tracepoint: validate provider/event name length with static assert

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

diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h
index b47b1e0e1c00ab5eb5d1a79356762b8852b35874..f85db068d378383d941dbc8271ed555a71d1a9b9 100644 (file)
--- a/include/lttng/tracepoint.h
+++ b/include/lttng/tracepoint.h
@@ -20,6 +20,8 @@
 #include <lttng/ust-compiler.h>
 #include <lttng/ust-tracer.h>
 
+#define LTTNG_UST_TRACEPOINT_NAME_LEN_MAX      256
+
 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
 /*
  * Instead of using SDT_USE_VARIADIC from 'sys/sdt.h', use our own namespaced
@@ -154,6 +156,25 @@ extern "C" {
 #define _TP_ARGS_DATA_VAR(...)         _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 #define _TP_PARAMS(...)                        __VA_ARGS__
 
+/*
+ * sizeof(#_provider) - 1 : length of the provider string (excluding \0).
+ * sizeof(#_name) - 1     : length of the name string (excluding \0).
+ * + 1                    : separator between provider and event name.
+ *
+ * Upper bound (inclusive) is LTTNG_UST_TRACEPOINT_NAME_LEN_MAX - 1 to
+ * account for \0.
+ *
+ * The comparison is:
+ *   left hand side:   sizeof(#_provider) - 1 + sizeof(#_name) - 1 + 1
+ *   right hand side:  LTTNG_UST_TRACEPOINT_NAME_LEN_MAX - 1
+ *   operator:         <=  (inclusive)
+ * Simplified in the code below.
+ */
+#define lttng_ust_tracepoint_validate_name_len(_provider, _name)                                               \
+       lttng_ust_static_assert(sizeof(#_provider) + sizeof(#_name) <= LTTNG_UST_TRACEPOINT_NAME_LEN_MAX,       \
+               "Tracepoint name length is too long",                                                           \
+               Tracepoint_name_length_is_too_long)
+
 /*
  * The tracepoint cb is marked always inline so we can distinguish
  * between caller's ip addresses within the probe using the return
@@ -446,6 +467,7 @@ extern struct lttng_ust_tracepoint * const __stop___tracepoints_ptrs[]
 #define _TP_EXTRACT_STRING(...)        #__VA_ARGS__
 
 #define _DEFINE_TRACEPOINT(_provider, _name, _args)                            \
+       lttng_ust_tracepoint_validate_name_len(_provider, _name);               \
        extern int __tracepoint_provider_##_provider;                           \
        static const char __tp_strtab_##_provider##___##_name[]                 \
                __attribute__((section("__tracepoints_strings"))) =             \