path: root/drivers/scsi
diff options
authorLukasz Dorau <lukasz.dorau@intel.com>2014-02-06 12:23:20 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-03-23 21:38:19 -0700
commitbe92db5e00d862acda06ff116d8f4728d24e3b49 (patch)
treebd7bf64a6fa4faba67a71fe3ee0ac390e23cca55 /drivers/scsi
parenta5748c58fc4200a5ec7a8ceadaa845ffb15cf56b (diff)
SCSI: isci: correct erroneous for_each_isci_host macro
commit c59053a23d586675c25d789a7494adfdc02fba57 upstream. 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> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/scsi')
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/scsi/isci/host.h b/drivers/scsi/isci/host.h
index 4911310a38f5..22a9bb1abae1 100644
--- a/drivers/scsi/isci/host.h
+++ b/drivers/scsi/isci/host.h
@@ -311,9 +311,8 @@ static inline struct Scsi_Host *to_shost(struct isci_host *ihost)
#define for_each_isci_host(id, ihost, pdev) \
- for (id = 0, ihost = to_pci_info(pdev)->hosts[id]; \
- id < ARRAY_SIZE(to_pci_info(pdev)->hosts) && ihost; \
- ihost = to_pci_info(pdev)->hosts[++id])
+ for (id = 0; id < SCI_MAX_CONTROLLERS && \
+ (ihost = to_pci_info(pdev)->hosts[id]); id++)
static inline void wait_for_start(struct isci_host *ihost)