sgi-xpc: fix up stale DBUG_ON statements

Clean up the stale DBUG_ON checks and add a couple new ones.

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 4 deletions

diff --git a/drivers/misc/sgi-xp/xpc_sn2.c b/drivers/misc/sgi-xp/xpc_sn2.c
index 7d05fb5f4fee..2e975762c32b 100644
--- a/drivers/misc/sgi-xp/xpc_sn2.c
+++ b/drivers/misc/sgi-xp/xpc_sn2.c
@@ -1106,8 +1106,6 @@ xpc_process_activate_IRQ_rcvd_sn2(void)
         int n_IRQs_expected;
         int n_IRQs_detected;
 
-        DBUG_ON(xpc_activate_IRQ_rcvd == 0);
-
         spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
         n_IRQs_expected = xpc_activate_IRQ_rcvd;
         xpc_activate_IRQ_rcvd = 0;
@@ -1726,6 +1724,7 @@ xpc_clear_local_msgqueue_flags_sn2(struct xpc_channel *ch)
                 msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
                                              (get % ch->local_nentries) *
                                              ch->entry_size);
+                DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
                 msg->flags = 0;
         } while (++get < ch_sn2->remote_GP.get);
 }
@@ -1740,11 +1739,18 @@ xpc_clear_remote_msgqueue_flags_sn2(struct xpc_channel *ch)
         struct xpc_msg_sn2 *msg;
         s64 put;
 
-        put = ch_sn2->w_remote_GP.put;
+        /* flags are zeroed when the buffer is allocated */
+        if (ch_sn2->remote_GP.put < ch->remote_nentries)
+                return;
+
+        put = max(ch_sn2->w_remote_GP.put, ch->remote_nentries);
         do {
                 msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
                                              (put % ch->remote_nentries) *
                                              ch->entry_size);
+                DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
+                DBUG_ON(!(msg->flags & XPC_M_SN2_DONE));
+                DBUG_ON(msg->number != put - ch->remote_nentries);
                 msg->flags = 0;
         } while (++put < ch_sn2->remote_GP.put);
 }
@@ -2280,8 +2286,9 @@ xpc_received_payload_sn2(struct xpc_channel *ch, void *payload)
         dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n",
                 (void *)msg, msg_number, ch->partid, ch->number);
 
-        DBUG_ON((((u64)msg - (u64)ch->remote_msgqueue) / ch->entry_size) !=
+        DBUG_ON((((u64)msg - (u64)ch->sn.sn2.remote_msgqueue) / ch->entry_size) !=
                 msg_number % ch->remote_nentries);
+        DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
         DBUG_ON(msg->flags & XPC_M_SN2_DONE);
 
         msg->flags |= XPC_M_SN2_DONE;