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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 | // 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" char tracing_mnt[PATH_MAX] = "/sys/kernel/debug"; char tracing_path[PATH_MAX] = "/sys/kernel/debug/tracing"; char tracing_events_path[PATH_MAX] = "/sys/kernel/debug/tracing/events"; static void __tracing_path_set(const char *tracing, const char *mountpoint) { snprintf(tracing_mnt, sizeof(tracing_mnt), "%s", mountpoint); snprintf(tracing_path, sizeof(tracing_path), "%s/%s", mountpoint, tracing); snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s", mountpoint, tracing, "events"); } static const char *tracing_path_tracefs_mount(void) { const char *mnt; mnt = tracefs__mount(); if (!mnt) return NULL; __tracing_path_set("", mnt); return mnt; } static const char *tracing_path_debugfs_mount(void) { const char *mnt; mnt = debugfs__mount(); if (!mnt) return NULL; __tracing_path_set("tracing/", mnt); return mnt; } 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, name) < 0) return NULL; return file; } void put_tracing_file(char *file) { free(file); } 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/%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_events_path, filename, sys, name); } else { snprintf(buf, size, "Error:\tFile %s/%s not found.\n" "Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n", tracing_events_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/%s\n" "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n", tracing_events_path, filename, tracing_mnt); } break; default: snprintf(buf, size, "%s", str_error_r(err, sbuf, sizeof(sbuf))); break; } return 0; } |