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

#ifndef _USTERR_SIGNAL_SAFE_H
#define _USTERR_SIGNAL_SAFE_H

/*
 * Copyright (C) 2009  Pierre-Marc Fournier
 * Copyright (C) 2011  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; version 2.1 of
 * the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <string.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>

#include <lttng/core.h>
#include <lttng/share.h>

enum ust_loglevel {
	UST_LOGLEVEL_UNKNOWN = 0,
	UST_LOGLEVEL_NORMAL,
	UST_LOGLEVEL_DEBUG,
};

extern volatile enum ust_loglevel ust_loglevel;
void init_usterr(void);

static inline int ust_debug(void)
{
	return ust_loglevel == UST_LOGLEVEL_DEBUG;
}

#ifndef UST_COMPONENT
//#error UST_COMPONENT is undefined
#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 USTERR_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.
 */

extern int ust_safe_snprintf(char *str, size_t n, const char *fmt, ...)
	__attribute__ ((format (printf, 3, 4)));

static inline void __attribute__ ((format (printf, 1, 2)))
	__check_ust_safe_fmt(const char *fmt, ...)
{
}

#define sigsafe_print_err(fmt, args...)					\
{									\
	/* Can't use dynamic allocation. Limit ourselves to USTERR_MAX_LEN chars. */ \
	char ____buf[USTERR_MAX_LEN];					\
	int ____saved_errno;						\
									\
	/* Save the errno. */						\
	____saved_errno = errno;					\
									\
	ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args);	\
									\
	/* Add end of string in case of buffer overflow. */		\
	____buf[sizeof(____buf) - 1] = 0;				\
									\
	patient_write(STDERR_FILENO, ____buf, strlen(____buf));		\
	/*								\
	 * Can't print errors because we are in the error printing code \
	 * path.							\
	 */								\
									\
	/* Restore errno, in order to be async-signal safe. */		\
	errno = ____saved_errno;					\
}

#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) syscall(SYS_gettid),	\
		## args, __func__);		\
		fflush(stderr);			\
	} while(0)

#ifdef LTTNG_UST_DEBUG
# define DBG(fmt, args...)			ERRMSG(fmt, ## args)
# define DBG_raw(fmt, args...)					\
	do {							\
		sigsafe_print_err(fmt, ## args);		\
		fflush(stderr);					\
	} while(0)
#else
# define DBG(fmt, args...)					\
	do {							\
		if (ust_debug())				\
			ERRMSG(fmt, ## args);			\
	} while (0)
# define DBG_raw(fmt, args...)					\
	do {							\
		if (ust_debug()) {				\
			sigsafe_print_err(fmt, ## args);	\
			fflush(stderr);				\
		}						\
	} while(0)
#endif
#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 (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE)
#define PERROR(call, args...)\
	do { \
		char buf[200] = "Error in strerror_r()"; \
		strerror_r(errno, buf, sizeof(buf)); \
		ERRMSG("Error: " call ": %s", ## args, buf); \
	} while(0);
#else
#define PERROR(call, args...)\
	do { \
		char *buf; \
		char tmp[200]; \
		buf = strerror_r(errno, tmp, sizeof(tmp)); \
		ERRMSG("Error: " call ": %s", ## args, 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
5e96a467 MD	1	#ifndef _USTERR_SIGNAL_SAFE_H
	2	#define _USTERR_SIGNAL_SAFE_H
	3
	4	/*
	5	* Copyright (C) 2009 Pierre-Marc Fournier
	6	* Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
30ffe279 NC	7	*
	8	* This library is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
5e96a467 MD	10	* License as published by the Free Software Foundation; version 2.1 of
5e96a467 MD	11	* the License.
30ffe279 NC	12	*
	13	* This library is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with this library; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	21	*/
	22
30ffe279 NC	23	#include <string.h>
	24	#include <sys/types.h>
	25	#include <sys/syscall.h>
	26	#include <errno.h>
	27	#include <stdarg.h>
	28	#include <stdio.h>
	29
4318ae1b MD	30	#include <lttng/core.h>
4318ae1b MD	31	#include <lttng/share.h>
30ffe279	32
5e96a467 MD	33	enum ust_loglevel {
	34	UST_LOGLEVEL_UNKNOWN = 0,
	35	UST_LOGLEVEL_NORMAL,
	36	UST_LOGLEVEL_DEBUG,
	37	};
	38
	39	extern volatile enum ust_loglevel ust_loglevel;
	40	void init_usterr(void);
	41
	42	static inline int ust_debug(void)
	43	{
	44	return ust_loglevel == UST_LOGLEVEL_DEBUG;
	45	}
	46
30ffe279 NC	47	#ifndef UST_COMPONENT
	48	//#error UST_COMPONENT is undefined
	49	#define UST_COMPONENT libust
	50	#endif
	51
	52	/* To stringify the expansion of a define */
1dbfff0c MD	53	#define UST_XSTR(d) UST_STR(d)
1dbfff0c MD	54	#define UST_STR(s) #s
30ffe279	55
37ed587a MD	56	#define USTERR_MAX_LEN 512
37ed587a MD	57
30ffe279 NC	58	/* We sometimes print in the tracing path, and tracing can occur in
	59	* signal handlers, so we must use a print method which is signal safe.
	60	*/
	61
	62	extern int ust_safe_snprintf(char str, size_t n, const char fmt, ...)
	63	__attribute__ ((format (printf, 3, 4)));
	64
	65	static inline void __attribute__ ((format (printf, 1, 2)))
	66	__check_ust_safe_fmt(const char *fmt, ...)
	67	{
	68	}
	69
5e96a467 MD	70	#define sigsafe_print_err(fmt, args...) \
5e96a467 MD	71	{ \
37ed587a MD	72	/* Can't use dynamic allocation. Limit ourselves to USTERR_MAX_LEN chars. */ \
37ed587a MD	73	char ____buf[USTERR_MAX_LEN]; \
5e96a467 MD	74	int ____saved_errno; \
	75	\
	76	/* Save the errno. */ \
	77	____saved_errno = errno; \
	78	\
	79	ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
	80	\
	81	/* Add end of string in case of buffer overflow. */ \
	82	____buf[sizeof(____buf) - 1] = 0; \
	83	\
	84	patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
	85	/* \
	86	* Can't print errors because we are in the error printing code \
	87	* path. \
	88	*/ \
	89	\
	90	/* Restore errno, in order to be async-signal safe. */ \
	91	errno = ____saved_errno; \
30ffe279 NC	92	}
30ffe279 NC	93
1dbfff0c	94	#define UST_STR_COMPONENT UST_XSTR(UST_COMPONENT)
30ffe279	95
5e96a467 MD	96	#define ERRMSG(fmt, args...) \
5e96a467 MD	97	do { \
1dbfff0c	98	sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" UST_XSTR(__LINE__) ")\n", \
5e96a467 MD	99	(long) getpid(), \
	100	(long) syscall(SYS_gettid), \
	101	## args, __func__); \
	102	fflush(stderr); \
	103	} while(0)
30ffe279	104
69400ac4	105	#ifdef LTTNG_UST_DEBUG
5e96a467 MD	106	# define DBG(fmt, args...) ERRMSG(fmt, ## args)
	107	# define DBG_raw(fmt, args...) \
	108	do { \
	109	sigsafe_print_err(fmt, ## args); \
	110	fflush(stderr); \
	111	} while(0)
30ffe279	112	#else
5e96a467 MD	113	# define DBG(fmt, args...) \
	114	do { \
	115	if (ust_debug()) \
	116	ERRMSG(fmt, ## args); \
	117	} while (0)
	118	# define DBG_raw(fmt, args...) \
	119	do { \
	120	if (ust_debug()) { \
	121	sigsafe_print_err(fmt, ## args); \
	122	fflush(stderr); \
	123	} \
	124	} while(0)
30ffe279 NC	125	#endif
	126	#define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
	127	#define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
	128	#define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
	129
	130	#if (_POSIX_C_SOURCE >= 200112L \|\| _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE)
	131	#define PERROR(call, args...)\
	132	do { \
	133	char buf[200] = "Error in strerror_r()"; \
	134	strerror_r(errno, buf, sizeof(buf)); \
	135	ERRMSG("Error: " call ": %s", ## args, buf); \
	136	} while(0);
	137	#else
	138	#define PERROR(call, args...)\
	139	do { \
	140	char *buf; \
	141	char tmp[200]; \
	142	buf = strerror_r(errno, tmp, sizeof(tmp)); \
	143	ERRMSG("Error: " call ": %s", ## args, buf); \
	144	} while(0);
	145	#endif
	146
5e96a467 MD	147	#define BUG_ON(condition) \
5e96a467 MD	148	do { \
b5a3dfa5	149	if (caa_unlikely(condition)) \
5e96a467 MD	150	ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
	151	} while(0)
	152	#define WARN_ON(condition) \
	153	do { \
b5a3dfa5	154	if (caa_unlikely(condition)) \
5e96a467 MD	155	WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
5e96a467 MD	156	} while(0)
30ffe279 NC	157	#define WARN_ON_ONCE(condition) WARN_ON(condition)
	158
	159	#endif /* _USTERR_SIGNAL_SAFE_H */