kernel_optimize_test/drivers/scsi/isci
Lukasz Dorau c59053a23d [SCSI] isci: correct erroneous for_each_isci_host macro
In the first place, the loop 'for' in the macro 'for_each_isci_host'
(drivers/scsi/isci/host.h:314) is incorrect, because it accesses
the 3rd element of 2 element array. After the 2nd iteration it executes
the instruction:
        ihost = to_pci_info(pdev)->hosts[2]
(while the size of the 'hosts' array equals 2) and reads an
out of range element.

In the second place, this loop is incorrectly optimized by GCC v4.8
(see http://marc.info/?l=linux-kernel&m=138998871911336&w=2).
As a result, on platforms with two SCU controllers,
the loop is executed more times than it can be (for i=0,1 and 2).
It causes kernel panic during entering the S3 state
and the following oops after 'rmmod isci':

BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8131360b>] __list_add+0x1b/0xc0
Oops: 0000 [#1] SMP
RIP: 0010:[<ffffffff8131360b>]  [<ffffffff8131360b>] __list_add+0x1b/0xc0
Call Trace:
  [<ffffffff81661b84>] __mutex_lock_slowpath+0x114/0x1b0
  [<ffffffff81661c3f>] mutex_lock+0x1f/0x30
  [<ffffffffa03e97cb>] sas_disable_events+0x1b/0x50 [libsas]
  [<ffffffffa03e9818>] sas_unregister_ha+0x18/0x60 [libsas]
  [<ffffffffa040316e>] isci_unregister+0x1e/0x40 [isci]
  [<ffffffffa0403efd>] isci_pci_remove+0x5d/0x100 [isci]
  [<ffffffff813391cb>] pci_device_remove+0x3b/0xb0
  [<ffffffff813fbf7f>] __device_release_driver+0x7f/0xf0
  [<ffffffff813fc8f8>] driver_detach+0xa8/0xb0
  [<ffffffff813fbb8b>] bus_remove_driver+0x9b/0x120
  [<ffffffff813fcf2c>] driver_unregister+0x2c/0x50
  [<ffffffff813381f3>] pci_unregister_driver+0x23/0x80
  [<ffffffffa04152f8>] isci_exit+0x10/0x1e [isci]
  [<ffffffff810d199b>] SyS_delete_module+0x16b/0x2d0
  [<ffffffff81012a21>] ? do_notify_resume+0x61/0xa0
  [<ffffffff8166ce29>] system_call_fastpath+0x16/0x1b

The loop has been corrected.
This patch fixes kernel panic during entering the S3 state
and the above oops.

Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
Reviewed-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Tested-by: Lukasz Dorau <lukasz.dorau@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-10 12:49:39 +04:00
..
host.c
host.h [SCSI] isci: correct erroneous for_each_isci_host macro 2014-03-10 12:49:39 +04:00
init.c
isci.h
Makefile
phy.c
phy.h
port_config.c [SCSI] isci: fix reset timeout handling 2014-03-10 12:48:16 +04:00
port.c
port.h
probe_roms.c
probe_roms.h
registers.h
remote_device.c [SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type 2013-05-10 07:47:52 -07:00
remote_device.h [SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type 2013-05-10 07:47:52 -07:00
remote_node_context.c
remote_node_context.h
remote_node_table.c
remote_node_table.h
request.c [SCSI] isci: fix breakage caused by >16byte CDB patch 2013-07-24 14:18:12 -07:00
request.h
sas.h
scu_completion_codes.h
scu_event_codes.h
scu_remote_node_context.h
scu_task_context.h
task.c [SCSI] isci: fix reset timeout handling 2014-03-10 12:48:16 +04:00
task.h
unsolicited_frame_control.c
unsolicited_frame_control.h