// SPDX-License-Identifier: GPL-2.0#ifndef _GNU_SOURCE# define _GNU_SOURCE#endif #include <stdio.h>#include <stdlib.h>#include <string.h>#include <linux/string.h>#include <errno.h>#include <unistd.h>#include "fs.h" #include "tracing_path.h" static char tracing_path[PATH_MAX]        = "/sys/kernel/tracing"; static void __tracing_path_set(const char *tracing, const char *mountpoint){	snprintf(tracing_path, sizeof(tracing_path), "%s/%s",		 mountpoint, tracing);} static const char *tracing_path_tracefs_mount(void){	const char *mnt; 	mnt = tracefs__mount();	if (!mnt)		return NULL; 	__tracing_path_set("", mnt); 	return tracing_path;} static const char *tracing_path_debugfs_mount(void){	const char *mnt; 	mnt = debugfs__mount();	if (!mnt)		return NULL; 	__tracing_path_set("tracing/", mnt); 	return tracing_path;} const char *tracing_path_mount(void){	const char *mnt; 	mnt = tracing_path_tracefs_mount();	if (mnt)		return mnt; 	mnt = tracing_path_debugfs_mount(); 	return mnt;} void tracing_path_set(const char *mntpt){	__tracing_path_set("tracing/", mntpt);} char *get_tracing_file(const char *name){	char *file; 	if (asprintf(&file, "%s%s", tracing_path_mount(), name) < 0)		return NULL; 	return file;} void put_tracing_file(char *file){	free(file);} char *get_events_file(const char *name){	char *file; 	if (asprintf(&file, "%s/events/%s", tracing_path_mount(), name) < 0)		return NULL; 	return file;} void put_events_file(char *file){	free(file);} DIR *tracing_events__opendir(void){	DIR *dir = NULL;	char *path = get_tracing_file("events"); 	if (path) {		dir = opendir(path);		put_events_file(path);	} 	return dir;} int tracing_events__scandir_alphasort(struct dirent ***namelist){	char *path = get_tracing_file("events");	int ret; 	if (!path) {		*namelist = NULL;		return 0;	} 	ret = scandir(path, namelist, NULL, alphasort);	put_events_file(path); 	return ret;} int tracing_path__strerror_open_tp(int err, char *buf, size_t size,				   const char *sys, const char *name){	char sbuf[128];	char filename[PATH_MAX]; 	snprintf(filename, PATH_MAX, "%s/%s", sys, name ?: "*"); 	switch (err) {	case ENOENT:		/*		 * We will get here if we can't find the tracepoint, but one of		 * debugfs or tracefs is configured, which means you probably		 * want some tracepoint which wasn't compiled in your kernel.		 * - jirka		 */		if (debugfs__configured() || tracefs__configured()) {			/* sdt markers */			if (!strncmp(filename, "sdt_", 4)) {				snprintf(buf, size,					"Error:\tFile %s/events/%s not found.\n"					"Hint:\tSDT event cannot be directly recorded on.\n"					"\tPlease first use 'perf probe %s:%s' before recording it.\n",					tracing_path, filename, sys, name);			} else {				snprintf(buf, size,					 "Error:\tFile %s/events/%s not found.\n"					 "Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n",					 tracing_path, filename);			}			break;		}		snprintf(buf, size, "%s",			 "Error:\tUnable to find debugfs/tracefs\n"			 "Hint:\tWas your kernel compiled with debugfs/tracefs support?\n"			 "Hint:\tIs the debugfs/tracefs filesystem mounted?\n"			 "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");		break;	case EACCES: {		snprintf(buf, size,			 "Error:\tNo permissions to read %s/events/%s\n"			 "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",			 tracing_path, filename, tracing_path_mount());	}		break;	default:		snprintf(buf, size, "%s", str_error_r(err, sbuf, sizeof(sbuf)));		break;	} 	return 0;}