| 1 | /* |
| 2 | * SPDX-License-Identifier: LGPL-2.1-only |
| 3 | * |
| 4 | * Copyright (C) 2009 Pierre-Marc Fournier |
| 5 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 6 | */ |
| 7 | |
| 8 | #ifndef _UST_COMMON_LOGGING_H |
| 9 | #define _UST_COMMON_LOGGING_H |
| 10 | |
| 11 | #include <string.h> |
| 12 | #include <sys/types.h> |
| 13 | #include <errno.h> |
| 14 | #include <stdarg.h> |
| 15 | #include <stdbool.h> |
| 16 | #include <stdio.h> |
| 17 | |
| 18 | #include <lttng/ust-utils.h> |
| 19 | #include <urcu/compiler.h> |
| 20 | #include <urcu/system.h> |
| 21 | |
| 22 | #include "common/patient.h" |
| 23 | #include "common/compat/tid.h" |
| 24 | #include "common/safe-snprintf.h" |
| 25 | |
| 26 | enum lttng_ust_log_level { |
| 27 | LTTNG_UST_LOG_LEVEL_UNKNOWN = 0, |
| 28 | LTTNG_UST_LOG_LEVEL_SILENT, |
| 29 | LTTNG_UST_LOG_LEVEL_DEBUG, |
| 30 | }; |
| 31 | |
| 32 | enum lttng_ust_log_critical_action { |
| 33 | LTTNG_UST_LOG_CRITICAL_ACTION_UNKNOWN = 0, |
| 34 | LTTNG_UST_LOG_CRITICAL_ACTION_NONE, |
| 35 | LTTNG_UST_LOG_CRITICAL_ACTION_ABORT, |
| 36 | }; |
| 37 | |
| 38 | extern int lttng_ust_log_level /* enum lttng_ust_log_level */ |
| 39 | __attribute__((visibility("hidden"))); |
| 40 | |
| 41 | extern int lttng_ust_log_critical_action /* enum lttng_ust_log_critical_action */ |
| 42 | __attribute__((visibility("hidden"))); |
| 43 | |
| 44 | /* |
| 45 | * Initialize the global log level from the "LTTNG_UST_DEBUG" environment |
| 46 | * variable and the global log critical action from "LTTNG_UST_ABORT_ON_CRITICAL". |
| 47 | * |
| 48 | * This could end up being called concurrently by multiple threads but doesn't |
| 49 | * require a mutex since the input is invariant across threads and the result |
| 50 | * will be the same. |
| 51 | */ |
| 52 | void lttng_ust_logging_init(void) |
| 53 | __attribute__((visibility("hidden"))); |
| 54 | |
| 55 | #ifdef LTTNG_UST_DEBUG |
| 56 | static inline |
| 57 | bool lttng_ust_logging_debug_enabled(void) |
| 58 | { |
| 59 | return true; |
| 60 | } |
| 61 | #else /* #ifdef LTTNG_UST_DEBUG */ |
| 62 | static inline |
| 63 | bool lttng_ust_logging_debug_enabled(void) |
| 64 | { |
| 65 | int current_log_level; |
| 66 | |
| 67 | current_log_level = CMM_LOAD_SHARED(lttng_ust_log_level); |
| 68 | |
| 69 | /* If the global log level is unknown, lazy-initialize it. */ |
| 70 | if (caa_unlikely(current_log_level == LTTNG_UST_LOG_LEVEL_UNKNOWN)) { |
| 71 | lttng_ust_logging_init(); |
| 72 | current_log_level = CMM_LOAD_SHARED(lttng_ust_log_level); |
| 73 | } |
| 74 | |
| 75 | return current_log_level == LTTNG_UST_LOG_LEVEL_DEBUG; |
| 76 | } |
| 77 | #endif /* #ifdef LTTNG_UST_DEBUG */ |
| 78 | |
| 79 | #ifdef LTTNG_UST_ABORT_ON_CRITICAL |
| 80 | static inline |
| 81 | bool lttng_ust_logging_abort_on_critical_enabled(void) |
| 82 | { |
| 83 | return true; |
| 84 | } |
| 85 | #else /* #ifdef LTTNG_UST_ABORT_ON_CRITICAL */ |
| 86 | static inline |
| 87 | bool lttng_ust_logging_abort_on_critical_enabled(void) |
| 88 | { |
| 89 | int current_log_critical_action; |
| 90 | |
| 91 | current_log_critical_action = CMM_LOAD_SHARED(lttng_ust_log_critical_action); |
| 92 | |
| 93 | /* If the global log critical action is unknown, lazy-initialize it. */ |
| 94 | if (caa_unlikely(current_log_critical_action == LTTNG_UST_LOG_CRITICAL_ACTION_UNKNOWN)) { |
| 95 | lttng_ust_logging_init(); |
| 96 | current_log_critical_action = CMM_LOAD_SHARED(lttng_ust_log_critical_action); |
| 97 | } |
| 98 | |
| 99 | return current_log_critical_action == LTTNG_UST_LOG_CRITICAL_ACTION_ABORT; |
| 100 | } |
| 101 | #endif /* #ifdef LTTNG_UST_ABORT_ON_CRITICAL */ |
| 102 | |
| 103 | /* |
| 104 | * The default component for log statements. |
| 105 | */ |
| 106 | #ifndef UST_COMPONENT |
| 107 | #define UST_COMPONENT libust |
| 108 | #endif |
| 109 | |
| 110 | #define LTTNG_UST_LOG_MAX_LEN 512 |
| 111 | |
| 112 | /* |
| 113 | * We sometimes print in the tracing path, and tracing can occur in |
| 114 | * signal handlers, so we must use a print method which is signal safe. |
| 115 | */ |
| 116 | /* Can't use dynamic allocation. Limit ourselves to LTTNG_UST_LOG_MAX_LEN chars. */ |
| 117 | /* Add end of string in case of buffer overflow. */ |
| 118 | #define sigsafe_print_err(fmt, args...) \ |
| 119 | do { \ |
| 120 | if (lttng_ust_logging_debug_enabled()) { \ |
| 121 | char ____buf[LTTNG_UST_LOG_MAX_LEN]; \ |
| 122 | int ____saved_errno; \ |
| 123 | \ |
| 124 | ____saved_errno = errno; /* signal-safety */ \ |
| 125 | ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \ |
| 126 | ____buf[sizeof(____buf) - 1] = 0; \ |
| 127 | ust_patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \ |
| 128 | errno = ____saved_errno; /* signal-safety */ \ |
| 129 | fflush(stderr); \ |
| 130 | } \ |
| 131 | } while (0) |
| 132 | |
| 133 | #define LTTNG_UST_STR_COMPONENT lttng_ust_stringify(UST_COMPONENT) |
| 134 | |
| 135 | #define ERRMSG(fmt, args...) \ |
| 136 | do { \ |
| 137 | sigsafe_print_err(LTTNG_UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" lttng_ust_stringify(__LINE__) ")\n", \ |
| 138 | (long) getpid(), \ |
| 139 | (long) lttng_gettid(), \ |
| 140 | ## args, __func__); \ |
| 141 | } while(0) |
| 142 | |
| 143 | |
| 144 | #define DBG(fmt, args...) ERRMSG(fmt, ## args) |
| 145 | #define DBG_raw(fmt, args...) sigsafe_print_err(fmt, ## args) |
| 146 | #define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args) |
| 147 | #define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args) |
| 148 | #define CRIT(fmt, args...) \ |
| 149 | do { \ |
| 150 | ERRMSG("Critical: " fmt, ## args); \ |
| 151 | if (lttng_ust_logging_abort_on_critical_enabled()) { \ |
| 152 | abort(); \ |
| 153 | } \ |
| 154 | } while(0) |
| 155 | |
| 156 | #if !defined(__GLIBC__) || ((_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE)) |
| 157 | /* |
| 158 | * Version using XSI strerror_r. |
| 159 | */ |
| 160 | #define PERROR(call, args...) \ |
| 161 | do { \ |
| 162 | if (lttng_ust_logging_debug_enabled()) { \ |
| 163 | char perror_buf[200] = "Error in strerror_r()"; \ |
| 164 | strerror_r(errno, perror_buf, \ |
| 165 | sizeof(perror_buf)); \ |
| 166 | ERRMSG("Error: " call ": %s", ## args, \ |
| 167 | perror_buf); \ |
| 168 | } \ |
| 169 | } while(0) |
| 170 | #else |
| 171 | /* |
| 172 | * Version using GNU strerror_r, for linux with appropriate defines. |
| 173 | */ |
| 174 | #define PERROR(call, args...) \ |
| 175 | do { \ |
| 176 | if (lttng_ust_logging_debug_enabled()) { \ |
| 177 | char *perror_buf; \ |
| 178 | char perror_tmp[200]; \ |
| 179 | perror_buf = strerror_r(errno, perror_tmp, \ |
| 180 | sizeof(perror_tmp)); \ |
| 181 | ERRMSG("Error: " call ": %s", ## args, \ |
| 182 | perror_buf); \ |
| 183 | } \ |
| 184 | } while(0) |
| 185 | #endif |
| 186 | |
| 187 | #define BUG_ON(condition) \ |
| 188 | do { \ |
| 189 | if (caa_unlikely(condition)) \ |
| 190 | ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \ |
| 191 | } while(0) |
| 192 | #define WARN_ON(condition) \ |
| 193 | do { \ |
| 194 | if (caa_unlikely(condition)) \ |
| 195 | WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \ |
| 196 | } while(0) |
| 197 | #define WARN_ON_ONCE(condition) WARN_ON(condition) |
| 198 | |
| 199 | #endif /* _UST_COMMON_LOGGING_H */ |