Fix: liblttng-ust-fork Makefile flags mismatch

[lttng-ust.git] / liblttng-ust / tracepoint.c

diff --git a/liblttng-ust/tracepoint.c b/liblttng-ust/tracepoint.c
index 7144fab40003c586a726fff5a6b4544f14d4c36c..d7293dab31697d94164f785b0aace9f9824da898 100644 (file)
--- a/liblttng-ust/tracepoint.c
+++ b/liblttng-ust/tracepoint.c
@@ -23,6 +23,7 @@
 #include <errno.h>
 #include <stdint.h>
 #include <stddef.h>
+#include <stdio.h>
 
 #include <urcu/arch.h>
 #include <urcu-bp.h>
@@ -37,7 +38,7 @@
 #include <helper.h>
 
 #include "tracepoint-internal.h"
-#include "ltt-tracer-core.h"
+#include "lttng-tracer-core.h"
 #include "jhash.h"
 #include "error.h"
 
@@ -77,7 +78,7 @@ static CDS_LIST_HEAD(libs);
  * Tracepoint hash table, containing the active tracepoints.
  * Protected by tracepoint mutex.
  */
-#define TRACEPOINT_HASH_BITS 6
+#define TRACEPOINT_HASH_BITS 12
 #define TRACEPOINT_TABLE_SIZE (1 << TRACEPOINT_HASH_BITS)
 static struct cds_hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE];
 
@@ -94,6 +95,7 @@ struct tracepoint_entry {
        struct cds_hlist_node hlist;
        struct tracepoint_probe *probes;
        int refcount;   /* Number of times armed. 0 if disarmed. */
+       const char *signature;
        char name[0];
 };
 
@@ -136,13 +138,15 @@ static void debug_print_probes(struct tracepoint_entry *entry)
 
 static void *
 tracepoint_entry_add_probe(struct tracepoint_entry *entry,
-                          void *probe, void *data)
+                          void (*probe)(void), void *data)
 {
        int nr_probes = 0;
        struct tracepoint_probe *old, *new;
 
-       WARN_ON(!probe);
-
+       if (!probe) {
+               WARN_ON(1);
+               return ERR_PTR(-EINVAL);
+       }
        debug_print_probes(entry);
        old = entry->probes;
        if (old) {
@@ -168,8 +172,8 @@ tracepoint_entry_add_probe(struct tracepoint_entry *entry,
 }
 
 static void *
-tracepoint_entry_remove_probe(struct tracepoint_entry *entry, void *probe,
-                             void *data)
+tracepoint_entry_remove_probe(struct tracepoint_entry *entry,
+                             void (*probe)(void), void *data)
 {
        int nr_probes = 0, nr_del = 0, i;
        struct tracepoint_probe *old, *new;
@@ -243,7 +247,8 @@ static struct tracepoint_entry *get_tracepoint(const char *name)
  * Add the tracepoint to the tracepoint hash table. Must be called with
  * tracepoint mutex held.
  */
-static struct tracepoint_entry *add_tracepoint(const char *name)
+static struct tracepoint_entry *add_tracepoint(const char *name,
+               const char *signature)
 {
        struct cds_hlist_head *head;
        struct cds_hlist_node *node;
@@ -274,6 +279,7 @@ static struct tracepoint_entry *add_tracepoint(const char *name)
        e->name[name_len] = '\0';
        e->probes = NULL;
        e->refcount = 0;
+       e->signature = signature;
        cds_hlist_add_head(&e->hlist, head);
        return e;
 }
@@ -295,6 +301,23 @@ static void set_tracepoint(struct tracepoint_entry **entry,
        struct tracepoint *elem, int active)
 {
        WARN_ON(strncmp((*entry)->name, elem->name, LTTNG_UST_SYM_NAME_LEN - 1) != 0);
+       /*
+        * Check that signatures match before connecting a probe to a
+        * tracepoint. Warn the user if they don't.
+        */
+       if (strcmp(elem->signature, (*entry)->signature) != 0) {
+               static int warned = 0;
+
+               /* Only print once, don't flood console. */
+               if (!warned) {
+                       WARN("Tracepoint signature mismatch, not enabling one or more tracepoints. Ensure that the tracepoint probes prototypes match the application.");
+                       WARN("Tracepoint \"%s\" signatures: call: \"%s\" vs probe: \"%s\".",
+                               elem->name, elem->signature, (*entry)->signature);
+                       warned = 1;
+               }
+               /* Don't accept connecting non-matching signatures. */
+               return;
+       }
 
        /*
         * rcu_assign_pointer has a cmm_smp_wmb() which makes sure that the new
@@ -370,14 +393,15 @@ static void tracepoint_update_probes(void)
 }
 
 static struct tracepoint_probe *
-tracepoint_add_probe(const char *name, void *probe, void *data)
+tracepoint_add_probe(const char *name, void (*probe)(void), void *data,
+               const char *signature)
 {
        struct tracepoint_entry *entry;
        struct tracepoint_probe *old;
 
        entry = get_tracepoint(name);
        if (!entry) {
-               entry = add_tracepoint(name);
+               entry = add_tracepoint(name, signature);
                if (IS_ERR(entry))
                        return (struct tracepoint_probe *)entry;
        }
@@ -396,7 +420,8 @@ tracepoint_add_probe(const char *name, void *probe, void *data)
  * The probe address must at least be aligned on the architecture pointer size.
  * Called with the tracepoint mutex held.
  */
-int __tracepoint_probe_register(const char *name, void *probe, void *data)
+int __tracepoint_probe_register(const char *name, void (*probe)(void),
+               void *data, const char *signature)
 {
        void *old;
        int ret = 0;
@@ -404,7 +429,7 @@ int __tracepoint_probe_register(const char *name, void *probe, void *data)
        DBG("Registering probe to tracepoint %s", name);
 
        pthread_mutex_lock(&tracepoint_mutex);
-       old = tracepoint_add_probe(name, probe, data);
+       old = tracepoint_add_probe(name, probe, data, signature);
        if (IS_ERR(old)) {
                ret = PTR_ERR(old);
                goto end;
@@ -417,7 +442,8 @@ end:
        return ret;
 }
 
-static void *tracepoint_remove_probe(const char *name, void *probe, void *data)
+static void *tracepoint_remove_probe(const char *name, void (*probe)(void),
+               void *data)
 {
        struct tracepoint_entry *entry;
        void *old;
@@ -439,7 +465,8 @@ static void *tracepoint_remove_probe(const char *name, void *probe, void *data)
  * @probe: probe function pointer
  * @probe: probe data pointer
  */
-int __tracepoint_probe_unregister(const char *name, void *probe, void *data)
+int __tracepoint_probe_unregister(const char *name, void (*probe)(void),
+               void *data)
 {
        void *old;
        int ret = 0;
@@ -476,14 +503,14 @@ static void tracepoint_add_old_probes(void *old)
  *
  * caller must call tracepoint_probe_update_all()
  */
-int tracepoint_probe_register_noupdate(const char *name, void *probe,
-                                      void *data)
+int tracepoint_probe_register_noupdate(const char *name, void (*probe)(void),
+                                      void *data, const char *signature)
 {
        void *old;
        int ret = 0;
 
        pthread_mutex_lock(&tracepoint_mutex);
-       old = tracepoint_add_probe(name, probe, data);
+       old = tracepoint_add_probe(name, probe, data, signature);
        if (IS_ERR(old)) {
                ret = PTR_ERR(old);
                goto end;
@@ -502,7 +529,7 @@ end:
  * caller must call tracepoint_probe_update_all()
  * Called with the tracepoint mutex held.
  */
-int tracepoint_probe_unregister_noupdate(const char *name, void *probe,
+int tracepoint_probe_unregister_noupdate(const char *name, void (*probe)(void),
                                         void *data)
 {
        void *old;