[lttng-ust.git] / include / usterr-signal-safe.h

/*
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 * Copyright (C) 2009 Pierre-Marc Fournier
 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#ifndef _USTERR_SIGNAL_SAFE_H
#define _USTERR_SIGNAL_SAFE_H

#include <string.h>
#include <sys/types.h>
#include <errno.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <ust-share.h>
#include "ust-tid.h"
#include "ust-snprintf.h"

enum ust_err_loglevel {
	UST_ERR_LOGLEVEL_UNKNOWN = 0,
	UST_ERR_LOGLEVEL_NORMAL,
	UST_ERR_LOGLEVEL_DEBUG,
};

__attribute__((visibility("hidden")))
extern volatile enum ust_err_loglevel ust_err_loglevel;

__attribute__((visibility("hidden")))
void ust_err_init(void);

#ifdef LTTNG_UST_DEBUG
static inline bool ust_err_debug_enabled(void)
{
	return true;
}
#else /* #ifdef LTTNG_UST_DEBUG */
static inline bool ust_err_debug_enabled(void)
{
	return ust_err_loglevel == UST_ERR_LOGLEVEL_DEBUG;
}
#endif /* #else #ifdef LTTNG_UST_DEBUG */

/*
 * The default component for error messages.
 */
#ifndef UST_COMPONENT
#define UST_COMPONENT libust
#endif

/* To stringify the expansion of a define */
#define UST_XSTR(d) UST_STR(d)
#define UST_STR(s) #s

#define UST_ERR_MAX_LEN	512

/*
 * We sometimes print in the tracing path, and tracing can occur in
 * signal handlers, so we must use a print method which is signal safe.
 */
/* Can't use dynamic allocation. Limit ourselves to UST_ERR_MAX_LEN chars. */
/* Add end of string in case of buffer overflow. */
#define sigsafe_print_err(fmt, args...)					\
do {									\
	if (ust_err_debug_enabled()) {					\
		char ____buf[UST_ERR_MAX_LEN];				\
		int ____saved_errno;					\
									\
		____saved_errno = errno;	/* signal-safety */	\
		ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
		____buf[sizeof(____buf) - 1] = 0;			\
		ust_patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
		errno = ____saved_errno;	/* signal-safety */	\
		fflush(stderr);						\
	}								\
} while (0)

#define UST_STR_COMPONENT UST_XSTR(UST_COMPONENT)

#define ERRMSG(fmt, args...)			\
	do {					\
		sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" UST_XSTR(__LINE__) ")\n", \
		(long) getpid(),		\
		(long) lttng_gettid(),		\
		## args, __func__);		\
	} while(0)


#define DBG(fmt, args...)	ERRMSG(fmt, ## args)
#define DBG_raw(fmt, args...)	sigsafe_print_err(fmt, ## args)
#define WARN(fmt, args...)	ERRMSG("Warning: " fmt, ## args)
#define ERR(fmt, args...)	ERRMSG("Error: " fmt, ## args)
#define BUG(fmt, args...)	ERRMSG("BUG: " fmt, ## args)

#if !defined(__GLIBC__) || ((_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE))
/*
 * Version using XSI strerror_r.
 */
#define PERROR(call, args...)						\
	do {								\
		if (ust_err_debug_enabled()) {				\
			char perror_buf[200] = "Error in strerror_r()";	\
			strerror_r(errno, perror_buf,			\
					sizeof(perror_buf));		\
			ERRMSG("Error: " call ": %s", ## args, 		\
					perror_buf);			\
		}							\
	} while(0)
#else
/*
 * Version using GNU strerror_r, for linux with appropriate defines.
 */
#define PERROR(call, args...)						\
	do {								\
		if (ust_err_debug_enabled()) {				\
			char *perror_buf;				\
			char perror_tmp[200];				\
			perror_buf = strerror_r(errno, perror_tmp,	\
					sizeof(perror_tmp));		\
			ERRMSG("Error: " call ": %s", ## args,		\
					perror_buf);			\
		}							\
	} while(0)
#endif

#define BUG_ON(condition)					\
	do {							\
		if (caa_unlikely(condition))			\
			ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__);	\
	} while(0)
#define WARN_ON(condition)					\
	do {							\
		if (caa_unlikely(condition))			\
			WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
	} while(0)
#define WARN_ON_ONCE(condition) WARN_ON(condition)

#endif /* _USTERR_SIGNAL_SAFE_H */
Commit	Line	Data
	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 _USTERR_SIGNAL_SAFE_H
	9	#define _USTERR_SIGNAL_SAFE_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	#include <ust-share.h>
	18	#include "ust-tid.h"
	19	#include "ust-snprintf.h"
	20
	21	enum ust_err_loglevel {
	22	UST_ERR_LOGLEVEL_UNKNOWN = 0,
	23	UST_ERR_LOGLEVEL_NORMAL,
	24	UST_ERR_LOGLEVEL_DEBUG,
	25	};
	26
	27	__attribute__((visibility("hidden")))
	28	extern volatile enum ust_err_loglevel ust_err_loglevel;
	29
	30	__attribute__((visibility("hidden")))
	31	void ust_err_init(void);
	32
	33	#ifdef LTTNG_UST_DEBUG
	34	static inline bool ust_err_debug_enabled(void)
	35	{
	36	return true;
	37	}
	38	#else /* #ifdef LTTNG_UST_DEBUG */
	39	static inline bool ust_err_debug_enabled(void)
	40	{
	41	return ust_err_loglevel == UST_ERR_LOGLEVEL_DEBUG;
	42	}
	43	#endif /* #else #ifdef LTTNG_UST_DEBUG */
	44
	45	/*
	46	* The default component for error messages.
	47	*/
	48	#ifndef UST_COMPONENT
	49	#define UST_COMPONENT libust
	50	#endif
	51
	52	/* To stringify the expansion of a define */
	53	#define UST_XSTR(d) UST_STR(d)
	54	#define UST_STR(s) #s
	55
	56	#define UST_ERR_MAX_LEN 512
	57
	58	/*
	59	* We sometimes print in the tracing path, and tracing can occur in
	60	* signal handlers, so we must use a print method which is signal safe.
	61	*/
	62	/* Can't use dynamic allocation. Limit ourselves to UST_ERR_MAX_LEN chars. */
	63	/* Add end of string in case of buffer overflow. */
	64	#define sigsafe_print_err(fmt, args...) \
	65	do { \
	66	if (ust_err_debug_enabled()) { \
	67	char ____buf[UST_ERR_MAX_LEN]; \
	68	int ____saved_errno; \
	69	\
	70	____saved_errno = errno; /* signal-safety */ \
	71	ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
	72	____buf[sizeof(____buf) - 1] = 0; \
	73	ust_patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
	74	errno = ____saved_errno; /* signal-safety */ \
	75	fflush(stderr); \
	76	} \
	77	} while (0)
	78
	79	#define UST_STR_COMPONENT UST_XSTR(UST_COMPONENT)
	80
	81	#define ERRMSG(fmt, args...) \
	82	do { \
	83	sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" UST_XSTR(__LINE__) ")\n", \
	84	(long) getpid(), \
	85	(long) lttng_gettid(), \
	86	## args, __func__); \
	87	} while(0)
	88
	89
	90	#define DBG(fmt, args...) ERRMSG(fmt, ## args)
	91	#define DBG_raw(fmt, args...) sigsafe_print_err(fmt, ## args)
	92	#define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
	93	#define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
	94	#define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
	95
	96	#if !defined(__GLIBC__) \|\| ((_POSIX_C_SOURCE >= 200112L \|\| _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE))
	97	/*
	98	* Version using XSI strerror_r.
	99	*/
	100	#define PERROR(call, args...) \
	101	do { \
	102	if (ust_err_debug_enabled()) { \
	103	char perror_buf[200] = "Error in strerror_r()"; \
	104	strerror_r(errno, perror_buf, \
	105	sizeof(perror_buf)); \
	106	ERRMSG("Error: " call ": %s", ## args, \
	107	perror_buf); \
	108	} \
	109	} while(0)
	110	#else
	111	/*
	112	* Version using GNU strerror_r, for linux with appropriate defines.
	113	*/
	114	#define PERROR(call, args...) \
	115	do { \
	116	if (ust_err_debug_enabled()) { \
	117	char *perror_buf; \
	118	char perror_tmp[200]; \
	119	perror_buf = strerror_r(errno, perror_tmp, \
	120	sizeof(perror_tmp)); \
	121	ERRMSG("Error: " call ": %s", ## args, \
	122	perror_buf); \
	123	} \
	124	} while(0)
	125	#endif
	126
	127	#define BUG_ON(condition) \
	128	do { \
	129	if (caa_unlikely(condition)) \
	130	ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
	131	} while(0)
	132	#define WARN_ON(condition) \
	133	do { \
	134	if (caa_unlikely(condition)) \
	135	WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
	136	} while(0)
	137	#define WARN_ON_ONCE(condition) WARN_ON(condition)
	138
	139	#endif /* _USTERR_SIGNAL_SAFE_H */