Output "(null)" when ctf_string()'s arg is NULL

[lttng-ust.git] / include / lttng / ust-tracepoint-event.h

diff --git a/include/lttng/ust-tracepoint-event.h b/include/lttng/ust-tracepoint-event.h
index aa8b50f86e5a44aa055a72f3e89e46772efe8c10..26ca1d57c53220196ce3ecf1e74593a139a7a626 100644 (file)
--- a/include/lttng/ust-tracepoint-event.h
+++ b/include/lttng/ust-tracepoint-event.h
@@ -30,6 +30,8 @@
 #include <lttng/tracepoint.h>
 #include <string.h>
 
+#define __LTTNG_UST_NULL_STRING        "(null)"
+
 #undef tp_list_for_each_entry_rcu
 #define tp_list_for_each_entry_rcu(pos, head, member)  \
        for (pos = cds_list_entry(tp_rcu_dereference_bp((head)->next), __typeof__(*pos), member);       \
@@ -328,7 +330,8 @@ static void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args));
 
 #undef _ctf_string
 #define _ctf_string(_item, _src, _nowrite)                                    \
-       __event_len += __dynamic_len[__dynamic_len_idx++] = strlen(_src) + 1;
+       __event_len += __dynamic_len[__dynamic_len_idx++] =                    \
+               strlen((_src) ? (_src) : __LTTNG_UST_NULL_STRING) + 1;
 
 #undef _ctf_enum
 #define _ctf_enum(_provider, _name, _type, _item, _src, _nowrite)              \
@@ -471,7 +474,8 @@ size_t __event_get_size__##_provider##___##_name(size_t *__dynamic_len, _TP_ARGS
 #undef _ctf_string
 #define _ctf_string(_item, _src, _nowrite)                                    \
        {                                                                      \
-               const void *__ctf_tmp_ptr = (_src);                            \
+               const void *__ctf_tmp_ptr =                                    \
+                       ((_src) ? (_src) : __LTTNG_UST_NULL_STRING);           \
                memcpy(__stack_data, &__ctf_tmp_ptr, sizeof(void *));          \
                __stack_data += sizeof(void *);                                \
        }
@@ -608,13 +612,19 @@ size_t __event_get_align__##_provider##___##_name(_TP_ARGS_PROTO(_args))      \
 
 #undef _ctf_string
 #define _ctf_string(_item, _src, _nowrite)                             \
-       lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(*(_src)));      \
-       if (__chan->ops->u.has_strcpy)                                  \
-               __chan->ops->event_strcpy(&__ctx, _src,                 \
-                       __get_dynamic_len(dest));                       \
-       else                                                            \
-               __chan->ops->event_write(&__ctx, _src,                  \
-                       __get_dynamic_len(dest));
+       {                                                                       \
+               const char *__ctf_tmp_string =                                  \
+                       ((_src) ? (_src) : __LTTNG_UST_NULL_STRING);            \
+               lib_ring_buffer_align_ctx(&__ctx,                               \
+                       lttng_alignof(*__ctf_tmp_string));                      \
+               if (__chan->ops->u.has_strcpy)                                  \
+                       __chan->ops->event_strcpy(&__ctx, __ctf_tmp_string,     \
+                               __get_dynamic_len(dest));                       \
+               else                                                            \
+                       __chan->ops->event_write(&__ctx, __ctf_tmp_string,      \
+                               __get_dynamic_len(dest));                       \
+       }
+
 
 #undef _ctf_enum
 #define _ctf_enum(_provider, _name, _type, _item, _src, _nowrite)      \
@@ -642,11 +652,23 @@ size_t __event_get_align__##_provider##___##_name(_TP_ARGS_PROTO(_args))      \
 #define _TP_SESSION_CHECK(session, csession)   1
 #endif /* TP_SESSION_CHECK */
 
+/*
+ * Use of __builtin_return_address(0) sometimes seems to cause stack
+ * corruption on 32-bit PowerPC. Disable this feature on that
+ * architecture for now by always using the NULL value for the ip
+ * context.
+ */
 #undef _TP_IP_PARAM
 #ifdef TP_IP_PARAM
 #define _TP_IP_PARAM(x)                (x)
 #else /* TP_IP_PARAM */
+
+#if defined(__PPC__) && !defined(__PPC64__)
+#define _TP_IP_PARAM(x)                NULL
+#else /* #if defined(__PPC__) && !defined(__PPC64__) */
 #define _TP_IP_PARAM(x)                __builtin_return_address(0)
+#endif /* #else #if defined(__PPC__) && !defined(__PPC64__) */
+
 #endif /* TP_IP_PARAM */
 
 /*
@@ -663,9 +685,10 @@ void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args));      \
 static                                                                       \
 void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args))              \
 {                                                                            \
-       struct lttng_event *__event = (struct lttng_event *) __tp_data;                       \
+       struct lttng_event *__event = (struct lttng_event *) __tp_data;       \
        struct lttng_channel *__chan = __event->chan;                         \
        struct lttng_ust_lib_ring_buffer_ctx __ctx;                           \
+       struct lttng_stack_ctx __lttng_ctx;                                   \
        size_t __event_len, __event_align;                                    \
        size_t __dynamic_len_idx = 0;                                         \
        union {                                                               \
@@ -703,8 +726,12 @@ void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args))          \
        __event_len = __event_get_size__##_provider##___##_name(__stackvar.__dynamic_len, \
                 _TP_ARGS_DATA_VAR(_args));                                   \
        __event_align = __event_get_align__##_provider##___##_name(_TP_ARGS_VAR(_args)); \
+       memset(&__lttng_ctx, 0, sizeof(__lttng_ctx));                         \
+       __lttng_ctx.event = __event;                                          \
+       __lttng_ctx.chan_ctx = tp_rcu_dereference_bp(__chan->ctx);            \
+       __lttng_ctx.event_ctx = tp_rcu_dereference_bp(__event->ctx);          \
        lib_ring_buffer_ctx_init(&__ctx, __chan->chan, __event, __event_len,  \
-                                __event_align, -1, __chan->handle);          \
+                                __event_align, -1, __chan->handle, &__lttng_ctx); \
        __ctx.ip = _TP_IP_PARAM(TP_IP_PARAM);                                 \
        __ret = __chan->ops->event_reserve(&__ctx, __event->id);              \
        if (__ret < 0)                                                        \