Messages in this thread | | | Subject | Re: [PATCH] brcmfmac: stop watchdog before detach and free everything | From | Arend van Spriel <> | Date | Mon, 28 May 2018 11:51:57 +0200 |
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On 5/28/2018 9:50 AM, Michael Trimarchi wrote: > Watchdog need to be stopped in brcmf_sdio_remove to avoid > i > The system is going down NOW! > [ 1348.110759] Unable to handle kernel NULL pointer dereference at virtual address 000002f8 > Sent SIGTERM to all processes > [ 1348.121412] Mem abort info: > [ 1348.126962] ESR = 0x96000004 > [ 1348.130023] Exception class = DABT (current EL), IL = 32 bits > [ 1348.135948] SET = 0, FnV = 0 > [ 1348.138997] EA = 0, S1PTW = 0 > [ 1348.142154] Data abort info: > [ 1348.145045] ISV = 0, ISS = 0x00000004 > [ 1348.148884] CM = 0, WnR = 0 > [ 1348.151861] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____) > [ 1348.158475] [00000000000002f8] pgd=0000000000000000 > [ 1348.163364] Internal error: Oops: 96000004 [#1] PREEMPT SMP > [ 1348.168927] Modules linked in: ipv6 > [ 1348.172421] CPU: 3 PID: 1421 Comm: brcmf_wdog/mmc0 Not tainted 4.17.0-rc5-next-20180517 #18 > [ 1348.180757] Hardware name: Amarula A64-Relic (DT) > [ 1348.185455] pstate: 60000005 (nZCv daif -PAN -UAO) > [ 1348.190251] pc : brcmf_sdiod_freezer_count+0x0/0x20 > [ 1348.195124] lr : brcmf_sdio_watchdog_thread+0x64/0x290
Hi Michael,
Thanks for the patch. In normal scenario the callstack looks like this:
brcmf_sdio_remove() -> brcmf_detach() -> brcmf_bus_stop() -> brcmf_sdio_bus_stop()
In brcmf_sdio_bus_stop() the watchdog is terminated. So in what scenario did you encounter this null pointer deref?
Regards, Arend
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