diff options
| author | Maurizio Lombardi <mlombard@redhat.com> | 2017-05-24 14:09:44 +0200 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2017-05-24 15:14:42 -0400 |
| commit | c2dd893a3b0772d1c680e109b9d5715d7f73022b (patch) | |
| tree | 7998ac1335780ce2bed868707cad265e9588efc9 /drivers/scsi/bnx2fc | |
| parent | ddff7ed45edce4a4c92949d3c61cd25d229c4a14 (diff) | |
scsi: bnx2fc: fix race condition in bnx2fc_get_host_stats()
If multiple tasks attempt to read the stats, it may happen that the
start_req_done completion is re-initialized while still being used by
another task, causing a list corruption.
This patch fixes the bug by adding a mutex to serialize the calls to
bnx2fc_get_host_stats().
WARNING: at lib/list_debug.c:48 list_del+0x6e/0xa0() (Not tainted)
Hardware name: PowerEdge R820
list_del corruption. prev->next should be ffff882035627d90, but was ffff884069541588
Pid: 40267, comm: perl Not tainted 2.6.32-642.3.1.el6.x86_64 #1
Call Trace:
[<ffffffff8107c691>] ? warn_slowpath_common+0x91/0xe0
[<ffffffff8107c796>] ? warn_slowpath_fmt+0x46/0x60
[<ffffffff812ad16e>] ? list_del+0x6e/0xa0
[<ffffffff81547eed>] ? wait_for_common+0x14d/0x180
[<ffffffff8106c4a0>] ? default_wake_function+0x0/0x20
[<ffffffff81547fd3>] ? wait_for_completion_timeout+0x13/0x20
[<ffffffffa05410b1>] ? bnx2fc_get_host_stats+0xa1/0x280 [bnx2fc]
[<ffffffffa04cf630>] ? fc_stat_show+0x90/0xc0 [scsi_transport_fc]
[<ffffffffa04cf8b6>] ? show_fcstat_tx_frames+0x16/0x20 [scsi_transport_fc]
[<ffffffff8137c647>] ? dev_attr_show+0x27/0x50
[<ffffffff8113b9be>] ? __get_free_pages+0xe/0x50
[<ffffffff812170e1>] ? sysfs_read_file+0x111/0x200
[<ffffffff8119a305>] ? vfs_read+0xb5/0x1a0
[<ffffffff8119b0b6>] ? fget_light_pos+0x16/0x50
[<ffffffff8119a651>] ? sys_read+0x51/0xb0
[<ffffffff810ee1fe>] ? __audit_syscall_exit+0x25e/0x290
[<ffffffff8100b0d2>] ? system_call_fastpath+0x16/0x1b
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Acked-by: Chad Dupuis <chad.dupuis@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/bnx2fc')
| -rw-r--r-- | drivers/scsi/bnx2fc/bnx2fc.h | 1 | ||||
| -rw-r--r-- | drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 10 |
2 files changed, 9 insertions, 2 deletions
diff --git a/drivers/scsi/bnx2fc/bnx2fc.h b/drivers/scsi/bnx2fc/bnx2fc.h index 4fc8ed5fe067..1f424e40afdf 100644 --- a/drivers/scsi/bnx2fc/bnx2fc.h +++ b/drivers/scsi/bnx2fc/bnx2fc.h @@ -191,6 +191,7 @@ struct bnx2fc_hba { struct bnx2fc_cmd_mgr *cmd_mgr; spinlock_t hba_lock; struct mutex hba_mutex; + struct mutex hba_stats_mutex; unsigned long adapter_state; #define ADAPTER_STATE_UP 0 #define ADAPTER_STATE_GOING_DOWN 1 diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c index 93b5a0012417..902722dc4ce3 100644 --- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c +++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c @@ -663,15 +663,17 @@ static struct fc_host_statistics *bnx2fc_get_host_stats(struct Scsi_Host *shost) if (!fw_stats) return NULL; + mutex_lock(&hba->hba_stats_mutex); + bnx2fc_stats = fc_get_host_stats(shost); init_completion(&hba->stat_req_done); if (bnx2fc_send_stat_req(hba)) - return bnx2fc_stats; + goto unlock_stats_mutex; rc = wait_for_completion_timeout(&hba->stat_req_done, (2 * HZ)); if (!rc) { BNX2FC_HBA_DBG(lport, "FW stat req timed out\n"); - return bnx2fc_stats; + goto unlock_stats_mutex; } BNX2FC_STATS(hba, rx_stat2, fc_crc_cnt); bnx2fc_stats->invalid_crc_count += hba->bfw_stats.fc_crc_cnt; @@ -693,6 +695,9 @@ static struct fc_host_statistics *bnx2fc_get_host_stats(struct Scsi_Host *shost) memcpy(&hba->prev_stats, hba->stats_buffer, sizeof(struct fcoe_statistics_params)); + +unlock_stats_mutex: + mutex_unlock(&hba->hba_stats_mutex); return bnx2fc_stats; } @@ -1340,6 +1345,7 @@ static struct bnx2fc_hba *bnx2fc_hba_create(struct cnic_dev *cnic) } spin_lock_init(&hba->hba_lock); mutex_init(&hba->hba_mutex); + mutex_init(&hba->hba_stats_mutex); hba->cnic = cnic; |