This patch seem to be fine. Please consider this patch as Acked-by: "Nandigama, Nagalakshmi" <Nagalakshmi.Nandigama@xxxxxxx> Regards, Nagalakshmi -----Original Message----- From: Alexey Khoroshilov [mailto:khoroshilov@xxxxxxxxx] Sent: Thursday, April 05, 2012 9:20 AM To: Nandigama, Nagalakshmi; James E.J. Bottomley Cc: Alexey Khoroshilov; linux-scsi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; ldv-project@xxxxxxxxx Subject: [PATCH] [SCSI] mpt2sas: fix double mutex lock in NON_BLOCKING state If state is NON_BLOCKING and mutex_trylock is succeed, the control flow goes to mutex_lock_interruptible() that is a deadlock. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx> --- drivers/scsi/mpt2sas/mpt2sas_ctl.c | 24 ++++++++++++++++-------- 1 files changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/mpt2sas/mpt2sas_ctl.c b/drivers/scsi/mpt2sas/mpt2sas_ctl.c index 1c6d2b4..9bd7ffc 100644 --- a/drivers/scsi/mpt2sas/mpt2sas_ctl.c +++ b/drivers/scsi/mpt2sas/mpt2sas_ctl.c @@ -648,8 +648,10 @@ _ctl_do_mpt_command(struct MPT2SAS_ADAPTER *ioc, issue_reset = 0; - if (state == NON_BLOCKING && !mutex_trylock(&ioc->ctl_cmds.mutex)) - return -EAGAIN; + if (state == NON_BLOCKING) { + if (!mutex_trylock(&ioc->ctl_cmds.mutex)) + return -EAGAIN; + } else if (mutex_lock_interruptible(&ioc->ctl_cmds.mutex)) return -ERESTARTSYS; @@ -1587,8 +1589,10 @@ _ctl_diag_register(void __user *arg, enum block_state state) if (_ctl_verify_adapter(karg.hdr.ioc_number, &ioc) == -1 || !ioc) return -ENODEV; - if (state == NON_BLOCKING && !mutex_trylock(&ioc->ctl_cmds.mutex)) - return -EAGAIN; + if (state == NON_BLOCKING) { + if (!mutex_trylock(&ioc->ctl_cmds.mutex)) + return -EAGAIN; + } else if (mutex_lock_interruptible(&ioc->ctl_cmds.mutex)) return -ERESTARTSYS; rc = _ctl_diag_register_2(ioc, &karg); @@ -1932,8 +1936,10 @@ _ctl_diag_release(void __user *arg, enum block_state state) return 0; } - if (state == NON_BLOCKING && !mutex_trylock(&ioc->ctl_cmds.mutex)) - return -EAGAIN; + if (state == NON_BLOCKING) { + if (!mutex_trylock(&ioc->ctl_cmds.mutex)) + return -EAGAIN; + } else if (mutex_lock_interruptible(&ioc->ctl_cmds.mutex)) return -ERESTARTSYS; @@ -2033,8 +2039,10 @@ _ctl_diag_read_buffer(void __user *arg, enum block_state state) } /* Get a free request frame and save the message context. */ - if (state == NON_BLOCKING && !mutex_trylock(&ioc->ctl_cmds.mutex)) - return -EAGAIN; + if (state == NON_BLOCKING) { + if (!mutex_trylock(&ioc->ctl_cmds.mutex)) + return -EAGAIN; + } else if (mutex_lock_interruptible(&ioc->ctl_cmds.mutex)) return -ERESTARTSYS; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
