X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fevent-rule-kprobe.c;fp=src%2Fcommon%2Fevent-rule-kprobe.c;h=8d4b8c474c48b722ce37ac8b7b846e77a3addc8c;hp=0000000000000000000000000000000000000000;hb=d3a684eebfe788a7527368d65d7f020bdd1e61d9;hpb=b2081a0f39bce45b3d1cf063308a9b77712f1a9f

diff --git a/src/common/event-rule-kprobe.c b/src/common/event-rule-kprobe.c
new file mode 100644
index 000000000..8d4b8c474
--- /dev/null
+++ b/src/common/event-rule-kprobe.c
@@ -0,0 +1,522 @@
+/*
+ * Copyright (C) 2019 - Jonathan Rajotte-Julien <jonathan.rajotte-julien@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License, version 2.1 only,
+ * as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <lttng/constant.h>
+#include <lttng/event-rule/event-rule-internal.h>
+#include <lttng/event-rule/kprobe-internal.h>
+#include <common/macros.h>
+#include <common/error.h>
+#include <common/runas.h>
+#include <assert.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#define IS_KPROBE_EVENT_RULE(rule) ( \
+	lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_KPROBE \
+	)
+
+#if (LTTNG_SYMBOL_NAME_LEN == 256)
+#define LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API "255"
+#endif
+
+static
+void lttng_event_rule_kprobe_destroy(struct lttng_event_rule *rule)
+{
+	struct lttng_event_rule_kprobe *kprobe;
+
+	kprobe = container_of(rule, struct lttng_event_rule_kprobe,
+			parent);
+
+	free(kprobe->name);
+	free(kprobe->probe.symbol_name);
+	free(kprobe);
+}
+
+static
+bool lttng_event_rule_kprobe_validate(
+		const struct lttng_event_rule *rule)
+{
+	bool valid = false;
+	struct lttng_event_rule_kprobe *kprobe;
+
+	if (!rule) {
+		goto end;
+	}
+
+	kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent);
+
+	/* Required field */
+	if (!kprobe->name) {
+		ERR("Invalid name event rule: a name must be set.");
+		goto end;
+	}
+	if (kprobe->probe.set == LTTNG_DOMAIN_NONE) {
+		ERR("Invalid kprobe event rule: a source must be set.");
+		goto end;
+	}
+
+	valid = true;
+end:
+	return valid;
+}
+
+static
+int lttng_event_rule_kprobe_serialize(
+		const struct lttng_event_rule *rule,
+		struct lttng_dynamic_buffer *buf,
+		int *fd_to_send)
+{
+	int ret;
+	size_t name_len, probe_symbol_name_len;
+	struct lttng_event_rule_kprobe *kprobe;
+	struct lttng_event_rule_kprobe_comm kprobe_comm;
+
+	if (!rule || !IS_KPROBE_EVENT_RULE(rule)) {
+		ret = -1;
+		goto end;
+	}
+
+	DBG("Serializing kprobe event rule");
+	kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent);
+
+	name_len = strlen(kprobe->name) + 1;
+
+	if (kprobe->probe.symbol_name != NULL) {
+		probe_symbol_name_len = strlen(kprobe->probe.symbol_name) + 1;
+	} else {
+		probe_symbol_name_len = 0;
+	}
+
+	kprobe_comm.name_len = name_len;
+	kprobe_comm.probe_symbol_name_len = probe_symbol_name_len;
+	kprobe_comm.probe_address = kprobe->probe.address;
+	kprobe_comm.probe_offset = kprobe->probe.offset;
+
+	ret = lttng_dynamic_buffer_append(
+			buf, &kprobe_comm, sizeof(kprobe_comm));
+	if (ret) {
+		goto end;
+	}
+	ret = lttng_dynamic_buffer_append(buf, kprobe->name, name_len);
+	if (ret) {
+		goto end;
+	}
+	ret = lttng_dynamic_buffer_append(
+			buf, kprobe->probe.symbol_name, probe_symbol_name_len);
+	if (ret) {
+		goto end;
+	}
+
+	if (fd_to_send) {
+		/* Nothing to send */
+		*fd_to_send = -1;
+	}
+end:
+	return ret;
+}
+
+static
+bool lttng_event_rule_kprobe_is_equal(const struct lttng_event_rule *_a,
+		const struct lttng_event_rule *_b)
+{
+	bool is_equal = false;
+	struct lttng_event_rule_kprobe *a, *b;
+
+	a = container_of(_a, struct lttng_event_rule_kprobe, parent);
+	b = container_of(_b, struct lttng_event_rule_kprobe, parent);
+
+	/* Quick checks */
+	if (!!a->name != !!b->name) {
+		goto end;
+	}
+
+	if (!!a->probe.symbol_name != !!b->probe.symbol_name) {
+		goto end;
+	}
+
+	/* Long check */
+	/* kprobe is invalid if this is not true */
+	/* TODO: validate that a kprobe MUST have a name */
+	assert(a->name);
+	assert(b->name);
+	if (strcmp(a->name, b->name)) {
+		goto end;
+	}
+
+	if (a->probe.symbol_name) {
+		/* Both have symbol name due to previous checks */
+		if (strcmp(a->probe.symbol_name, b->probe.symbol_name)) {
+			goto end;
+		}
+	}
+
+	if (a->probe.offset != b->probe.offset) {
+		goto end;
+	}
+
+	if (a->probe.address != b->probe.address) {
+		goto end;
+	}
+
+	is_equal = true;
+end:
+	return is_equal;
+}
+
+static
+enum lttng_error_code lttng_event_rule_kprobe_populate(struct lttng_event_rule *rule, uid_t uid, gid_t gid)
+{
+	/* Nothing to do */
+	return LTTNG_OK;
+}
+
+static const char *lttng_event_rule_kprobe_get_filter(
+		const struct lttng_event_rule *rule)
+{
+	/* Not supported */
+	return NULL;
+}
+
+static const struct lttng_filter_bytecode *
+lttng_event_rule_kprobe_get_filter_bytecode(const struct lttng_event_rule *rule)
+{
+	/* Not supported */
+	return NULL;
+}
+
+static
+struct lttng_event_exclusion *lttng_event_rule_kprobe_generate_exclusions(struct lttng_event_rule *rule)
+{
+	/* Not supported */
+	return NULL;
+}
+
+struct lttng_event_rule *lttng_event_rule_kprobe_create()
+{
+	struct lttng_event_rule_kprobe *rule;
+
+	rule = zmalloc(sizeof(struct lttng_event_rule_kprobe));
+	if (!rule) {
+		return NULL;
+	}
+
+	lttng_event_rule_init(&rule->parent, LTTNG_EVENT_RULE_TYPE_KPROBE);
+	rule->parent.validate = lttng_event_rule_kprobe_validate;
+	rule->parent.serialize = lttng_event_rule_kprobe_serialize;
+	rule->parent.equal = lttng_event_rule_kprobe_is_equal;
+	rule->parent.destroy = lttng_event_rule_kprobe_destroy;
+	rule->parent.populate = lttng_event_rule_kprobe_populate;
+	rule->parent.get_filter = lttng_event_rule_kprobe_get_filter;
+	rule->parent.get_filter_bytecode = lttng_event_rule_kprobe_get_filter_bytecode;
+	rule->parent.generate_exclusions = lttng_event_rule_kprobe_generate_exclusions;
+	return &rule->parent;
+}
+
+LTTNG_HIDDEN
+ssize_t lttng_event_rule_kprobe_create_from_buffer(
+		const struct lttng_buffer_view *view,
+		struct lttng_event_rule **_event_rule)
+{
+	ssize_t ret, offset = 0;
+	enum lttng_event_rule_status status;
+	const struct lttng_event_rule_kprobe_comm *kprobe_comm;
+	const char *name;
+	const char *probe_symbol_name = NULL;
+	struct lttng_buffer_view current_view;
+	struct lttng_event_rule *rule = NULL;
+	struct lttng_event_rule_kprobe *kprobe = NULL;
+
+	if (!_event_rule) {
+		ret = -1;
+		goto end;
+	}
+
+	if (view->size < sizeof(*kprobe_comm)) {
+		ERR("Failed to initialize from malformed event rule kprobe: buffer too short to contain header");
+		ret = -1;
+		goto end;
+	}
+
+	current_view = lttng_buffer_view_from_view(
+			view, offset, sizeof(*kprobe_comm));
+	kprobe_comm = (typeof(kprobe_comm)) current_view.data;
+	if (!kprobe_comm) {
+		ret = -1;
+		goto end;
+	}
+
+	rule = lttng_event_rule_kprobe_create();
+	if (!rule) {
+		ERR("Failed to create event rule kprobe");
+		ret = -1;
+		goto end;
+	}
+
+	kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent);
+
+	/* Skip to payload */
+	offset += current_view.size;
+	/* Map the name */
+	current_view = lttng_buffer_view_from_view(
+			view, offset, kprobe_comm->name_len);
+	name = current_view.data;
+	if (!name) {
+		ret = -1;
+		goto end;
+	}
+
+	if (kprobe_comm->name_len == 1 ||
+			name[kprobe_comm->name_len - 1] != '\0' ||
+			strlen(name) != kprobe_comm->name_len - 1) {
+		/*
+		 * Check that the name is not NULL, is NULL-terminated, and
+		 * does not contain a NULL before the last byte.
+		 */
+		ret = -1;
+		goto end;
+	}
+
+	/* Skip after the name */
+	offset += kprobe_comm->name_len;
+	if (!kprobe_comm->probe_symbol_name_len) {
+		goto skip_probe_symbol_name;
+	}
+
+	/* Map the probe_symbol_name */
+	current_view = lttng_buffer_view_from_view(
+			view, offset, kprobe_comm->probe_symbol_name_len);
+	probe_symbol_name = current_view.data;
+	if (!probe_symbol_name) {
+		ret = -1;
+		goto end;
+	}
+
+	if (kprobe_comm->probe_symbol_name_len == 1 ||
+			probe_symbol_name[kprobe_comm->probe_symbol_name_len -
+					  1] != '\0' ||
+			strlen(probe_symbol_name) !=
+					kprobe_comm->probe_symbol_name_len -
+							1) {
+		/*
+		 * Check that the filter expression is not NULL, is
+		 * NULL-terminated, and does not contain a NULL before the last
+		 * byte.
+		 */
+		ret = -1;
+		goto end;
+	}
+
+	/* Skip after the pattern */
+	offset += kprobe_comm->probe_symbol_name_len;
+
+skip_probe_symbol_name:
+
+	status = lttng_event_rule_kprobe_set_name(rule, name);
+	if (status != LTTNG_EVENT_RULE_STATUS_OK) {
+		ERR("Failed to set event rule kprobe name");
+		ret = -1;
+		goto end;
+	}
+	kprobe->probe.offset = kprobe_comm->probe_offset;
+	kprobe->probe.address = kprobe_comm->probe_address;
+	if (probe_symbol_name) {
+		kprobe->probe.symbol_name = strdup(probe_symbol_name);
+		if (!kprobe->probe.symbol_name) {
+			ERR("Failed to set event rule kprobe probe symbol name");
+			ret = -1;
+			goto end;
+		}
+	}
+
+	*_event_rule = rule;
+	rule = NULL;
+	ret = offset;
+end:
+	lttng_event_rule_destroy(rule);
+	return ret;
+}
+
+enum lttng_event_rule_status lttng_event_rule_kprobe_set_source(
+		struct lttng_event_rule *rule, const char *source)
+{
+	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
+	int match;
+	char s_hex[19];
+	char name[LTTNG_SYMBOL_NAME_LEN];
+	struct lttng_event_rule_kprobe *kprobe;
+
+	/* TODO: support multiple call for this, we must free the symbol name if
+	 * that happens !!!
+	 */
+
+	if (!source || !IS_KPROBE_EVENT_RULE(rule) || !rule) {
+		status = LTTNG_EVENT_RULE_STATUS_INVALID;
+		goto end;
+	}
+
+	kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent);
+
+	/* Check for symbol+offset */
+	match = sscanf(source, "%18s[^'+']+%18s", name, s_hex);
+	if (match == 2) {
+		/* TODO double validate termination handling of this */
+		kprobe->probe.symbol_name =
+				strndup(name, LTTNG_SYMBOL_NAME_LEN);
+		if (!kprobe->probe.symbol_name) {
+			status = LTTNG_EVENT_RULE_STATUS_ERROR;
+			goto end;
+		}
+		if (*s_hex == '\0') {
+			status = LTTNG_EVENT_RULE_STATUS_INVALID;
+			goto end;
+		}
+		kprobe->probe.offset = strtoul(s_hex, NULL, 0);
+		kprobe->probe.address = 0;
+		kprobe->probe.set = true;
+		goto end;
+	}
+
+	/* Check for symbol */
+	if (isalpha(name[0]) || name[0] == '_') {
+		match = sscanf(source,
+				"%" LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API
+				"s",
+				name);
+		if (match == 1) {
+			/* TODO double validate termination handling of this */
+			kprobe->probe.symbol_name =
+					strndup(name, LTTNG_SYMBOL_NAME_LEN);
+			if (!kprobe->probe.symbol_name) {
+				status = LTTNG_EVENT_RULE_STATUS_ERROR;
+				goto end;
+			}
+			kprobe->probe.offset = 0;
+			kprobe->probe.address = 0;
+			kprobe->probe.set = true;
+			goto end;
+		}
+	}
+
+	/* Check for address */
+	match = sscanf(source, "%18s", s_hex);
+	if (match > 0) {
+		if (*s_hex == '\0') {
+			status = LTTNG_EVENT_RULE_STATUS_INVALID;
+			goto end;
+		}
+		kprobe->probe.address = strtoul(s_hex, NULL, 0);
+		kprobe->probe.offset = 0;
+		kprobe->probe.symbol_name = NULL;
+		kprobe->probe.set = true;
+		goto end;
+	}
+
+	/* No match */
+	status = LTTNG_EVENT_RULE_STATUS_INVALID;
+
+end:
+	return status;
+}
+
+enum lttng_event_rule_status lttng_event_rule_kprobe_set_name(
+		struct lttng_event_rule *rule, const char *name)
+{
+	char *name_copy = NULL;
+	struct lttng_event_rule_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_kprobe, parent);
+	name_copy = strdup(name);
+	if (!name_copy) {
+		status = LTTNG_EVENT_RULE_STATUS_ERROR;
+		goto end;
+	}
+
+	if (kprobe->name) {
+		free(kprobe->name);
+	}
+
+	kprobe->name = name_copy;
+	name_copy = NULL;
+end:
+	return status;
+}
+
+enum lttng_event_rule_status lttng_event_rule_kprobe_get_name(
+		const struct lttng_event_rule *rule, const char **name)
+{
+	struct lttng_event_rule_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_kprobe, parent);
+	if (!kprobe->name) {
+		status = LTTNG_EVENT_RULE_STATUS_UNSET;
+		goto end;
+	}
+
+	*name = kprobe->name;
+end:
+	return status;
+}
+
+LTTNG_HIDDEN
+uint64_t lttng_event_rule_kprobe_get_address(
+		const struct lttng_event_rule *rule)
+{
+	struct lttng_event_rule_kprobe *kprobe;
+
+	assert(rule && IS_KPROBE_EVENT_RULE(rule));
+
+	kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent);
+
+	return kprobe->probe.address;
+}
+
+LTTNG_HIDDEN
+uint64_t lttng_event_rule_kprobe_get_offset(
+		const struct lttng_event_rule *rule)
+{
+	struct lttng_event_rule_kprobe *kprobe;
+
+	assert(rule && IS_KPROBE_EVENT_RULE(rule));
+
+	kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent);
+	return kprobe->probe.offset;
+}
+
+LTTNG_HIDDEN
+const char *lttng_event_rule_kprobe_get_symbol_name(
+		const struct lttng_event_rule *rule)
+{
+	struct lttng_event_rule_kprobe *kprobe;
+
+	assert(rule && IS_KPROBE_EVENT_RULE(rule));
+
+	kprobe = container_of(rule, struct lttng_event_rule_kprobe, parent);
+	return kprobe->probe.symbol_name;
+}