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path: root/kernel/trace/trace_events_filter.c
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Diffstat (limited to 'kernel/trace/trace_events_filter.c')
-rw-r--r--kernel/trace/trace_events_filter.c292
1 files changed, 180 insertions, 112 deletions
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index db6e54bdb59..93660fbbf62 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -27,8 +27,6 @@
#include "trace.h"
#include "trace_output.h"
-static DEFINE_MUTEX(filter_mutex);
-
enum filter_op_ids
{
OP_OR,
@@ -165,6 +163,20 @@ static int filter_pred_string(struct filter_pred *pred, void *event,
return match;
}
+/* Filter predicate for char * pointers */
+static int filter_pred_pchar(struct filter_pred *pred, void *event,
+ int val1, int val2)
+{
+ char **addr = (char **)(event + pred->offset);
+ int cmp, match;
+
+ cmp = strncmp(*addr, pred->str_val, pred->str_len);
+
+ match = (!cmp) ^ pred->not;
+
+ return match;
+}
+
/*
* Filter predicate for dynamic sized arrays of characters.
* These are implemented through a list of strings at the end
@@ -178,11 +190,13 @@ static int filter_pred_string(struct filter_pred *pred, void *event,
static int filter_pred_strloc(struct filter_pred *pred, void *event,
int val1, int val2)
{
- int str_loc = *(int *)(event + pred->offset);
+ u32 str_item = *(u32 *)(event + pred->offset);
+ int str_loc = str_item & 0xffff;
+ int str_len = str_item >> 16;
char *addr = (char *)(event + str_loc);
int cmp, match;
- cmp = strncmp(addr, pred->str_val, pred->str_len);
+ cmp = strncmp(addr, pred->str_val, str_len);
match = (!cmp) ^ pred->not;
@@ -294,12 +308,12 @@ void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s)
{
struct event_filter *filter = call->filter;
- mutex_lock(&filter_mutex);
- if (filter->filter_string)
+ mutex_lock(&event_mutex);
+ if (filter && filter->filter_string)
trace_seq_printf(s, "%s\n", filter->filter_string);
else
trace_seq_printf(s, "none\n");
- mutex_unlock(&filter_mutex);
+ mutex_unlock(&event_mutex);
}
void print_subsystem_event_filter(struct event_subsystem *system,
@@ -307,12 +321,12 @@ void print_subsystem_event_filter(struct event_subsystem *system,
{
struct event_filter *filter = system->filter;
- mutex_lock(&filter_mutex);
- if (filter->filter_string)
+ mutex_lock(&event_mutex);
+ if (filter && filter->filter_string)
trace_seq_printf(s, "%s\n", filter->filter_string);
else
trace_seq_printf(s, "none\n");
- mutex_unlock(&filter_mutex);
+ mutex_unlock(&event_mutex);
}
static struct ftrace_event_field *
@@ -376,26 +390,32 @@ void destroy_preds(struct ftrace_event_call *call)
struct event_filter *filter = call->filter;
int i;
+ if (!filter)
+ return;
+
for (i = 0; i < MAX_FILTER_PRED; i++) {
if (filter->preds[i])
filter_free_pred(filter->preds[i]);
}
kfree(filter->preds);
+ kfree(filter->filter_string);
kfree(filter);
call->filter = NULL;
}
-int init_preds(struct ftrace_event_call *call)
+static int init_preds(struct ftrace_event_call *call)
{
struct event_filter *filter;
struct filter_pred *pred;
int i;
+ if (call->filter)
+ return 0;
+
filter = call->filter = kzalloc(sizeof(*filter), GFP_KERNEL);
if (!call->filter)
return -ENOMEM;
- call->filter_active = 0;
filter->n_preds = 0;
filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL);
@@ -417,33 +437,56 @@ oom:
return -ENOMEM;
}
-EXPORT_SYMBOL_GPL(init_preds);
-static void filter_free_subsystem_preds(struct event_subsystem *system)
+static int init_subsystem_preds(struct event_subsystem *system)
{
- struct event_filter *filter = system->filter;
struct ftrace_event_call *call;
- int i;
+ int err;
- if (filter->n_preds) {
- for (i = 0; i < filter->n_preds; i++)
- filter_free_pred(filter->preds[i]);
- kfree(filter->preds);
- filter->preds = NULL;
- filter->n_preds = 0;
+ list_for_each_entry(call, &ftrace_events, list) {
+ if (!call->define_fields)
+ continue;
+
+ if (strcmp(call->system, system->name) != 0)
+ continue;
+
+ err = init_preds(call);
+ if (err)
+ return err;
}
- mutex_lock(&event_mutex);
+ return 0;
+}
+
+enum {
+ FILTER_DISABLE_ALL,
+ FILTER_INIT_NO_RESET,
+ FILTER_SKIP_NO_RESET,
+};
+
+static void filter_free_subsystem_preds(struct event_subsystem *system,
+ int flag)
+{
+ struct ftrace_event_call *call;
+
list_for_each_entry(call, &ftrace_events, list) {
if (!call->define_fields)
continue;
- if (!strcmp(call->system, system->name)) {
- filter_disable_preds(call);
- remove_filter_string(call->filter);
+ if (strcmp(call->system, system->name) != 0)
+ continue;
+
+ if (flag == FILTER_INIT_NO_RESET) {
+ call->filter->no_reset = false;
+ continue;
}
+
+ if (flag == FILTER_SKIP_NO_RESET && call->filter->no_reset)
+ continue;
+
+ filter_disable_preds(call);
+ remove_filter_string(call->filter);
}
- mutex_unlock(&event_mutex);
}
static int filter_add_pred_fn(struct filter_parse_state *ps,
@@ -471,12 +514,7 @@ static int filter_add_pred_fn(struct filter_parse_state *ps,
return 0;
}
-enum {
- FILTER_STATIC_STRING = 1,
- FILTER_DYN_STRING
-};
-
-static int is_string_field(const char *type)
+int filter_assign_type(const char *type)
{
if (strstr(type, "__data_loc") && strstr(type, "char"))
return FILTER_DYN_STRING;
@@ -484,12 +522,19 @@ static int is_string_field(const char *type)
if (strchr(type, '[') && strstr(type, "char"))
return FILTER_STATIC_STRING;
- return 0;
+ return FILTER_OTHER;
+}
+
+static bool is_string_field(struct ftrace_event_field *field)
+{
+ return field->filter_type == FILTER_DYN_STRING ||
+ field->filter_type == FILTER_STATIC_STRING ||
+ field->filter_type == FILTER_PTR_STRING;
}
static int is_legal_op(struct ftrace_event_field *field, int op)
{
- if (is_string_field(field->type) && (op != OP_EQ && op != OP_NE))
+ if (is_string_field(field) && (op != OP_EQ && op != OP_NE))
return 0;
return 1;
@@ -540,21 +585,24 @@ static filter_pred_fn_t select_comparison_fn(int op, int field_size,
static int filter_add_pred(struct filter_parse_state *ps,
struct ftrace_event_call *call,
- struct filter_pred *pred)
+ struct filter_pred *pred,
+ bool dry_run)
{
struct ftrace_event_field *field;
filter_pred_fn_t fn;
unsigned long long val;
- int string_type;
+ int ret;
pred->fn = filter_pred_none;
if (pred->op == OP_AND) {
pred->pop_n = 2;
- return filter_add_pred_fn(ps, call, pred, filter_pred_and);
+ fn = filter_pred_and;
+ goto add_pred_fn;
} else if (pred->op == OP_OR) {
pred->pop_n = 2;
- return filter_add_pred_fn(ps, call, pred, filter_pred_or);
+ fn = filter_pred_or;
+ goto add_pred_fn;
}
field = find_event_field(call, pred->field_name);
@@ -570,62 +618,55 @@ static int filter_add_pred(struct filter_parse_state *ps,
return -EINVAL;
}
- string_type = is_string_field(field->type);
- if (string_type) {
- if (string_type == FILTER_STATIC_STRING)
+ if (is_string_field(field)) {
+ pred->str_len = field->size;
+
+ if (field->filter_type == FILTER_STATIC_STRING)
fn = filter_pred_string;
- else
+ else if (field->filter_type == FILTER_DYN_STRING)
fn = filter_pred_strloc;
- pred->str_len = field->size;
- if (pred->op == OP_NE)
- pred->not = 1;
- return filter_add_pred_fn(ps, call, pred, fn);
+ else {
+ fn = filter_pred_pchar;
+ pred->str_len = strlen(pred->str_val);
+ }
} else {
- if (strict_strtoull(pred->str_val, 0, &val)) {
+ if (field->is_signed)
+ ret = strict_strtoll(pred->str_val, 0, &val);
+ else
+ ret = strict_strtoull(pred->str_val, 0, &val);
+ if (ret) {
parse_error(ps, FILT_ERR_ILLEGAL_INTVAL, 0);
return -EINVAL;
}
pred->val = val;
- }
- fn = select_comparison_fn(pred->op, field->size, field->is_signed);
- if (!fn) {
- parse_error(ps, FILT_ERR_INVALID_OP, 0);
- return -EINVAL;
+ fn = select_comparison_fn(pred->op, field->size,
+ field->is_signed);
+ if (!fn) {
+ parse_error(ps, FILT_ERR_INVALID_OP, 0);
+ return -EINVAL;
+ }
}
if (pred->op == OP_NE)
pred->not = 1;
- return filter_add_pred_fn(ps, call, pred, fn);
+add_pred_fn:
+ if (!dry_run)
+ return filter_add_pred_fn(ps, call, pred, fn);
+ return 0;
}
static int filter_add_subsystem_pred(struct filter_parse_state *ps,
struct event_subsystem *system,
struct filter_pred *pred,
- char *filter_string)
+ char *filter_string,
+ bool dry_run)
{
- struct event_filter *filter = system->filter;
struct ftrace_event_call *call;
int err = 0;
+ bool fail = true;
- if (!filter->preds) {
- filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
- GFP_KERNEL);
-
- if (!filter->preds)
- return -ENOMEM;
- }
-
- if (filter->n_preds == MAX_FILTER_PRED) {
- parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
- return -ENOSPC;
- }
-
- filter->preds[filter->n_preds] = pred;
- filter->n_preds++;
-
- mutex_lock(&event_mutex);
list_for_each_entry(call, &ftrace_events, list) {
if (!call->define_fields)
@@ -634,18 +675,24 @@ static int filter_add_subsystem_pred(struct filter_parse_state *ps,
if (strcmp(call->system, system->name))
continue;
- err = filter_add_pred(ps, call, pred);
- if (err) {
- mutex_unlock(&event_mutex);
- filter_free_subsystem_preds(system);
- parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
- goto out;
- }
- replace_filter_string(call->filter, filter_string);
+ if (call->filter->no_reset)
+ continue;
+
+ err = filter_add_pred(ps, call, pred, dry_run);
+ if (err)
+ call->filter->no_reset = true;
+ else
+ fail = false;
+
+ if (!dry_run)
+ replace_filter_string(call->filter, filter_string);
}
- mutex_unlock(&event_mutex);
-out:
- return err;
+
+ if (fail) {
+ parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
+ return err;
+ }
+ return 0;
}
static void parse_init(struct filter_parse_state *ps,
@@ -1004,12 +1051,14 @@ static int check_preds(struct filter_parse_state *ps)
static int replace_preds(struct event_subsystem *system,
struct ftrace_event_call *call,
struct filter_parse_state *ps,
- char *filter_string)
+ char *filter_string,
+ bool dry_run)
{
char *operand1 = NULL, *operand2 = NULL;
struct filter_pred *pred;
struct postfix_elt *elt;
int err;
+ int n_preds = 0;
err = check_preds(ps);
if (err)
@@ -1028,19 +1077,14 @@ static int replace_preds(struct event_subsystem *system,
continue;
}
+ if (n_preds++ == MAX_FILTER_PRED) {
+ parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
+ return -ENOSPC;
+ }
+
if (elt->op == OP_AND || elt->op == OP_OR) {
pred = create_logical_pred(elt->op);
- if (call) {
- err = filter_add_pred(ps, call, pred);
- filter_free_pred(pred);
- } else
- err = filter_add_subsystem_pred(ps, system,
- pred, filter_string);
- if (err)
- return err;
-
- operand1 = operand2 = NULL;
- continue;
+ goto add_pred;
}
if (!operand1 || !operand2) {
@@ -1049,12 +1093,15 @@ static int replace_preds(struct event_subsystem *system,
}
pred = create_pred(elt->op, operand1, operand2);
- if (call) {
- err = filter_add_pred(ps, call, pred);
- filter_free_pred(pred);
- } else
+add_pred:
+ if (!pred)
+ return -ENOMEM;
+ if (call)
+ err = filter_add_pred(ps, call, pred, false);
+ else
err = filter_add_subsystem_pred(ps, system, pred,
- filter_string);
+ filter_string, dry_run);
+ filter_free_pred(pred);
if (err)
return err;
@@ -1070,12 +1117,16 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
struct filter_parse_state *ps;
- mutex_lock(&filter_mutex);
+ 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);
- mutex_unlock(&filter_mutex);
+ mutex_unlock(&event_mutex);
return 0;
}
@@ -1094,7 +1145,7 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
goto out;
}
- err = replace_preds(NULL, call, ps, filter_string);
+ err = replace_preds(NULL, call, ps, filter_string, false);
if (err)
append_filter_err(ps, call->filter);
@@ -1103,7 +1154,7 @@ out:
postfix_clear(ps);
kfree(ps);
out_unlock:
- mutex_unlock(&filter_mutex);
+ mutex_unlock(&event_mutex);
return err;
}
@@ -1115,12 +1166,16 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
struct filter_parse_state *ps;
- mutex_lock(&filter_mutex);
+ 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);
+ filter_free_subsystem_preds(system, FILTER_DISABLE_ALL);
remove_filter_string(system->filter);
- mutex_unlock(&filter_mutex);
+ mutex_unlock(&event_mutex);
return 0;
}
@@ -1129,7 +1184,6 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
if (!ps)
goto out_unlock;
- filter_free_subsystem_preds(system);
replace_filter_string(system->filter, filter_string);
parse_init(ps, filter_ops, filter_string);
@@ -1139,16 +1193,30 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
goto out;
}
- err = replace_preds(system, NULL, ps, filter_string);
- if (err)
+ filter_free_subsystem_preds(system, FILTER_INIT_NO_RESET);
+
+ /* try to see the filter can be applied to which events */
+ err = replace_preds(system, NULL, ps, filter_string, true);
+ if (err) {
append_filter_err(ps, system->filter);
+ goto out;
+ }
+
+ filter_free_subsystem_preds(system, FILTER_SKIP_NO_RESET);
+
+ /* really apply the filter to the events */
+ err = replace_preds(system, NULL, ps, filter_string, false);
+ if (err) {
+ append_filter_err(ps, system->filter);
+ filter_free_subsystem_preds(system, 2);
+ }
out:
filter_opstack_clear(ps);
postfix_clear(ps);
kfree(ps);
out_unlock:
- mutex_unlock(&filter_mutex);
+ mutex_unlock(&event_mutex);
return err;
}