2021-11-30 09:33:02

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH] powerpc/powermac: Add missing lockdep_register_key()

KeyWest i2c @0xf8001003 irq 42 /uni-n@f8000000/i2c@f8001000
BUG: key c2d00cbc has not been registered!
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(1)
WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:4801 lockdep_init_map_type+0x4c0/0xb4c
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.5-gentoo-PowerMacG4 #9
NIP: c01a9428 LR: c01a9428 CTR: 00000000
REGS: e1033cf0 TRAP: 0700 Not tainted (5.15.5-gentoo-PowerMacG4)
MSR: 00029032 <EE,ME,IR,DR,RI> CR: 24002002 XER: 00000000

GPR00: c01a9428 e1033db0 c2d1cf20 00000016 00000004 00000001 c01c0630 e1033a73
GPR08: 00000000 00000000 00000000 e1033db0 24002004 00000000 f8729377 00000003
GPR16: c1829a9c 00000000 18305357 c1416fc0 c1416f80 c006ac60 c2d00ca8 c1416f00
GPR24: 00000000 c21586f0 c2160000 00000000 c2d00cbc c2170000 c216e1a0 c2160000
NIP [c01a9428] lockdep_init_map_type+0x4c0/0xb4c
LR [c01a9428] lockdep_init_map_type+0x4c0/0xb4c
Call Trace:
[e1033db0] [c01a9428] lockdep_init_map_type+0x4c0/0xb4c (unreliable)
[e1033df0] [c1c177b8] kw_i2c_add+0x334/0x424
[e1033e20] [c1c18294] pmac_i2c_init+0x9ec/0xa9c
[e1033e80] [c1c1a790] smp_core99_probe+0xbc/0x35c
[e1033eb0] [c1c03cb0] kernel_init_freeable+0x190/0x5a4
[e1033f10] [c000946c] kernel_init+0x28/0x154
[e1033f30] [c0035148] ret_from_kernel_thread+0x14/0x1c

Add missing lockdep_register_key()

Reported-by: Erhard Furtner <[email protected]>
Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/platforms/powermac/low_i2c.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/platforms/powermac/low_i2c.c b/arch/powerpc/platforms/powermac/low_i2c.c
index f77a59b5c2e1..de34fa34c42d 100644
--- a/arch/powerpc/platforms/powermac/low_i2c.c
+++ b/arch/powerpc/platforms/powermac/low_i2c.c
@@ -582,6 +582,7 @@ static void __init kw_i2c_add(struct pmac_i2c_host_kw *host,
bus->close = kw_i2c_close;
bus->xfer = kw_i2c_xfer;
mutex_init(&bus->mutex);
+ lockdep_register_key(&bus->lock_key);
lockdep_set_class(&bus->mutex, &bus->lock_key);
if (controller == busnode)
bus->flags = pmac_i2c_multibus;
--
2.33.1



2021-11-30 13:53:28

by Erhard Furtner

[permalink] [raw]
Subject: Re: [PATCH] powerpc/powermac: Add missing lockdep_register_key()

On Tue, 30 Nov 2021 10:32:42 +0100
Christophe Leroy <[email protected]> wrote:

> KeyWest i2c @0xf8001003 irq 42 /uni-n@f8000000/i2c@f8001000
> BUG: key c2d00cbc has not been registered!
> ------------[ cut here ]------------
> DEBUG_LOCKS_WARN_ON(1)
> WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:4801 lockdep_init_map_type+0x4c0/0xb4c
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.5-gentoo-PowerMacG4 #9
> NIP: c01a9428 LR: c01a9428 CTR: 00000000
> REGS: e1033cf0 TRAP: 0700 Not tainted (5.15.5-gentoo-PowerMacG4)
> MSR: 00029032 <EE,ME,IR,DR,RI> CR: 24002002 XER: 00000000
>
> GPR00: c01a9428 e1033db0 c2d1cf20 00000016 00000004 00000001 c01c0630 e1033a73
> GPR08: 00000000 00000000 00000000 e1033db0 24002004 00000000 f8729377 00000003
> GPR16: c1829a9c 00000000 18305357 c1416fc0 c1416f80 c006ac60 c2d00ca8 c1416f00
> GPR24: 00000000 c21586f0 c2160000 00000000 c2d00cbc c2170000 c216e1a0 c2160000
> NIP [c01a9428] lockdep_init_map_type+0x4c0/0xb4c
> LR [c01a9428] lockdep_init_map_type+0x4c0/0xb4c
> Call Trace:
> [e1033db0] [c01a9428] lockdep_init_map_type+0x4c0/0xb4c (unreliable)
> [e1033df0] [c1c177b8] kw_i2c_add+0x334/0x424
> [e1033e20] [c1c18294] pmac_i2c_init+0x9ec/0xa9c
> [e1033e80] [c1c1a790] smp_core99_probe+0xbc/0x35c
> [e1033eb0] [c1c03cb0] kernel_init_freeable+0x190/0x5a4
> [e1033f10] [c000946c] kernel_init+0x28/0x154
> [e1033f30] [c0035148] ret_from_kernel_thread+0x14/0x1c
>
> Add missing lockdep_register_key()
>
> Reported-by: Erhard Furtner <[email protected]>
> Signed-off-by: Christophe Leroy <[email protected]>
> ---
> arch/powerpc/platforms/powermac/low_i2c.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/powerpc/platforms/powermac/low_i2c.c b/arch/powerpc/platforms/powermac/low_i2c.c
> index f77a59b5c2e1..de34fa34c42d 100644
> --- a/arch/powerpc/platforms/powermac/low_i2c.c
> +++ b/arch/powerpc/platforms/powermac/low_i2c.c
> @@ -582,6 +582,7 @@ static void __init kw_i2c_add(struct pmac_i2c_host_kw *host,
> bus->close = kw_i2c_close;
> bus->xfer = kw_i2c_xfer;
> mutex_init(&bus->mutex);
> + lockdep_register_key(&bus->lock_key);
> lockdep_set_class(&bus->mutex, &bus->lock_key);
> if (controller == busnode)
> bus->flags = pmac_i2c_multibus;
> --
> 2.33.1
>

The patch applied on 5.15.5 but unfortunately was not enough to fix the lockdep bug.

Originally was bug #200055 (https://bugzilla.kernel.org/show_bug.cgi?id=200055).

Regards,
Erhard

2021-11-30 14:06:18

by Christophe Leroy

[permalink] [raw]
Subject: Re: [PATCH] powerpc/powermac: Add missing lockdep_register_key()



Le 30/11/2021 à 14:53, Erhard F. a écrit :
> On Tue, 30 Nov 2021 10:32:42 +0100
> Christophe Leroy <[email protected]> wrote:
>
>> KeyWest i2c @0xf8001003 irq 42 /uni-n@f8000000/i2c@f8001000
>> BUG: key c2d00cbc has not been registered!
>> ------------[ cut here ]------------
>> DEBUG_LOCKS_WARN_ON(1)
>> WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:4801 lockdep_init_map_type+0x4c0/0xb4c
>> Modules linked in:
>> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.5-gentoo-PowerMacG4 #9
>> NIP: c01a9428 LR: c01a9428 CTR: 00000000
>> REGS: e1033cf0 TRAP: 0700 Not tainted (5.15.5-gentoo-PowerMacG4)
>> MSR: 00029032 <EE,ME,IR,DR,RI> CR: 24002002 XER: 00000000
>>
>> GPR00: c01a9428 e1033db0 c2d1cf20 00000016 00000004 00000001 c01c0630 e1033a73
>> GPR08: 00000000 00000000 00000000 e1033db0 24002004 00000000 f8729377 00000003
>> GPR16: c1829a9c 00000000 18305357 c1416fc0 c1416f80 c006ac60 c2d00ca8 c1416f00
>> GPR24: 00000000 c21586f0 c2160000 00000000 c2d00cbc c2170000 c216e1a0 c2160000
>> NIP [c01a9428] lockdep_init_map_type+0x4c0/0xb4c
>> LR [c01a9428] lockdep_init_map_type+0x4c0/0xb4c
>> Call Trace:
>> [e1033db0] [c01a9428] lockdep_init_map_type+0x4c0/0xb4c (unreliable)
>> [e1033df0] [c1c177b8] kw_i2c_add+0x334/0x424
>> [e1033e20] [c1c18294] pmac_i2c_init+0x9ec/0xa9c
>> [e1033e80] [c1c1a790] smp_core99_probe+0xbc/0x35c
>> [e1033eb0] [c1c03cb0] kernel_init_freeable+0x190/0x5a4
>> [e1033f10] [c000946c] kernel_init+0x28/0x154
>> [e1033f30] [c0035148] ret_from_kernel_thread+0x14/0x1c
>>
>> Add missing lockdep_register_key()
>>
>> Reported-by: Erhard Furtner <[email protected]>
>> Signed-off-by: Christophe Leroy <[email protected]>
>> ---
>> arch/powerpc/platforms/powermac/low_i2c.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/powerpc/platforms/powermac/low_i2c.c b/arch/powerpc/platforms/powermac/low_i2c.c
>> index f77a59b5c2e1..de34fa34c42d 100644
>> --- a/arch/powerpc/platforms/powermac/low_i2c.c
>> +++ b/arch/powerpc/platforms/powermac/low_i2c.c
>> @@ -582,6 +582,7 @@ static void __init kw_i2c_add(struct pmac_i2c_host_kw *host,
>> bus->close = kw_i2c_close;
>> bus->xfer = kw_i2c_xfer;
>> mutex_init(&bus->mutex);
>> + lockdep_register_key(&bus->lock_key);
>> lockdep_set_class(&bus->mutex, &bus->lock_key);
>> if (controller == busnode)
>> bus->flags = pmac_i2c_multibus;
>> --
>> 2.33.1
>>
>
> The patch applied on 5.15.5 but unfortunately was not enough to fix the lockdep bug.
>
> Originally was bug #200055 (https://bugzilla.kernel.org/show_bug.cgi?id=200055).
>

Is that still exactly the same backtrace , ie still pointing to
kw_i2c_add() ?

Because I see from original bug that in fact the offending commit added
lockdep_set_class() at 3 places. So it is likely that
lockdep_register_key() also needs to be added at the two other places.

So if the call trace now gives pmu_i2c_probe() or smu_i2c_probe() then
you could try and add lockdep_register_key() also there and see if it
fixes things.

Christophe

2021-12-07 13:28:42

by Michael Ellerman

[permalink] [raw]
Subject: Re: [PATCH] powerpc/powermac: Add missing lockdep_register_key()

On Tue, 30 Nov 2021 10:32:42 +0100, Christophe Leroy wrote:
> KeyWest i2c @0xf8001003 irq 42 /uni-n@f8000000/i2c@f8001000
> BUG: key c2d00cbc has not been registered!
> ------------[ cut here ]------------
> DEBUG_LOCKS_WARN_ON(1)
> WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:4801 lockdep_init_map_type+0x4c0/0xb4c
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.5-gentoo-PowerMacG4 #9
> NIP: c01a9428 LR: c01a9428 CTR: 00000000
> REGS: e1033cf0 TRAP: 0700 Not tainted (5.15.5-gentoo-PowerMacG4)
> MSR: 00029032 <EE,ME,IR,DR,RI> CR: 24002002 XER: 00000000
>
> [...]

Applied to powerpc/next.

[1/1] powerpc/powermac: Add missing lockdep_register_key()
https://git.kernel.org/powerpc/c/df1f679d19edb9eeb67cc2f96b29375f21991945

cheers