} operand;
};
+struct pred_stack {
+ struct filter_pred **preds;
+ int index;
+};
+
#define DEFINE_COMPARISON_PRED(type) \
-static int filter_pred_##type(struct filter_pred *pred, void *event, \
- int val1, int val2) \
+static int filter_pred_##type(struct filter_pred *pred, void *event) \
{ \
type *addr = (type *)(event + pred->offset); \
type val = (type)pred->val; \
}
#define DEFINE_EQUALITY_PRED(size) \
-static int filter_pred_##size(struct filter_pred *pred, void *event, \
- int val1, int val2) \
+static int filter_pred_##size(struct filter_pred *pred, void *event) \
{ \
u##size *addr = (u##size *)(event + pred->offset); \
u##size val = (u##size)pred->val; \
DEFINE_EQUALITY_PRED(16);
DEFINE_EQUALITY_PRED(8);
-static int filter_pred_and(struct filter_pred *pred __attribute((unused)),
- void *event __attribute((unused)),
- int val1, int val2)
-{
- return val1 && val2;
-}
-
-static int filter_pred_or(struct filter_pred *pred __attribute((unused)),
- void *event __attribute((unused)),
- int val1, int val2)
-{
- return val1 || val2;
-}
-
/* Filter predicate for fixed sized arrays of characters */
-static int filter_pred_string(struct filter_pred *pred, void *event,
- int val1, int val2)
+static int filter_pred_string(struct filter_pred *pred, void *event)
{
char *addr = (char *)(event + pred->offset);
int cmp, match;
}
/* Filter predicate for char * pointers */
-static int filter_pred_pchar(struct filter_pred *pred, void *event,
- int val1, int val2)
+static int filter_pred_pchar(struct filter_pred *pred, void *event)
{
char **addr = (char **)(event + pred->offset);
int cmp, match;
* and add it to the address of the entry, and at last we have
* the address of the string.
*/
-static int filter_pred_strloc(struct filter_pred *pred, void *event,
- int val1, int val2)
+static int filter_pred_strloc(struct filter_pred *pred, void *event)
{
u32 str_item = *(u32 *)(event + pred->offset);
int str_loc = str_item & 0xffff;
return match;
}
-static int filter_pred_none(struct filter_pred *pred, void *event,
- int val1, int val2)
+static int filter_pred_none(struct filter_pred *pred, void *event)
{
return 0;
}
pred->not ^= not;
}
+enum move_type {
+ MOVE_DOWN,
+ MOVE_UP_FROM_LEFT,
+ MOVE_UP_FROM_RIGHT
+};
+
+static struct filter_pred *
+get_pred_parent(struct filter_pred *pred, struct filter_pred *preds,
+ int index, enum move_type *move)
+{
+ if (pred->parent & FILTER_PRED_IS_RIGHT)
+ *move = MOVE_UP_FROM_RIGHT;
+ else
+ *move = MOVE_UP_FROM_LEFT;
+ pred = &preds[pred->parent & ~FILTER_PRED_IS_RIGHT];
+
+ return pred;
+}
+
+/*
+ * A series of AND or ORs where found together. Instead of
+ * climbing up and down the tree branches, an array of the
+ * ops were made in order of checks. We can just move across
+ * the array and short circuit if needed.
+ */
+static int process_ops(struct filter_pred *preds,
+ struct filter_pred *op, void *rec)
+{
+ struct filter_pred *pred;
+ int match = 0;
+ int type;
+ int i;
+
+ /*
+ * Micro-optimization: We set type to true if op
+ * is an OR and false otherwise (AND). Then we
+ * just need to test if the match is equal to
+ * the type, and if it is, we can short circuit the
+ * rest of the checks:
+ *
+ * if ((match && op->op == OP_OR) ||
+ * (!match && op->op == OP_AND))
+ * return match;
+ */
+ type = op->op == OP_OR;
+
+ for (i = 0; i < op->val; i++) {
+ pred = &preds[op->ops[i]];
+ match = pred->fn(pred, rec);
+ if (!!match == type)
+ return match;
+ }
+ return match;
+}
+
/* return 1 if event matches, 0 otherwise (discard) */
int filter_match_preds(struct event_filter *filter, void *rec)
{
- int match, top = 0, val1 = 0, val2 = 0;
- int stack[MAX_FILTER_PRED];
+ int match = -1;
+ enum move_type move = MOVE_DOWN;
+ struct filter_pred *preds;
struct filter_pred *pred;
- int i;
+ struct filter_pred *root;
+ int n_preds;
+ int done = 0;
+
+ /* no filter is considered a match */
+ if (!filter)
+ return 1;
+
+ n_preds = filter->n_preds;
+
+ if (!n_preds)
+ return 1;
+
+ /*
+ * n_preds, root and filter->preds are protect with preemption disabled.
+ */
+ preds = rcu_dereference_sched(filter->preds);
+ root = rcu_dereference_sched(filter->root);
+ if (!root)
+ return 1;
+
+ pred = root;
- for (i = 0; i < filter->n_preds; i++) {
- pred = filter->preds[i];
- if (!pred->pop_n) {
- match = pred->fn(pred, rec, val1, val2);
- stack[top++] = match;
+ /* match is currently meaningless */
+ match = -1;
+
+ do {
+ switch (move) {
+ case MOVE_DOWN:
+ /* only AND and OR have children */
+ if (pred->left != FILTER_PRED_INVALID) {
+ /* If ops is set, then it was folded. */
+ if (!pred->ops) {
+ /* keep going to down the left side */
+ pred = &preds[pred->left];
+ continue;
+ }
+ /* We can treat folded ops as a leaf node */
+ match = process_ops(preds, pred, rec);
+ } else
+ match = pred->fn(pred, rec);
+ /* If this pred is the only pred */
+ if (pred == root)
+ break;
+ pred = get_pred_parent(pred, preds,
+ pred->parent, &move);
+ continue;
+ case MOVE_UP_FROM_LEFT:
+ /*
+ * Check for short circuits.
+ *
+ * Optimization: !!match == (pred->op == OP_OR)
+ * is the same as:
+ * if ((match && pred->op == OP_OR) ||
+ * (!match && pred->op == OP_AND))
+ */
+ if (!!match == (pred->op == OP_OR)) {
+ if (pred == root)
+ break;
+ pred = get_pred_parent(pred, preds,
+ pred->parent, &move);
+ continue;
+ }
+ /* now go down the right side of the tree. */
+ pred = &preds[pred->right];
+ move = MOVE_DOWN;
+ continue;
+ case MOVE_UP_FROM_RIGHT:
+ /* We finished this equation. */
+ if (pred == root)
+ break;
+ pred = get_pred_parent(pred, preds,
+ pred->parent, &move);
continue;
}
- if (pred->pop_n > top) {
- WARN_ON_ONCE(1);
- return 0;
- }
- val1 = stack[--top];
- val2 = stack[--top];
- match = pred->fn(pred, rec, val1, val2);
- stack[top++] = match;
- }
+ done = 1;
+ } while (!done);
- return stack[--top];
+ return match;
}
EXPORT_SYMBOL_GPL(filter_match_preds);
static void remove_filter_string(struct event_filter *filter)
{
+ if (!filter)
+ return;
+
kfree(filter->filter_string);
filter->filter_string = NULL;
}
void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s)
{
- struct event_filter *filter = call->filter;
+ struct event_filter *filter;
mutex_lock(&event_mutex);
+ filter = call->filter;
if (filter && filter->filter_string)
trace_seq_printf(s, "%s\n", filter->filter_string);
else
void print_subsystem_event_filter(struct event_subsystem *system,
struct trace_seq *s)
{
- struct event_filter *filter = system->filter;
+ struct event_filter *filter;
mutex_lock(&event_mutex);
+ filter = system->filter;
if (filter && filter->filter_string)
trace_seq_printf(s, "%s\n", filter->filter_string);
else
pred->regex.len = 0;
}
-static int filter_set_pred(struct filter_pred *dest,
+static int __alloc_pred_stack(struct pred_stack *stack, int n_preds)
+{
+ stack->preds = kzalloc(sizeof(*stack->preds)*(n_preds + 1), GFP_KERNEL);
+ if (!stack->preds)
+ return -ENOMEM;
+ stack->index = n_preds;
+ return 0;
+}
+
+static void __free_pred_stack(struct pred_stack *stack)
+{
+ kfree(stack->preds);
+ stack->index = 0;
+}
+
+static int __push_pred_stack(struct pred_stack *stack,
+ struct filter_pred *pred)
+{
+ int index = stack->index;
+
+ if (WARN_ON(index == 0))
+ return -ENOSPC;
+
+ stack->preds[--index] = pred;
+ stack->index = index;
+ return 0;
+}
+
+static struct filter_pred *
+__pop_pred_stack(struct pred_stack *stack)
+{
+ struct filter_pred *pred;
+ int index = stack->index;
+
+ pred = stack->preds[index++];
+ if (!pred)
+ return NULL;
+
+ stack->index = index;
+ return pred;
+}
+
+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 *dest = &filter->preds[idx];
+ struct filter_pred *left;
+ struct filter_pred *right;
+
*dest = *src;
if (src->field_name) {
dest->field_name = kstrdup(src->field_name, GFP_KERNEL);
return -ENOMEM;
}
dest->fn = fn;
+ dest->index = idx;
- return 0;
+ if (dest->op == OP_OR || dest->op == OP_AND) {
+ right = __pop_pred_stack(stack);
+ left = __pop_pred_stack(stack);
+ if (!left || !right)
+ return -EINVAL;
+ /*
+ * If both children can be folded
+ * and they are the same op as this op or a leaf,
+ * then this op can be folded.
+ */
+ if (left->index & FILTER_PRED_FOLD &&
+ (left->op == dest->op ||
+ left->left == FILTER_PRED_INVALID) &&
+ right->index & FILTER_PRED_FOLD &&
+ (right->op == dest->op ||
+ right->left == FILTER_PRED_INVALID))
+ dest->index |= FILTER_PRED_FOLD;
+
+ dest->left = left->index & ~FILTER_PRED_FOLD;
+ dest->right = right->index & ~FILTER_PRED_FOLD;
+ left->parent = dest->index & ~FILTER_PRED_FOLD;
+ right->parent = dest->index | FILTER_PRED_IS_RIGHT;
+ } else {
+ /*
+ * Make dest->left invalid to be used as a quick
+ * way to know this is a leaf node.
+ */
+ dest->left = FILTER_PRED_INVALID;
+
+ /* All leafs allow folding the parent ops. */
+ dest->index |= FILTER_PRED_FOLD;
+ }
+
+ return __push_pred_stack(stack, dest);
}
-static void filter_disable_preds(struct ftrace_event_call *call)
+static void __free_preds(struct event_filter *filter)
{
- struct event_filter *filter = call->filter;
int i;
- call->flags &= ~TRACE_EVENT_FL_FILTERED;
+ if (filter->preds) {
+ for (i = 0; i < filter->a_preds; i++)
+ kfree(filter->preds[i].field_name);
+ kfree(filter->preds);
+ filter->preds = NULL;
+ }
+ filter->a_preds = 0;
filter->n_preds = 0;
-
- for (i = 0; i < MAX_FILTER_PRED; i++)
- filter->preds[i]->fn = filter_pred_none;
}
-static void __free_preds(struct event_filter *filter)
+static void filter_disable(struct ftrace_event_call *call)
{
- int i;
+ call->flags &= ~TRACE_EVENT_FL_FILTERED;
+}
+static void __free_filter(struct event_filter *filter)
+{
if (!filter)
return;
- for (i = 0; i < MAX_FILTER_PRED; i++) {
- if (filter->preds[i])
- filter_free_pred(filter->preds[i]);
- }
- kfree(filter->preds);
+ __free_preds(filter);
kfree(filter->filter_string);
kfree(filter);
}
+/*
+ * Called when destroying the ftrace_event_call.
+ * The call is being freed, so we do not need to worry about
+ * the call being currently used. This is for module code removing
+ * the tracepoints from within it.
+ */
void destroy_preds(struct ftrace_event_call *call)
{
- __free_preds(call->filter);
+ __free_filter(call->filter);
call->filter = NULL;
- call->flags &= ~TRACE_EVENT_FL_FILTERED;
}
-static struct event_filter *__alloc_preds(void)
+static struct event_filter *__alloc_filter(void)
{
struct event_filter *filter;
+
+ filter = kzalloc(sizeof(*filter), GFP_KERNEL);
+ return filter;
+}
+
+static int __alloc_preds(struct event_filter *filter, int n_preds)
+{
struct filter_pred *pred;
int i;
- filter = kzalloc(sizeof(*filter), GFP_KERNEL);
- if (!filter)
- return ERR_PTR(-ENOMEM);
+ if (filter->preds)
+ __free_preds(filter);
- filter->n_preds = 0;
+ filter->preds =
+ kzalloc(sizeof(*filter->preds) * n_preds, GFP_KERNEL);
- filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL);
if (!filter->preds)
- goto oom;
+ return -ENOMEM;
- for (i = 0; i < MAX_FILTER_PRED; i++) {
- pred = kzalloc(sizeof(*pred), GFP_KERNEL);
- if (!pred)
- goto oom;
+ filter->a_preds = n_preds;
+ filter->n_preds = 0;
+
+ for (i = 0; i < n_preds; i++) {
+ pred = &filter->preds[i];
pred->fn = filter_pred_none;
- filter->preds[i] = pred;
}
- return filter;
-
-oom:
- __free_preds(filter);
- return ERR_PTR(-ENOMEM);
-}
-
-static int init_preds(struct ftrace_event_call *call)
-{
- if (call->filter)
- return 0;
-
- call->flags &= ~TRACE_EVENT_FL_FILTERED;
- call->filter = __alloc_preds();
- if (IS_ERR(call->filter))
- return PTR_ERR(call->filter);
-
return 0;
}
-static int init_subsystem_preds(struct event_subsystem *system)
+static void filter_free_subsystem_preds(struct event_subsystem *system)
{
struct ftrace_event_call *call;
- int err;
list_for_each_entry(call, &ftrace_events, list) {
if (strcmp(call->class->system, system->name) != 0)
continue;
- err = init_preds(call);
- if (err)
- return err;
+ filter_disable(call);
+ remove_filter_string(call->filter);
}
-
- return 0;
}
-static void filter_free_subsystem_preds(struct event_subsystem *system)
+static void filter_free_subsystem_filters(struct event_subsystem *system)
{
struct ftrace_event_call *call;
list_for_each_entry(call, &ftrace_events, list) {
if (strcmp(call->class->system, system->name) != 0)
continue;
-
- filter_disable_preds(call);
- remove_filter_string(call->filter);
+ __free_filter(call->filter);
+ call->filter = NULL;
}
}
struct ftrace_event_call *call,
struct event_filter *filter,
struct filter_pred *pred,
+ struct pred_stack *stack,
filter_pred_fn_t fn)
{
int idx, err;
- if (filter->n_preds == MAX_FILTER_PRED) {
+ if (WARN_ON(filter->n_preds == filter->a_preds)) {
parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
return -ENOSPC;
}
idx = filter->n_preds;
- filter_clear_pred(filter->preds[idx]);
- err = filter_set_pred(filter->preds[idx], pred, fn);
+ filter_clear_pred(&filter->preds[idx]);
+ err = filter_set_pred(filter, idx, stack, pred, fn);
if (err)
return err;
struct ftrace_event_call *call,
struct event_filter *filter,
struct filter_pred *pred,
+ struct pred_stack *stack,
bool dry_run)
{
struct ftrace_event_field *field;
unsigned long long val;
int ret;
- pred->fn = filter_pred_none;
+ fn = pred->fn = filter_pred_none;
- if (pred->op == OP_AND) {
- pred->pop_n = 2;
- fn = filter_pred_and;
+ if (pred->op == OP_AND)
goto add_pred_fn;
- } else if (pred->op == OP_OR) {
- pred->pop_n = 2;
- fn = filter_pred_or;
+ else if (pred->op == OP_OR)
goto add_pred_fn;
- }
field = find_event_field(call, pred->field_name);
if (!field) {
add_pred_fn:
if (!dry_run)
- return filter_add_pred_fn(ps, call, filter, pred, fn);
+ return filter_add_pred_fn(ps, call, filter, pred, stack, fn);
return 0;
}
return 0;
}
+static int count_preds(struct filter_parse_state *ps)
+{
+ struct postfix_elt *elt;
+ int n_preds = 0;
+
+ list_for_each_entry(elt, &ps->postfix, list) {
+ if (elt->op == OP_NONE)
+ continue;
+ n_preds++;
+ }
+
+ return n_preds;
+}
+
+/*
+ * The tree is walked at filtering of an event. If the tree is not correctly
+ * built, it may cause an infinite loop. Check here that the tree does
+ * indeed terminate.
+ */
+static int check_pred_tree(struct event_filter *filter,
+ struct filter_pred *root)
+{
+ struct filter_pred *preds;
+ struct filter_pred *pred;
+ enum move_type move = MOVE_DOWN;
+ int count = 0;
+ int done = 0;
+ int max;
+
+ /*
+ * The max that we can hit a node is three times.
+ * Once going down, once coming up from left, and
+ * once coming up from right. This is more than enough
+ * since leafs are only hit a single time.
+ */
+ max = 3 * filter->n_preds;
+
+ preds = filter->preds;
+ if (!preds)
+ return -EINVAL;
+ pred = root;
+
+ do {
+ if (WARN_ON(count++ > max))
+ return -EINVAL;
+
+ switch (move) {
+ case MOVE_DOWN:
+ if (pred->left != FILTER_PRED_INVALID) {
+ pred = &preds[pred->left];
+ continue;
+ }
+ /* A leaf at the root is just a leaf in the tree */
+ if (pred == root)
+ break;
+ pred = get_pred_parent(pred, preds,
+ pred->parent, &move);
+ continue;
+ case MOVE_UP_FROM_LEFT:
+ pred = &preds[pred->right];
+ move = MOVE_DOWN;
+ continue;
+ case MOVE_UP_FROM_RIGHT:
+ if (pred == root)
+ break;
+ pred = get_pred_parent(pred, preds,
+ pred->parent, &move);
+ continue;
+ }
+ done = 1;
+ } while (!done);
+
+ /* We are fine. */
+ return 0;
+}
+
+static int count_leafs(struct filter_pred *preds, struct filter_pred *root)
+{
+ struct filter_pred *pred;
+ enum move_type move = MOVE_DOWN;
+ int count = 0;
+ int done = 0;
+
+ pred = root;
+
+ do {
+ switch (move) {
+ case MOVE_DOWN:
+ if (pred->left != FILTER_PRED_INVALID) {
+ pred = &preds[pred->left];
+ continue;
+ }
+ /* A leaf at the root is just a leaf in the tree */
+ if (pred == root)
+ return 1;
+ count++;
+ pred = get_pred_parent(pred, preds,
+ pred->parent, &move);
+ continue;
+ case MOVE_UP_FROM_LEFT:
+ pred = &preds[pred->right];
+ move = MOVE_DOWN;
+ continue;
+ case MOVE_UP_FROM_RIGHT:
+ if (pred == root)
+ break;
+ pred = get_pred_parent(pred, preds,
+ pred->parent, &move);
+ continue;
+ }
+ done = 1;
+ } while (!done);
+
+ return count;
+}
+
+static int fold_pred(struct filter_pred *preds, struct filter_pred *root)
+{
+ struct filter_pred *pred;
+ enum move_type move = MOVE_DOWN;
+ int count = 0;
+ int children;
+ int done = 0;
+
+ /* No need to keep the fold flag */
+ root->index &= ~FILTER_PRED_FOLD;
+
+ /* If the root is a leaf then do nothing */
+ if (root->left == FILTER_PRED_INVALID)
+ return 0;
+
+ /* count the children */
+ children = count_leafs(preds, &preds[root->left]);
+ children += count_leafs(preds, &preds[root->right]);
+
+ root->ops = kzalloc(sizeof(*root->ops) * children, GFP_KERNEL);
+ if (!root->ops)
+ return -ENOMEM;
+
+ root->val = children;
+
+ pred = root;
+ do {
+ switch (move) {
+ case MOVE_DOWN:
+ if (pred->left != FILTER_PRED_INVALID) {
+ pred = &preds[pred->left];
+ continue;
+ }
+ if (WARN_ON(count == children))
+ return -EINVAL;
+ pred->index &= ~FILTER_PRED_FOLD;
+ root->ops[count++] = pred->index;
+ pred = get_pred_parent(pred, preds,
+ pred->parent, &move);
+ continue;
+ case MOVE_UP_FROM_LEFT:
+ pred = &preds[pred->right];
+ move = MOVE_DOWN;
+ continue;
+ case MOVE_UP_FROM_RIGHT:
+ if (pred == root)
+ break;
+ pred = get_pred_parent(pred, preds,
+ pred->parent, &move);
+ continue;
+ }
+ done = 1;
+ } while (!done);
+
+ return 0;
+}
+
+/*
+ * To optimize the processing of the ops, if we have several "ors" or
+ * "ands" together, we can put them in an array and process them all
+ * together speeding up the filter logic.
+ */
+static int fold_pred_tree(struct event_filter *filter,
+ struct filter_pred *root)
+{
+ struct filter_pred *preds;
+ struct filter_pred *pred;
+ enum move_type move = MOVE_DOWN;
+ int done = 0;
+ int err;
+
+ preds = filter->preds;
+ if (!preds)
+ return -EINVAL;
+ pred = root;
+
+ do {
+ switch (move) {
+ case MOVE_DOWN:
+ if (pred->index & FILTER_PRED_FOLD) {
+ err = fold_pred(preds, pred);
+ if (err)
+ return err;
+ /* Folded nodes are like leafs */
+ } else if (pred->left != FILTER_PRED_INVALID) {
+ pred = &preds[pred->left];
+ continue;
+ }
+
+ /* A leaf at the root is just a leaf in the tree */
+ if (pred == root)
+ break;
+ pred = get_pred_parent(pred, preds,
+ pred->parent, &move);
+ continue;
+ case MOVE_UP_FROM_LEFT:
+ pred = &preds[pred->right];
+ move = MOVE_DOWN;
+ continue;
+ case MOVE_UP_FROM_RIGHT:
+ if (pred == root)
+ break;
+ pred = get_pred_parent(pred, preds,
+ pred->parent, &move);
+ continue;
+ }
+ done = 1;
+ } while (!done);
+
+ return 0;
+}
+
static int replace_preds(struct ftrace_event_call *call,
struct event_filter *filter,
struct filter_parse_state *ps,
{
char *operand1 = NULL, *operand2 = NULL;
struct filter_pred *pred;
+ struct filter_pred *root;
struct postfix_elt *elt;
+ struct pred_stack stack = { }; /* init to NULL */
int err;
int n_preds = 0;
+ n_preds = count_preds(ps);
+ if (n_preds >= MAX_FILTER_PRED) {
+ parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
+ return -ENOSPC;
+ }
+
err = check_preds(ps);
if (err)
return err;
+ if (!dry_run) {
+ err = __alloc_pred_stack(&stack, n_preds);
+ if (err)
+ return err;
+ err = __alloc_preds(filter, n_preds);
+ if (err)
+ goto fail;
+ }
+
+ n_preds = 0;
list_for_each_entry(elt, &ps->postfix, list) {
if (elt->op == OP_NONE) {
if (!operand1)
operand2 = elt->operand;
else {
parse_error(ps, FILT_ERR_TOO_MANY_OPERANDS, 0);
- return -EINVAL;
+ err = -EINVAL;
+ goto fail;
}
continue;
}
- if (n_preds++ == MAX_FILTER_PRED) {
+ if (WARN_ON(n_preds++ == MAX_FILTER_PRED)) {
parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
- return -ENOSPC;
+ err = -ENOSPC;
+ goto fail;
}
if (elt->op == OP_AND || elt->op == OP_OR) {
if (!operand1 || !operand2) {
parse_error(ps, FILT_ERR_MISSING_FIELD, 0);
- return -EINVAL;
+ err = -EINVAL;
+ goto fail;
}
pred = create_pred(elt->op, operand1, operand2);
add_pred:
- if (!pred)
- return -ENOMEM;
- err = filter_add_pred(ps, call, filter, pred, dry_run);
+ if (!pred) {
+ err = -ENOMEM;
+ goto fail;
+ }
+ err = filter_add_pred(ps, call, filter, pred, &stack, dry_run);
filter_free_pred(pred);
if (err)
- return err;
+ goto fail;
operand1 = operand2 = NULL;
}
- return 0;
+ if (!dry_run) {
+ /* We should have one item left on the stack */
+ pred = __pop_pred_stack(&stack);
+ if (!pred)
+ return -EINVAL;
+ /* This item is where we start from in matching */
+ root = pred;
+ /* Make sure the stack is empty */
+ pred = __pop_pred_stack(&stack);
+ if (WARN_ON(pred)) {
+ err = -EINVAL;
+ filter->root = NULL;
+ goto fail;
+ }
+ err = check_pred_tree(filter, root);
+ if (err)
+ goto fail;
+
+ /* Optimize the tree */
+ err = fold_pred_tree(filter, root);
+ if (err)
+ goto fail;
+
+ /* We don't set root until we know it works */
+ barrier();
+ filter->root = root;
+ }
+
+ err = 0;
+fail:
+ __free_pred_stack(&stack);
+ return err;
}
+struct filter_list {
+ struct list_head list;
+ struct event_filter *filter;
+};
+
static int replace_system_preds(struct event_subsystem *system,
struct filter_parse_state *ps,
char *filter_string)
{
struct ftrace_event_call *call;
+ struct filter_list *filter_item;
+ struct filter_list *tmp;
+ LIST_HEAD(filter_list);
bool fail = true;
int err;
list_for_each_entry(call, &ftrace_events, list) {
- struct event_filter *filter = call->filter;
if (strcmp(call->class->system, system->name) != 0)
continue;
- /* try to see if the filter can be applied */
- err = replace_preds(call, filter, ps, filter_string, true);
+ /*
+ * Try to see if the filter can be applied
+ * (filter arg is ignored on dry_run)
+ */
+ err = replace_preds(call, NULL, ps, filter_string, true);
if (err)
+ goto fail;
+ }
+
+ list_for_each_entry(call, &ftrace_events, list) {
+ struct event_filter *filter;
+
+ if (strcmp(call->class->system, system->name) != 0)
continue;
- /* really apply the filter */
- filter_disable_preds(call);
- err = replace_preds(call, filter, ps, filter_string, false);
+ filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL);
+ if (!filter_item)
+ goto fail_mem;
+
+ list_add_tail(&filter_item->list, &filter_list);
+
+ filter_item->filter = __alloc_filter();
+ if (!filter_item->filter)
+ goto fail_mem;
+ filter = filter_item->filter;
+
+ /* Can only fail on no memory */
+ err = replace_filter_string(filter, filter_string);
if (err)
- filter_disable_preds(call);
- else {
+ goto fail_mem;
+
+ err = replace_preds(call, filter, ps, filter_string, false);
+ if (err) {
+ filter_disable(call);
+ parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
+ append_filter_err(ps, filter);
+ } else
call->flags |= TRACE_EVENT_FL_FILTERED;
- replace_filter_string(filter, filter_string);
- }
+ /*
+ * Regardless of if this returned an error, we still
+ * replace the filter for the call.
+ */
+ filter = call->filter;
+ call->filter = filter_item->filter;
+ filter_item->filter = filter;
+
fail = false;
}
- if (fail) {
- parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
- return -EINVAL;
+ if (fail)
+ goto fail;
+
+ /*
+ * The calls can still be using the old filters.
+ * Do a synchronize_sched() to ensure all calls are
+ * done with them before we free them.
+ */
+ synchronize_sched();
+ list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
+ __free_filter(filter_item->filter);
+ list_del(&filter_item->list);
+ kfree(filter_item);
}
return 0;
+ fail:
+ /* No call succeeded */
+ list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
+ list_del(&filter_item->list);
+ kfree(filter_item);
+ }
+ parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
+ return -EINVAL;
+ fail_mem:
+ /* If any call succeeded, we still need to sync */
+ if (!fail)
+ synchronize_sched();
+ list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
+ __free_filter(filter_item->filter);
+ list_del(&filter_item->list);
+ kfree(filter_item);
+ }
+ return -ENOMEM;
}
int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
{
- int err;
struct filter_parse_state *ps;
+ struct event_filter *filter;
+ struct event_filter *tmp;
+ int err = 0;
mutex_lock(&event_mutex);
- err = init_preds(call);
- if (err)
- goto out_unlock;
-
if (!strcmp(strstrip(filter_string), "0")) {
- filter_disable_preds(call);
- remove_filter_string(call->filter);
+ filter_disable(call);
+ filter = call->filter;
+ if (!filter)
+ goto out_unlock;
+ call->filter = NULL;
+ /* Make sure the filter is not being used */
+ synchronize_sched();
+ __free_filter(filter);
goto out_unlock;
}
if (!ps)
goto out_unlock;
- filter_disable_preds(call);
- replace_filter_string(call->filter, filter_string);
+ filter = __alloc_filter();
+ if (!filter) {
+ kfree(ps);
+ goto out_unlock;
+ }
+
+ replace_filter_string(filter, filter_string);
parse_init(ps, filter_ops, filter_string);
err = filter_parse(ps);
if (err) {
- append_filter_err(ps, call->filter);
+ append_filter_err(ps, filter);
goto out;
}
- err = replace_preds(call, call->filter, ps, filter_string, false);
- if (err)
- append_filter_err(ps, call->filter);
- else
+ err = replace_preds(call, filter, ps, filter_string, false);
+ if (err) {
+ filter_disable(call);
+ append_filter_err(ps, filter);
+ } else
call->flags |= TRACE_EVENT_FL_FILTERED;
out:
+ /*
+ * Always swap the call filter with the new filter
+ * even if there was an error. If there was an error
+ * in the filter, we disable the filter and show the error
+ * string
+ */
+ tmp = call->filter;
+ call->filter = filter;
+ if (tmp) {
+ /* Make sure the call is done with the filter */
+ synchronize_sched();
+ __free_filter(tmp);
+ }
filter_opstack_clear(ps);
postfix_clear(ps);
kfree(ps);
int apply_subsystem_event_filter(struct event_subsystem *system,
char *filter_string)
{
- int err;
struct filter_parse_state *ps;
+ struct event_filter *filter;
+ int err = 0;
mutex_lock(&event_mutex);
- err = init_subsystem_preds(system);
- if (err)
- goto out_unlock;
-
if (!strcmp(strstrip(filter_string), "0")) {
filter_free_subsystem_preds(system);
remove_filter_string(system->filter);
+ filter = system->filter;
+ system->filter = NULL;
+ /* Ensure all filters are no longer used */
+ synchronize_sched();
+ filter_free_subsystem_filters(system);
+ __free_filter(filter);
goto out_unlock;
}
if (!ps)
goto out_unlock;
- replace_filter_string(system->filter, filter_string);
+ filter = __alloc_filter();
+ if (!filter)
+ goto out;
+
+ replace_filter_string(filter, filter_string);
+ /*
+ * No event actually uses the system filter
+ * we can free it without synchronize_sched().
+ */
+ __free_filter(system->filter);
+ system->filter = filter;
parse_init(ps, filter_ops, filter_string);
err = filter_parse(ps);
struct event_filter *filter = event->filter;
event->filter = NULL;
- __free_preds(filter);
+ __free_filter(filter);
}
int ftrace_profile_set_filter(struct perf_event *event, int event_id,
if (event->filter)
goto out_unlock;
- filter = __alloc_preds();
- if (IS_ERR(filter)) {
+ filter = __alloc_filter();
+ if (!filter) {
err = PTR_ERR(filter);
goto out_unlock;
}
err = -ENOMEM;
ps = kzalloc(sizeof(*ps), GFP_KERNEL);
if (!ps)
- goto free_preds;
+ goto free_filter;
parse_init(ps, filter_ops, filter_str);
err = filter_parse(ps);
postfix_clear(ps);
kfree(ps);
-free_preds:
+free_filter:
if (err)
- __free_preds(filter);
+ __free_filter(filter);
out_unlock:
mutex_unlock(&event_mutex);
projects / mv-sheeva.git / blobdiff