rx: Statically check rx_statisticsAtomic size

Currently, rx_GetStatistics assumes that struct rx_statistics and
rx_statisticsAtomic have the same size (we just memcpy between them).
However, this is never checked, and rx_statistics contains many 'int'
fields where rx_statisticsAtomic has rx_atomic_t fields.

If these are not the same size, our rx stats will silently break, so
add a static assert to make sure they are the same size.

Change-Id: I889867f4a85530c30dd15d32d1822144ea128a95
Reviewed-on: https://gerrit.openafs.org/13414
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>

diff --git a/src/rx/rx_stats.c b/src/rx/rx_stats.c
index 2693137..2daa548 100644 (file)
--- a/src/rx/rx_stats.c
+++ b/src/rx/rx_stats.c
@@ -33,8 +33,8 @@
 
 #if !defined(KERNEL)
 #include <roken.h>
-#include <afs/opr.h>
 #endif
+#include <afs/opr.h>
 
 #ifdef KERNEL
 /* no kmutex, no atomic emulation...*/
@@ -67,7 +67,9 @@ struct rx_statisticsAtomic rx_stats;
 struct rx_statistics *
 rx_GetStatistics(void) {
     struct rx_statistics *stats = rxi_Alloc(sizeof(struct rx_statistics));
+
     MUTEX_ENTER(&rx_stats_mutex);
+    opr_StaticAssert(sizeof(*stats) == sizeof(rx_stats));
     memcpy(stats, &rx_stats, sizeof(struct rx_statistics));
     MUTEX_EXIT(&rx_stats_mutex);