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 and global/local variable setting, the functions
are mutually signalled to cooperate.
Signed-off-by: Mark Balantzyan <mbala...@gmail.com>
---
Changelog v2
Lacked a version number but added properly terminated else condition at
(former) line 2300.
Changelog v3
Fixes "return -EAGAIN" lines which were erroneously tabbed as if to be guarded
by "if" conditions lying above them.
Changelog v4
Removes a pair of needless mutexes in init() function, allows for checking of
NULL
condition outside of race-fixing mutexes in functions mptctl_do_mpt_command(),
mptctl_do_fw_command, and mptctl_hp_hostinfo().
drivers/message/fusion/mptctl.c | 59 ++++++++++++++++++++++++---------
1 file changed, 43 insertions(+), 16 deletions(-)
diff --git a/drivers/message/fusion/mptctl.c b/drivers/message/fusion/mptctl.c
index 4470630d..21af0ee8 100644
--- a/drivers/message/fusion/mptctl.c
+++ b/drivers/message/fusion/mptctl.c
@@ -816,12 +816,17 @@ mptctl_do_fw_download(int ioc, char __user *ufwbuf,
size_t fwlen)
/* Valid device. Get a message frame and construct the FW
download message.
*/
- if ((mf = mpt_get_msg_frame(mptctl_id, iocp)) == NULL)
+ mutex_lock(&mpctl_mutex);
+ mf = mpt_get_msg_frame(mptctl_id, iocp);
+ mutex_unlock(&mpctl_mutex);
+ if (mf == NULL) {
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 +948,9 @@ 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:
@@ -1889,8 +1896,12 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg,
void __user *mfPtr)
/* Get a free request frame and save the message context.
*/
- if ((mf = mpt_get_msg_frame(mptctl_id, ioc)) == NULL)
- return -EAGAIN;
+ mutex_lock(&mpctl_mutex);
+ mf = mpt_get_msg_frame(mptctl_id, ioc);
+ mutex_unlock(&mpctl_mutex);
+ if (mf == NULL) {
+ return -EAGAIN;
+ }
hdr = (MPIHeader_t *) mf;
msgContext = le32_to_cpu(hdr->MsgContext);
@@ -2271,11 +2282,14 @@ 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",
@@ -2287,8 +2301,11 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg,
void __user *mfPtr)
}
}
- } else
+ } 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 +2580,10 @@ mptctl_hp_hostinfo(unsigned long arg, unsigned int
data_size)
/*
* Gather ISTWI(Industry Standard Two Wire Interface) Data
*/
- if ((mf = mpt_get_msg_frame(mptctl_id, ioc)) == NULL) {
+ mutex_lock(&mpctl_mutex);
+ mf = mpt_get_msg_frame(mptctl_id, ioc);
+ mutex_unlock(&mpctl_mutex);
+ if (mf == NULL) {
dfailprintk(ioc, printk(MYIOC_s_WARN_FMT
"%s, no msg frames!!\n", ioc->name, __func__));
goto out;
@@ -2593,7 +2613,9 @@ 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,
@@ -2991,6 +3013,7 @@ static int __init mptctl_init(void)
{
int err;
int where = 1;
+ u8 m_id, m_taskmgmt_id;
show_mptmod_ver(my_NAME, my_VERSION);
@@ -3010,25 +3033,26 @@ static int __init mptctl_init(void)
* Install our handler
*/
++where;
- mptctl_id = mpt_register(mptctl_reply, MPTCTL_DRIVER,
+ m_id = mpt_register(mptctl_reply, MPTCTL_DRIVER,
"mptctl_reply");
- if (!mptctl_id || mptctl_id >= MPT_MAX_PROTOCOL_DRIVERS) {
+ if (!m_id || m_id >= MPT_MAX_PROTOCOL_DRIVERS) {
printk(KERN_ERR MYNAM ": ERROR: Failed to register with Fusion
MPT base driver\n");
misc_deregister(&mptctl_miscdev);
err = -EBUSY;
goto out_fail;
}
+ mptctl_id = m_id; // registration with Fusion MPT base successful
- mptctl_taskmgmt_id = mpt_register(mptctl_taskmgmt_reply, MPTCTL_DRIVER,
+ m_taskmgmt_id = mpt_register(mptctl_taskmgmt_reply, MPTCTL_DRIVER,
"mptctl_taskmgmt_reply");
- if (!mptctl_taskmgmt_id || mptctl_taskmgmt_id >=
MPT_MAX_PROTOCOL_DRIVERS) {
+ if (!m_taskmgmt_id || m_taskmgmt_id >= MPT_MAX_PROTOCOL_DRIVERS) {
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;
}
-
+ mptctl_taskmgmt_id = m_taskmgmt_id; // registration with Fusion MPT
base successful
mpt_reset_register(mptctl_id, mptctl_ioc_reset);
mpt_event_register(mptctl_id, mptctl_event_process);
@@ -3044,13 +3068,14 @@ 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 +3083,8 @@ 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
