Re: brcmfmac: Possible memleak brcmf_sdiod_sgtable_alloc

[Arend van Spriel <arend.vanspriel@broadcom.com>]

On 7/26/2017 8:12 AM, Stefan Wahren wrote:
> Hi Arend,
>
>> Stefan Wahren <stefan.wahren@i2se.com> hat am 23. Juli 2017 um 02:24 geschrieben:
>>
>>
>>
>>> Arend van Spriel <arend.vanspriel@broadcom.com> hat am 22. Juli 2017 um 21:40 geschrieben:
>>>
>>>
>>> On 22-07-17 15:18, Stefan Wahren wrote:
>>>> Hi,
>>>>
>>>> with enabled memleak detector on 4.13-rc1 (Raspberry Pi Zero W) i get the following:
>>>>
>>>> root@raspberrypi:/sys/kernel/debug# cat kmemleak
>>>> unreferenced object 0xd824e400 (size 1024):
>>>>    comm "kworker/0:0", pid 3, jiffies 4294939822 (age 873.420s)
>>>>    hex dump (first 32 bytes):
>>>>      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>>>>      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>>>>    backtrace:
>>>>      [<c07f741c>] kmemleak_alloc+0x60/0xc8
>>>>      [<c024cb44>] __kmalloc+0x184/0x2f4
>>>>      [<c03dc1c8>] sg_kmalloc+0x48/0x4c
>>>>      [<c03dc0dc>] __sg_alloc_table+0x78/0x11c
>>>>      [<c03dc5d0>] sg_alloc_table+0x2c/0x5c
>>>>      [<bf07d7e8>] brcmf_sdiod_sgtable_alloc+0xc0/0x110 [brcmfmac]
>>>>      [<bf07b814>] brcmf_sdio_probe+0x24c/0x970 [brcmfmac]
>>>>      [<bf07c6fc>] brcmf_ops_sdio_probe+0x17c/0x244 [brcmfmac]
>>>>      [<c057d5b4>] sdio_bus_probe+0xb4/0x124
>>>>      [<c04add08>] driver_probe_device+0x1d8/0x438
>>>>      [<c04ae00c>] __driver_attach+0xa4/0x108
>>>>      [<c04abe20>] bus_for_each_dev+0x84/0x98
>>>>      [<c04ad644>] driver_attach+0x28/0x30
>>>>      [<c04ad084>] bus_add_driver+0xe4/0x24c
>>>>      [<c04ae834>] driver_register+0xac/0xf0
>>>>      [<c057d7dc>] sdio_register_driver+0x2c/0x34
>>>
>>> Hi Stefan,
>>>
>>> Thanks for the report. Checking elixir it shows two call sites to
>>> brcmf_sdiod_sgtable_alloc() [1]. This is rather unexpected. We did move
>>> the call so this might be a merge issue.
>>>
>>> 4d7928959 sdio.c (Hante Meuleman   2016-02-17 11:27:07 +0100:
>>> 3867)     brcmf_sdiod_sgtable_alloc(sdiodev);
>>>
>>> e0045bf80 sdio.c (Hante Meuleman   2016-01-19 12:39:24 +0100:
>>> 4180)     brcmf_sdiod_sgtable_alloc(bus->sdiodev);
>>>
>>> The most recent change is:
>>>
>>> commit 4d7928959832 ("brcmfmac: switch to new platform data") found in
>>> patchwork [2], which shows the added call, but no removal so the merge
>>> issue is probably internal with us (me :-( ).
>>>
>>> Again thanks for the report. Below change should fix the issue.
>>
>> Yes, this fixed the leak. Thanks for you fast reply.
>
> do you plan to send a proper patch for this?

Sure. Catching up after my vacation.

Regards,
Arend