Print compiler warning/runtime warning and truncate too long tracepoint names

- also apply to loglevel names.
- -Wsystem-headers needs to be used to get gcc to show the
  warnings from system headers (which is the category in which the
  tracepoint event declaration headers falls into).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/liblttng-ust/ltt-events.c b/liblttng-ust/ltt-events.c
index 9650e8b0703d608492d61ac273e1ef6f1768296b..f69eb07a8181ebb395afbc28d877c62291d0217c 100644 (file)
--- a/liblttng-ust/ltt-events.c
+++ b/liblttng-ust/ltt-events.c
@@ -94,14 +94,20 @@ int add_pending_probe(struct ltt_event *event, const char *name)
 {
        struct cds_hlist_head *head;
        struct ust_pending_probe *e;
-       size_t name_len = strlen(name) + 1;
-       uint32_t hash = jhash(name, name_len - 1, 0);
+       size_t name_len = strlen(name);
+       uint32_t hash;
 
+       if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) {
+               WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1);
+               name_len = LTTNG_UST_SYM_NAME_LEN - 1;
+       }
+       hash = jhash(name, name_len, 0);
        head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)];
        e = zmalloc(sizeof(struct ust_pending_probe) + name_len);
        if (!e)
                return -ENOMEM;
-       memcpy(&e->name[0], name, name_len);
+       memcpy(&e->name[0], name, name_len + 1);
+       e->name[name_len] = '\0';
        cds_hlist_add_head(&e->node, head);
        e->event = event;
        event->pending_probe = e;
@@ -133,10 +139,10 @@ int pending_probe_fix_events(const struct lttng_event_desc *desc)
        struct cds_hlist_node *node, *p;
        struct ust_pending_probe *e;
        const char *name = desc->name;
-       size_t name_len = strlen(name) + 1;
-       uint32_t hash = jhash(name, name_len - 1, 0);
        int ret = 0;
        struct lttng_ust_event event_param;
+       size_t name_len = strlen(name);
+       uint32_t hash;
 
        /*
         * For this event, we need to lookup the loglevel. If active (in
@@ -209,12 +215,17 @@ int pending_probe_fix_events(const struct lttng_event_desc *desc)
                }
        }
 
+       if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) {
+               WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1);
+               name_len = LTTNG_UST_SYM_NAME_LEN - 1;
+       }
+       hash = jhash(name, name_len, 0);
        head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)];
        cds_hlist_for_each_entry_safe(e, node, p, head, node) {
                struct ltt_event *event;
                struct ltt_channel *chan;
 
-               if (strcmp(name, e->name))
+               if (strncmp(name, e->name, LTTNG_UST_SYM_NAME_LEN - 1))
                        continue;
                event = e->event;
                chan = event->chan;
@@ -490,7 +501,9 @@ int ltt_event_create(struct ltt_channel *chan,
         * creation). Might require a hash if we have lots of events.
         */
        cds_list_for_each_entry(event, &chan->session->events, list) {
-               if (event->desc && !strcmp(event->desc->name, event_param->name)) {
+               if (event->desc && !strncmp(event->desc->name,
+                               event_param->name,
+                               LTTNG_UST_SYM_NAME_LEN - 1)) {
                        ret = -EEXIST;
                        goto exist;
                }

diff --git a/liblttng-ust/ltt-probes.c b/liblttng-ust/ltt-probes.c
index 216ed17cc2cc5d03bb24583ab4371004c02d7090..9dc2356088e8b7a69bcb36f1180384266bae654f 100644 (file)
--- a/liblttng-ust/ltt-probes.c
+++ b/liblttng-ust/ltt-probes.c
@@ -60,7 +60,8 @@ const struct lttng_event_desc *find_event(const char *name)
 
        cds_list_for_each_entry(probe_desc, &probe_list, head) {
                for (i = 0; i < probe_desc->nr_events; i++) {
-                       if (!strcmp(probe_desc->event_desc[i]->name, name))
+                       if (!strncmp(probe_desc->event_desc[i]->name, name,
+                                       LTTNG_UST_SYM_NAME_LEN - 1))
                                return probe_desc->event_desc[i];
                }
        }
@@ -227,11 +228,17 @@ struct loglevel_entry *get_loglevel(const char *name)
        struct cds_hlist_head *head;
        struct cds_hlist_node *node;
        struct loglevel_entry *e;
-       uint32_t hash = jhash(name, strlen(name), 0);
+       size_t name_len = strlen(name);
+       uint32_t hash;
 
+       if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) {
+               WARN("Truncating loglevel name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1);
+               name_len = LTTNG_UST_SYM_NAME_LEN - 1;
+       }
+       hash = jhash(name, name_len, 0);
        head = &loglevel_table[hash & (LOGLEVEL_TABLE_SIZE - 1)];
        cds_hlist_for_each_entry(e, node, head, hlist) {
-               if (!strcmp(name, e->name))
+               if (!strncmp(name, e->name, LTTNG_UST_SYM_NAME_LEN - 1))
                        return e;
        }
        return NULL;
@@ -274,7 +281,8 @@ void _probes_create_loglevel_events(struct loglevel_entry *entry,
                                if (atoll(entry->name) == ev_ll->value) {
                                        match = 1;
                                }
-                       } else if (!strcmp(ev_ll->identifier, entry->name)) {
+                       } else if (!strncmp(ev_ll->identifier, entry->name,
+                                       LTTNG_UST_SYM_NAME_LEN - 1)) {
                                match = 1;
                        }
 
@@ -314,14 +322,19 @@ struct session_loglevel *add_loglevel(const char *name,
        struct cds_hlist_node *node;
        struct loglevel_entry *e;
        struct session_loglevel *sl;
-       size_t name_len = strlen(name) + 1;
-       uint32_t hash = jhash(name, name_len-1, 0);
        int found = 0;
+       size_t name_len = strlen(name);
+       uint32_t hash;
 
+       if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) {
+               WARN("Truncating loglevel name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1);
+               name_len = LTTNG_UST_SYM_NAME_LEN - 1;
+       }
+       hash = jhash(name, name_len, 0);
        /* loglevel entry */
        head = &loglevel_table[hash & (LOGLEVEL_TABLE_SIZE - 1)];
        cds_hlist_for_each_entry(e, node, head, hlist) {
-               if (!strcmp(name, e->name)) {
+               if (!strncmp(name, e->name, LTTNG_UST_SYM_NAME_LEN - 1)) {
                        found = 1;
                        break;
                }
@@ -332,10 +345,11 @@ struct session_loglevel *add_loglevel(const char *name,
                 * Using zmalloc here to allocate a variable length element. Could
                 * cause some memory fragmentation if overused.
                 */
-               e = zmalloc(sizeof(struct loglevel_entry) + name_len);
+               e = zmalloc(sizeof(struct loglevel_entry) + name_len + 1);
                if (!e)
                        return ERR_PTR(-ENOMEM);
-               memcpy(&e->name[0], name, name_len);
+               memcpy(&e->name[0], name, name_len + 1);
+               e->name[name_len] = '\0';
                cds_hlist_add_head(&e->hlist, head);
                CDS_INIT_LIST_HEAD(&e->session_list);
        }
@@ -512,7 +526,7 @@ struct session_wildcard *add_wildcard(const char *name,
 
        /* wildcard entry */
        cds_list_for_each_entry(e, &wildcard_list, list) {
-               if (!strcmp(name, e->name)) {
+               if (!strncmp(name, e->name, LTTNG_UST_SYM_NAME_LEN - 1)) {
                        found = 1;
                        break;
                }

diff --git a/liblttng-ust/tracepoint.c b/liblttng-ust/tracepoint.c
index 0393aa467a282b17139a05ae17fd8336e7271fb9..f146d382b7717955875938a1169d8436515ee043 100644 (file)
--- a/liblttng-ust/tracepoint.c
+++ b/liblttng-ust/tracepoint.c
@@ -31,6 +31,7 @@
 #include <urcu/compiler.h>
 
 #include <lttng/tracepoint.h>
+#include <lttng/ust-abi.h>     /* for LTTNG_UST_SYM_NAME_LEN */
 
 #include <usterr-signal-safe.h>
 #include <helper.h>
@@ -207,11 +208,17 @@ static struct tracepoint_entry *get_tracepoint(const char *name)
        struct cds_hlist_head *head;
        struct cds_hlist_node *node;
        struct tracepoint_entry *e;
-       uint32_t hash = jhash(name, strlen(name), 0);
+       size_t name_len = strlen(name);
+       uint32_t hash;
 
+       if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) {
+               WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1);
+               name_len = LTTNG_UST_SYM_NAME_LEN - 1;
+       }
+       hash = jhash(name, name_len, 0);
        head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)];
        cds_hlist_for_each_entry(e, node, head, hlist) {
-               if (!strcmp(name, e->name))
+               if (!strncmp(name, e->name, LTTNG_UST_SYM_NAME_LEN - 1))
                        return e;
        }
        return NULL;
@@ -226,12 +233,17 @@ static struct tracepoint_entry *add_tracepoint(const char *name)
        struct cds_hlist_head *head;
        struct cds_hlist_node *node;
        struct tracepoint_entry *e;
-       size_t name_len = strlen(name) + 1;
-       uint32_t hash = jhash(name, name_len-1, 0);
+       size_t name_len = strlen(name);
+       uint32_t hash;
 
+       if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) {
+               WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1);
+               name_len = LTTNG_UST_SYM_NAME_LEN - 1;
+       }
+       hash = jhash(name, name_len, 0);
        head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)];
        cds_hlist_for_each_entry(e, node, head, hlist) {
-               if (!strcmp(name, e->name)) {
+               if (!strncmp(name, e->name, LTTNG_UST_SYM_NAME_LEN - 1)) {
                        DBG("tracepoint %s busy", name);
                        return ERR_PTR(-EEXIST);        /* Already there */
                }
@@ -240,10 +252,11 @@ static struct tracepoint_entry *add_tracepoint(const char *name)
         * Using zmalloc here to allocate a variable length element. Could
         * cause some memory fragmentation if overused.
         */
-       e = zmalloc(sizeof(struct tracepoint_entry) + name_len);
+       e = zmalloc(sizeof(struct tracepoint_entry) + name_len + 1);
        if (!e)
                return ERR_PTR(-ENOMEM);
-       memcpy(&e->name[0], name, name_len);
+       memcpy(&e->name[0], name, name_len + 1);
+       e->name[name_len] = '\0';
        e->probes = NULL;
        e->refcount = 0;
        cds_hlist_add_head(&e->hlist, head);
@@ -266,7 +279,7 @@ static void remove_tracepoint(struct tracepoint_entry *e)
 static void set_tracepoint(struct tracepoint_entry **entry,
        struct tracepoint *elem, int active)
 {
-       WARN_ON(strcmp((*entry)->name, elem->name) != 0);
+       WARN_ON(strncmp((*entry)->name, elem->name, LTTNG_UST_SYM_NAME_LEN - 1) != 0);
 
        /*
         * rcu_assign_pointer has a cmm_smp_wmb() which makes sure that the new

diff --git a/tests/demo/Makefile.am b/tests/demo/Makefile.am
index 40e43690e11c28a2a41faa4646206a92990f9378..6e4a603b7aa78541154b92f7dd1fbc2398285b48 100644 (file)
--- a/tests/demo/Makefile.am
+++ b/tests/demo/Makefile.am
@@ -1,4 +1,6 @@
-AM_CPPFLAGS = -I$(top_srcdir)/include
+# -Wsystem-headers is needed to print warnings in the tracepoint
+# description file.
+AM_CPPFLAGS = -I$(top_srcdir)/include -Wsystem-headers
 
 # We install the plugins into the /tmp/lttng-ust-divert directory to
 # please libtool, which absolutely needs a target install location. We

diff --git a/tests/fork/Makefile.am b/tests/fork/Makefile.am
index 29464f41495593485e073b29427e88c96464f55b..48b3da2874481ebea7560d2e7edbbd2098ef79dd 100644 (file)
--- a/tests/fork/Makefile.am
+++ b/tests/fork/Makefile.am
@@ -1,4 +1,4 @@
-AM_CPPFLAGS = -I$(top_srcdir)/include
+AM_CPPFLAGS = -I$(top_srcdir)/include -Wsystem-headers
 
 noinst_PROGRAMS = fork fork2
 fork_SOURCES = fork.c ust_tests_fork.h

diff --git a/tests/hello.cxx/Makefile.am b/tests/hello.cxx/Makefile.am
index 81c2a5017f1c7283a77395c05ce4fe8d9012cb89..3e84796a731b4ecf965e57bae6d0f0f967190e99 100644 (file)
--- a/tests/hello.cxx/Makefile.am
+++ b/tests/hello.cxx/Makefile.am
@@ -1,4 +1,4 @@
-AM_CPPFLAGS = -I$(top_srcdir)/include
+AM_CPPFLAGS = -I$(top_srcdir)/include -Wsystem-headers
 
 noinst_PROGRAMS = hello
 hello_SOURCES = hello.cpp tp.c ust_tests_hello.h

diff --git a/tests/hello/Makefile.am b/tests/hello/Makefile.am
index 50b7b5e2e9065120bcc3fa8a49afed830e86a3e6..d866b6da6a1a9851c4061badeadef113243c9e4e 100644 (file)
--- a/tests/hello/Makefile.am
+++ b/tests/hello/Makefile.am
@@ -1,4 +1,4 @@
-AM_CPPFLAGS = -I$(top_srcdir)/include
+AM_CPPFLAGS = -I$(top_srcdir)/include -Wsystem-headers
 
 noinst_PROGRAMS = hello
 hello_SOURCES = hello.c tp.c ust_tests_hello.h