Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing/filters: Add comment for match callbacks
  tracing/filters: Fix MATCH_FULL filter matching for PTR_STRING
  tracing/filters: Fix MATCH_MIDDLE_ONLY filter matching
  lib: Introduce strnstr()
  tracing/filters: Fix MATCH_END_ONLY filter matching
  tracing/filters: Fix MATCH_FRONT_ONLY filter matching
  ftrace: Fix MATCH_END_ONLY function filter
  tracing/x86: Derive arch from bits argument in recordmcount.pl
  ring-buffer: Add rb_list_head() wrapper around new reader page next field
  ring-buffer: Wrap a list.next reference with rb_list_head()

3 files changed, 25 insertions, 14 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7968762..1e6640f 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1690,7 +1690,7 @@ ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
 static int ftrace_match(char *str, char *regex, int len, int type)
 {
 	int matched = 0;
-	char *ptr;
+	int slen;
 
 	switch (type) {
 	case MATCH_FULL:
@@ -1706,8 +1706,8 @@ static int ftrace_match(char *str, char *regex, int len, int type)
 			matched = 1;
 		break;
 	case MATCH_END_ONLY:
-		ptr = strstr(str, regex);
-		if (ptr && (ptr[len] == 0))
+		slen = strlen(str);
+		if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
 			matched = 1;
 		break;
 	}
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 2326b04..edefe3b 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2869,7 +2869,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	 * Splice the empty reader page into the list around the head.
 	 */
 	reader = rb_set_head_page(cpu_buffer);
-	cpu_buffer->reader_page->list.next = reader->list.next;
+	cpu_buffer->reader_page->list.next = rb_list_head(reader->list.next);
 	cpu_buffer->reader_page->list.prev = reader->list.prev;
 
 	/*
@@ -2906,7 +2906,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	 *
 	 * Now make the new head point back to the reader page.
 	 */
-	reader->list.next->prev = &cpu_buffer->reader_page->list;
+	rb_list_head(reader->list.next)->prev = &cpu_buffer->reader_page->list;
 	rb_inc_page(cpu_buffer, &cpu_buffer->head_page);
 
 	/* Finally update the reader page to the new head */
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 50504cb..e42af9a 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -211,8 +211,9 @@ static int filter_pred_pchar(struct filter_pred *pred, void *event,
 {
 	char **addr = (char **)(event + pred->offset);
 	int cmp, match;
+	int len = strlen(*addr) + 1;	/* including tailing '\0' */
 
-	cmp = pred->regex.match(*addr, &pred->regex, pred->regex.field_len);
+	cmp = pred->regex.match(*addr, &pred->regex, len);
 
 	match = cmp ^ pred->not;
 
@@ -251,7 +252,18 @@ static int filter_pred_none(struct filter_pred *pred, void *event,
 	return 0;
 }
 
-/* Basic regex callbacks */
+/*
+ * regex_match_foo - Basic regex callbacks
+ *
+ * @str: the string to be searched
+ * @r:   the regex structure containing the pattern string
+ * @len: the length of the string to be searched (including '\0')
+ *
+ * Note:
+ * - @str might not be NULL-terminated if it's of type DYN_STRING
+ *   or STATIC_STRING
+ */
+
 static int regex_match_full(char *str, struct regex *r, int len)
 {
 	if (strncmp(str, r->pattern, len) == 0)
@@ -261,23 +273,24 @@ static int regex_match_full(char *str, struct regex *r, int len)
 
 static int regex_match_front(char *str, struct regex *r, int len)
 {
-	if (strncmp(str, r->pattern, len) == 0)
+	if (strncmp(str, r->pattern, r->len) == 0)
 		return 1;
 	return 0;
 }
 
 static int regex_match_middle(char *str, struct regex *r, int len)
 {
-	if (strstr(str, r->pattern))
+	if (strnstr(str, r->pattern, len))
 		return 1;
 	return 0;
 }
 
 static int regex_match_end(char *str, struct regex *r, int len)
 {
-	char *ptr = strstr(str, r->pattern);
+	int strlen = len - 1;
 
-	if (ptr && (ptr[r->len] == 0))
+	if (strlen >= r->len &&
+	    memcmp(str + strlen - r->len, r->pattern, r->len) == 0)
 		return 1;
 	return 0;
 }
@@ -781,10 +794,8 @@ static int filter_add_pred(struct filter_parse_state *ps,
 			pred->regex.field_len = field->size;
 		} else if (field->filter_type == FILTER_DYN_STRING)
 			fn = filter_pred_strloc;
-		else {
+		else
 			fn = filter_pred_pchar;
-			pred->regex.field_len = strlen(pred->regex.pattern);
-		}
 	} else {
 		if (field->is_signed)
 			ret = strict_strtoll(pred->regex.pattern, 0, &val);