1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 2592d5a6bSJiri Olsa #ifndef _GNU_SOURCE 3592d5a6bSJiri Olsa # define _GNU_SOURCE 4592d5a6bSJiri Olsa #endif 5592d5a6bSJiri Olsa 6592d5a6bSJiri Olsa #include <stdio.h> 7592d5a6bSJiri Olsa #include <stdlib.h> 8592d5a6bSJiri Olsa #include <string.h> 9b31e3e33SArnaldo Carvalho de Melo #include <linux/string.h> 10988bdb31SJiri Olsa #include <errno.h> 11988bdb31SJiri Olsa #include <unistd.h> 124605eab3SJiri Olsa #include "fs.h" 13592d5a6bSJiri Olsa 14592d5a6bSJiri Olsa #include "tracing_path.h" 15592d5a6bSJiri Olsa 16592d5a6bSJiri Olsa 17ccb5597fSJiri Olsa char tracing_mnt[PATH_MAX] = "/sys/kernel/debug"; 18ccb5597fSJiri Olsa char tracing_path[PATH_MAX] = "/sys/kernel/debug/tracing"; 19ccb5597fSJiri Olsa char tracing_events_path[PATH_MAX] = "/sys/kernel/debug/tracing/events"; 20592d5a6bSJiri Olsa 21592d5a6bSJiri Olsa 22592d5a6bSJiri Olsa static void __tracing_path_set(const char *tracing, const char *mountpoint) 23592d5a6bSJiri Olsa { 24dc240c5dSJiri Olsa snprintf(tracing_mnt, sizeof(tracing_mnt), "%s", mountpoint); 25592d5a6bSJiri Olsa snprintf(tracing_path, sizeof(tracing_path), "%s/%s", 26592d5a6bSJiri Olsa mountpoint, tracing); 27592d5a6bSJiri Olsa snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s", 28592d5a6bSJiri Olsa mountpoint, tracing, "events"); 29592d5a6bSJiri Olsa } 30592d5a6bSJiri Olsa 31592d5a6bSJiri Olsa static const char *tracing_path_tracefs_mount(void) 32592d5a6bSJiri Olsa { 33592d5a6bSJiri Olsa const char *mnt; 34592d5a6bSJiri Olsa 354605eab3SJiri Olsa mnt = tracefs__mount(); 36592d5a6bSJiri Olsa if (!mnt) 37592d5a6bSJiri Olsa return NULL; 38592d5a6bSJiri Olsa 39592d5a6bSJiri Olsa __tracing_path_set("", mnt); 40592d5a6bSJiri Olsa 41592d5a6bSJiri Olsa return mnt; 42592d5a6bSJiri Olsa } 43592d5a6bSJiri Olsa 44592d5a6bSJiri Olsa static const char *tracing_path_debugfs_mount(void) 45592d5a6bSJiri Olsa { 46592d5a6bSJiri Olsa const char *mnt; 47592d5a6bSJiri Olsa 484605eab3SJiri Olsa mnt = debugfs__mount(); 49592d5a6bSJiri Olsa if (!mnt) 50592d5a6bSJiri Olsa return NULL; 51592d5a6bSJiri Olsa 52592d5a6bSJiri Olsa __tracing_path_set("tracing/", mnt); 53592d5a6bSJiri Olsa 54592d5a6bSJiri Olsa return mnt; 55592d5a6bSJiri Olsa } 56592d5a6bSJiri Olsa 57592d5a6bSJiri Olsa const char *tracing_path_mount(void) 58592d5a6bSJiri Olsa { 59592d5a6bSJiri Olsa const char *mnt; 60592d5a6bSJiri Olsa 61592d5a6bSJiri Olsa mnt = tracing_path_tracefs_mount(); 62592d5a6bSJiri Olsa if (mnt) 63592d5a6bSJiri Olsa return mnt; 64592d5a6bSJiri Olsa 65592d5a6bSJiri Olsa mnt = tracing_path_debugfs_mount(); 66592d5a6bSJiri Olsa 67592d5a6bSJiri Olsa return mnt; 68592d5a6bSJiri Olsa } 69592d5a6bSJiri Olsa 70592d5a6bSJiri Olsa void tracing_path_set(const char *mntpt) 71592d5a6bSJiri Olsa { 72592d5a6bSJiri Olsa __tracing_path_set("tracing/", mntpt); 73592d5a6bSJiri Olsa } 74592d5a6bSJiri Olsa 75592d5a6bSJiri Olsa char *get_tracing_file(const char *name) 76592d5a6bSJiri Olsa { 77592d5a6bSJiri Olsa char *file; 78592d5a6bSJiri Olsa 79592d5a6bSJiri Olsa if (asprintf(&file, "%s/%s", tracing_path, name) < 0) 80592d5a6bSJiri Olsa return NULL; 81592d5a6bSJiri Olsa 82592d5a6bSJiri Olsa return file; 83592d5a6bSJiri Olsa } 84592d5a6bSJiri Olsa 85592d5a6bSJiri Olsa void put_tracing_file(char *file) 86592d5a6bSJiri Olsa { 87592d5a6bSJiri Olsa free(file); 88592d5a6bSJiri Olsa } 89988bdb31SJiri Olsa 9027cf5706SRavi Bangoria int tracing_path__strerror_open_tp(int err, char *buf, size_t size, 9127cf5706SRavi Bangoria const char *sys, const char *name) 92988bdb31SJiri Olsa { 93988bdb31SJiri Olsa char sbuf[128]; 9427cf5706SRavi Bangoria char filename[PATH_MAX]; 9527cf5706SRavi Bangoria 9627cf5706SRavi Bangoria snprintf(filename, PATH_MAX, "%s/%s", sys, name ?: "*"); 97988bdb31SJiri Olsa 98988bdb31SJiri Olsa switch (err) { 99988bdb31SJiri Olsa case ENOENT: 1004f234f06SJiri Olsa /* 1014f234f06SJiri Olsa * We will get here if we can't find the tracepoint, but one of 1024f234f06SJiri Olsa * debugfs or tracefs is configured, which means you probably 1034f234f06SJiri Olsa * want some tracepoint which wasn't compiled in your kernel. 1044f234f06SJiri Olsa * - jirka 1054f234f06SJiri Olsa */ 1064605eab3SJiri Olsa if (debugfs__configured() || tracefs__configured()) { 10727cf5706SRavi Bangoria /* sdt markers */ 10827cf5706SRavi Bangoria if (!strncmp(filename, "sdt_", 4)) { 10927cf5706SRavi Bangoria snprintf(buf, size, 11027cf5706SRavi Bangoria "Error:\tFile %s/%s not found.\n" 11127cf5706SRavi Bangoria "Hint:\tSDT event cannot be directly recorded on.\n" 11227cf5706SRavi Bangoria "\tPlease first use 'perf probe %s:%s' before recording it.\n", 11327cf5706SRavi Bangoria tracing_events_path, filename, sys, name); 11427cf5706SRavi Bangoria } else { 115988bdb31SJiri Olsa snprintf(buf, size, 116988bdb31SJiri Olsa "Error:\tFile %s/%s not found.\n" 117988bdb31SJiri Olsa "Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n", 1184f234f06SJiri Olsa tracing_events_path, filename); 11927cf5706SRavi Bangoria } 120988bdb31SJiri Olsa break; 121988bdb31SJiri Olsa } 122988bdb31SJiri Olsa snprintf(buf, size, "%s", 1234f234f06SJiri Olsa "Error:\tUnable to find debugfs/tracefs\n" 1244f234f06SJiri Olsa "Hint:\tWas your kernel compiled with debugfs/tracefs support?\n" 1254f234f06SJiri Olsa "Hint:\tIs the debugfs/tracefs filesystem mounted?\n" 126988bdb31SJiri Olsa "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'"); 127988bdb31SJiri Olsa break; 128988bdb31SJiri Olsa case EACCES: { 129988bdb31SJiri Olsa snprintf(buf, size, 130988bdb31SJiri Olsa "Error:\tNo permissions to read %s/%s\n" 131988bdb31SJiri Olsa "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n", 132dc240c5dSJiri Olsa tracing_events_path, filename, tracing_mnt); 133988bdb31SJiri Olsa } 134988bdb31SJiri Olsa break; 135988bdb31SJiri Olsa default: 136b31e3e33SArnaldo Carvalho de Melo snprintf(buf, size, "%s", str_error_r(err, sbuf, sizeof(sbuf))); 137988bdb31SJiri Olsa break; 138988bdb31SJiri Olsa } 139988bdb31SJiri Olsa 140988bdb31SJiri Olsa return 0; 141988bdb31SJiri Olsa } 142