X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fevent-rule%2Fkernel-kprobe.cpp;fp=src%2Fcommon%2Fevent-rule%2Fkernel-kprobe.cpp;h=d33d446055c2f1f152276aad719ee2ba3c02f539;hp=0000000000000000000000000000000000000000;hb=a6bc4ca9d659caf016ef932fcd944029737ac57c;hpb=97535efaa975ca52bf02c2d5e76351bfd2e3defa

diff --git a/src/common/event-rule/kernel-kprobe.cpp b/src/common/event-rule/kernel-kprobe.cpp
new file mode 100644
index 000000000..d33d44605
--- /dev/null
+++ b/src/common/event-rule/kernel-kprobe.cpp
@@ -0,0 +1,495 @@
+/*
+ * Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#include <common/credentials.h>
+#include <common/error.h>
+#include <common/hashtable/hashtable.h>
+#include <common/hashtable/utils.h>
+#include <common/macros.h>
+#include <common/mi-lttng.h>
+#include <common/payload-view.h>
+#include <common/payload.h>
+#include <common/runas.h>
+#include <ctype.h>
+#include <lttng/constant.h>
+#include <lttng/event-rule/event-rule-internal.h>
+#include <lttng/event-rule/event-rule.h>
+#include <lttng/event-rule/kernel-kprobe-internal.h>
+#include <lttng/kernel-probe-internal.h>
+#include <lttng/kernel-probe.h>
+#include <stdio.h>
+
+#define IS_KPROBE_EVENT_RULE(rule) \
+	(lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_KERNEL_KPROBE)
+
+#if (LTTNG_SYMBOL_NAME_LEN == 256)
+#define LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API "255"
+#endif
+
+static void lttng_event_rule_kernel_kprobe_destroy(struct lttng_event_rule *rule)
+{
+	struct lttng_event_rule_kernel_kprobe *kprobe;
+
+	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
+
+	lttng_kernel_probe_location_destroy(kprobe->location);
+	free(kprobe->name);
+	free(kprobe);
+}
+
+static bool lttng_event_rule_kernel_kprobe_validate(
+		const struct lttng_event_rule *rule)
+{
+	bool valid = false;
+	struct lttng_event_rule_kernel_kprobe *kprobe;
+
+	if (!rule) {
+		goto end;
+	}
+
+	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
+
+	/* Required field. */
+	if (!kprobe->name) {
+		ERR("Invalid name event rule: a name must be set.");
+		goto end;
+	}
+
+	/* Required field. */
+	if(!kprobe->location) {
+		ERR("Invalid name event rule: a location must be set.");
+		goto end;
+	}
+
+	valid = true;
+end:
+	return valid;
+}
+
+static int lttng_event_rule_kernel_kprobe_serialize(
+		const struct lttng_event_rule *rule,
+		struct lttng_payload *payload)
+{
+	int ret;
+	size_t name_len, header_offset, size_before_location;
+	struct lttng_event_rule_kernel_kprobe *kprobe;
+	struct lttng_event_rule_kernel_kprobe_comm kprobe_comm;
+	struct lttng_event_rule_kernel_kprobe_comm *header;
+
+	if (!rule || !IS_KPROBE_EVENT_RULE(rule)) {
+		ret = -1;
+		goto end;
+	}
+
+	header_offset = payload->buffer.size;
+
+	DBG("Serializing kprobe event rule.");
+	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
+
+	name_len = strlen(kprobe->name) + 1;
+	kprobe_comm.name_len = name_len;
+
+	ret = lttng_dynamic_buffer_append(
+			&payload->buffer, &kprobe_comm, sizeof(kprobe_comm));
+	if (ret) {
+		goto end;
+	}
+
+	ret = lttng_dynamic_buffer_append(&payload->buffer, kprobe->name, name_len);
+	if (ret) {
+		goto end;
+	}
+
+	size_before_location = payload->buffer.size;
+
+	ret = lttng_kernel_probe_location_serialize(kprobe->location, payload);
+	if (ret < 0) {
+		goto end;
+	}
+
+	/* Update the header regarding the probe size. */
+	header = (struct lttng_event_rule_kernel_kprobe_comm*) (
+			(char *) payload->buffer.data + header_offset);
+	header->location_len = payload->buffer.size - size_before_location;
+
+	ret = 0;
+
+end:
+	return ret;
+}
+
+static bool lttng_event_rule_kernel_kprobe_is_equal(const struct lttng_event_rule *_a,
+		const struct lttng_event_rule *_b)
+{
+	bool is_equal = false;
+	struct lttng_event_rule_kernel_kprobe *a, *b;
+
+	a = container_of(_a, struct lttng_event_rule_kernel_kprobe, parent);
+	b = container_of(_b, struct lttng_event_rule_kernel_kprobe, parent);
+
+	/* Quick checks */
+	if (!!a->name != !!b->name) {
+		goto end;
+	}
+
+	/* Long check */
+	LTTNG_ASSERT(a->name);
+	LTTNG_ASSERT(b->name);
+	if (strcmp(a->name, b->name)) {
+		goto end;
+	}
+
+	is_equal = lttng_kernel_probe_location_is_equal(
+			a->location, b->location);
+end:
+	return is_equal;
+}
+
+static enum lttng_error_code lttng_event_rule_kernel_kprobe_generate_filter_bytecode(
+		struct lttng_event_rule *rule,
+		const struct lttng_credentials *creds)
+{
+	/* Nothing to do. */
+	return LTTNG_OK;
+}
+
+static const char *lttng_event_rule_kernel_kprobe_get_filter(
+		const struct lttng_event_rule *rule)
+{
+	/* Not supported. */
+	return NULL;
+}
+
+static const struct lttng_bytecode *
+lttng_event_rule_kernel_kprobe_get_filter_bytecode(const struct lttng_event_rule *rule)
+{
+	/* Not supported. */
+	return NULL;
+}
+
+static enum lttng_event_rule_generate_exclusions_status
+lttng_event_rule_kernel_kprobe_generate_exclusions(const struct lttng_event_rule *rule,
+		struct lttng_event_exclusion **exclusions)
+{
+	/* Not supported. */
+	*exclusions = NULL;
+	return LTTNG_EVENT_RULE_GENERATE_EXCLUSIONS_STATUS_NONE;
+}
+
+static unsigned long
+lttng_event_rule_kernel_kprobe_hash(
+		const struct lttng_event_rule *rule)
+{
+	unsigned long hash;
+	struct lttng_event_rule_kernel_kprobe *krule =
+			container_of(rule, typeof(*krule), parent);
+
+	hash = hash_key_ulong((void *) LTTNG_EVENT_RULE_TYPE_KERNEL_KPROBE,
+			lttng_ht_seed);
+	hash ^= hash_key_str(krule->name, lttng_ht_seed);
+	hash ^= lttng_kernel_probe_location_hash(krule->location);
+
+	return hash;
+}
+
+static
+int kernel_probe_set_location(
+		struct lttng_event_rule_kernel_kprobe *kprobe,
+		const struct lttng_kernel_probe_location *location)
+{
+	int ret;
+	struct lttng_kernel_probe_location *location_copy = NULL;
+
+	if (!kprobe || !location || kprobe->location) {
+		ret = -1;
+		goto end;
+	}
+
+	location_copy = lttng_kernel_probe_location_copy(location);
+	if (!location_copy) {
+		ret = -1;
+		goto end;
+	}
+
+	kprobe->location = location_copy;
+	location_copy = NULL;
+	ret = 0;
+end:
+	lttng_kernel_probe_location_destroy(location_copy);
+	return ret;
+}
+
+static
+enum lttng_error_code lttng_event_rule_kernel_kprobe_mi_serialize(
+		const struct lttng_event_rule *rule, struct mi_writer *writer)
+{
+	int ret;
+	enum lttng_error_code ret_code;
+	enum lttng_event_rule_status status;
+	const char *event_name = NULL;
+	const struct lttng_kernel_probe_location *location = NULL;
+
+	LTTNG_ASSERT(rule);
+	LTTNG_ASSERT(writer);
+	LTTNG_ASSERT(IS_KPROBE_EVENT_RULE(rule));
+
+	status = lttng_event_rule_kernel_kprobe_get_event_name(
+			rule, &event_name);
+	LTTNG_ASSERT(status == LTTNG_EVENT_RULE_STATUS_OK);
+	LTTNG_ASSERT(event_name);
+
+	status = lttng_event_rule_kernel_kprobe_get_location(rule, &location);
+	LTTNG_ASSERT(status == LTTNG_EVENT_RULE_STATUS_OK);
+	LTTNG_ASSERT(location);
+
+	/* Open event rule kernel kprobe element. */
+	ret = mi_lttng_writer_open_element(
+			writer, mi_lttng_element_event_rule_kernel_kprobe);
+	if (ret) {
+		goto mi_error;
+	}
+
+	/* Name. */
+	ret = mi_lttng_writer_write_element_string(writer,
+			mi_lttng_element_event_rule_event_name, event_name);
+	if (ret) {
+		goto mi_error;
+	}
+
+	/* Probe location. */
+	ret_code = lttng_kernel_probe_location_mi_serialize(location, writer);
+	if (ret_code != LTTNG_OK) {
+		goto end;
+	}
+
+	/* Close event rule kernel kprobe element. */
+	ret = mi_lttng_writer_close_element(writer);
+	if (ret) {
+		goto mi_error;
+	}
+
+	ret_code = LTTNG_OK;
+	goto end;
+
+mi_error:
+	ret_code = LTTNG_ERR_MI_IO_FAIL;
+end:
+	return ret_code;
+}
+
+struct lttng_event_rule *lttng_event_rule_kernel_kprobe_create(
+		const struct lttng_kernel_probe_location *location)
+{
+	struct lttng_event_rule *rule = NULL;
+	struct lttng_event_rule_kernel_kprobe *krule;
+
+	krule = (lttng_event_rule_kernel_kprobe *) zmalloc(sizeof(struct lttng_event_rule_kernel_kprobe));
+	if (!krule) {
+		goto end;
+	}
+
+	rule = &krule->parent;
+	lttng_event_rule_init(&krule->parent, LTTNG_EVENT_RULE_TYPE_KERNEL_KPROBE);
+	krule->parent.validate = lttng_event_rule_kernel_kprobe_validate;
+	krule->parent.serialize = lttng_event_rule_kernel_kprobe_serialize;
+	krule->parent.equal = lttng_event_rule_kernel_kprobe_is_equal;
+	krule->parent.destroy = lttng_event_rule_kernel_kprobe_destroy;
+	krule->parent.generate_filter_bytecode =
+			lttng_event_rule_kernel_kprobe_generate_filter_bytecode;
+	krule->parent.get_filter = lttng_event_rule_kernel_kprobe_get_filter;
+	krule->parent.get_filter_bytecode =
+			lttng_event_rule_kernel_kprobe_get_filter_bytecode;
+	krule->parent.generate_exclusions =
+			lttng_event_rule_kernel_kprobe_generate_exclusions;
+	krule->parent.hash = lttng_event_rule_kernel_kprobe_hash;
+	krule->parent.mi_serialize = lttng_event_rule_kernel_kprobe_mi_serialize;
+
+	if (kernel_probe_set_location(krule, location)) {
+		lttng_event_rule_destroy(rule);
+		rule = NULL;
+	}
+
+end:
+	return rule;
+}
+
+ssize_t lttng_event_rule_kernel_kprobe_create_from_payload(
+		struct lttng_payload_view *view,
+		struct lttng_event_rule **_event_rule)
+{
+	ssize_t ret, offset = 0;
+	enum lttng_event_rule_status status;
+	const struct lttng_event_rule_kernel_kprobe_comm *kprobe_comm;
+	const char *name;
+	struct lttng_buffer_view current_buffer_view;
+	struct lttng_event_rule *rule = NULL;
+	struct lttng_kernel_probe_location *location = NULL;
+
+	if (!_event_rule) {
+		ret = -1;
+		goto end;
+	}
+
+	current_buffer_view = lttng_buffer_view_from_view(
+			&view->buffer, offset, sizeof(*kprobe_comm));
+	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
+		ERR("Failed to initialize from malformed event rule kprobe: buffer too short to contain header.");
+		ret = -1;
+		goto end;
+	}
+
+	kprobe_comm = (typeof(kprobe_comm)) current_buffer_view.data;
+
+	/* Skip to payload */
+	offset += current_buffer_view.size;
+
+	{
+		/* Map the name. */
+		struct lttng_payload_view current_payload_view =
+				lttng_payload_view_from_view(view, offset,
+						kprobe_comm->name_len);
+
+		if (!lttng_payload_view_is_valid(&current_payload_view)) {
+			ret = -1;
+			goto end;
+		}
+
+		name = current_payload_view.buffer.data;
+		if (!lttng_buffer_view_contains_string(
+				&current_payload_view.buffer, name,
+				kprobe_comm->name_len)) {
+			ret = -1;
+			goto end;
+		}
+	}
+
+	/* Skip after the name. */
+	offset += kprobe_comm->name_len;
+
+	/* Map the kernel probe location. */
+	{
+		struct lttng_payload_view current_payload_view =
+				lttng_payload_view_from_view(view, offset,
+						kprobe_comm->location_len);
+
+		if (!lttng_payload_view_is_valid(&current_payload_view)) {
+			ret = -1;
+			goto end;
+		}
+
+		ret = lttng_kernel_probe_location_create_from_payload(
+				&current_payload_view, &location);
+		if (ret < 0) {
+			ret = -1;
+			goto end;
+		}
+	}
+
+	if (ret != kprobe_comm->location_len) {
+		ret = -1;
+		goto end;
+	}
+
+	/* Skip after the location */
+	offset += kprobe_comm->location_len;
+
+	rule = lttng_event_rule_kernel_kprobe_create(location);
+	if (!rule) {
+		ERR("Failed to create event rule kprobe.");
+		ret = -1;
+		goto end;
+	}
+
+	status = lttng_event_rule_kernel_kprobe_set_event_name(rule, name);
+	if (status != LTTNG_EVENT_RULE_STATUS_OK) {
+		ERR("Failed to set event rule kprobe name.");
+		ret = -1;
+		goto end;
+	}
+
+	*_event_rule = rule;
+	rule = NULL;
+	ret = offset;
+end:
+	lttng_kernel_probe_location_destroy(location);
+	lttng_event_rule_destroy(rule);
+	return ret;
+}
+
+enum lttng_event_rule_status lttng_event_rule_kernel_kprobe_get_location(
+		const struct lttng_event_rule *rule,
+		const struct lttng_kernel_probe_location **location)
+{
+	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
+	struct lttng_event_rule_kernel_kprobe *kprobe;
+
+	if (!rule || !IS_KPROBE_EVENT_RULE(rule) || !location) {
+		status = LTTNG_EVENT_RULE_STATUS_INVALID;
+		goto end;
+	}
+
+	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
+	*location = kprobe->location;
+
+	if (!*location) {
+		status = LTTNG_EVENT_RULE_STATUS_UNSET;
+		goto end;
+	}
+
+end:
+	return status;
+}
+
+enum lttng_event_rule_status lttng_event_rule_kernel_kprobe_set_event_name(
+		struct lttng_event_rule *rule, const char *name)
+{
+	char *name_copy = NULL;
+	struct lttng_event_rule_kernel_kprobe *kprobe;
+	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
+
+	if (!rule || !IS_KPROBE_EVENT_RULE(rule) || !name ||
+			strlen(name) == 0) {
+		status = LTTNG_EVENT_RULE_STATUS_INVALID;
+		goto end;
+	}
+
+	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
+	name_copy = strdup(name);
+	if (!name_copy) {
+		status = LTTNG_EVENT_RULE_STATUS_ERROR;
+		goto end;
+	}
+
+	free(kprobe->name);
+
+	kprobe->name = name_copy;
+	name_copy = NULL;
+end:
+	return status;
+}
+
+enum lttng_event_rule_status lttng_event_rule_kernel_kprobe_get_event_name(
+		const struct lttng_event_rule *rule, const char **name)
+{
+	struct lttng_event_rule_kernel_kprobe *kprobe;
+	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
+
+	if (!rule || !IS_KPROBE_EVENT_RULE(rule) || !name) {
+		status = LTTNG_EVENT_RULE_STATUS_INVALID;
+		goto end;
+	}
+
+	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
+	if (!kprobe->name) {
+		status = LTTNG_EVENT_RULE_STATUS_UNSET;
+		goto end;
+	}
+
+	*name = kprobe->name;
+end:
+	return status;
+}