tracing/filter: Separate predicate init and filter addition

Making the code cleaner by having one function to fully prepare
the predicate (create_pred), and another to add the predicate to
the filter (filter_add_pred).

As a benefit, this way the dry_run flag stays only inside the
replace_preds function and is not passed deeper.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1313072754-4620-3-git-send-email-jolsa@redhat.com
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 23 insertions, 33 deletions

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index cb295a117ee7..61c8dec3b2b7 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -685,8 +685,7 @@ __pop_pred_stack(struct pred_stack *stack)
 static int filter_set_pred(struct event_filter *filter,
                            int idx,
                            struct pred_stack *stack,
-                           struct filter_pred *src,
-                           filter_pred_fn_t fn)
+                           struct filter_pred *src)
 {
         struct filter_pred *dest = &filter->preds[idx];
         struct filter_pred *left;
@@ -698,7 +697,6 @@ static int filter_set_pred(struct event_filter *filter,
                 if (!dest->field_name)
                         return -ENOMEM;
         }
-        dest->fn = fn;
         dest->index = idx;
 
         if (dest->op == OP_OR || dest->op == OP_AND) {
@@ -836,12 +834,10 @@ static void filter_free_subsystem_filters(struct event_subsystem *system)
         }
 }
 
-static int filter_add_pred_fn(struct filter_parse_state *ps,
-                              struct ftrace_event_call *call,
-                              struct event_filter *filter,
-                              struct filter_pred *pred,
-                              struct pred_stack *stack,
-                              filter_pred_fn_t fn)
+static int filter_add_pred(struct filter_parse_state *ps,
+                           struct event_filter *filter,
+                           struct filter_pred *pred,
+                           struct pred_stack *stack)
 {
         int idx, err;
 
@@ -852,7 +848,7 @@ static int filter_add_pred_fn(struct filter_parse_state *ps,
 
         idx = filter->n_preds;
         filter_clear_pred(&filter->preds[idx]);
-        err = filter_set_pred(filter, idx, stack, pred, fn);
+        err = filter_set_pred(filter, idx, stack, pred);
         if (err)
                 return err;
 
@@ -933,25 +929,16 @@ static filter_pred_fn_t select_comparison_fn(int op, int field_size,
         return fn;
 }
 
-static int filter_add_pred(struct filter_parse_state *ps,
-                           struct ftrace_event_call *call,
-                           struct event_filter *filter,
-                           struct filter_pred *pred,
-                           struct pred_stack *stack,
-                           bool dry_run)
+static int init_pred(struct filter_parse_state *ps,
+                     struct ftrace_event_call *call,
+                     struct filter_pred *pred)
+
 {
         struct ftrace_event_field *field;
-        filter_pred_fn_t fn;
+        filter_pred_fn_t fn = filter_pred_none;
         unsigned long long val;
         int ret;
 
-        fn = pred->fn = filter_pred_none;
-
-        if (pred->op == OP_AND)
-                goto add_pred_fn;
-        else if (pred->op == OP_OR)
-                goto add_pred_fn;
-
         field = find_event_field(call, pred->field_name);
         if (!field) {
                 parse_error(ps, FILT_ERR_FIELD_NOT_FOUND, 0);
@@ -997,9 +984,7 @@ static int filter_add_pred(struct filter_parse_state *ps,
         if (pred->op == OP_NE)
                 pred->not = 1;
 
-add_pred_fn:
-        if (!dry_run)
-                return filter_add_pred_fn(ps, call, filter, pred, stack, fn);
+        pred->fn = fn;
         return 0;
 }
 
@@ -1299,6 +1284,7 @@ parse_operand:
 }
 
 static struct filter_pred *create_pred(struct filter_parse_state *ps,
+                                       struct ftrace_event_call *call,
                                        int op, char *operand1, char *operand2)
 {
         static struct filter_pred pred;
@@ -1321,7 +1307,7 @@ static struct filter_pred *create_pred(struct filter_parse_state *ps,
         strcpy(pred.regex.pattern, operand2);
         pred.regex.len = strlen(pred.regex.pattern);
 
-        return &pred;
+        return init_pred(ps, call, &pred) ? NULL : &pred;
 }
 
 static int check_preds(struct filter_parse_state *ps)
@@ -1630,16 +1616,20 @@ static int replace_preds(struct ftrace_event_call *call,
                         goto fail;
                 }
 
-                pred = create_pred(ps, elt->op, operand1, operand2);
+                pred = create_pred(ps, call, elt->op, operand1, operand2);
                 if (!pred) {
                         err = -ENOMEM;
                         goto fail;
                 }
-                err = filter_add_pred(ps, call, filter, pred, &stack, dry_run);
-                filter_free_pred(pred);
-                if (err)
-                        goto fail;
+                if (!dry_run) {
+                        err = filter_add_pred(ps, filter, pred, &stack);
+                        if (err) {
+                                filter_free_pred(pred);
+                                goto fail;
+                        }
+                }
 
+                filter_free_pred(pred);
                 operand1 = operand2 = NULL;
         }