SoW-2020-0002: Trace Hit Counters
[lttng-tools.git] / src / bin / lttng-sessiond / trace-kernel.c
index 2623b2971a5273a0e84dd0a711243c99268e2a80..b550ccab5e12ba8214aea4fe4182c8e5d5092d3e 100644 (file)
 
 #include <lttng/event.h>
 #include <lttng/lttng-error.h>
+#include <lttng/kernel-function.h>
 #include <lttng/kernel-probe.h>
 #include <lttng/userspace-probe.h>
 #include <lttng/userspace-probe-internal.h>
 #include <lttng/event-rule/event-rule.h>
 #include <lttng/event-rule/event-rule-internal.h>
-#include <lttng/event-rule/kprobe.h>
-#include <lttng/event-rule/kprobe-internal.h>
+#include <lttng/event-rule/kernel-function.h>
+#include <lttng/event-rule/kernel-function-internal.h>
+#include <lttng/event-rule/kernel-probe.h>
+#include <lttng/event-rule/kernel-probe-internal.h>
 #include <lttng/event-rule/syscall.h>
 #include <lttng/event-rule/syscall-internal.h>
 #include <lttng/event-rule/tracepoint.h>
 #include <lttng/event-rule/tracepoint-internal.h>
-#include <lttng/event-rule/uprobe-internal.h>
+#include <lttng/event-rule/userspace-probe-internal.h>
+#include <lttng/map/map.h>
+#include <lttng/map-key-internal.h>
 #include <common/common.h>
 #include <common/defaults.h>
 #include <common/trace-chunk.h>
 #include "lttng-sessiond.h"
 #include "notification-thread-commands.h"
 
+/* Next available map key. Access under next_map_key_lock. */
+static uint64_t _next_map_key;
+static pthread_mutex_t next_map_key_lock = PTHREAD_MUTEX_INITIALIZER;
+
+/*
+ * Return the incremented value of next_map_key.
+ */
+static uint64_t get_next_map_key(void)
+{
+       uint64_t ret;
+
+       pthread_mutex_lock(&next_map_key_lock);
+       ret = ++_next_map_key;
+       pthread_mutex_unlock(&next_map_key_lock);
+       return ret;
+}
+
 /*
  * Find the channel name for the given kernel session.
  */
@@ -66,10 +88,40 @@ struct ltt_kernel_channel *trace_kernel_get_channel_by_name(
 }
 
 /*
- * Find the event for the given channel.
+ * Find the map name for the given kernel session.
+ */
+struct ltt_kernel_map *trace_kernel_get_map_by_name(
+               const char *name, struct ltt_kernel_session *session)
+{
+       struct ltt_kernel_map *map;
+
+       assert(session);
+       assert(name);
+
+       DBG("Trying to find map %s", name);
+
+       cds_list_for_each_entry(map, &session->map_list.head, list) {
+               enum lttng_map_status status;
+               const char *cur_map_name;
+
+               status = lttng_map_get_name(map->map, &cur_map_name);
+               assert(status == LTTNG_MAP_STATUS_OK);
+
+               if (strcmp(name, cur_map_name) == 0) {
+                       DBG("Found map by name %s", name);
+                       return map;
+               }
+       }
+
+       return NULL;
+}
+
+/*
+ * Find the event for the given channel or map.
  */
 struct ltt_kernel_event *trace_kernel_find_event(
-               char *name, struct ltt_kernel_channel *channel,
+               struct ltt_kernel_event_list *events_list,
+               uint64_t tracer_token, char *name,
                enum lttng_event_type type,
                struct lttng_bytecode *filter)
 {
@@ -77,9 +129,11 @@ struct ltt_kernel_event *trace_kernel_find_event(
        int found = 0;
 
        assert(name);
-       assert(channel);
 
-       cds_list_for_each_entry(ev, &channel->events_list.head, list) {
+       cds_list_for_each_entry(ev, &events_list->head, list) {
+               if (ev->event->token != tracer_token) {
+                       continue;
+               }
                if (type != LTTNG_EVENT_ALL && ev->type != type) {
                        continue;
                }
@@ -100,10 +154,10 @@ struct ltt_kernel_event *trace_kernel_find_event(
                break;
        }
        if (found) {
-               DBG("Found event %s for channel %s", name,
-                       channel->channel->name);
+               DBG("Kernel event %s found", name);
                return ev;
        } else {
+               DBG("Kernel event %s not found", name);
                return NULL;
        }
 }
@@ -160,9 +214,11 @@ struct ltt_kernel_session *trace_kernel_create_session(void)
        lks->fd = -1;
        lks->metadata_stream_fd = -1;
        lks->channel_count = 0;
+       lks->map_count = 0;
        lks->stream_count_global = 0;
        lks->metadata = NULL;
        CDS_INIT_LIST_HEAD(&lks->channel_list.head);
+       CDS_INIT_LIST_HEAD(&lks->map_list.head);
 
        lks->tracker_pid = process_attr_tracker_create();
        if (!lks->tracker_pid) {
@@ -274,6 +330,68 @@ error:
        return NULL;
 }
 
+struct ltt_kernel_map *trace_kernel_create_map(
+               const struct lttng_map *map)
+{
+       struct ltt_kernel_map *kernel_map = NULL;
+       unsigned int i, number_dimensions;
+
+       kernel_map = zmalloc(sizeof(*kernel_map));
+       if (!kernel_map) {
+               PERROR("ltt_kernel_map zmalloc");
+               goto end;
+       }
+
+       switch (lttng_map_get_boundary_policy(map)) {
+       case LTTNG_MAP_BOUNDARY_POLICY_OVERFLOW:
+               kernel_map->counter_conf.arithmetic = LTTNG_KERNEL_COUNTER_ARITHMETIC_MODULAR;
+               break;
+       default:
+               abort();
+       }
+
+       switch (lttng_map_get_bitness(map)) {
+       case LTTNG_MAP_BITNESS_32BITS:
+               kernel_map->counter_conf.bitness = LTTNG_KERNEL_COUNTER_BITNESS_32;
+               break;
+       case LTTNG_MAP_BITNESS_64BITS:
+               kernel_map->counter_conf.bitness = LTTNG_KERNEL_COUNTER_BITNESS_64;
+               break;
+       default:
+               abort();
+       }
+
+       kernel_map->counter_conf.coalesce_hits = lttng_map_get_coalesce_hits(map);
+
+       number_dimensions = lttng_map_get_dimension_count(map);
+       assert(number_dimensions <= LTTNG_KERNEL_COUNTER_DIMENSION_MAX);
+
+       kernel_map->counter_conf.number_dimensions = number_dimensions;
+
+       for (i = 0; i < kernel_map->counter_conf.number_dimensions; i++) {
+               enum lttng_map_status map_status;
+               uint64_t dimension_length;
+
+               map_status = lttng_map_get_dimension_length(map, i,
+                               &dimension_length);
+               assert(map_status == LTTNG_MAP_STATUS_OK);
+
+               kernel_map->counter_conf.dimensions[i].size = dimension_length;
+
+               //FIXME: We need to turn on overflow and underflow
+               kernel_map->counter_conf.dimensions[i].has_overflow = false;
+               kernel_map->counter_conf.dimensions[i].has_underflow = false;
+       }
+
+       kernel_map->fd = -1;
+       kernel_map->enabled = 1;
+       kernel_map->key = get_next_map_key();
+
+       kernel_map->event_counters_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
+end:
+       return kernel_map;
+}
+
 /*
  * Allocate and init a kernel context object.
  *
@@ -485,6 +603,7 @@ error:
 enum lttng_error_code trace_kernel_create_event_notifier_rule(
                struct lttng_trigger *trigger,
                uint64_t token,
+               uint64_t error_counter_index,
                struct ltt_kernel_event_notifier_rule **event_notifier_rule)
 {
        enum lttng_error_code ret = LTTNG_OK;
@@ -501,9 +620,9 @@ enum lttng_error_code trace_kernel_create_event_notifier_rule(
        assert(condition);
 
        condition_type = lttng_condition_get_type(condition);
-       assert(condition_type == LTTNG_CONDITION_TYPE_EVENT_RULE_HIT);
+       assert(condition_type == LTTNG_CONDITION_TYPE_ON_EVENT);
 
-       condition_status = lttng_condition_event_rule_get_rule(
+       condition_status = lttng_condition_on_event_get_rule(
                        condition, &event_rule);
        assert(condition_status == LTTNG_CONDITION_STATUS_OK);
        assert(event_rule);
@@ -522,6 +641,7 @@ enum lttng_error_code trace_kernel_create_event_notifier_rule(
        local_kernel_token_event_rule->fd = -1;
        local_kernel_token_event_rule->enabled = 1;
        local_kernel_token_event_rule->token = token;
+       local_kernel_token_event_rule->error_counter_index = error_counter_index;
 
        /* Get the reference of the event rule. */
        lttng_trigger_get(trigger);
@@ -538,19 +658,26 @@ error:
        return ret;
 }
 
+enum trace_kernel_event_type {
+       TRACE_KERNEL_EVENT_TYPE_NOTIFIER,
+       TRACE_KERNEL_EVENT_TYPE_COUNTER,
+};
+
 /*
- * Initialize a kernel trigger from an event rule.
+ * Initialize a kernel event from an event rule.
  */
-enum lttng_error_code trace_kernel_init_event_notifier_from_event_rule(
+static
+enum lttng_error_code trace_kernel_init_event_from_event_rule(
                const struct lttng_event_rule *rule,
-               struct lttng_kernel_event_notifier *kernel_event_notifier)
+               struct lttng_kernel_event *kernel_event,
+               enum trace_kernel_event_type event_type)
 {
        enum lttng_error_code ret_code;
        const char *name;
        int strncpy_ret;
 
        switch (lttng_event_rule_get_type(rule)) {
-       case LTTNG_EVENT_RULE_TYPE_KPROBE:
+       case LTTNG_EVENT_RULE_TYPE_KERNEL_PROBE:
        {
                uint64_t address = 0, offset = 0;
                const char *symbol_name = NULL;
@@ -558,7 +685,7 @@ enum lttng_error_code trace_kernel_init_event_notifier_from_event_rule(
                enum lttng_kernel_probe_location_status k_status;
                enum lttng_event_rule_status status;
 
-               status = lttng_event_rule_kprobe_get_location(rule, &location);
+               status = lttng_event_rule_kernel_probe_get_location(rule, &location);
                if (status != LTTNG_EVENT_RULE_STATUS_OK) {
                        ret_code = LTTNG_ERR_PROBE_LOCATION_INVAL;
                        goto error;
@@ -585,12 +712,68 @@ enum lttng_error_code trace_kernel_init_event_notifier_from_event_rule(
                        abort();
                }
 
-               kernel_event_notifier->event.instrumentation = LTTNG_KERNEL_KPROBE;
-               kernel_event_notifier->event.u.kprobe.addr = address;
-               kernel_event_notifier->event.u.kprobe.offset = offset;
+               kernel_event->instrumentation = LTTNG_KERNEL_KPROBE;
+               kernel_event->u.kprobe.addr = address;
+               kernel_event->u.kprobe.offset = offset;
+               if (symbol_name) {
+                       strncpy_ret = lttng_strncpy(
+                                       kernel_event->u.kprobe.symbol_name,
+                                       symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
+
+                       if (strncpy_ret) {
+                               ret_code = LTTNG_ERR_INVALID;
+                               goto error;
+                       }
+               }
+
+               kernel_event->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
+
+               status = lttng_event_rule_kernel_probe_get_event_name(rule, &name);
+               assert(status == LTTNG_EVENT_RULE_STATUS_OK);
+               ret_code = LTTNG_OK;
+               break;
+       }
+       case LTTNG_EVENT_RULE_TYPE_KERNEL_FUNCTION:
+       {
+               uint64_t address = 0, offset = 0;
+               const char *symbol_name = NULL;
+               const struct lttng_kernel_function_location *location = NULL;
+               enum lttng_kernel_function_location_status k_status;
+               enum lttng_event_rule_status status;
+
+               status = lttng_event_rule_kernel_function_get_location(rule, &location);
+               if (status != LTTNG_EVENT_RULE_STATUS_OK) {
+                       ret_code = LTTNG_ERR_PROBE_LOCATION_INVAL;
+                       goto error;
+               }
+
+               switch (lttng_kernel_function_location_get_type(location)) {
+               case LTTNG_KERNEL_FUNCTION_LOCATION_TYPE_ADDRESS:
+               {
+                       k_status = lttng_kernel_function_location_address_get_address(
+                                       location, &address);
+                       assert(k_status == LTTNG_KERNEL_FUNCTION_LOCATION_STATUS_OK);
+                       break;
+               }
+               case LTTNG_KERNEL_FUNCTION_LOCATION_TYPE_SYMBOL_OFFSET:
+               {
+                       k_status = lttng_kernel_function_location_symbol_get_offset(
+                                       location, &offset);
+                       assert(k_status == LTTNG_KERNEL_FUNCTION_LOCATION_STATUS_OK);
+                       symbol_name = lttng_kernel_function_location_symbol_get_name(
+                                       location);
+                       break;
+               }
+               default:
+                       abort();
+               }
+
+               kernel_event->instrumentation = LTTNG_KERNEL_KRETPROBE;
+               kernel_event->u.kretprobe.addr = address;
+               kernel_event->u.kretprobe.offset = offset;
                if (symbol_name) {
                        strncpy_ret = lttng_strncpy(
-                                       kernel_event_notifier->event.u.kprobe.symbol_name,
+                                       kernel_event->u.kretprobe.symbol_name,
                                        symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 
                        if (strncpy_ret) {
@@ -599,25 +782,26 @@ enum lttng_error_code trace_kernel_init_event_notifier_from_event_rule(
                        }
                }
 
-               kernel_event_notifier->event.u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
-               status = lttng_event_rule_kprobe_get_name(rule, &name);
+               kernel_event->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
+
+               status = lttng_event_rule_kernel_function_get_event_name(rule, &name);
                assert(status == LTTNG_EVENT_RULE_STATUS_OK);
                ret_code = LTTNG_OK;
                break;
        }
-       case LTTNG_EVENT_RULE_TYPE_UPROBE:
+       case LTTNG_EVENT_RULE_TYPE_USERSPACE_PROBE:
        {
                const struct lttng_userspace_probe_location* location = NULL;
                const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
                enum lttng_event_rule_status status;
 
-               status = lttng_event_rule_uprobe_get_location(rule, &location);
+               status = lttng_event_rule_userspace_probe_get_location(rule, &location);
                if (status != LTTNG_EVENT_RULE_STATUS_OK) {
                        ret_code = LTTNG_ERR_PROBE_LOCATION_INVAL;
                        goto error;
                }
 
-               kernel_event_notifier->event.instrumentation = LTTNG_KERNEL_UPROBE;
+               kernel_event->instrumentation = LTTNG_KERNEL_UPROBE;
 
                lookup = lttng_userspace_probe_location_get_lookup_method(
                                location);
@@ -633,20 +817,20 @@ enum lttng_error_code trace_kernel_init_event_notifier_from_event_rule(
                switch (lttng_userspace_probe_location_lookup_method_get_type(lookup)) {
                case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
                        /* Get the file descriptor on the target binary. */
-                       kernel_event_notifier->event.u.uprobe.fd =
+                       kernel_event->u.uprobe.fd =
                                        lttng_userspace_probe_location_function_get_binary_fd(location);
 
                        break;
                case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
                        /* Get the file descriptor on the target binary. */
-                       kernel_event_notifier->event.u.uprobe.fd =
+                       kernel_event->u.uprobe.fd =
                                        lttng_userspace_probe_location_tracepoint_get_binary_fd(location);
                        break;
                default:
                        abort();
                }
 
-               status = lttng_event_rule_uprobe_get_name(rule, &name);
+               status = lttng_event_rule_userspace_probe_get_event_name(rule, &name);
                assert(status == LTTNG_EVENT_RULE_STATUS_OK);
                ret_code = LTTNG_OK;
                break;
@@ -661,7 +845,7 @@ enum lttng_error_code trace_kernel_init_event_notifier_from_event_rule(
 
                assert(domain == LTTNG_DOMAIN_KERNEL);
                assert(status == LTTNG_EVENT_RULE_STATUS_OK);
-               kernel_event_notifier->event.instrumentation =
+               kernel_event->instrumentation =
                                LTTNG_KERNEL_TRACEPOINT;
 
                ret_code = LTTNG_OK;
@@ -675,24 +859,31 @@ enum lttng_error_code trace_kernel_init_event_notifier_from_event_rule(
 
                assert(status == LTTNG_EVENT_RULE_STATUS_OK);
 
-               kernel_event_notifier->event.instrumentation =
+               kernel_event->instrumentation =
                                LTTNG_KERNEL_SYSCALL;
-               kernel_event_notifier->event.u.syscall.abi =
+               kernel_event->u.syscall.abi =
                                LTTNG_KERNEL_SYSCALL_ABI_ALL;
-               kernel_event_notifier->event.u.syscall.entryexit =
-                               LTTNG_KERNEL_SYSCALL_ENTRY;
-               kernel_event_notifier->event.u.syscall.match =
+               kernel_event->u.syscall.match =
                                LTTNG_KERNEL_SYSCALL_MATCH_NAME;
+               switch (event_type) {
+               case TRACE_KERNEL_EVENT_TYPE_COUNTER:
+                       kernel_event->u.syscall.entryexit =
+                                       LTTNG_KERNEL_SYSCALL_ENTRYEXIT;
+                       break;
+               case TRACE_KERNEL_EVENT_TYPE_NOTIFIER:
+                       kernel_event->u.syscall.entryexit =
+                                       LTTNG_KERNEL_SYSCALL_ENTRY;
+                       break;
+               }
                ret_code = LTTNG_OK;
                break;
        }
-       case LTTNG_EVENT_RULE_TYPE_KRETPROBE:
        default:
                abort();
                break;
        }
 
-       strncpy_ret = lttng_strncpy(kernel_event_notifier->event.name, name,
+       strncpy_ret = lttng_strncpy(kernel_event->name, name,
                        LTTNG_KERNEL_SYM_NAME_LEN);
        if (strncpy_ret) {
                ret_code = LTTNG_ERR_INVALID;
@@ -702,6 +893,25 @@ enum lttng_error_code trace_kernel_init_event_notifier_from_event_rule(
 error:
        return ret_code;
 }
+
+enum lttng_error_code trace_kernel_init_event_notifier_from_event_rule(
+               const struct lttng_event_rule *rule,
+               struct lttng_kernel_event_notifier *kernel_event_notifier)
+{
+       return trace_kernel_init_event_from_event_rule(rule,
+                       &kernel_event_notifier->event,
+                       TRACE_KERNEL_EVENT_TYPE_NOTIFIER);
+}
+
+enum lttng_error_code trace_kernel_init_event_counter_from_event_rule(
+               const struct lttng_event_rule *rule,
+               struct lttng_kernel_counter_event *kernel_counter_event)
+{
+       return trace_kernel_init_event_from_event_rule(rule,
+                       &kernel_counter_event->event,
+                       TRACE_KERNEL_EVENT_TYPE_COUNTER);
+}
+
 /*
  * Allocate and initialize a kernel metadata.
  *
@@ -857,6 +1067,41 @@ void trace_kernel_destroy_event(struct ltt_kernel_event *event)
        free(event);
 }
 
+/*
+ * Free kernel event counter structure from RCU context
+ */
+static void free_event_counter_rcu(struct rcu_head *rcu_node)
+{
+       struct ltt_kernel_event_counter *event_counter = caa_container_of(rcu_node,
+                       struct ltt_kernel_event_counter, rcu_node);
+
+       free(event_counter);
+}
+/*
+ * Cleanup kernel event counter structure.
+ */
+void trace_kernel_destroy_event_counter(struct ltt_kernel_event_counter *event_counter)
+{
+       assert(event_counter);
+
+       if (event_counter->fd >= 0) {
+               int ret;
+
+               DBG("[trace] Closing event counter fd %d", event_counter->fd);
+               /* Close kernel fd */
+               ret = close(event_counter->fd);
+               if (ret) {
+                       PERROR("close");
+               }
+       } else {
+               DBG("[trace] Tearing down event counter (no associated file descriptor)");
+       }
+
+       lttng_map_key_put(event_counter->key);
+       call_rcu(&event_counter->rcu_node, free_event_counter_rcu);
+}
+
+
 /*
  * Cleanup kernel event structure.
  */
@@ -954,6 +1199,38 @@ void trace_kernel_destroy_channel(struct ltt_kernel_channel *channel)
        free(channel);
 }
 
+/*
+ * Cleanup kernel map structure.
+ */
+void trace_kernel_destroy_map(struct ltt_kernel_map *map)
+{
+       int ret;
+       struct ltt_kernel_event_counter *event_counter;
+       struct lttng_ht_iter iter;
+
+       assert(map);
+
+       DBG("[trace] Closing map fd %d", map->fd);
+       /* Close kernel fd */
+       if (map->fd >= 0) {
+               ret = close(map->fd);
+               if (ret) {
+                       PERROR("close");
+               }
+       }
+
+       /* For each event counter in the map hashtable */
+       cds_lfht_for_each_entry(map->event_counters_ht->ht, &iter.iter,
+                       event_counter, ht_node.node) {
+               trace_kernel_destroy_event_counter(event_counter);
+       }
+
+       /* Remove from map list */
+       cds_list_del(&map->list);
+
+       free(map);
+}
+
 /*
  * Cleanup kernel metadata structure.
  */
@@ -984,6 +1261,7 @@ void trace_kernel_destroy_metadata(struct ltt_kernel_metadata *metadata)
 void trace_kernel_destroy_session(struct ltt_kernel_session *session)
 {
        struct ltt_kernel_channel *channel, *ctmp;
+       struct ltt_kernel_map *map, *map_tmp;
        int ret;
 
        assert(session);
@@ -1012,6 +1290,10 @@ void trace_kernel_destroy_session(struct ltt_kernel_session *session)
        cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
                trace_kernel_destroy_channel(channel);
        }
+
+       cds_list_for_each_entry_safe(map, map_tmp, &session->map_list.head, list) {
+               trace_kernel_destroy_map(map);
+       }
 }
 
 /* Free elements needed by destroy notifiers. */
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