Fix: noargs probes should calculate alignment and event length

[lttng-modules.git] / probes / lttng-events.h

diff --git a/probes/lttng-events.h b/probes/lttng-events.h
index 96062042d038ab4303fd9f2b71fce4401ea33e42..ba9563b15cf94ac093511f7de1eb90f5624f75b8 100644 (file)
--- a/probes/lttng-events.h
+++ b/probes/lttng-events.h
@@ -186,6 +186,10 @@ void trace_##_name(void *__data);
 #define __field_hex(_type, _item)                              \
        __field_full(_type, _item, __BYTE_ORDER, 16)
 
+#undef __field_oct
+#define __field_oct(_type, _item)                              \
+       __field_full(_type, _item, __BYTE_ORDER, 8)
+
 #undef __field_network
 #define __field_network(_type, _item)                          \
        __field_full(_type, _item, __BIG_ENDIAN, 10)
@@ -327,6 +331,7 @@ static void __event_probe__##_name(void *__data);
 static const struct lttng_event_desc __event_desc___##_map = {         \
        .fields = __event_fields___##_template,                         \
        .name = #_map,                                                  \
+       .kname = #_name,                                                \
        .probe_callback = (void *) TP_PROBE_CB(_template),              \
        .nr_fields = ARRAY_SIZE(__event_fields___##_template),          \
        .owner = THIS_MODULE,                                           \
@@ -451,10 +456,19 @@ static __used struct lttng_probe_desc TP_ID(__probe_desc___, TRACE_SYSTEM) = {
 static inline size_t __event_get_size__##_name(size_t *__dynamic_len, _proto) \
 {                                                                            \
        size_t __event_len = 0;                                               \
-       unsigned int __dynamic_len_idx = 0;                                   \
+       unsigned int __dynamic_len_idx __attribute__((unused)) = 0;           \
+                                                                             \
+       _tstruct                                                              \
+       return __event_len;                                                   \
+}
+
+#undef DECLARE_EVENT_CLASS_NOARGS
+#define DECLARE_EVENT_CLASS_NOARGS(_name, _tstruct, _assign, _print)         \
+static inline size_t __event_get_size__##_name(size_t *__dynamic_len)        \
+{                                                                            \
+       size_t __event_len = 0;                                               \
+       unsigned int __dynamic_len_idx __attribute__((unused)) = 0;           \
                                                                              \
-       if (0)                                                                \
-               (void) __dynamic_len_idx;       /* don't warn if unused */    \
        _tstruct                                                              \
        return __event_len;                                                   \
 }
@@ -509,6 +523,15 @@ static inline size_t __event_get_align__##_name(_proto)                          \
        return __event_align;                                                 \
 }
 
+#undef DECLARE_EVENT_CLASS_NOARGS
+#define DECLARE_EVENT_CLASS_NOARGS(_name, _tstruct, _assign, _print)         \
+static inline size_t __event_get_align__##_name(void)                        \
+{                                                                            \
+       size_t __event_align = 1;                                             \
+       _tstruct                                                              \
+       return __event_align;                                                 \
+}
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 
@@ -548,12 +571,16 @@ static inline size_t __event_get_align__##_name(_proto)                         \
 #undef TP_STRUCT__entry
 #define TP_STRUCT__entry(args...) args
 
-#undef DECLARE_EVENT_CLASS
-#define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print)  \
+#undef DECLARE_EVENT_CLASS_NOARGS
+#define DECLARE_EVENT_CLASS_NOARGS(_name, _tstruct, _assign, _print)         \
 struct __event_typemap__##_name {                                            \
        _tstruct                                                              \
 };
 
+#undef DECLARE_EVENT_CLASS
+#define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print)  \
+       DECLARE_EVENT_CLASS_NOARGS(_name, _tstruct, _assign, _print)
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 
@@ -690,24 +717,22 @@ __assign_##dest##_3:                                                      \
  */
 #undef tp_copy_string_from_user
 #define tp_copy_string_from_user(dest, src)                            \
-       __assign_##dest:                                                \
-       {                                                               \
-               size_t __ustrlen;                                       \
-                                                                       \
-               if (0)                                                  \
-                       (void) __typemap.dest;                          \
-               lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(__typemap.dest));\
-               __ustrlen = __get_dynamic_array_len(dest);              \
-               if (likely(__ustrlen > 1)) {                            \
-                       __chan->ops->event_write_from_user(&__ctx, src, \
-                               __ustrlen - 1);                         \
-               }                                                       \
-               __chan->ops->event_memset(&__ctx, 0, 1);                \
-       }                                                               \
+__assign_##dest:                                                       \
+       if (0)                                                          \
+               (void) __typemap.dest;                                  \
+       lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(__typemap.dest)); \
+       __chan->ops->event_strcpy_from_user(&__ctx, src,                \
+               __get_dynamic_array_len(dest));                         \
        goto __end_field_##dest;
+
 #undef tp_strcpy
 #define tp_strcpy(dest, src)                                           \
-       tp_memcpy(dest, src, __get_dynamic_array_len(dest))
+__assign_##dest:                                                       \
+       if (0)                                                          \
+               (void) __typemap.dest;                                  \
+       lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(__typemap.dest)); \
+       __chan->ops->event_strcpy(&__ctx, src, __get_dynamic_array_len(dest)); \
+       goto __end_field_##dest;
 
 /* Named field types must be defined in lttng-types.h */
 
@@ -744,6 +769,11 @@ __assign_##dest##_3:                                                       \
 #define _TP_SESSION_CHECK(session, csession)   1
 #endif /* TP_SESSION_CHECK */
 
+/*
+ * __dynamic_len array length is twice the number of fields due to
+ * __dynamic_array_enc_ext_2() and tp_memcpy_dyn_2(), which are the
+ * worse case, needing 2 entries per field.
+ */
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print)  \
 static void __event_probe__##_name(void *__data, _proto)                     \
@@ -752,15 +782,11 @@ static void __event_probe__##_name(void *__data, _proto)                \
        struct lttng_channel *__chan = __event->chan;                         \
        struct lib_ring_buffer_ctx __ctx;                                     \
        size_t __event_len, __event_align;                                    \
-       size_t __dynamic_len_idx = 0;                                         \
-       size_t __dynamic_len[ARRAY_SIZE(__event_fields___##_name)];           \
-       struct __event_typemap__##_name __typemap;                            \
+       size_t __dynamic_len_idx __attribute__((unused)) = 0;                 \
+       size_t __dynamic_len[2 * ARRAY_SIZE(__event_fields___##_name)] __attribute__((unused)); \
+       struct __event_typemap__##_name __typemap __attribute__((unused));    \
        int __ret;                                                            \
                                                                              \
-       if (0) {                                                              \
-               (void) __dynamic_len_idx;       /* don't warn if unused */    \
-               (void) __typemap;               /* don't warn if unused */    \
-       }                                                                     \
        if (!_TP_SESSION_CHECK(session, __chan->session))                     \
                return;                                                       \
        if (unlikely(!ACCESS_ONCE(__chan->session->active)))                  \
@@ -792,6 +818,9 @@ static void __event_probe__##_name(void *__data)                          \
        struct lttng_channel *__chan = __event->chan;                         \
        struct lib_ring_buffer_ctx __ctx;                                     \
        size_t __event_len, __event_align;                                    \
+       size_t __dynamic_len_idx __attribute__((unused)) = 0;                 \
+       size_t __dynamic_len[2 * ARRAY_SIZE(__event_fields___##_name)] __attribute__((unused)); \
+       struct __event_typemap__##_name __typemap __attribute__((unused));    \
        int __ret;                                                            \
                                                                              \
        if (!_TP_SESSION_CHECK(session, __chan->session))                     \
@@ -802,8 +831,8 @@ static void __event_probe__##_name(void *__data)                          \
                return;                                                       \
        if (unlikely(!ACCESS_ONCE(__event->enabled)))                         \
                return;                                                       \
-       __event_len = 0;                                                      \
-       __event_align = 1;                                                    \
+       __event_len = __event_get_size__##_name(__dynamic_len);               \
+       __event_align = __event_get_align__##_name();                         \
        lib_ring_buffer_ctx_init(&__ctx, __chan->chan, __event, __event_len,  \
                                 __event_align, -1);                          \
        __ret = __chan->ops->event_reserve(&__ctx, __event->id);              \