Re: [3.1-rc6] kmalloc(64) leak from IDE

[Bjorn Helgaas]

On Fri, Sep 23, 2011 at 10:34 AM, Bernd Schubert
<bernd.schubert@xxxxxxxxxxxxxxxxxx> wrote:
> On 09/23/2011 06:08 PM, Bjorn Helgaas wrote:
>>
>> On Fri, Sep 23, 2011 at 9:58 AM, Bernd Schubert
>> <bernd.schubert@xxxxxxxxxxxxxxxxxx>  wrote:
>>>
>>> On 09/23/2011 09:21 AM, Borislav Petkov wrote:
>>>>
>>>> On Thu, Sep 22, 2011 at 01:23:37PM -0700, Simon Kirby wrote:
>>>>>
>>>>> Yes, that seems to have made it stop complaining about the IDE path.
>>>>
>>>> Good, thanks for testing. It would be great if you left it running for
>>>> a couple of days like this to see whether there aren't any other issues
>>>> with the patch. I'll send it with a proper description to Dave soonish
>>>> since this is a real bug.
>>>>
>>>>> All I see from kmemleak now is:
>>>>
>>>> Yep, not IDE-related. Adding linux-acpi.
>>>
>>>
>>>>
>>>>> unreferenced object 0xe7481a00 (size 256):
>>>>>   comm "swapper", pid 1, jiffies 4294892509 (age 515.560s)
>>>>>   hex dump (first 32 bytes):
>>>>>     00 00 00 28 ff ff ef ff 60 78 4e e7 00 02 00 00  ...(....`xN.....
>>>>>     47 01 f8 0c f8 0c 01 08 00 00 00 00 0c 03 00 00  G...............
>>>>>   backtrace:
>>>>>     [<c1495c47>] kmemleak_alloc+0x27/0x50
>>>>>     [<c10b3563>] __kmalloc+0xf3/0x1c0
>>>>>     [<c149e0b0>] pci_acpi_scan_root+0x11e/0x272
>>>>>     [<c149916b>] acpi_pci_root_add+0x163/0x256
>>>>>     [<c12adddc>] acpi_device_probe+0x3a/0xf4
>>>>>     [<c1302e38>] driver_probe_device+0x68/0x160
>>>>>     [<c1302fb9>] __driver_attach+0x89/0x90
>>>>>     [<c1302718>] bus_for_each_dev+0x48/0x70
>>>>>     [<c1302cc9>] driver_attach+0x19/0x20
>>>>>     [<c130213f>] bus_add_driver+0x17f/0x240
>>>>>     [<c1303345>] driver_register+0x65/0x120
>>>>>     [<c12af273>] acpi_bus_register_driver+0x3a/0x3f
>>>>>     [<c16d421f>] acpi_pci_root_init+0x1b/0x2a
>>>>>     [<c1001030>] do_one_initcall+0x30/0x160
>>>>>     [<c16b920b>] kernel_init+0x78/0x10c
>>>>>     [<c14a1b76>] kernel_thread_helper+0x6/0xd
>>>>> unreferenced object 0xe74e7860 (size 16):
>>>>>   comm "swapper", pid 1, jiffies 4294892509 (age 515.560s)
>>>>>   hex dump (first 16 bytes):
>>>>>     50 43 49 20 42 75 73 20 30 30 30 30 3a 30 30 00  PCI Bus 0000:00.
>>>>>   backtrace:
>>>>>     [<c1495c47>] kmemleak_alloc+0x27/0x50
>>>>>     [<c10b3563>] __kmalloc+0xf3/0x1c0
>>>>>     [<c1290cce>] kvasprintf+0x2e/0x50
>>>>>     [<c1290d01>] kasprintf+0x11/0x20
>>>>>     [<c149e0da>] pci_acpi_scan_root+0x148/0x272
>>>>>     [<c149916b>] acpi_pci_root_add+0x163/0x256
>>>>>     [<c12adddc>] acpi_device_probe+0x3a/0xf4
>>>>>     [<c1302e38>] driver_probe_device+0x68/0x160
>>>>>     [<c1302fb9>] __driver_attach+0x89/0x90
>>>>>     [<c1302718>] bus_for_each_dev+0x48/0x70
>>>>>     [<c1302cc9>] driver_attach+0x19/0x20
>>>>>     [<c130213f>] bus_add_driver+0x17f/0x240
>>>>>     [<c1303345>] driver_register+0x65/0x120
>>>>>     [<c12af273>] acpi_bus_register_driver+0x3a/0x3f
>>>>>     [<c16d421f>] acpi_pci_root_init+0x1b/0x2a
>>>>>     [<c1001030>] do_one_initcall+0x30/0x160
>>>>>
>>>>> ...which is probably a separate, non-recurring leak.
>>>>>
>>>>>> Also, I'm sure you know IDE is deprecated, so what are the chances of
>>>>>> moving this box to libata? Also, can you send me your .config pls?
>>>>>
>>>>> Yeah, I was going to get around to that eventually. :) Config (and
>>>>> earlier kmemleak output) here: http://0x.ca/sim/ref/3.1-rc6-blue/
>>>>
>>>> Ok, thanks.
>>>>
>>>
>>> I think I reported those already some time ago:
>>>
>>> https://lkml.org/lkml/2011/6/21/95
>>
>> Rats.  And you even posted a patch
>> (https://lkml.org/lkml/2011/6/21/132).  I was cc'd, but unfortunately
>> to an old email address that no longer works.  I'll follow up on it
>> and make sure it's fixed (probably in 3.2 since it's minor and we're
>> so late in 3.1).
>
> Ah great, I thought you are simply too busy to look into it. We are all just
> changing our mail addresses too often :)
>
> Do you mind if I ping you directly once kernel.org is up again? We have a
> few test systems here, that fail to boot with recent kernels (just a system
> hard reset). The issue was introduced in between 2.6.27 and 2.6.32 and it is
> pci mmconfig related, probably due to a troublesome acpi bios. I filled a
> bugzilla some time ago and never got a responds on it. But I also need to
> update it with my latest finding...

Please do, and you don't need to wait for kernel.org to come back
(though it'd be good to include any bugzilla URLs if you know them).
Just email me and copy linux-pci (since it seems PCI
MMCONFIG-related), and we can try to make some progress.  It's very
important to fix regressions as quickly as possible.

Bjorn
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