// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * builtin-probe.c
   *
   * Builtin probe command: Set up probe events by C expression
   *
   * Written by Masami Hiramatsu <mhiramat@redhat.com>

   */

  #include <sys/utsname.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <errno.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <stdlib.h>
  #include <string.h>

  #include "builtin.h"

  #include "namespaces.h"

  #include "util/build-id.h"

  #include "util/strlist.h"

  #include "util/strfilter.h"

  #include "util/symbol_conf.h"

  #include "util/debug.h"

  #include <subcmd/parse-options.h>

  #include "util/probe-finder.h"

  #include "util/probe-event.h"

  #include "util/probe-file.h"

  #include <linux/string.h>

  #include <linux/zalloc.h>

  #define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"

  #define DEFAULT_FUNC_FILTER "!_*"

  #define DEFAULT_LIST_FILTER "*"

  
  /* Session management structure */
  static struct {

  	int command;	/* Command short_name */

  	bool list_events;

  	bool uprobes;

  	bool quiet;

  	bool target_used;

  	int nevents;
  	struct perf_probe_event events[MAX_PROBES];

  	struct line_range line_range;

  	char *target;

  	struct strfilter *filter;

  	struct nsinfo *nsi;

  } params;

  /* Parse an event definition. Note that any error must die. */

  static int parse_probe_event(const char *str)

  {

  	struct perf_probe_event *pev = &params.events[params.nevents];

  	int ret;

  	pr_debug("probe-definition(%d): %s
  ", params.nevents, str);

  	if (++params.nevents == MAX_PROBES) {
  		pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
  		return -1;
  	}

  	pev->uprobes = params.uprobes;

  	if (params.target) {
  		pev->target = strdup(params.target);
  		if (!pev->target)
  			return -ENOMEM;

  		params.target_used = true;

  	}

  	pev->nsi = nsinfo__get(params.nsi);

  	/* Parse a perf-probe command into event */

  	ret = parse_perf_probe_command(str, pev);

  	pr_debug("%d arguments
  ", pev->nargs);

  
  	return ret;

  }

  static int params_add_filter(const char *str)
  {
  	const char *err = NULL;
  	int ret = 0;
  
  	pr_debug2("Add filter: %s
  ", str);
  	if (!params.filter) {
  		params.filter = strfilter__new(str, &err);
  		if (!params.filter)
  			ret = err ? -EINVAL : -ENOMEM;
  	} else
  		ret = strfilter__or(params.filter, str, &err);
  
  	if (ret == -EINVAL) {
  		pr_err("Filter parse error at %td.
  ", err - str + 1);
  		pr_err("Source: \"%s\"
  ", str);
  		pr_err("         %*c
  ", (int)(err - str + 1), '^');
  	}
  
  	return ret;
  }

  static int set_target(const char *ptr)
  {
  	int found = 0;
  	const char *buf;
  
  	/*
  	 * The first argument after options can be an absolute path
  	 * to an executable / library or kernel module.
  	 *
  	 * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
  	 * short module name.
  	 */
  	if (!params.target && ptr && *ptr == '/') {

  		params.target = strdup(ptr);
  		if (!params.target)
  			return -ENOMEM;

  		params.target_used = false;

  		found = 1;
  		buf = ptr + (strlen(ptr) - 3);
  
  		if (strcmp(buf, ".ko"))
  			params.uprobes = true;
  
  	}
  
  	return found;
  }

  static int parse_probe_event_argv(int argc, const char **argv)

  {

  	int i, len, ret, found_target;

  	char *buf;

  	found_target = set_target(argv[0]);

  	if (found_target < 0)
  		return found_target;

  	if (found_target && argc == 1)
  		return 0;

  	/* Bind up rest arguments */
  	len = 0;

  	for (i = 0; i < argc; i++) {
  		if (i == 0 && found_target)
  			continue;

  		len += strlen(argv[i]) + 1;

  	}

  	buf = zalloc(len + 1);
  	if (buf == NULL)
  		return -ENOMEM;

  	len = 0;

  	for (i = 0; i < argc; i++) {
  		if (i == 0 && found_target)
  			continue;

  		len += sprintf(&buf[len], "%s ", argv[i]);

  	}

  	ret = parse_probe_event(buf);

  	free(buf);

  	return ret;

  }

  static int opt_set_target(const struct option *opt, const char *str,

  			int unset __maybe_unused)

  {
  	int ret = -ENOENT;

  	char *tmp;

  	if  (str) {

  		if (!strcmp(opt->long_name, "exec"))
  			params.uprobes = true;

  		else if (!strcmp(opt->long_name, "module"))
  			params.uprobes = false;

  		else
  			return ret;

  		/* Expand given path to absolute path, except for modulename */
  		if (params.uprobes || strchr(str, '/')) {

  			tmp = nsinfo__realpath(str, params.nsi);

  			if (!tmp) {
  				pr_warning("Failed to get the absolute path of %s: %m
  ", str);
  				return ret;
  			}
  		} else {
  			tmp = strdup(str);
  			if (!tmp)
  				return -ENOMEM;
  		}

  		free(params.target);

  		params.target = tmp;

  		params.target_used = false;

  		ret = 0;
  	}
  
  	return ret;
  }

  static int opt_set_target_ns(const struct option *opt __maybe_unused,
  			     const char *str, int unset __maybe_unused)
  {
  	int ret = -ENOENT;
  	pid_t ns_pid;
  	struct nsinfo *nsip;
  
  	if (str) {
  		errno = 0;
  		ns_pid = (pid_t)strtol(str, NULL, 10);
  		if (errno != 0) {
  			ret = -errno;
  			pr_warning("Failed to parse %s as a pid: %s
  ", str,
  				   strerror(errno));
  			return ret;
  		}
  		nsip = nsinfo__new(ns_pid);
  		if (nsip && nsip->need_setns)
  			params.nsi = nsinfo__get(nsip);
  		nsinfo__put(nsip);
  
  		ret = 0;
  	}
  
  	return ret;
  }

  /* Command option callbacks */

  #ifdef HAVE_DWARF_SUPPORT

  static int opt_show_lines(const struct option *opt,

  			  const char *str, int unset __maybe_unused)

  {

  	int ret = 0;

  	if (!str)
  		return 0;

  	if (params.command == 'L') {

  		pr_warning("Warning: more than one --line options are"
  			   " detected. Only the first one is valid.
  ");
  		return 0;
  	}

  	params.command = opt->short_name;

  	ret = parse_line_range_desc(str, &params.line_range);

  
  	return ret;

  }

  static int opt_show_vars(const struct option *opt,

  			 const char *str, int unset __maybe_unused)

  {
  	struct perf_probe_event *pev = &params.events[params.nevents];
  	int ret;
  
  	if (!str)
  		return 0;
  
  	ret = parse_probe_event(str);
  	if (!ret && pev->nargs != 0) {
  		pr_err("  Error: '--vars' doesn't accept arguments.
  ");
  		return -EINVAL;
  	}

  	params.command = opt->short_name;

  
  	return ret;
  }

  #else
  # define opt_show_lines NULL
  # define opt_show_vars NULL

  #endif

  static int opt_add_probe_event(const struct option *opt,
  			      const char *str, int unset __maybe_unused)
  {
  	if (str) {
  		params.command = opt->short_name;
  		return parse_probe_event(str);
  	}
  
  	return 0;
  }
  
  static int opt_set_filter_with_command(const struct option *opt,
  				       const char *str, int unset)

  {
  	if (!unset)

  		params.command = opt->short_name;

  
  	if (str)
  		return params_add_filter(str);
  
  	return 0;
  }

  static int opt_set_filter(const struct option *opt __maybe_unused,
  			  const char *str, int unset __maybe_unused)

  {

  	if (str)
  		return params_add_filter(str);

  	return 0;

  }

  static int init_params(void)

  {

  	return line_range__init(&params.line_range);

  }
  
  static void cleanup_params(void)
  {
  	int i;
  
  	for (i = 0; i < params.nevents; i++)
  		clear_perf_probe_event(params.events + i);

  	line_range__clear(&params.line_range);
  	free(params.target);

  	strfilter__delete(params.filter);

  	nsinfo__put(params.nsi);

  	memset(&params, 0, sizeof(params));
  }

  static void pr_err_with_code(const char *msg, int err)
  {

  	char sbuf[STRERR_BUFSIZE];

  	pr_err("%s", msg);

  	pr_debug(" Reason: %s (Code: %d)",

  		 str_error_r(-err, sbuf, sizeof(sbuf)), err);

  	pr_err("
  ");
  }

  static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
  {
  	int ret;
  	int i, k;
  	const char *event = NULL, *group = NULL;

  	ret = init_probe_symbol_maps(pevs->uprobes);
  	if (ret < 0)
  		return ret;

  	ret = convert_perf_probe_events(pevs, npevs);
  	if (ret < 0)
  		goto out_cleanup;

  	if (params.command == 'D') {	/* it shows definition */
  		ret = show_probe_trace_events(pevs, npevs);
  		goto out_cleanup;
  	}

  	ret = apply_perf_probe_events(pevs, npevs);
  	if (ret < 0)
  		goto out_cleanup;
  
  	for (i = k = 0; i < npevs; i++)
  		k += pevs[i].ntevs;
  
  	pr_info("Added new event%s
  ", (k > 1) ? "s:" : ":");
  	for (i = 0; i < npevs; i++) {
  		struct perf_probe_event *pev = &pevs[i];
  
  		for (k = 0; k < pev->ntevs; k++) {
  			struct probe_trace_event *tev = &pev->tevs[k];

  			/* Skipped events have no event name */
  			if (!tev->event)
  				continue;

  
  			/* We use tev's name for showing new events */
  			show_perf_probe_event(tev->group, tev->event, pev,
  					      tev->point.module, false);
  
  			/* Save the last valid name */
  			event = tev->event;
  			group = tev->group;
  		}
  	}
  
  	/* Note that it is possible to skip all events because of blacklist */
  	if (event) {
  		/* Show how to use the event. */
  		pr_info("
  You can now use it in all perf tools, such as:
  
  ");
  		pr_info("\tperf record -e %s:%s -aR sleep 1
  
  ", group, event);
  	}
  
  out_cleanup:
  	cleanup_perf_probe_events(pevs, npevs);

  	exit_probe_symbol_maps();

  	return ret;
  }

  static int del_perf_probe_caches(struct strfilter *filter)
  {
  	struct probe_cache *cache;
  	struct strlist *bidlist;
  	struct str_node *nd;
  	int ret;

  	bidlist = build_id_cache__list_all(false);

  	if (!bidlist) {
  		ret = -errno;
  		pr_debug("Failed to get buildids: %d
  ", ret);
  		return ret ?: -ENOMEM;
  	}
  
  	strlist__for_each_entry(nd, bidlist) {

  		cache = probe_cache__new(nd->s, NULL);

  		if (!cache)
  			continue;
  		if (probe_cache__filter_purge(cache, filter) < 0 ||
  		    probe_cache__commit(cache) < 0)
  			pr_warning("Failed to remove entries for %s
  ", nd->s);
  		probe_cache__delete(cache);
  	}
  	return 0;
  }

  static int perf_del_probe_events(struct strfilter *filter)
  {
  	int ret, ret2, ufd = -1, kfd = -1;
  	char *str = strfilter__string(filter);
  	struct strlist *klist = NULL, *ulist = NULL;
  	struct str_node *ent;
  
  	if (!str)
  		return -EINVAL;
  
  	pr_debug("Delete filter: \'%s\'
  ", str);

  	if (probe_conf.cache)
  		return del_perf_probe_caches(filter);

  	/* Get current event names */
  	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
  	if (ret < 0)
  		goto out;
  
  	klist = strlist__new(NULL, NULL);

  	ulist = strlist__new(NULL, NULL);
  	if (!klist || !ulist) {
  		ret = -ENOMEM;
  		goto out;
  	}

  
  	ret = probe_file__get_events(kfd, filter, klist);
  	if (ret == 0) {

  		strlist__for_each_entry(ent, klist)

  			pr_info("Removed event: %s
  ", ent->s);
  
  		ret = probe_file__del_strlist(kfd, klist);
  		if (ret < 0)
  			goto error;

  	} else if (ret == -ENOMEM)
  		goto error;

  
  	ret2 = probe_file__get_events(ufd, filter, ulist);
  	if (ret2 == 0) {

  		strlist__for_each_entry(ent, ulist)

  			pr_info("Removed event: %s
  ", ent->s);
  
  		ret2 = probe_file__del_strlist(ufd, ulist);
  		if (ret2 < 0)
  			goto error;

  	} else if (ret2 == -ENOMEM)
  		goto error;

  
  	if (ret == -ENOENT && ret2 == -ENOENT)

  		pr_warning("\"%s\" does not hit any event.
  ", str);
  	else
  		ret = 0;

  
  error:
  	if (kfd >= 0)
  		close(kfd);
  	if (ufd >= 0)
  		close(ufd);
  out:
  	strlist__delete(klist);
  	strlist__delete(ulist);
  	free(str);
  
  	return ret;
  }

  #ifdef HAVE_DWARF_SUPPORT
  #define PROBEDEF_STR	\
  	"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
  #else
  #define PROBEDEF_STR	"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
  #endif

  static int

  __cmd_probe(int argc, const char **argv)

  {
  	const char * const probe_usage[] = {
  		"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
  		"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
  		"perf probe [<options>] --del '[GROUP:]EVENT' ...",

  		"perf probe --list [GROUP:]EVENT ...",

  #ifdef HAVE_DWARF_SUPPORT

  		"perf probe [<options>] --line 'LINEDESC'",
  		"perf probe [<options>] --vars 'PROBEPOINT'",

  #endif

  		"perf probe [<options>] --funcs",

  		NULL

  	};

  	struct option options[] = {

  	OPT_INCR('v', "verbose", &verbose,

  		    "be more verbose (show parsed arguments, etc)"),

  	OPT_BOOLEAN('q', "quiet", &params.quiet,

  		    "be quiet (do not show any messages)"),

  	OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",

  			     "list up probe events",
  			     opt_set_filter_with_command, DEFAULT_LIST_FILTER),

  	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",

  		     opt_set_filter_with_command),

  	OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,

  		"probe point definition, where
  "

  		"\t\tGROUP:\tGroup name (optional)
  "
  		"\t\tEVENT:\tEvent name
  "

  		"\t\tFUNC:\tFunction name
  "

  		"\t\tOFF:\tOffset from function entry (in byte)
  "

  		"\t\t%return:\tPut the probe at function return
  "

  #ifdef HAVE_DWARF_SUPPORT

  		"\t\tSRC:\tSource code path
  "

  		"\t\tRL:\tRelative line number from function entry.
  "
  		"\t\tAL:\tAbsolute line number in file.
  "
  		"\t\tPT:\tLazy expression of line code.
  "

  		"\t\tARG:\tProbe argument (local variable name or
  "

  		"\t\t\tkprobe-tracer argument format.)
  ",

  #else
  		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)
  ",
  #endif

  		opt_add_probe_event),

  	OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
  		"Show trace event definition of given traceevent for k/uprobe_events.",
  		opt_add_probe_event),

  	OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"

  		    " with existing name"),

  	OPT_CALLBACK('L', "line", NULL,

  		     "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",

  		     "Show source code lines.", opt_show_lines),

  	OPT_CALLBACK('V', "vars", NULL,
  		     "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
  		     "Show accessible variables on PROBEDEF", opt_show_vars),

  	OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,

  		    "Show external variables too (with --vars only)"),

  	OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
  		"Show variables location range in scope (with --vars only)"),

  	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
  		   "file", "vmlinux pathname"),

  	OPT_STRING('s', "source", &symbol_conf.source_prefix,
  		   "directory", "path to kernel source"),

  	OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
  		"Don't search inlined functions"),

  	OPT__DRY_RUN(&probe_event_dry_run),

  	OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,

  		 "Set how many probe points can be found for a probe."),

  	OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
  			     "Show potential probe-able functions.",

  			     opt_set_filter_with_command, DEFAULT_FUNC_FILTER),

  	OPT_CALLBACK('\0', "filter", NULL,
  		     "[!]FILTER", "Set a filter (with --vars/funcs only)
  "
  		     "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,
  "
  		     "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
  		     opt_set_filter),

  	OPT_CALLBACK('x', "exec", NULL, "executable|path",
  			"target executable name or path", opt_set_target),

  	OPT_CALLBACK('m', "module", NULL, "modname|path",
  		"target module name (for online) or path (for offline)",
  		opt_set_target),

  	OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,

  		    "Enable symbol demangling"),

  	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
  		    "Enable kernel symbol demangling"),

  	OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),

  	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
  		   "Look for files with symbols relative to this directory"),

  	OPT_CALLBACK(0, "target-ns", NULL, "pid",
  		     "target pid for namespace contexts", opt_set_target_ns),

  	OPT_END()

  	};

  	int ret;

  	set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
  	set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);

  	set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);

  	set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
  #ifdef HAVE_DWARF_SUPPORT
  	set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
  	set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);

  #else
  # define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
  	set_nobuild('L', "line", false);
  	set_nobuild('V', "vars", false);
  	set_nobuild('\0', "externs", false);
  	set_nobuild('\0', "range", false);
  	set_nobuild('k', "vmlinux", true);
  	set_nobuild('s', "source", true);
  	set_nobuild('\0', "no-inlines", true);
  # undef set_nobuild

  #endif

  	set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);

  	argc = parse_options(argc, argv, options, probe_usage,

  			     PARSE_OPT_STOP_AT_NON_OPTION);

  	if (argc > 0) {
  		if (strcmp(argv[0], "-") == 0) {

  			usage_with_options_msg(probe_usage, options,
  				"'-' is not supported.
  ");

  		}

  		if (params.command && params.command != 'a') {

  			usage_with_options_msg(probe_usage, options,
  				"another command except --add is set.
  ");

  		}

  		ret = parse_probe_event_argv(argc, argv);
  		if (ret < 0) {

  			pr_err_with_code("  Error: Command Parse Error.", ret);

  			return ret;
  		}

  		params.command = 'a';

  	}

  	if (params.quiet) {
  		if (verbose != 0) {
  			pr_err("  Error: -v and -q are exclusive.
  ");
  			return -EINVAL;
  		}
  		verbose = -1;
  	}

  	if (probe_conf.max_probes == 0)
  		probe_conf.max_probes = MAX_PROBES;

  	/*
  	 * Only consider the user's kernel image path if given.
  	 */
  	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);

  	/*
  	 * Except for --list, --del and --add, other command doesn't depend
  	 * nor change running kernel. So if user gives offline vmlinux,
  	 * ignore its buildid.
  	 */
  	if (!strchr("lda", params.command) && symbol_conf.vmlinux_name)
  		symbol_conf.ignore_vmlinux_buildid = true;

  	switch (params.command) {
  	case 'l':

  		if (params.uprobes) {

  			pr_err("  Error: Don't use --list with --exec.
  ");
  			parse_options_usage(probe_usage, options, "l", true);
  			parse_options_usage(NULL, options, "x", true);
  			return -EINVAL;

  		}

  		ret = show_perf_probe_events(params.filter);

  		if (ret < 0)

  			pr_err_with_code("  Error: Failed to show event list.", ret);

  		return ret;

  	case 'F':

  		ret = show_available_funcs(params.target, params.nsi,
  					   params.filter, params.uprobes);

  		if (ret < 0)

  			pr_err_with_code("  Error: Failed to show functions.", ret);

  		return ret;

  #ifdef HAVE_DWARF_SUPPORT

  	case 'L':

  		ret = show_line_range(&params.line_range, params.target,

  				      params.nsi, params.uprobes);

  		if (ret < 0)

  			pr_err_with_code("  Error: Failed to show lines.", ret);

  		return ret;

  	case 'V':

  		if (!params.filter)
  			params.filter = strfilter__new(DEFAULT_VAR_FILTER,
  						       NULL);

  		ret = show_available_vars(params.events, params.nevents,

  					  params.filter);

  		if (ret < 0)

  			pr_err_with_code("  Error: Failed to show vars.", ret);

  		return ret;

  #endif

  	case 'd':

  		ret = perf_del_probe_events(params.filter);

  		if (ret < 0) {

  			pr_err_with_code("  Error: Failed to delete events.", ret);

  			return ret;
  		}

  		break;

  	case 'D':

  	case 'a':

  		/* Ensure the last given target is used */
  		if (params.target && !params.target_used) {

  			pr_err("  Error: -x/-m must follow the probe definitions.
  ");
  			parse_options_usage(probe_usage, options, "m", true);
  			parse_options_usage(NULL, options, "x", true);
  			return -EINVAL;

  		}

  		ret = perf_add_probe_events(params.events, params.nevents);

  		if (ret < 0) {

  
  			/*
  			 * When perf_add_probe_events() fails it calls
  			 * cleanup_perf_probe_events(pevs, npevs), i.e.
  			 * cleanup_perf_probe_events(params.events, params.nevents), which
  			 * will call clear_perf_probe_event(), so set nevents to zero
  			 * to avoid cleanup_params() to call clear_perf_probe_event() again
  			 * on the same pevs.
  			 */
  			params.nevents = 0;

  			pr_err_with_code("  Error: Failed to add events.", ret);

  			return ret;
  		}

  		break;
  	default:
  		usage_with_options(probe_usage, options);

  	}

  	return 0;
  }

  int cmd_probe(int argc, const char **argv)

  {
  	int ret;

  	ret = init_params();
  	if (!ret) {

  		ret = __cmd_probe(argc, argv);

  		cleanup_params();
  	}

  	return ret < 0 ? ret : 0;

  }