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 7968762c8167..1e6640f80454 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 2326b04c95c4..edefe3b2801b 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 50504cb228de..e42af9aad69f 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);