[PATCH] I2O: Bugfixes to get I2O working again

From: Markus Lidel <Markus.Lidel@shadowconnect.com>

- Fixed locking of struct i2o_exec_wait in Executive-OSM

- Removed LCT Notify in i2o_exec_probe() which caused freeing memory and
  accessing freed memory during first enumeration of I2O devices

- Added missing locking in i2o_exec_lct_notify()

- removed put_device() of I2O controller in i2o_iop_remove() which caused
  the controller structure get freed to early

- Fixed size of mempool in i2o_iop_alloc()

- Fixed access to freed memory in i2o_msg_get()

See http://bugzilla.kernel.org/show_bug.cgi?id=6561

Signed-off-by: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 42 insertions, 39 deletions

diff --git a/drivers/message/i2o/exec-osm.c b/drivers/message/i2o/exec-osm.c
index 5ea133c59afb..7bd4d85d0b42 100644
--- a/drivers/message/i2o/exec-osm.c
+++ b/drivers/message/i2o/exec-osm.c
@@ -55,6 +55,7 @@ struct i2o_exec_wait {
         u32 m;                  /* message id */
         struct i2o_message *msg;        /* pointer to the reply message */
         struct list_head list;  /* node in global wait list */
+        spinlock_t lock;        /* lock before modifying */
 };
 
 /* Work struct needed to handle LCT NOTIFY replies */
@@ -87,6 +88,7 @@ static struct i2o_exec_wait *i2o_exec_wait_alloc(void)
                 return NULL;
 
         INIT_LIST_HEAD(&wait->list);
+        spin_lock_init(&wait->lock);
 
         return wait;
 };
@@ -125,6 +127,7 @@ int i2o_msg_post_wait_mem(struct i2o_controller *c, struct i2o_message *msg,
         DECLARE_WAIT_QUEUE_HEAD(wq);
         struct i2o_exec_wait *wait;
         static u32 tcntxt = 0x80000000;
+        long flags;
         int rc = 0;
 
         wait = i2o_exec_wait_alloc();
@@ -146,33 +149,28 @@ int i2o_msg_post_wait_mem(struct i2o_controller *c, struct i2o_message *msg,
         wait->tcntxt = tcntxt++;
         msg->u.s.tcntxt = cpu_to_le32(wait->tcntxt);
 
+        wait->wq = &wq;
+        /*
+         * we add elements to the head, because if a entry in the list will
+         * never be removed, we have to iterate over it every time
+         */
+        list_add(&wait->list, &i2o_exec_wait_list);
+
         /*
          * Post the message to the controller. At some point later it will
          * return. If we time out before it returns then complete will be zero.
          */
         i2o_msg_post(c, msg);
 
-        if (!wait->complete) {
-                wait->wq = &wq;
-                /*
-                 * we add elements add the head, because if a entry in the list
-                 * will never be removed, we have to iterate over it every time
-                 */
-                list_add(&wait->list, &i2o_exec_wait_list);
-
-                wait_event_interruptible_timeout(wq, wait->complete,
-                                                 timeout * HZ);
+        wait_event_interruptible_timeout(wq, wait->complete, timeout * HZ);
 
-                wait->wq = NULL;
-        }
+        spin_lock_irqsave(&wait->lock, flags);
 
-        barrier();
+        wait->wq = NULL;
 
-        if (wait->complete) {
+        if (wait->complete)
                 rc = le32_to_cpu(wait->msg->body[0]) >> 24;
-                i2o_flush_reply(c, wait->m);
-                i2o_exec_wait_free(wait);
-        } else {
+        else {
                 /*
                  * We cannot remove it now. This is important. When it does
                  * terminate (which it must do if the controller has not
@@ -186,6 +184,13 @@ int i2o_msg_post_wait_mem(struct i2o_controller *c, struct i2o_message *msg,
                 rc = -ETIMEDOUT;
         }
 
+        spin_unlock_irqrestore(&wait->lock, flags);
+
+        if (rc != -ETIMEDOUT) {
+                i2o_flush_reply(c, wait->m);
+                i2o_exec_wait_free(wait);
+        }
+
         return rc;
 };
 
@@ -213,7 +218,6 @@ static int i2o_msg_post_wait_complete(struct i2o_controller *c, u32 m,
 {
         struct i2o_exec_wait *wait, *tmp;
         unsigned long flags;
-        static spinlock_t lock = SPIN_LOCK_UNLOCKED;
         int rc = 1;
 
         /*
@@ -223,23 +227,24 @@ static int i2o_msg_post_wait_complete(struct i2o_controller *c, u32 m,
          * already expired. Not much we can do about that except log it for
          * debug purposes, increase timeout, and recompile.
          */
-        spin_lock_irqsave(&lock, flags);
         list_for_each_entry_safe(wait, tmp, &i2o_exec_wait_list, list) {
                 if (wait->tcntxt == context) {
-                        list_del(&wait->list);
+                        spin_lock_irqsave(&wait->lock, flags);
 
-                        spin_unlock_irqrestore(&lock, flags);
+                        list_del(&wait->list);
 
                         wait->m = m;
                         wait->msg = msg;
                         wait->complete = 1;
 
-                        barrier();
-
-                        if (wait->wq) {
-                                wake_up_interruptible(wait->wq);
+                        if (wait->wq)
                                 rc = 0;
-                        } else {
+                        else
+                                rc = -1;
+
+                        spin_unlock_irqrestore(&wait->lock, flags);
+
+                        if (rc) {
                                 struct device *dev;
 
                                 dev = &c->pdev->dev;
@@ -248,15 +253,13 @@ static int i2o_msg_post_wait_complete(struct i2o_controller *c, u32 m,
                                          c->name);
                                 i2o_dma_free(dev, &wait->dma);
                                 i2o_exec_wait_free(wait);
-                                rc = -1;
-                        }
+                        } else
+                                wake_up_interruptible(wait->wq);
 
                         return rc;
                 }
         }
 
-        spin_unlock_irqrestore(&lock, flags);
-
         osm_warn("%s: Bogus reply in POST WAIT (tr-context: %08x)!\n", c->name,
                  context);
 
@@ -322,14 +325,9 @@ static DEVICE_ATTR(product_id, S_IRUGO, i2o_exec_show_product_id, NULL);
 static int i2o_exec_probe(struct device *dev)
 {
         struct i2o_device *i2o_dev = to_i2o_device(dev);
-        struct i2o_controller *c = i2o_dev->iop;
 
         i2o_event_register(i2o_dev, &i2o_exec_driver, 0, 0xffffffff);
 
-        c->exec = i2o_dev;
-
-        i2o_exec_lct_notify(c, c->lct->change_ind + 1);
-
         device_create_file(dev, &dev_attr_vendor_id);
         device_create_file(dev, &dev_attr_product_id);
 
@@ -523,6 +521,8 @@ static int i2o_exec_lct_notify(struct i2o_controller *c, u32 change_ind)
         struct device *dev;
         struct i2o_message *msg;
 
+        down(&c->lct_lock);
+
         dev = &c->pdev->dev;
 
         if (i2o_dma_realloc
@@ -545,6 +545,8 @@ static int i2o_exec_lct_notify(struct i2o_controller *c, u32 change_ind)
 
         i2o_msg_post(c, msg);
 
+        up(&c->lct_lock);
+
         return 0;
 };
 
diff --git a/drivers/message/i2o/iop.c b/drivers/message/i2o/iop.c
index 492167446936..febbdd4e0605 100644
--- a/drivers/message/i2o/iop.c
+++ b/drivers/message/i2o/iop.c
@@ -804,8 +804,6 @@ void i2o_iop_remove(struct i2o_controller *c)
 
         /* Ask the IOP to switch to RESET state */
         i2o_iop_reset(c);
-
-        put_device(&c->device);
 }
 
 /**
@@ -1059,7 +1057,7 @@ struct i2o_controller *i2o_iop_alloc(void)
 
         snprintf(poolname, sizeof(poolname), "i2o_%s_msg_inpool", c->name);
         if (i2o_pool_alloc
-            (&c->in_msg, poolname, I2O_INBOUND_MSG_FRAME_SIZE * 4,
+            (&c->in_msg, poolname, I2O_INBOUND_MSG_FRAME_SIZE * 4 + sizeof(u32),
              I2O_MSG_INPOOL_MIN)) {
                 kfree(c);
                 return ERR_PTR(-ENOMEM);
diff --git a/include/linux/i2o.h b/include/linux/i2o.h
index dd7d627bf66f..c115e9e840b4 100644
--- a/include/linux/i2o.h
+++ b/include/linux/i2o.h
@@ -1114,8 +1114,11 @@ static inline struct i2o_message *i2o_msg_get(struct i2o_controller *c)
 
         mmsg->mfa = readl(c->in_port);
         if (unlikely(mmsg->mfa >= c->in_queue.len)) {
+                u32 mfa = mmsg->mfa;
+
                 mempool_free(mmsg, c->in_msg.mempool);
-                if(mmsg->mfa == I2O_QUEUE_EMPTY)
+
+                if (mfa == I2O_QUEUE_EMPTY)
                         return ERR_PTR(-EBUSY);
                 return ERR_PTR(-EFAULT);
         }