Pass full strings to DTrace probes

Whenever string is passed as an argument to a DTrace probe, its length
should be properly computed. Until now in order to get length of the
input buffer size_of(char *) was used - which evalutes to 4 or 8
(depending on the architecture). To get a proper length,
size_of(DTRACE_CHARBUF_NAME(buffer_name)) should be used.

1 files changed, 4 insertions, 2 deletions

diff --git a/erts/emulator/beam/erl_async.c b/erts/emulator/beam/erl_async.c
index e6d72f569b..aaeab0d56c 100644
--- a/erts/emulator/beam/erl_async.c
+++ b/erts/emulator/beam/erl_async.c
@@ -279,7 +279,8 @@ static ERTS_INLINE void async_add(ErtsAsync *a, ErtsAsyncQ* q)
     if (DTRACE_ENABLED(aio_pool_add)) {
         DTRACE_CHARBUF(port_str, 16);
 
-        erts_snprintf(port_str, sizeof(port_str), "%T", a->port);
+        erts_snprintf(port_str, sizeof(DTRACE_CHARBUF_NAME(port_str)),
+                      "%T", a->port);
         /* DTRACE TODO: Get the queue length from erts_thr_q_enqueue() ? */
         len = -1;
         DTRACE2(aio_pool_add, port_str, len);
@@ -314,7 +315,8 @@ static ERTS_INLINE ErtsAsync *async_get(ErtsThrQ_t *q,
             if (DTRACE_ENABLED(aio_pool_get)) {
                 DTRACE_CHARBUF(port_str, 16);
 
-                erts_snprintf(port_str, sizeof(port_str), "%T", a->port);
+                erts_snprintf(port_str, sizeof(DTRACE_CHARBUF_NAME(port_str)),
+                              "%T", a->port);
                 /* DTRACE TODO: Get the length from erts_thr_q_dequeue() ? */
                 len = -1;
                 DTRACE2(aio_pool_get, port_str, len);