mptfusion: combine fw_event_work and its event_data

Tack the firmware reply event_data payload to the end of its
corresponding struct fw_event_work allocation.  Rework fw_event_work
allocation calculations to include the event_data size where
appropriate.

This clarifies the code a bit and avoids the following smatch warnings:

  drivers/message/fusion/mptsas.c:1003 mptsas_queue_device_delete()
    error: memcpy() 'fw_event->event_data' too small (29 vs 36)

  drivers/message/fusion/mptsas.c:1017 mptsas_queue_rescan() error: not
    allocating enough data 168 vs 160

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

2 files changed, 7 insertions, 11 deletions

diff --git a/drivers/message/fusion/mptsas.c b/drivers/message/fusion/mptsas.c
index a0d4218103db..b0b74c4d2645 100644
--- a/drivers/message/fusion/mptsas.c
+++ b/drivers/message/fusion/mptsas.c
@@ -990,11 +990,10 @@ mptsas_queue_device_delete(MPT_ADAPTER *ioc,
         MpiEventDataSasDeviceStatusChange_t *sas_event_data)
 {
         struct fw_event_work *fw_event;
-        int sz;
 
-        sz = offsetof(struct fw_event_work, event_data) +
-            sizeof(MpiEventDataSasDeviceStatusChange_t);
-        fw_event = kzalloc(sz, GFP_ATOMIC);
+        fw_event = kzalloc(sizeof(*fw_event) +
+                           sizeof(MpiEventDataSasDeviceStatusChange_t),
+                           GFP_ATOMIC);
         if (!fw_event) {
                 printk(MYIOC_s_WARN_FMT "%s: failed at (line=%d)\n",
                     ioc->name, __func__, __LINE__);
@@ -1011,10 +1010,8 @@ static void
 mptsas_queue_rescan(MPT_ADAPTER *ioc)
 {
         struct fw_event_work *fw_event;
-        int sz;
 
-        sz = offsetof(struct fw_event_work, event_data);
-        fw_event = kzalloc(sz, GFP_ATOMIC);
+        fw_event = kzalloc(sizeof(*fw_event), GFP_ATOMIC);
         if (!fw_event) {
                 printk(MYIOC_s_WARN_FMT "%s: failed at (line=%d)\n",
                     ioc->name, __func__, __LINE__);
@@ -4983,7 +4980,7 @@ static int
 mptsas_event_process(MPT_ADAPTER *ioc, EventNotificationReply_t *reply)
 {
         u32 event = le32_to_cpu(reply->Event);
-        int sz, event_data_sz;
+        int event_data_sz;
         struct fw_event_work *fw_event;
         unsigned long delay;
 
@@ -5093,8 +5090,7 @@ mptsas_event_process(MPT_ADAPTER *ioc, EventNotificationReply_t *reply)
 
         event_data_sz = ((reply->MsgLength * 4) -
             offsetof(EventNotificationReply_t, Data));
-        sz = offsetof(struct fw_event_work, event_data) + event_data_sz;
-        fw_event = kzalloc(sz, GFP_ATOMIC);
+        fw_event = kzalloc(sizeof(*fw_event) + event_data_sz, GFP_ATOMIC);
         if (!fw_event) {
                 printk(MYIOC_s_WARN_FMT "%s: failed at (line=%d)\n", ioc->name,
                  __func__, __LINE__);
diff --git a/drivers/message/fusion/mptsas.h b/drivers/message/fusion/mptsas.h
index 57e86ab77661..c396483d3624 100644
--- a/drivers/message/fusion/mptsas.h
+++ b/drivers/message/fusion/mptsas.h
@@ -110,7 +110,7 @@ struct fw_event_work {
         MPT_ADAPTER     *ioc;
         u32                     event;
         u8                      retries;
-        u8                      __attribute__((aligned(4))) event_data[1];
+        char                    event_data[0] __aligned(4);
 };
 
 struct mptsas_discovery_event {