853 lines · 18.9 KB · C
RawDownload
// SPDX-License-Identifier: GPL-2.0/* * in kernel monitor support: allows rv to control in-kernel monitors. * * Copyright (C) 2022 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org> */#include <getopt.h>#include <stdlib.h>#include <stdio.h>#include <string.h>#include <errno.h>#include <unistd.h>#include <dirent.h> #include <trace.h>#include <utils.h>#include <rv.h> static int config_has_id;static int config_is_container;static int config_my_pid;static int config_trace; static char *config_initial_reactor;static char *config_reactor; /* * __ikm_read_enable - reads monitor's enable status * * __does not log errors. * * Returns the current status, or -1 if the monitor does not exist, * __hence not logging errors. */static int __ikm_read_enable(char *monitor_name){	char path[MAX_PATH];	long long enabled;	int retval; 	snprintf(path, MAX_PATH, "rv/monitors/%s/enable", monitor_name); 	retval = tracefs_instance_file_read_number(NULL, path, &enabled);	if (retval < 0)		return -1; 	return enabled;} /* * __ikm_find_monitor - find the full name of a possibly nested module * * __does not log errors. * * Returns 1 if we found the monitor, -1 on error and 0 if it does not exist. * The string out_name is populated with the full name, which can be * equal to monitor_name or container/monitor_name if nested */static int __ikm_find_monitor_name(char *monitor_name, char *out_name){	char *available_monitors, *cursor, *line;	int len = strlen(monitor_name);	int found = 0; 	available_monitors = tracefs_instance_file_read(NULL, "rv/available_monitors", NULL);	if (!available_monitors)		return -1; 	config_is_container = 0;	cursor = available_monitors;	while ((line = strsep(&cursor, "\n"))) {		char *colon = strchr(line, ':'); 		if (strcmp(line, monitor_name) && (!colon || strcmp(colon + 1, monitor_name)))			continue; 		strncpy(out_name, line, 2 * MAX_DA_NAME_LEN);		out_name[2 * MAX_DA_NAME_LEN - 1] = '\0'; 		if (colon) {			out_name[colon - line] = '/';		} else {			/* If there are children, they are on the next line. */			line = strsep(&cursor, "\n");			if (line && !strncmp(line, monitor_name, len) && line[len] == ':')				config_is_container = 1;		} 		found = 1;		break;	} 	free(available_monitors);	return found;} /* * ikm_read_enable - reads monitor's enable status * * Returns the current status, or -1 on error. */static int ikm_read_enable(char *monitor_name){	int enabled; 	enabled = __ikm_read_enable(monitor_name);	if (enabled < 0) {		err_msg("ikm: fail read enabled: %d\n", enabled);		return -1;	} 	debug_msg("ikm: read enabled: %d\n", enabled); 	return enabled;} /* * ikm_write_enable - write to the monitor's enable file * * Return the number of bytes written, -1 on error. */static int ikm_write_enable(char *monitor_name, char *enable_disable){	char path[MAX_PATH];	int retval; 	debug_msg("ikm: writing enabled: %s\n", enable_disable); 	snprintf(path, MAX_PATH, "rv/monitors/%s/enable", monitor_name);	retval = tracefs_instance_file_write(NULL, path, enable_disable);	if (retval < strlen(enable_disable)) {		err_msg("ikm: writing enabled: %s\n", enable_disable);		return -1;	} 	return retval;} /* * ikm_enable - enable a monitor * * Returns -1 on failure. Success otherwise. */static int ikm_enable(char *monitor_name){	return ikm_write_enable(monitor_name, "1");} /* * ikm_disable - disable a monitor * * Returns -1 on failure. Success otherwise. */static int ikm_disable(char *monitor_name){	return ikm_write_enable(monitor_name, "0");} /* * ikm_read_desc - read monitors' description * * Return a dynamically allocated string with the monitor's * description, NULL otherwise. */static char *ikm_read_desc(char *monitor_name){	char path[MAX_PATH];	char *desc; 	snprintf(path, MAX_PATH, "rv/monitors/%s/desc", monitor_name);	desc = tracefs_instance_file_read(NULL, path, NULL);	if (!desc) {		err_msg("ikm: error reading monitor %s desc\n", monitor_name);		return NULL;	} 	*strstr(desc, "\n") = '\0'; 	return desc;} /* * ikm_fill_monitor_definition - fill monitor's definition * * Returns -1 on error, 1 if the monitor does not belong in the container, 0 otherwise. * container can be NULL */static int ikm_fill_monitor_definition(char *name, struct monitor *ikm, char *container){	int enabled;	char *desc, *nested_name; 	nested_name = strstr(name, ":");	if (nested_name) {		/* it belongs in container if it starts with "container:" */		if (container) {			int len = strlen(container); 			if (strncmp(name, container, len) || name[len] != ':')				return 1;		}		*nested_name = '/';		++nested_name;		ikm->nested = 1;	} else {		if (container)			return 1;		nested_name = name;		ikm->nested = 0;	} 	enabled = ikm_read_enable(name);	if (enabled < 0) {		err_msg("ikm: monitor %s fail to read enable file, bug?\n", name);		return -1;	} 	desc = ikm_read_desc(name);	if (!desc) {		err_msg("ikm: monitor %s does not have desc file, bug?\n", name);		return -1;	} 	strncpy(ikm->name, nested_name, sizeof(ikm->name) - 1);	ikm->name[sizeof(ikm->name) - 1] = '\0';	ikm->enabled = enabled;	strncpy(ikm->desc, desc, sizeof(ikm->desc) - 1);	ikm->desc[sizeof(ikm->desc) - 1] = '\0';	free(desc); 	return 0;} /* * ikm_write_reactor - switch the reactor to *reactor * * Return the number or characters written, -1 on error. */static int ikm_write_reactor(char *monitor_name, char *reactor){	char path[MAX_PATH];	int retval; 	snprintf(path, MAX_PATH, "rv/monitors/%s/reactors", monitor_name);	retval = tracefs_instance_file_write(NULL, path, reactor);	debug_msg("ikm: write \"%s\" reactors: %d\n", reactor, retval); 	return retval;} /* * ikm_read_reactor - read the reactors file * * Returns a dynamically allocated string with monitor's * available reactors, or NULL on error. */static char *ikm_read_reactor(char *monitor_name){	char path[MAX_PATH];	char *reactors; 	snprintf(path, MAX_PATH, "rv/monitors/%s/reactors", monitor_name);	reactors = tracefs_instance_file_read(NULL, path, NULL);	if (!reactors) {		err_msg("ikm: fail reading monitor's %s reactors file\n", monitor_name);		return NULL;	} 	return reactors;} /* * ikm_get_current_reactor - get the current enabled reactor * * Reads the reactors file and find the currently enabled * [reactor]. * * Returns a dynamically allocated memory with the current * reactor. NULL otherwise. */static char *ikm_get_current_reactor(char *monitor_name){	char *reactors = ikm_read_reactor(monitor_name);	char *curr_reactor = NULL;	char *start;	char *end; 	if (!reactors)		return NULL; 	start = strstr(reactors, "[");	if (!start)		goto out_free; 	start++; 	end = strstr(start, "]");	if (!end)		goto out_free; 	*end = '\0'; 	curr_reactor = calloc(strlen(start) + 1, sizeof(char));	if (!curr_reactor)		goto out_free; 	strncpy(curr_reactor, start, strlen(start));	debug_msg("ikm: read current reactor %s\n", curr_reactor); out_free:	free(reactors); 	return curr_reactor;} static int ikm_has_id(char *monitor_name){	char path[MAX_PATH];	char *format;	int has_id; 	snprintf(path, MAX_PATH, "events/rv/event_%s/format", monitor_name);	format = tracefs_instance_file_read(NULL, path, NULL);	if (!format) {		err_msg("ikm: fail reading monitor's %s format event file\n", monitor_name);		return -1;	} 	/* print fmt: "%d: %s x %s -> %s %s", REC->id, ... */	has_id = !!strstr(format, "REC->id"); 	debug_msg("ikm: monitor %s has id: %s\n", monitor_name, has_id ? "yes" : "no"); 	free(format); 	return has_id;} /** * ikm_list_monitors - list all available monitors * * Returns 0 on success, -1 otherwise. */int ikm_list_monitors(char *container){	char *available_monitors;	struct monitor ikm = {0};	char *curr, *next;	int retval, list_monitor = 0; 	available_monitors = tracefs_instance_file_read(NULL, "rv/available_monitors", NULL); 	if (!available_monitors) {		err_msg("ikm: available monitors is not available, is CONFIG_RV enabled?\n");		return -1;	} 	curr = available_monitors;	do {		next = strstr(curr, "\n");		*next = '\0'; 		retval = ikm_fill_monitor_definition(curr, &ikm, container);		if (retval < 0)			err_msg("ikm: error reading %d in kernel monitor, skipping\n", curr); 		if (!retval) {			int indent = ikm.nested && !container; 			list_monitor = 1;			printf("%s%-*s %s %s\n", indent ? " - " : "",			       indent ? MAX_DA_NAME_LEN - 3 : MAX_DA_NAME_LEN,			       ikm.name, ikm.desc, ikm.enabled ? "[ON]" : "[OFF]");		}		curr = ++next; 	} while (strlen(curr)); 	if (!list_monitor) {		if (container)			printf("-- No monitor found in container %s --\n", container);		else			printf("-- No monitor found --\n");	} 	free(available_monitors); 	return 0;} static void ikm_print_header(struct trace_seq *s){	trace_seq_printf(s, "%16s-%-8s %5s %5s ", "<TASK>", "PID", "[CPU]", "TYPE");	if (config_has_id)		trace_seq_printf(s, "%8s ", "ID"); 	trace_seq_printf(s, "%24s x %-24s -> %-24s %s\n",			 "STATE",			 "EVENT",			 "NEXT_STATE",			 "FINAL"); 	trace_seq_printf(s, "%16s %-8s %5s %5s ", " | ", " | ", " | ", " | "); 	if (config_has_id)		trace_seq_printf(s, "%8s ", " | "); 	trace_seq_printf(s, "%24s   %-24s    %-24s %s\n",			 " | ",			 " | ",			 " | ",			 "|"); } /* * ikm_event_handler - callback to handle event events * * Called any time a rv:"monitor"_event events is generated. * It parses and prints event. */static intikm_event_handler(struct trace_seq *s, struct tep_record *record,		  struct tep_event *trace_event, void *context){	/* if needed: struct trace_instance *inst = context; */	char *state, *event, *next_state;	unsigned long long final_state;	unsigned long long pid;	unsigned long long id;	int val;	bool missing_id; 	if (config_has_id)		missing_id = tep_get_field_val(s, trace_event, "id", record, &id, 1); 	tep_get_common_field_val(s, trace_event, "common_pid", record, &pid, 1); 	if (config_has_id && (config_my_pid == id))		return 0;	else if (config_my_pid == pid)		return 0; 	tep_print_event(trace_event->tep, s, record, "%16s-%-8d [%.3d] ",			TEP_PRINT_COMM, TEP_PRINT_PID, TEP_PRINT_CPU); 	if (config_is_container)		tep_print_event(trace_event->tep, s, record, "%s ", TEP_PRINT_NAME);	else		trace_seq_printf(s, "event "); 	if (config_has_id) {		if (missing_id)			/* placeholder if we are dealing with a mixed-type container*/			trace_seq_printf(s, "        ");		else			trace_seq_printf(s, "%8llu ", id);	} 	state = tep_get_field_raw(s, trace_event, "state", record, &val, 0);	event = tep_get_field_raw(s, trace_event, "event", record, &val, 0);	next_state = tep_get_field_raw(s, trace_event, "next_state", record, &val, 0);	tep_get_field_val(s, trace_event, "final_state", record, &final_state, 1); 	trace_seq_printf(s, "%24s x %-24s -> %-24s %s\n",			 state,			 event,			 next_state,			 final_state ? "Y" : "N"); 	trace_seq_do_printf(s);	trace_seq_reset(s); 	return 0;} /* * ikm_error_handler - callback to handle error events * * Called any time a rv:"monitor"_errors events is generated. * It parses and prints event. */static intikm_error_handler(struct trace_seq *s, struct tep_record *record,		  struct tep_event *trace_event, void *context){	unsigned long long pid, id;	int cpu = record->cpu;	char *state, *event;	int val;	bool missing_id; 	if (config_has_id)		missing_id = tep_get_field_val(s, trace_event, "id", record, &id, 1); 	tep_get_common_field_val(s, trace_event, "common_pid", record, &pid, 1); 	if (config_has_id && config_my_pid == id)		return 0;	else if (config_my_pid == pid)

Lines 1–500 of 853.