[lttng-ust.git] / liblttng-ust-dl / lttng-ust-dl.c

/*
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 * Copyright (C) 2013 Paul Woegerer <paul.woegerer@mentor.com>
 * Copyright (C) 2015 Antoine Busque <abusque@efficios.com>
 * Copyright (C) 2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#define _LGPL_SOURCE
#include <limits.h>
#include <stdio.h>
#include <stdint.h>
#include <sys/types.h>
#include <unistd.h>

#include <ust-dlfcn.h>
#include <lttng/ust-elf.h>
#include <lttng/ust-events.h>
#include <ust-helper.h>
#include "usterr-signal-safe.h"

/* Include link.h last else it conflicts with ust-dlfcn. */
#include <link.h>

#define TRACEPOINT_DEFINE
#include "ust_dl.h"

static void *(*__lttng_ust_plibc_dlopen)(const char *filename, int flags);
#ifdef HAVE_DLMOPEN
static void *(*__lttng_ust_plibc_dlmopen)(Lmid_t nsid, const char *filename,
		int flags);
#endif
static int (*__lttng_ust_plibc_dlclose)(void *handle);

static __attribute__((constructor))
void _lttng_ust_dl_init(void)
{
	ust_err_init();
}

static
void *_lttng_ust_dl_libc_dlopen(const char *filename, int flags)
{
	if (!__lttng_ust_plibc_dlopen) {
		__lttng_ust_plibc_dlopen = dlsym(RTLD_NEXT, "dlopen");
		if (!__lttng_ust_plibc_dlopen) {
			fprintf(stderr, "%s\n", dlerror());
			return NULL;
		}
	}
	return __lttng_ust_plibc_dlopen(filename, flags);
}

#ifdef HAVE_DLMOPEN
static
void *_lttng_ust_dl_libc_dlmopen(Lmid_t nsid, const char *filename,
		int flags)
{
	if (!__lttng_ust_plibc_dlmopen) {
		__lttng_ust_plibc_dlmopen = dlsym(RTLD_NEXT, "dlmopen");
		if (!__lttng_ust_plibc_dlmopen) {
			fprintf(stderr, "%s\n", dlerror());
			return NULL;
		}
	}
	return __lttng_ust_plibc_dlmopen(nsid, filename, flags);
}
#endif

static
int _lttng_ust_dl_libc_dlclose(void *handle)
{
	if (!__lttng_ust_plibc_dlclose) {
		__lttng_ust_plibc_dlclose = dlsym(RTLD_NEXT, "dlclose");
		if (!__lttng_ust_plibc_dlclose) {
			fprintf(stderr, "%s\n", dlerror());
			return -1;
		}
	}
	return __lttng_ust_plibc_dlclose(handle);
}

static
void lttng_ust_dl_dlopen(void *so_base, const char *so_name,
		int flags, void *ip)
{
	char resolved_path[PATH_MAX];
	struct lttng_ust_elf *elf;
	uint64_t memsz;
	uint8_t *build_id = NULL;
	size_t build_id_len;
	char *dbg_file = NULL;
	uint32_t crc;
	int has_build_id = 0, has_debug_link = 0;
	int ret;

	if (!realpath(so_name, resolved_path)) {
		ERR("could not resolve path '%s'", so_name);
		return;
	}

	elf = lttng_ust_elf_create(resolved_path);
	if (!elf) {
		ERR("could not access file %s", resolved_path);
		return;
	}

	ret = lttng_ust_elf_get_memsz(elf, &memsz);
	if (ret) {
		goto end;
	}
	ret = lttng_ust_elf_get_build_id(
		elf, &build_id, &build_id_len, &has_build_id);
	if (ret) {
		goto end;
	}
	ret = lttng_ust_elf_get_debug_link(
		elf, &dbg_file, &crc, &has_debug_link);
	if (ret) {
		goto end;
	}

	tracepoint(lttng_ust_dl, dlopen,
		ip, so_base, resolved_path, flags, memsz,
		has_build_id, has_debug_link);

	if (has_build_id) {
		tracepoint(lttng_ust_dl, build_id,
			ip, so_base, build_id, build_id_len);
	}

	if (has_debug_link) {
		tracepoint(lttng_ust_dl, debug_link,
			ip, so_base, dbg_file, crc);
	}

end:
	free(dbg_file);
	free(build_id);
	lttng_ust_elf_destroy(elf);
	return;
}

#ifdef HAVE_DLMOPEN
static
void lttng_ust_dl_dlmopen(void *so_base, Lmid_t nsid, const char *so_name,
		int flags, void *ip)
{
	char resolved_path[PATH_MAX];
	struct lttng_ust_elf *elf;
	uint64_t memsz;
	uint8_t *build_id = NULL;
	size_t build_id_len;
	char *dbg_file = NULL;
	uint32_t crc;
	int has_build_id = 0, has_debug_link = 0;
	int ret;

	if (!realpath(so_name, resolved_path)) {
		ERR("could not resolve path '%s'", so_name);
		return;
	}

	elf = lttng_ust_elf_create(resolved_path);
	if (!elf) {
		ERR("could not access file %s", resolved_path);
		return;
	}

	ret = lttng_ust_elf_get_memsz(elf, &memsz);
	if (ret) {
		goto end;
	}
	ret = lttng_ust_elf_get_build_id(
		elf, &build_id, &build_id_len, &has_build_id);
	if (ret) {
		goto end;
	}
	ret = lttng_ust_elf_get_debug_link(
		elf, &dbg_file, &crc, &has_debug_link);
	if (ret) {
		goto end;
	}

	tracepoint(lttng_ust_dl, dlmopen,
		ip, so_base, nsid, resolved_path, flags, memsz,
		has_build_id, has_debug_link);

	if (has_build_id) {
		tracepoint(lttng_ust_dl, build_id,
			ip, so_base, build_id, build_id_len);
	}

	if (has_debug_link) {
		tracepoint(lttng_ust_dl, debug_link,
			ip, so_base, dbg_file, crc);
	}

end:
	free(dbg_file);
	free(build_id);
	lttng_ust_elf_destroy(elf);
	return;
}
#endif

void *dlopen(const char *filename, int flags)
{
	void *handle;

	handle = _lttng_ust_dl_libc_dlopen(filename, flags);
	if (__tracepoint_ptrs_registered && handle) {
		struct link_map *p = NULL;
		int ret;

		ret = dlinfo(handle, RTLD_DI_LINKMAP, &p);
		if (ret != -1 && p != NULL && p->l_addr != 0) {
			lttng_ust_dl_dlopen((void *) p->l_addr,
				p->l_name, flags, LTTNG_UST_CALLER_IP());
		}
	}
	lttng_ust_dl_update(LTTNG_UST_CALLER_IP());
	return handle;
}

#ifdef HAVE_DLMOPEN
void *dlmopen(Lmid_t nsid, const char *filename, int flags)
{
	void *handle;

	handle = _lttng_ust_dl_libc_dlmopen(nsid, filename, flags);
	if (__tracepoint_ptrs_registered && handle) {
		struct link_map *p = NULL;
		int ret;

		ret = dlinfo(handle, RTLD_DI_LINKMAP, &p);
		if (ret != -1 && p != NULL && p->l_addr != 0) {
			lttng_ust_dl_dlmopen((void *) p->l_addr,
				nsid, p->l_name, flags,
				LTTNG_UST_CALLER_IP());
		}
	}
	lttng_ust_dl_update(LTTNG_UST_CALLER_IP());
	return handle;

}
#endif

int dlclose(void *handle)
{
	int ret;

	if (__tracepoint_ptrs_registered) {
		struct link_map *p = NULL;

		ret = dlinfo(handle, RTLD_DI_LINKMAP, &p);
		if (ret != -1 && p != NULL && p->l_addr != 0) {
			tracepoint(lttng_ust_dl, dlclose,
				LTTNG_UST_CALLER_IP(),
				(void *) p->l_addr);
		}
	}
	ret = _lttng_ust_dl_libc_dlclose(handle);
	lttng_ust_dl_update(LTTNG_UST_CALLER_IP());
	return ret;
}
Commit	Line	Data
	1	/*
	2	* SPDX-License-Identifier: LGPL-2.1-only
	3	*
	4	* Copyright (C) 2013 Paul Woegerer <paul.woegerer@mentor.com>
	5	* Copyright (C) 2015 Antoine Busque <abusque@efficios.com>
	6	* Copyright (C) 2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	7	*/
	8
	9	#define _LGPL_SOURCE
	10	#include <limits.h>
	11	#include <stdio.h>
	12	#include <stdint.h>
	13	#include <sys/types.h>
	14	#include <unistd.h>
	15
	16	#include <ust-dlfcn.h>
	17	#include <lttng/ust-elf.h>
	18	#include <lttng/ust-events.h>
	19	#include <ust-helper.h>
	20	#include "usterr-signal-safe.h"
	21
	22	/* Include link.h last else it conflicts with ust-dlfcn. */
	23	#include <link.h>
	24
	25	#define TRACEPOINT_DEFINE
	26	#include "ust_dl.h"
	27
	28	static void (__lttng_ust_plibc_dlopen)(const char *filename, int flags);
	29	#ifdef HAVE_DLMOPEN
	30	static void (__lttng_ust_plibc_dlmopen)(Lmid_t nsid, const char *filename,
	31	int flags);
	32	#endif
	33	static int (__lttng_ust_plibc_dlclose)(void handle);
	34
	35	static __attribute__((constructor))
	36	void _lttng_ust_dl_init(void)
	37	{
	38	ust_err_init();
	39	}
	40
	41	static
	42	void _lttng_ust_dl_libc_dlopen(const char filename, int flags)
	43	{
	44	if (!__lttng_ust_plibc_dlopen) {
	45	__lttng_ust_plibc_dlopen = dlsym(RTLD_NEXT, "dlopen");
	46	if (!__lttng_ust_plibc_dlopen) {
	47	fprintf(stderr, "%s\n", dlerror());
	48	return NULL;
	49	}
	50	}
	51	return __lttng_ust_plibc_dlopen(filename, flags);
	52	}
	53
	54	#ifdef HAVE_DLMOPEN
	55	static
	56	void _lttng_ust_dl_libc_dlmopen(Lmid_t nsid, const char filename,
	57	int flags)
	58	{
	59	if (!__lttng_ust_plibc_dlmopen) {
	60	__lttng_ust_plibc_dlmopen = dlsym(RTLD_NEXT, "dlmopen");
	61	if (!__lttng_ust_plibc_dlmopen) {
	62	fprintf(stderr, "%s\n", dlerror());
	63	return NULL;
	64	}
	65	}
	66	return __lttng_ust_plibc_dlmopen(nsid, filename, flags);
	67	}
	68	#endif
	69
	70	static
	71	int _lttng_ust_dl_libc_dlclose(void *handle)
	72	{
	73	if (!__lttng_ust_plibc_dlclose) {
	74	__lttng_ust_plibc_dlclose = dlsym(RTLD_NEXT, "dlclose");
	75	if (!__lttng_ust_plibc_dlclose) {
	76	fprintf(stderr, "%s\n", dlerror());
	77	return -1;
	78	}
	79	}
	80	return __lttng_ust_plibc_dlclose(handle);
	81	}
	82
	83	static
	84	void lttng_ust_dl_dlopen(void so_base, const char so_name,
	85	int flags, void *ip)
	86	{
	87	char resolved_path[PATH_MAX];
	88	struct lttng_ust_elf *elf;
	89	uint64_t memsz;
	90	uint8_t *build_id = NULL;
	91	size_t build_id_len;
	92	char *dbg_file = NULL;
	93	uint32_t crc;
	94	int has_build_id = 0, has_debug_link = 0;
	95	int ret;
	96
	97	if (!realpath(so_name, resolved_path)) {
	98	ERR("could not resolve path '%s'", so_name);
	99	return;
	100	}
	101
	102	elf = lttng_ust_elf_create(resolved_path);
	103	if (!elf) {
	104	ERR("could not access file %s", resolved_path);
	105	return;
	106	}
	107
	108	ret = lttng_ust_elf_get_memsz(elf, &memsz);
	109	if (ret) {
	110	goto end;
	111	}
	112	ret = lttng_ust_elf_get_build_id(
	113	elf, &build_id, &build_id_len, &has_build_id);
	114	if (ret) {
	115	goto end;
	116	}
	117	ret = lttng_ust_elf_get_debug_link(
	118	elf, &dbg_file, &crc, &has_debug_link);
	119	if (ret) {
	120	goto end;
	121	}
	122
	123	tracepoint(lttng_ust_dl, dlopen,
	124	ip, so_base, resolved_path, flags, memsz,
	125	has_build_id, has_debug_link);
	126
	127	if (has_build_id) {
	128	tracepoint(lttng_ust_dl, build_id,
	129	ip, so_base, build_id, build_id_len);
	130	}
	131
	132	if (has_debug_link) {
	133	tracepoint(lttng_ust_dl, debug_link,
	134	ip, so_base, dbg_file, crc);
	135	}
	136
	137	end:
	138	free(dbg_file);
	139	free(build_id);
	140	lttng_ust_elf_destroy(elf);
	141	return;
	142	}
	143
	144	#ifdef HAVE_DLMOPEN
	145	static
	146	void lttng_ust_dl_dlmopen(void so_base, Lmid_t nsid, const char so_name,
	147	int flags, void *ip)
	148	{
	149	char resolved_path[PATH_MAX];
	150	struct lttng_ust_elf *elf;
	151	uint64_t memsz;
	152	uint8_t *build_id = NULL;
	153	size_t build_id_len;
	154	char *dbg_file = NULL;
	155	uint32_t crc;
	156	int has_build_id = 0, has_debug_link = 0;
	157	int ret;
	158
	159	if (!realpath(so_name, resolved_path)) {
	160	ERR("could not resolve path '%s'", so_name);
	161	return;
	162	}
	163
	164	elf = lttng_ust_elf_create(resolved_path);
	165	if (!elf) {
	166	ERR("could not access file %s", resolved_path);
	167	return;
	168	}
	169
	170	ret = lttng_ust_elf_get_memsz(elf, &memsz);
	171	if (ret) {
	172	goto end;
	173	}
	174	ret = lttng_ust_elf_get_build_id(
	175	elf, &build_id, &build_id_len, &has_build_id);
	176	if (ret) {
	177	goto end;
	178	}
	179	ret = lttng_ust_elf_get_debug_link(
	180	elf, &dbg_file, &crc, &has_debug_link);
	181	if (ret) {
	182	goto end;
	183	}
	184
	185	tracepoint(lttng_ust_dl, dlmopen,
	186	ip, so_base, nsid, resolved_path, flags, memsz,
	187	has_build_id, has_debug_link);
	188
	189	if (has_build_id) {
	190	tracepoint(lttng_ust_dl, build_id,
	191	ip, so_base, build_id, build_id_len);
	192	}
	193
	194	if (has_debug_link) {
	195	tracepoint(lttng_ust_dl, debug_link,
	196	ip, so_base, dbg_file, crc);
	197	}
	198
	199	end:
	200	free(dbg_file);
	201	free(build_id);
	202	lttng_ust_elf_destroy(elf);
	203	return;
	204	}
	205	#endif
	206
	207	void dlopen(const char filename, int flags)
	208	{
	209	void *handle;
	210
	211	handle = _lttng_ust_dl_libc_dlopen(filename, flags);
	212	if (__tracepoint_ptrs_registered && handle) {
	213	struct link_map *p = NULL;
	214	int ret;
	215
	216	ret = dlinfo(handle, RTLD_DI_LINKMAP, &p);
	217	if (ret != -1 && p != NULL && p->l_addr != 0) {
	218	lttng_ust_dl_dlopen((void *) p->l_addr,
	219	p->l_name, flags, LTTNG_UST_CALLER_IP());
	220	}
	221	}
	222	lttng_ust_dl_update(LTTNG_UST_CALLER_IP());
	223	return handle;
	224	}
	225
	226	#ifdef HAVE_DLMOPEN
	227	void dlmopen(Lmid_t nsid, const char filename, int flags)
	228	{
	229	void *handle;
	230
	231	handle = _lttng_ust_dl_libc_dlmopen(nsid, filename, flags);
	232	if (__tracepoint_ptrs_registered && handle) {
	233	struct link_map *p = NULL;
	234	int ret;
	235
	236	ret = dlinfo(handle, RTLD_DI_LINKMAP, &p);
	237	if (ret != -1 && p != NULL && p->l_addr != 0) {
	238	lttng_ust_dl_dlmopen((void *) p->l_addr,
	239	nsid, p->l_name, flags,
	240	LTTNG_UST_CALLER_IP());
	241	}
	242	}
	243	lttng_ust_dl_update(LTTNG_UST_CALLER_IP());
	244	return handle;
	245
	246	}
	247	#endif
	248
	249	int dlclose(void *handle)
	250	{
	251	int ret;
	252
	253	if (__tracepoint_ptrs_registered) {
	254	struct link_map *p = NULL;
	255
	256	ret = dlinfo(handle, RTLD_DI_LINKMAP, &p);
	257	if (ret != -1 && p != NULL && p->l_addr != 0) {
	258	tracepoint(lttng_ust_dl, dlclose,
	259	LTTNG_UST_CALLER_IP(),
	260	(void *) p->l_addr);
	261	}
	262	}
	263	ret = _lttng_ust_dl_libc_dlclose(handle);
	264	lttng_ust_dl_update(LTTNG_UST_CALLER_IP());
	265	return ret;
	266	}