Certain functions in the driver, such as mptctl_do_fw_download() and
mptctl_do_mpt_command(), rely on the instance of mptctl_id, which does the
id-ing. There is race condition possible when these functions operate in
concurrency. Via, mutexes, the functions are mutually signalled to cooperate.

Signed-off-by: Mark Balantzyan <mbala...@gmail.com>

---
 drivers/message/fusion/mptctl.c | 36 ++++++++++++++++++++++++++-------
 1 file changed, 29 insertions(+), 7 deletions(-)

diff --git a/drivers/message/fusion/mptctl.c b/drivers/message/fusion/mptctl.c
index 4470630d..58ce0fc0 100644
--- a/drivers/message/fusion/mptctl.c
+++ b/drivers/message/fusion/mptctl.c
@@ -816,12 +816,15 @@ mptctl_do_fw_download(int ioc, char __user *ufwbuf, 
size_t fwlen)
 
                /*  Valid device. Get a message frame and construct the FW 
download message.
                */
+               mutex_lock(&mpctl_mutex);
                if ((mf = mpt_get_msg_frame(mptctl_id, iocp)) == NULL)
+               mutex_unlock(&mpctl_mutex);
                        return -EAGAIN;
        }
-
+       mutex_lock(&mpctl_mutex);
        dctlprintk(iocp, printk(MYIOC_s_DEBUG_FMT
            "mptctl_do_fwdl called. mptctl_id = %xh.\n", iocp->name, 
mptctl_id));
+       mutex_unlock(&mpctl_mutex);
        dctlprintk(iocp, printk(MYIOC_s_DEBUG_FMT "DbG: kfwdl.bufp  = %p\n",
            iocp->name, ufwbuf));
        dctlprintk(iocp, printk(MYIOC_s_DEBUG_FMT "DbG: kfwdl.fwlen = %d\n",
@@ -943,7 +946,9 @@ mptctl_do_fw_download(int ioc, char __user *ufwbuf, size_t 
fwlen)
        ReplyMsg = NULL;
        SET_MGMT_MSG_CONTEXT(iocp->ioctl_cmds.msg_context, dlmsg->MsgContext);
        INITIALIZE_MGMT_STATUS(iocp->ioctl_cmds.status)
+       mutex_lock(&mpctl_mutex);
        mpt_put_msg_frame(mptctl_id, iocp, mf);
+       mutex_lock(&mpctl_mutex);
 
        /* Now wait for the command to complete */
 retry_wait:
@@ -1889,7 +1894,9 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg, 
void __user *mfPtr)
 
        /* Get a free request frame and save the message context.
         */
+       mutex_lock(&mpctl_mutex);
         if ((mf = mpt_get_msg_frame(mptctl_id, ioc)) == NULL)
+       mutex_unlock(&mpctl_mutex);
                 return -EAGAIN;
 
        hdr = (MPIHeader_t *) mf;
@@ -2271,11 +2278,14 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg, 
void __user *mfPtr)
                DBG_DUMP_TM_REQUEST_FRAME(ioc, (u32 *)mf);
 
                if ((ioc->facts.IOCCapabilities & 
MPI_IOCFACTS_CAPABILITY_HIGH_PRI_Q) &&
-                   (ioc->facts.MsgVersion >= MPI_VERSION_01_05))
+                   (ioc->facts.MsgVersion >= MPI_VERSION_01_05)) {
+                       mutex_lock(&mpctl_mutex);
                        mpt_put_msg_frame_hi_pri(mptctl_id, ioc, mf);
-               else {
-                       rc =mpt_send_handshake_request(mptctl_id, ioc,
-                               sizeof(SCSITaskMgmt_t), (u32*)mf, CAN_SLEEP);
+                       mutex_unlock(&mpctl_mutex);
+               } else {
+                       mutex_lock(&mpctl_mutex);
+                       rc = mpt_send_handshake_request(mptctl_id, ioc, 
sizeof(SCSITaskMgmt_t), (u32 *)mf, CAN_SLEEP);
+                       mutex_unlock(&mpctl_mutex);
                        if (rc != 0) {
                                dfailprintk(ioc, printk(MYIOC_s_ERR_FMT
                                    "send_handshake FAILED! (ioc %p, mf %p)\n",
@@ -2288,7 +2298,9 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg, 
void __user *mfPtr)
                }
 
        } else
+               mutex_lock(&mpctl_mutex);
                mpt_put_msg_frame(mptctl_id, ioc, mf);
+               mutex_unlock(&mpctl_mutex);
 
        /* Now wait for the command to complete */
        timeout = (karg.timeout > 0) ? karg.timeout : MPT_IOCTL_DEFAULT_TIMEOUT;
@@ -2563,7 +2575,9 @@ mptctl_hp_hostinfo(unsigned long arg, unsigned int 
data_size)
        /* 
         * Gather ISTWI(Industry Standard Two Wire Interface) Data
         */
+       mutex_lock(&mpctl_mutex);
        if ((mf = mpt_get_msg_frame(mptctl_id, ioc)) == NULL) {
+       mutex_unlock(&mpctl_mutex);
                dfailprintk(ioc, printk(MYIOC_s_WARN_FMT
                        "%s, no msg frames!!\n", ioc->name, __func__));
                goto out;
@@ -2593,7 +2607,9 @@ mptctl_hp_hostinfo(unsigned long arg, unsigned int 
data_size)
        SET_MGMT_MSG_CONTEXT(ioc->ioctl_cmds.msg_context,
                                IstwiRWRequest->MsgContext);
        INITIALIZE_MGMT_STATUS(ioc->ioctl_cmds.status)
+       mutex_lock(&mpctl_mutex);
        mpt_put_msg_frame(mptctl_id, ioc, mf);
+       mutex_unlock(&mpctl_mutex);
 
 retry_wait:
        timeleft = wait_for_completion_timeout(&ioc->ioctl_cmds.done,
@@ -3010,9 +3026,11 @@ static int __init mptctl_init(void)
         *  Install our handler
         */
        ++where;
+       mutex_lock(&mpctl_mutex);
        mptctl_id = mpt_register(mptctl_reply, MPTCTL_DRIVER,
            "mptctl_reply");
        if (!mptctl_id || mptctl_id >= MPT_MAX_PROTOCOL_DRIVERS) {
+               mutex_unlock(&mpctl_mutex);
                printk(KERN_ERR MYNAM ": ERROR: Failed to register with Fusion 
MPT base driver\n");
                misc_deregister(&mptctl_miscdev);
                err = -EBUSY;
@@ -3022,13 +3040,14 @@ static int __init mptctl_init(void)
        mptctl_taskmgmt_id = mpt_register(mptctl_taskmgmt_reply, MPTCTL_DRIVER,
            "mptctl_taskmgmt_reply");
        if (!mptctl_taskmgmt_id || mptctl_taskmgmt_id >= 
MPT_MAX_PROTOCOL_DRIVERS) {
+               mutex_unlock(&mpctl_mutex);
                printk(KERN_ERR MYNAM ": ERROR: Failed to register with Fusion 
MPT base driver\n");
                mpt_deregister(mptctl_id);
                misc_deregister(&mptctl_miscdev);
                err = -EBUSY;
                goto out_fail;
        }
-
+       mutex_unlock(&mpctl_mutex);
        mpt_reset_register(mptctl_id, mptctl_ioc_reset);
        mpt_event_register(mptctl_id, mptctl_event_process);
 
@@ -3044,13 +3063,14 @@ out_fail:
 /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*/
 static void mptctl_exit(void)
 {
+       mutex_lock(&mpctl_mutex);
        misc_deregister(&mptctl_miscdev);
        printk(KERN_INFO MYNAM ": Deregistered /dev/%s @ (major,minor=%d,%d)\n",
                         mptctl_miscdev.name, MISC_MAJOR, mptctl_miscdev.minor);
 
        /* De-register event handler from base module */
        mpt_event_deregister(mptctl_id);
-
+
        /* De-register reset handler from base module */
        mpt_reset_deregister(mptctl_id);
 
@@ -3058,6 +3078,8 @@ static void mptctl_exit(void)
        mpt_deregister(mptctl_taskmgmt_id);
        mpt_deregister(mptctl_id);
 
+       mutex_unlock(&mpctl_mutex);
+
         mpt_device_driver_deregister(MPTCTL_DRIVER);
 
 }
-- 
2.17.1

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