From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Sun, 11 Dec 2011 15:20:01 +0000 (-0500)
Subject: Print compiler warning/runtime warning and truncate too long tracepoint names
X-Git-Tag: v1.9.1~10
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=ff412fb523eeacd9f2b698ccefc4f716ace9afd0;p=lttng-ust.git

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 9650e8b0..f69eb07a 100644
--- 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 216ed17c..9dc23560 100644
--- 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 0393aa46..f146d382 100644
--- 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 40e43690..6e4a603b 100644
--- 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 29464f41..48b3da28 100644
--- 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 81c2a501..3e84796a 100644
--- 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 50b7b5e2..d866b6da 100644
--- 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