   90.798659] [<8005a000>] register_lock_class+0x270/0x55c
>>> [   90.809247] [<8005cb64>] __lock_acquire+0x13c/0xf7c
>>> [   90.818964] [<8005e314>] lock_acquire+0x194/0x1dc
>>> [   90.828345] [<8003f27c>] flush_work+0x200/0x24c
>>> [   90.837374] [<80041dfc>] __cancel_work_timer+0x158/0x210
>>> [   90.847958] [<801a8770>] jffs2_sync_fs+0x20/0x54
>>> [   90.857173] [<80125cf4>] iterate_supers+0xf4/0x120
>>> [   90.866729] [<80158fc4>] sys_sync+0x44/0x9c
>>> [   90.875067] [<80014424>] syscall_common+0x34/0x58
>>>
>>> Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
>>> ---
>>>  fs/jffs2/super.c | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
>>> index 793ad30970ff..cae4ecda3c50 100644
>>> --- a/fs/jffs2/super.c
>>> +++ b/fs/jffs2/super.c
>>> @@ -101,7 +101,8 @@ static int jffs2_sync_fs(struct super_block *sb, int wait)
>>>  	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
>>>  
>>>  #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
>>> -	cancel_delayed_work_sync(&c->wbuf_dwork);
>>> +	if (jffs2_is_writebuffered(c))
>>> +		cancel_delayed_work_sync(&c->wbuf_dwork);
>>>  #endif
>>>  
>>>  	mutex_lock(&c->alloc_sem);
>>>
>> Reviewed-by: Hou Tao <houtao1@huawei.com>
>>
>> And I am curious that why is there NAND Flash without OOB area ? So for them
>> the ECC data must be saved in data area ?
>>
>> Regards,
>>
>> Tao
>>
>>
>>
Boris Brezillon Dec. 3, 2018, 7:52 a.m. UTC | #5 
On Fri, 2018-10-19 at 08:30:20 UTC, Daniel Santos wrote:
> jffs2_sync_fs makes the assumption that if CONFIG_JFFS2_FS_WRITEBUFFER
> is defined then a write buffer is available and has been initialized.
> However, this does is not the case when the mtd device has no
> out-of-band buffer:
> 
> int jffs2_nand_flash_setup(struct jffs2_sb_info *c)
> {
>         if (!c->mtd->oobsize)
>                 return 0;
> ...
> 
> The resulting call to cancel_delayed_work_sync passing a uninitialized
> (but zeroed) delayed_work struct forces lockdep to become disabled.
> 
> [   90.050639] overlayfs: upper fs does not support tmpfile.
> [   90.652264] INFO: trying to register non-static key.
> [   90.662171] the code is fine but needs lockdep annotation.
> [   90.673090] turning off the locking correctness validator.
> [   90.684021] CPU: 0 PID: 1762 Comm: mount_root Not tainted 4.14.63 #0
> [   90.696672] Stack : 00000000 00000000 80d8f6a2 00000038 805f0000 80444600 8fe364f4 805dfbe7
> [   90.713349]         80563a30 000006e2 8068370c 00000001 00000000 00000001 8e2fdc48 ffffffff
> [   90.730020]         00000000 00000000 80d90000 00000000 00000106 00000000 6465746e 312e3420
> [   90.746690]         6b636f6c 03bf0000 f8000000 20676e69 00000000 80000000 00000000 8e2c2a90
> [   90.763362]         80d90000 00000001 00000000 8e2c2a90 00000003 80260dc0 08052098 80680000
> [   90.780033]         ...
> [   90.784902] Call Trace:
> [   90.789793] [<8000f0d8>] show_stack+0xb8/0x148
> [   90.798659] [<8005a000>] register_lock_class+0x270/0x55c
> [   90.809247] [<8005cb64>] __lock_acquire+0x13c/0xf7c
> [   90.818964] [<8005e314>] lock_acquire+0x194/0x1dc
> [   90.828345] [<8003f27c>] flush_work+0x200/0x24c
> [   90.837374] [<80041dfc>] __cancel_work_timer+0x158/0x210
> [   90.847958] [<801a8770>] jffs2_sync_fs+0x20/0x54
> [   90.857173] [<80125cf4>] iterate_supers+0xf4/0x120
> [   90.866729] [<80158fc4>] sys_sync+0x44/0x9c
> [   90.875067] [<80014424>] syscall_common+0x34/0x58
> 
> Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
> Reviewed-by: Hou Tao <houtao1@huawei.com>

Applied to http://git.infradead.org/linux-mtd.git mtd/next, thanks.

Boris
diff mbox series

Patch

diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index 793ad30970ff..cae4ecda3c50 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -101,7 +101,8 @@  static int jffs2_sync_fs(struct super_block *sb, int wait)
 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 
 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
-	cancel_delayed_work_sync(&c->wbuf_dwork);
+	if (jffs2_is_writebuffered(c))
+		cancel_delayed_work_sync(&c->wbuf_dwork);
 #endif
 
 	mutex_lock(&c->alloc_sem);