]> git.karo-electronics.de Git - karo-tx-linux.git/commit
powerpc/eeh: Lock module while handling EEH event
authorGavin Shan <shangw@linux.vnet.ibm.com>
Mon, 17 Sep 2012 04:34:27 +0000 (04:34 +0000)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>
Tue, 18 Sep 2012 05:32:48 +0000 (15:32 +1000)
commitfeadf7c0a1a7c08c74bebb4a13b755f8c40e3bbc
tree00d8b8c42f57f566618dd0d0aea65190706ca4d8
parent8e9f69371536981a2a8c9ee4a49dbe3aa4946df4
powerpc/eeh: Lock module while handling EEH event

The EEH core is talking with the PCI device driver to determine the
action (purely reset, or PCI device removal). During the period, the
driver might be unloaded and in turn causes kernel crash as follows:

EEH: Detected PCI bus error on PHB#4-PE#10000
EEH: This PCI device has failed 3 times in the last hour
lpfc 0004:01:00.0: 0:2710 PCI channel disable preparing for reset
Unable to handle kernel paging request for data at address 0x00000490
Faulting instruction address: 0xd00000000e682c90
cpu 0x1: Vector: 300 (Data Access) at [c000000fc75ffa20]
    pc: d00000000e682c90: .lpfc_io_error_detected+0x30/0x240 [lpfc]
    lr: d00000000e682c8c: .lpfc_io_error_detected+0x2c/0x240 [lpfc]
    sp: c000000fc75ffca0
   msr: 8000000000009032
   dar: 490
 dsisr: 40000000
  current = 0xc000000fc79b88b0
  paca    = 0xc00000000edb0380  softe: 0  irq_happened: 0x00
    pid   = 3386, comm = eehd
enter ? for help
[c000000fc75ffca0c000000fc75ffd30 (unreliable)
[c000000fc75ffd30c00000000004fd3c .eeh_report_error+0x7c/0xf0
[c000000fc75ffdc0c00000000004ee00 .eeh_pe_dev_traverse+0xa0/0x180
[c000000fc75ffe70c00000000004ffd8 .eeh_handle_event+0x68/0x300
[c000000fc75fff00c0000000000503a0 .eeh_event_handler+0x130/0x1a0
[c000000fc75fff90c000000000020138 .kernel_thread+0x54/0x70
1:mon>

The patch increases the reference of the corresponding driver modules
while EEH core does the negotiation with PCI device driver so that the
corresponding driver modules can't be unloaded during the period and
we're safe to refer the callbacks.

Cc: stable@vger.kernel.org
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
arch/powerpc/platforms/pseries/eeh_driver.c