xref: /titanic_41/usr/src/cmd/sgs/include/rtld.h (revision 0db3240d392634cfff2f95fb6da34b56b8dc574f)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
#ifndef	_RTLD_H
#define	_RTLD_H

/*
 * Global include file for the runtime linker.
 */
#include <sys/mman.h>
#include <time.h>
#include <sgs.h>
#include <thread.h>
#include <synch.h>
#include <link.h>
#include <sys/avl.h>
#include <alist.h>
#include <libc_int.h>
#include <elfcap.h>

#ifdef	_SYSCALL32
#include <inttypes.h>
#endif

#ifdef	__cplusplus
extern "C" {
#endif

/*
 * We use rtld_ino_t instead of ino_t so that we can get
 * access to large inode values from 32-bit code.
 */
#ifdef _LP64
typedef ino_t		rtld_ino_t;
#else
typedef ino64_t		rtld_ino_t;
#endif

typedef struct rt_map	Rt_map;
typedef struct slookup	Slookup;
typedef struct sresult	Sresult;

/*
 * A binding descriptor.  Establishes the binding relationship between two
 * objects, the caller (originator) and the dependency (destination).
 *
 * Every relationship between two objects is tracked by a binding descriptor.
 * This descriptor is referenced from a link-map's DEPENDS and CALLERS lists.
 * Note, Aplist's are diagramed to fully expose the allocations required to
 * establish the data structure relationships.
 *
 *                                  Bnd_desc
 *                                 ----------
 *                    ------------| b_caller |
 *                   |            | b_depend | ----------
 *                   |            |          |           |
 *      Rt_map       |             ----------            |       Rt_map
 *    ----------     |                ^ ^                |     ----------
 *   |          | <--                 | |                 --> |          |
 *   |          |        --------     | |                     |          |
 *   | DEPENDS  | ----> |        |    | |     --------        |          |
 *   |          |       |        |    | |    |        | <---- | CALLERS  |
 *   |          |       |        | ---  |    |        |       |          |
 *   |          |       |        |       --- |        |       |          |
 *   |          |        --------            |        |       |          |
 *    ----------          Aplist              --------         ----------
 *                                             Aplist
 */
typedef struct {
	Rt_map		*b_caller;	/* caller (originator) of a binding */
	Rt_map		*b_depend;	/* dependency (destination) of a */
					/*	binding */
	uint_t		b_flags;	/* relationship of caller to the */
					/*	dependency */
} Bnd_desc;

#define	BND_NEEDED	0x0001		/* caller NEEDED the dependency */
#define	BND_REFER	0x0002		/* caller relocation references the */
					/*	dependency */
#define	BND_FILTER	0x0004		/* binding identifies filter, used */
					/*	for diagnostics only */
/*
 * Private structure for communication between rtld_db and rtld.
 *
 * We must bump the version number when ever an update in one of the
 * structures/fields that rtld_db reads is updated.  This hopefully permits
 * rtld_db implementations of the future to recognize core files produced on
 * older systems and deal with these core files accordingly.
 *
 * As of version 'R_RTLDDB_VERSION <= 2' the following fields were valid for
 * core file examination (basically the public Link_map):
 *
 *		ADDR()
 *		NAME()
 *		DYN()
 *		NEXT()
 *		PREV()
 *
 * Valid fields for R_RTLDDB_VERSION3
 *
 *		PATHNAME()
 *		PADSTART()
 *		PADIMLEN()
 *		MSIZE()
 *		FLAGS()
 *		FLAGS1()
 *
 * Valid fields for R_RTLDDB_VERSION4
 *
 *		TLSMODID()
 *
 * Valid fields for R_RTLDDB_VERSION5
 *
 *		Added rtld_flags & FLG_RT_RELOCED to stable flags range
 *
 * Valid fields for R_RTLDDB_VERSION6
 *
 *		rtd_dynlmlst converted from a List to APlist
 */
#define	R_RTLDDB_VERSION1	1	/* base version level - used for core */
					/*	file examination */
#define	R_RTLDDB_VERSION2	2	/* minor revision - not relevant for */
					/*	core files */
#define	R_RTLDDB_VERSION3	3
#define	R_RTLDDB_VERSION4	4
#define	R_RTLDDB_VERSION5	5
#define	R_RTLDDB_VERSION6	6
#define	R_RTLDDB_VERSION	R_RTLDDB_VERSION6	/* current version */

typedef struct rtld_db_priv {
	struct r_debug	rtd_rdebug;	/* original r_debug structure */
	Word		rtd_version;	/* version no. */
	size_t		rtd_objpad;	/* padding around mmap()ed objects */
	APlist		**rtd_dynlmlst;	/* pointer to dynlm_list pointer */
} Rtld_db_priv;

#ifdef _SYSCALL32
typedef struct rtld_db_priv32 {
	struct r_debug32 rtd_rdebug;	/* original r_debug structure */
	Elf32_Word	rtd_version;	/* version no. */
	Elf32_Word	rtd_objpad;	/* padding around mmap()ed objects */
	Elf32_Addr	rtd_dynlmlst;	/* pointer to dynlm_list */
} Rtld_db_priv32;
#endif	/* _SYSCALL32 */

/*
 * External function definitions.  ld.so.1 must convey information to libc in
 * regards to threading.  libc also provides routines for atexit() and message
 * localization.  libc provides the necessary interfaces via its RTLDINFO
 * structure and/or later _ld_libc() calls.
 *
 * These external functions are maintained for each link-map list, and used
 * where appropriate.  The functions are associated with the object that
 * provided them, so that should the object be deleted (say, from an alternative
 * link-map), the functions can be removed.
 */
typedef struct {
	Rt_map	*lc_lmp;			/* function provider */
	union {
		int		(*lc_func)();	/* external function pointer */
		uintptr_t	lc_val;		/* external value */
		char    	*lc_ptr;	/* external character pointer */
	} lc_un;
} Lc_desc;

/*
 * Link map list definition.  Link-maps are used to describe each loaded object.
 * Lists of these link-maps describe the various namespaces within a process.
 * The process executable and its dependencies are maintained on the lml_main
 * list.  The runtime linker, and its dependencies are maintained on the
 * lml_rtld list.  Additional lists can be created (see dlmopen()) for such
 * things as auditors and their dependencies.
 *
 * Each link-map list maintains an Alist of one, or more, linked lists of
 * link-maps.  For backward compatibility, the lm_head/lm_tail elements are
 * initialized to the first linked-list of link-maps:
 *
 *      Lm_list
 *    ----------
 *   | lm_tail  | ------------------------------------
 *   | lm_head  | --------------------                |
 *   |          |                     |     Rt_map    |     Rt_map
 *   |          |                     |     ------    |     ------
 *   |          |          Alist       --> |      |   |--> |      |
 *   |          |        ---------    |    |      | --     |      |
 *   | lm_lists | ----> |         |   |    |      |    --> |      |
 *   |          |       |---------|   |    |      |   |    |      |
 *   |          |       | lc_head | --      ------    |     ------
 *   |          |       | lc_tail | ------------------
 *   |          |       |---------|
 *    ----------        | lc_head |
 *                      | lc_tail |
 *                      |---------|
 *
 * Multiple link-map lists exist to support the addition of lazy loaded
 * families, filtee families, and dlopen() families.  The intent of these
 * lists is to insure that a family of objects that are to be loaded are
 * fully relocatable, and hence usable, before they become part of the main
 * (al_data[0]) link-map control list.  This main link-map control list is
 * the only list in existence when control is transferred to user code.
 *
 * During process initialization, the dynamic executable and its non-lazy
 * dependencies are maintained on al_data[0].  If a new object is loaded, then
 * this object is added to the next available control list [1], typically
 * al_data[1].  Any dependencies of this object that have not already been
 * loaded are added to the same control list.  Once all of the objects on the
 * new control list have been successfully relocated, the objects are moved from
 * the new control list to the highest control list to which objects of the new
 * control list bound to, typically al_data[1] to al_data[0].
 *
 * Each loading scenario can be broken down as follows:
 *
 *  setup() - only the initial link-map control list is used:
 *   i.	  create al_data[0]
 *   ii.  add new link-map for main on al_data[0]
 *   iii. analyze al_data[0] to add all non-lazy dependencies
 *   iv.  relocate al_data[0] dependencies.
 *
 *  dlopen() - the initiator can only be the initial link-map control list:
 *   i.   create al_data[1] from caller al_data[0]
 *   ii.  add new link-map for the dlopen'ed object on al_data[1]
 *   iii. analyze al_data[1] to add all non-lazy dependencies
 *   iv.  relocate al_data[1] dependencies, and move to al_data[0].
 *
 *  filtee and lazy loading processing - the initiator can be any link-map
 *  control list that is being relocated:
 *   i.   create al_data[y] from caller al_data[x]
 *   ii.  add new link-map for the new object on al_data[y]
 *   iii. analyze al_data[y] to add all non-lazy dependencies
 *   iv.  relocate al_data[y] dependencies, and move to al_data[x].
 *
 * This Alist therefore maintains a stack of link-map control lists.  The newest
 * link-map control list can locate symbols within any of the former lists,
 * however, control is not passed to a former list until the newest lists
 * processing is complete.  Thus, objects can't bind to new objects until they
 * have been fully analyzed and relocated.
 *
 * [1]  Note, additional link-map control list creation occurs after the head
 * link-map object (typically the dynamic executable) has been relocated.  This
 * staging is required to satisfy the binding requirements of copy relocations.
 * Copy relocations, effectively, transfer the bindings of the copied data
 * (say _iob in libc.so.1) to the copy location (_iob in the application).
 * Thus an object that might bind to the original copy data must be redirected
 * to the copy reference.  As the knowledge of a copy relocation having taken
 * place is only known after relocating the application, link-map control list
 * additions are suspended until after this relocation has completed.
 */
typedef struct {
	Rt_map		*lc_head;
	Rt_map		*lc_tail;
	APlist		*lc_now;	/* pending promoted bind-now objects */
	uint_t		lc_flags;
} Lm_cntl;

#define	LMC_FLG_ANALYZING	0x01	/* control list is being analyzed */
#define	LMC_FLG_RELOCATING	0x02	/* control list is being relocated */
#define	LMC_FLG_REANALYZE	0x04	/* repeat analysis (established when */
					/*	interposers are added */

struct lm_list {
	/*
	 * BEGIN: Exposed to rtld_db - don't move, don't delete
	 */
	Rt_map		*lm_head;	/* linked list pointers to active */
	Rt_map		*lm_tail;	/*	link-map list */
	APlist		*lm_handle;	/* not used by rtld_db - but spacing */
					/*	is required for flags */
	Word		lm_flags;
	/*
	 * END: Exposed to rtld_db - don't move, don't delete
	 */
	Alist		*lm_rti;	/* list of RTLDINFO tables */
	Audit_list	*lm_alp;	/* audit list descriptor */
	avl_tree_t	*lm_fpavl;	/* avl tree of objects loaded */
	Alist		*lm_lists;	/* active and pending link-map lists */
	char		***lm_environ;	/* pointer to environment array */
	Word		lm_tflags;	/* transferable flags */
	uint_t		lm_obj;		/* total number of objs on link-map */
	uint_t		lm_init;	/* new obj since last init processing */
	uint_t		lm_lazy;	/* number of objects with pending */
					/*	lazy dependencies */
	uint_t		lm_tls;		/* new obj that require TLS */
	uint_t		lm_lmid;	/* unique link-map list identifier, */
	char		*lm_lmidstr;	/* and associated diagnostic string */
	APlist		*lm_actaudit;	/* list of pending audit activity */
	Lc_desc		lm_lcs[CI_MAX];	/* external libc functions */
};

#ifdef	_SYSCALL32
struct lm_list32 {
	/*
	 * BEGIN: Exposed to rtld_db - don't move, don't delete
	 */
	Elf32_Addr	lm_head;
	Elf32_Addr	lm_tail;
	Elf32_Addr	lm_handle;
	Elf32_Word	lm_flags;
	/*
	 * END: Exposed to rtld_db - don't move, don't delete
	 */
	Elf32_Addr	lm_rti;
	Elf32_Addr	lm_fpavl;
	Elf32_Addr	lm_lists;
	Elf32_Addr	lm_environ;
	Elf32_Word	lm_tflags;
	uint_t		lm_obj;
	uint_t		lm_init;
	uint_t		lm_lazy;
	uint_t		lm_tls;
	uint_t		lm_lmid;
	Elf32_Addr	lm_lmidstr;
	Elf32_Addr	lm_actaudit;
	Elf32_Addr	lm_lcs[CI_MAX];
};
#endif /* _SYSCALL32 */

/*
 * Possible Link_map list flags (Lm_list.lm_flags)
 */
/*
 * BEGIN: Exposed to rtld_db - don't move, don't delete
 */
#define	LML_FLG_BASELM		0x00000001	/* primary link-map */
#define	LML_FLG_RTLDLM		0x00000002	/* rtld link-map */
/*
 * END: Exposed to rtld_db - don't move, don't delete
 */
#define	LML_FLG_NOAUDIT		0x00000004	/* symbol auditing disabled */
#define	LML_FLG_PLTREL		0x00000008	/* deferred plt relocation */
						/* 	initialization */
						/*	(ld.so.1 only) */
#define	LML_FLG_HOLDLOCK	0x00000010	/* hold the rtld mutex lock */
#define	LML_FLG_ENVIRON		0x00000020	/* environ var initialized */
#define	LML_FLG_INTRPOSE	0x00000040	/* interposing objs on list */
#define	LML_FLG_LOCAUDIT	0x00000080	/* local auditors exists for */
						/*	this link-map list */
#define	LML_FLG_LOADAVAIL	0x00000100	/* load anything available */
#define	LML_FLG_IGNRELERR	0x00000200	/* ignore relocation errors - */
						/*	internal for crle(1) */
#define	LML_FLG_DBNOTIF		0x00000400	/* binding activity going on */
#define	LML_FLG_STARTREL	0x00000800	/* relocation started */
#define	LML_FLG_ATEXIT		0x00001000	/* atexit processing */
#define	LML_FLG_OBJADDED	0x00002000	/* object(s) added */
#define	LML_FLG_OBJDELETED	0x00004000	/* object(s) deleted */
#define	LML_FLG_OBJREEVAL	0x00008000	/* existing object(s) needs */
						/*	tsort reevaluation */
#define	LML_FLG_INTRPOSETSORT	0x00020000	/* interpose tsorting done */
#define	LML_FLG_AUDITNOTIFY	0x00040000	/* audit consistent required */
#define	LML_FLG_GROUPSEXIST	0x00080000	/* local groups exist */

#define	LML_FLG_TRC_LDDSTUB	0x00100000	/* identify lddstub */
#define	LML_FLG_TRC_ENABLE	0x00200000	/* tracing enabled (ldd) */
#define	LML_FLG_TRC_WARN	0x00400000	/* print warnings for undefs */
#define	LML_FLG_TRC_VERBOSE	0x00800000	/* verbose (versioning) trace */
#define	LML_FLG_TRC_SEARCH	0x01000000	/* trace search paths */
#define	LML_FLG_TRC_UNREF	0x02000000	/* trace unreferenced */
						/*	dependencies */
#define	LML_FLG_TRC_UNUSED	0x04000000	/* trace unused dependencies */
#define	LML_FLG_TRC_INIT	0x08000000	/* print .init order */
#define	LML_FLG_TRC_NOUNRESWEAK	0x10000000	/* unresolved weak references */
						/*	are not allowed */
#define	LML_FLG_TRC_NOPAREXT	0x20000000	/* unresolved PARENT/EXTERN */
						/*	references are not */
						/*	allowed */
#define	LML_MSK_TRC		0xfff00000	/* tracing mask */

/*
 * Possible Link_map transferable flags (Lm_list.lm_tflags), i.e., link-map
 * list flags that can be propagated to any new link-map list created.
 */
#define	LML_TFLG_NOLAZYLD	0x00000001	/* lazy loading disabled */
#define	LML_TFLG_NODIRECT	0x00000002	/* direct bindings disabled */

#define	LML_TFLG_LOADFLTR	0x00000008	/* trigger filtee loading */

#define	LML_TFLG_AUD_PREINIT	0x00001000	/* preinit (audit) exists */
#define	LML_TFLG_AUD_OBJSEARCH	0x00002000	/* objsearch (audit) exists */
#define	LML_TFLG_AUD_OBJOPEN	0x00004000	/* objopen (audit) exists */
#define	LML_TFLG_AUD_OBJFILTER	0x00008000	/* objfilter (audit) exists */
#define	LML_TFLG_AUD_OBJCLOSE	0x00010000	/* objclose (audit) exists */
#define	LML_TFLG_AUD_SYMBIND	0x00020000	/* symbind (audit) exists */
#define	LML_TFLG_AUD_PLTENTER	0x00040000	/* pltenter (audit) exists */
#define	LML_TFLG_AUD_PLTEXIT	0x00080000	/* pltexit (audit) exists */
#define	LML_TFLG_AUD_ACTIVITY	0x00100000	/* activity (audit) exists */

/*
 * NOTE: Each auditing module establishes a set of audit flags, AFLAGS(), that
 * define the auditing interfaces the module offers.  These auditing flags are
 * the LML_TFLG_AUD_ flags defined above.  Global auditors result in setting
 * the lm_tflags too.  Local auditors only use the AFLAGS().  All tests for
 * auditing inspect the lm_tflags and AFLAGS() for a specific auditing
 * interface, and thus use the same flag to test for both types of auditors.
 */
#define	LML_TFLG_AUD_MASK	0x0ffff000	/* audit interfaces mask */

/*
 * Define a Group Handle.
 *
 * The capability of ld.so.1 to associate a group of objects, look for symbols
 * within that group, ensure that groups are isolated from one another (with
 * regard to relocations), and to unload a group, centers around a handle.
 *
 * Dependencies can be added to an existing handle as the dependencies are
 * lazily loaded.  The core dependencies on the handle are the ldd(1) list of
 * the referenced object.
 *
 * Handles can be created from:
 *
 *  -	a dlopen() request.  This associates a caller to a reference object,
 * 	and the referenced objects dependencies.  This group of objects can
 *	then be inspected for symbols (dlsym()).
 *  -	a filtering request.  This associates a filter (caller) to a referenced
 *	object (filtee).  The redirection of filter symbols to their filtee
 *	counterpart is essentially a dlsym() using the filtee's handle.
 *
 * The handle created for these events is referred to as a public handle.  This
 * handle tracks the referenced object, all of the dependencies of the
 * referenced object, and the caller (parent).
 *
 * Presently, an object may have two handles, one requested with RTLD_FIRST
 * and one without.
 *
 * A handle may be referenced by any number of callers (parents).  A reference
 * count tracks the number.  A dlclose() operation drops the reference count,
 * and when the count is zero, the handle is used to determine the family of
 * objects to unload.  As bindings may occur to objects on the handle from
 * other handles, it may not be possible to remove a complete family of objects
 * or the handle itself.  Handles in this state are moved to an orphan list.
 * A handle on the orphan list is taken off the orphan list if the associated
 * object is reopened.  Otherwise, the handle remains on the orphan list for
 * the duration of the process.  The orphan list is inspected any time objects
 * are unloaded, to determine if the orphaned objects can also be unloaded.
 *
 * Handles can also be created for internal uses:
 *
 *  -	to promote objects to RTLD_NOW.
 *  -	to establish families for symbol binding fallback, required when lazy
 *	loadable objects are still pending.
 *
 * The handle created for these events is referred to as a private handle.  This
 * handle does not need to track the caller (parent), and because of this, does
 * not need to be considered during dlclose() operations, as the handle can not
 * be referenced by callers outside of the referenced objects family.
 *
 * Note, a private handle is essentially a subset of a public handle.  Should
 * an internal operation require a private handle, and a public handle already
 * exist, the public handle can be used.  Should an external operation require
 * a public handle, and a private handle exist, the private handle is promoted
 * to a public handle.  Any handle that gets created will remain in existence
 * for the life time of the referenced object.
 *
 * Objects can be dlopened using RTLD_NOW.  This attribute requires that all
 * relocations of the object, and its dependencies are processed immediately,
 * before return to the caller.  Typically, an object is loaded without
 * RTLD_NOW, and procedure linkage relocations are satisfied when their
 * associated function is first called.  If an object is already loaded, and an
 * RTLD_NOW request is made, then the object, and its dependencies, most undergo
 * additional relocation processing.   This promotion from lazy binding to
 * immediate binding is carried out using handles, as the handle defines the
 * dependencies that must be processed.
 *
 * To ensure that objects within a lazy loadable environment can be relocated,
 * no matter whether the objects have their dependencies described completely,
 * a symbol lookup fallback is employed.  Any pending lazy loadable objects are
 * loaded, and a handle established to search the object and it's dependencies
 * for the required symbol.
 *
 * A group handle (and its associated group descriptors), is referenced from
 * a link-map's HANDLES and GROUPS lists.  Note, Aplist's are diagramed to
 * fully expose the allocations required to establish the data structure
 * relationships.
 *
 *                                  Grp_desc
 *                                   Alist
 *                                 -----------
 *                            --> |           |
 *                           |    |-----------|
 *                           |    | gd_depend | ---------
 *                           |    |           |          |
 *                           |    |-----------|          |
 *                   --------|--- | gd_depend |          |
 *                  |        |    | (parent)  |          |
 *                  |        |    |-----------|          |
 *                  |        |    | gd_depend |          |
 *                  |        |    |           |          |
 *                  |        |    |           |          |
 *                  |        |     -----------           |
 *                  |        |                           |
 *                  |        |      Grp_hdl              |
 *                  |        |    -----------            |
 *                  |         -- | gh_depends |          |
 *                  |  --------- | gh_ownlmp  |          |
 *                  | |          |            |          |
 *                  | |          |            |          |
 *                  | |          |            |          |
 *      Rt_map      | |           ------------           |       Rt_map
 *    ----------    | |               ^ ^                |     ----------
 *   |          | <-  |               | |                 --> |          |
 *   |          | <---   --------     | |                     |          |
 *   | HANDLES  | ----> |        |    | |     --------        |          |
 *   |          |       |        |    | |    |        | <---- |  GROUPS  |
 *   |          |       |        | ---  |    |        |       |          |
 *   |          |       |        |       --- |        |       |          |
 *   |          |        --------            |        |       |          |
 *    ----------          Aplist              --------         ----------
 *                                             Aplist
 */
typedef struct {
	Alist		*gh_depends;	/* handle dependency list */
	Rt_map		*gh_ownlmp;	/* handle owners link-map */
	Lm_list		*gh_ownlml;	/* handle owners link-map list */
	uint_t		gh_refcnt;	/* handle reference count */
	uint_t		gh_flags;	/* handle flags (GPH_ values) */
} Grp_hdl;

/*
 * Define the two categories of handle.
 */
#define	GPH_PUBLIC	0x0001		/* handle returned to caller(s) */
#define	GPH_PRIVATE	0x0002		/* handle used internally */

/*
 * Define any flags that affects how the handle is used.
 */
#define	GPH_ZERO	0x0010		/* special handle for dlopen(0) */
#define	GPH_LDSO	0x0020		/* special handle for ld.so.1 */
#define	GPH_FIRST	0x0040		/* dlsym() can only use originating */
					/*	dependency */
#define	GPH_FILTEE	0x0080		/* handle identifies a filtee, used */
					/*	for diagnostics only */
/*
 * Define any state that is associated with the handle.
 */
#define	GPH_INITIAL	0x0100		/* handle is initialized */

/*
 * Define a Group Descriptor.
 *
 * Each dependency associated with a group handle is maintained by a group
 * descriptor.  The descriptor defines the associated dependency together with
 * flags that indicate how the dependency can be used.
 */
typedef struct {
	Rt_map		*gd_depend;	/* dependency */
	uint_t		gd_flags;	/* dependency flags (GPD_ values) */
} Grp_desc;

#define	GPD_DLSYM	0x0001		/* dependency available to dlsym() */
#define	GPD_RELOC	0x0002		/* dependency available to satisfy */
					/*	relocation binding */
#define	GPD_ADDEPS	0x0004		/* dependencies of this dependency */
					/*	should be added to handle */
#define	GPD_PARENT	0x0008		/* dependency is a parent */
#define	GPD_FILTER	0x0010		/* dependency is our filter */
#define	GPD_REMOVE	0x0100		/* descriptor is a candidate for */
					/*	removal from the group */

/*
 * Define threading structures.  For compatibility with libthread (T1_VERSION 1
 * and TI_VERSION 2) our locking structure is sufficient to hold a mutex or a
 * readers/writers lock.
 */
typedef struct {
	union {
		mutex_t		l_mutex;
		rwlock_t	l_rwlock;
	} u;
} Rt_lock;

typedef	cond_t	Rt_cond;

/*
 * Define a dynamic section information descriptor.  This parallels the entries
 * in the .dynamic section and holds auxiliary information to implement lazy
 * loading and filtee processing.
 */
typedef struct {
	uint_t	di_flags;
	void	*di_info;
} Dyninfo;

#define	FLG_DI_STDFLTR	0x00001		/* .dynamic entry for DT_FILTER */
#define	FLG_DI_AUXFLTR	0x00002		/* .dynamic entry for DT_AUXILIARY */
#define	FLG_DI_SYMFLTR	0x00004		/* .dynamic entry for DT_SYMFILTER */
					/*	and DT_SYMAUXILIARY */
#define	MSK_DI_FILTER	0x0000f		/* mask for all filter possibilities */

#define	FLG_DI_POSFLAG1	0x00010		/* .dynamic entry for DT_POSFLAG_1 */
#define	FLG_DI_NEEDED	0x00020		/* .dynamic entry for DT_NEEDED */
#define	FLG_DI_LAZY	0x00100		/* lazy needed entry - preceded by */
					/*    DF_P1_LAZYLOAD (DT_POSFLAG_1) */
#define	FLG_DI_GROUP	0x00200		/* group needed entry - preceded by */
					/*    DF_P1_GROUPPERM (DT_POSFLAG_1) */

#define	FLG_DI_LDD_DONE	0x01000		/* entry has been processed (ldd) */
#define	FLG_DI_LAZYFAIL	0x02000		/* the lazy loading of this entry */
					/*    failed */
/*
 * Data structure to track AVL tree of pathnames.  This structure provides the
 * basis of both the "not-found" node tree, and the "full-path" node tree.  Both
 * of these trees persist for the life of a process, although the "not-found"
 * tree may be moved aside during a dlopen() or dlsym() fall back operation.
 */
typedef struct {
	const char	*pn_name;	/* path name */
	avl_node_t	pn_avl;		/* avl book-keeping (see SGSOFFSETOF) */
	uint_t		pn_hash;	/* path name hash value */
} PathNode;

/*
 * Data structure to track AVL tree for full path names of objects that are
 * loaded into memory.
 */
typedef struct {
	PathNode	fpn_node;	/* path node */
	Rt_map		*fpn_lmp;	/* object link-map */
} FullPathNode;

/*
 * A given link-map can hold either a supplier or receiver copy
 * relocation list, but not both. This union is used to overlap
 * the space used for the two lists.
 */
typedef union {
	Alist	*rtc_r;		/* receiver list (Rel_copy) */
	APlist	*rtc_s;		/* supplier list (Rt_map *) */
} Rt_map_copy;


/*
 * Link-map definition.
 */
struct rt_map {
	/*
	 * BEGIN: Exposed to rtld_db - don't move, don't delete
	 */
	Link_map	rt_public;	/* public data */
	const char	*rt_pathname;	/* full pathname of loaded object */
	ulong_t		rt_padstart;	/* start of image (including padding) */
	ulong_t		rt_padimlen;	/* size of image (including padding */
	ulong_t		rt_msize;	/* total memory reservation range */
	uint_t		rt_flags;	/* state flags, see FLG below */
	uint_t		rt_flags1;	/* state flags1, see FL1 below */
	ulong_t		rt_tlsmodid;	/* TLS module id */
	/*
	 * END: Exposed to rtld_db - don't move, don't delete
	 */
	APlist		*rt_alias;	/* list of linked file names */
	APlist		*rt_fpnode;	/* list of FullPathNode AVL nodes */
	char		*rt_runpath;	/* LD_RUN_PATH and its equivalent */
	Alist		*rt_runlist;	/*	Pdesc structures */
	APlist		*rt_depends;	/* list of dependencies */
	APlist		*rt_callers;	/* list of callers */
	APlist		*rt_handles;	/* dlopen handles */
	APlist		*rt_groups;	/* groups we're a member of */
	struct fct	*rt_fct;	/* file class table for this object */
	void		*rt_priv;	/* private data, object type specific */
	Lm_list		*rt_list;	/* link map list we belong to */
	uint_t		rt_objfltrndx;	/* object filtees .dynamic index */
	uint_t		rt_symsfltrcnt;	/* number of standard symbol filtees */
	uint_t		rt_symafltrcnt;	/* number of auxiliary symbol filtees */
	int		rt_mode;	/* usage mode, see RTLD mode flags */
	int		rt_sortval;	/* temporary buffer to traverse graph */
	uint_t		rt_cycgroup;	/* cyclic group */
	dev_t		rt_stdev;	/* device id and inode number for .so */
	rtld_ino_t	rt_stino;	/*	multiple inclusion checks */
	const char	*rt_origname;	/* original pathname of loaded object */
	size_t		rt_dirsz;	/*	and its size */
	size_t		rt_lmsize;	/* size of the link-map allocation */
	Rt_map_copy	rt_copy;	/* list of copy relocations */
	Audit_desc	*rt_auditors;	/* audit descriptor array */
	Audit_info	*rt_audinfo;	/* audit information descriptor */
	Syminfo		*rt_syminfo;	/* elf .syminfo section - here */
					/*	because it is checked in */
					/*	common code */
	Addr		*rt_initarray;	/* .initarray table */
	Addr		*rt_finiarray;	/* .finiarray table */
	Addr		*rt_preinitarray; /* .preinitarray table */
	mmapobj_result_t *rt_mmaps;	/* array of mapping information */
	uint_t		rt_mmapcnt;	/*	and associated number */
	uint_t		rt_initarraysz;	/* size of .initarray table */
	uint_t		rt_finiarraysz;	/* size of .finiarray table */
	uint_t		rt_preinitarraysz; /* size of .preinitarray table */
	Dyninfo		*rt_dyninfo;	/* .dynamic information descriptors */
	uint_t		rt_dyninfocnt;	/* count of dyninfo entries */
	uint_t		rt_relacount;	/* no. of RELATIVE relocations */
	uint_t		rt_idx;		/* hold index within linkmap list */
	uint_t		rt_lazy;	/* number of lazy dependencies */
					/*	pending */
	Cap		*rt_cap;	/* capabilities data */
	Capchain	*rt_capchain;	/* capabilities chain data */
	uint_t		rt_cntl;	/* link-map control list we belong to */
	uint_t		rt_aflags;	/* auditor flags, see LML_TFLG_AUD_ */
					/* address of _init */
	void		(*rt_init)(void);
					/* address of _fini */
	void		(*rt_fini)(void);
					/* link map symbol interpreter */
	int		(*rt_symintp)(Slookup *, Sresult *, uint_t *, int *);
};

#ifdef _SYSCALL32
/*
 * Structure to allow 64-bit rtld_db to read 32-bit processes out of procfs.
 */
typedef union {
	uint32_t	rtc_r;
	uint32_t	rtc_s;
} Rt_map_copy32;

typedef struct rt_map32 {
	/*
	 * BEGIN: Exposed to rtld_db - don't move, don't delete
	 */
	Link_map32	rt_public;
	uint32_t	rt_pathname;
	uint32_t	rt_padstart;
	uint32_t	rt_padimlen;
	uint32_t	rt_msize;
	uint32_t	rt_flags;
	uint32_t	rt_flags1;
	uint32_t	rt_tlsmodid;
	/*
	 * END: Exposed to rtld_db - don't move, don't delete
	 */
	uint32_t	rt_alias;
	uint32_t	rt_fpnode;
	uint32_t	rt_runpath;
	uint32_t	rt_runlist;
	uint32_t	rt_depends;
	uint32_t	rt_callers;
	uint32_t	rt_handles;
	uint32_t	rt_groups;
	uint32_t	rt_fct;
	uint32_t	rt_priv;
	uint32_t 	rt_list;
	uint32_t 	rt_objfltrndx;
	uint32_t 	rt_symsfltrcnt;
	uint32_t 	rt_symafltrcnt;
	int32_t		rt_mode;
	int32_t		rt_sortval;
	uint32_t	rt_cycgroup;
	uint32_t	rt_stdev;
	uint32_t	rt_stino;
	uint32_t	rt_origname;
	uint32_t	rt_dirsz;
	Rt_map_copy32	rt_copy;
	uint32_t 	rt_auditors;
	uint32_t 	rt_audinfo;
	uint32_t	rt_syminfo;
	uint32_t	rt_initarray;
	uint32_t	rt_finiarray;
	uint32_t	rt_preinitarray;
	uint32_t	rt_mmaps;
	uint32_t	rt_mmapcnt;
	uint32_t	rt_initarraysz;
	uint32_t	rt_finiarraysz;
	uint32_t	rt_preinitarraysz;
	uint32_t 	rt_dyninfo;
	uint32_t 	rt_dyninfocnt;
	uint32_t	rt_relacount;
	uint32_t	rt_idx;
	uint32_t	rt_lazy;
	uint32_t	rt_cap;
	uint32_t	rt_capchain;
	uint32_t	rt_cntl;
	uint32_t	rt_aflags;
	uint32_t 	rt_init;
	uint32_t	rt_fini;
	uint32_t	rt_symintp;
} Rt_map32;

#endif	/* _SYSCALL32 */

/*
 * Link map state flags.
 */
/*
 * BEGIN: Exposed to rtld_db - don't move, don't delete
 */
#define	FLG_RT_ISMAIN	0x00000001	/* object represents main executable */
#define	FLG_RT_IMGALLOC	0x00000002	/* image is allocated (not mmap'ed) */
	/*
	 * Available for r_debug version >= R_RTLDDB_VERSION5
	 */
#define	FLG_RT_RELOCED	0x00000004	/* object has been relocated */
/*
 * END: Exposed to rtld_db - don't move, don't delete
 */
#define	FLG_RT_SETGROUP	0x00000008	/* group establishment required */
#define	FLG_RT_CAP	0x00000010	/* process $CAPABILITY expansion */
#define	FLG_RT_OBJECT	0x00000020	/* object processing (ie. .o's) */
#define	FLG_RT_NEWLOAD	0x00000040	/* object is newly loaded */
#define	FLG_RT_NODUMP	0x00000080	/* object can't be dldump(3x)'ed */
#define	FLG_RT_DELETE	0x00000100	/* object can be deleted */
#define	FLG_RT_ANALYZED	0x00000200	/* object has been analyzed */
#define	FLG_RT_INITDONE	0x00000400	/* objects .init has been completed */
#define	FLG_RT_TRANS	0x00000800	/* object is acting as a translator */
#define	FLG_RT_FIXED	0x00001000	/* image location is fixed */
#define	FLG_RT_PRELOAD	0x00002000	/* object was preloaded */
#define	FLG_RT_ALTER	0x00004000	/* alternative object used */
#define	FLG_RT_LOADFLTR	0x00008000	/* trigger filtee loading */
#define	FLG_RT_AUDIT	0x00010000	/* object is an auditor */
#define	FLG_RT_MODESET	0x00020000	/* MODE() has been initialized */
#define	FLG_RT_ANALZING	0x00040000	/* object is being analyzed */
#define	FLG_RT_INITFRST 0x00080000	/* execute .init first */
#define	FLG_RT_NOOPEN	0x00100000	/* dlopen() not allowed */
#define	FLG_RT_FINICLCT	0x00200000	/* fini has been collected (tsort) */
#define	FLG_RT_INITCALL	0x00400000	/* objects .init has been called */
#define	FLG_RT_OBJINTPO	0x00800000	/* object is a global interposer */
#define	FLG_RT_SYMINTPO	0x01000000	/* object contains symbol interposer */
#define	MSK_RT_INTPOSE	0x01800000	/* mask for all interposer */
					/*	possibilities */
#define	FLG_RT_MOVE	0x02000000	/* object needs move operation */
#define	FLG_RT_RELOCING	0x04000000	/* object is being relocated */
#define	FLG_RT_REGSYMS	0x08000000	/* object has DT_REGISTER entries */
#define	FLG_RT_INITCLCT	0x10000000	/* init has been collected (tsort) */
#define	FLG_RT_PUBHDL	0x20000000	/* generate a handle for this object */
#define	FLG_RT_PRIHDL	0x40000000	/*	either public or private */

#define	FL1_RT_COPYTOOK	0x00000001	/* copy relocation taken */
#define	FL1_RT_ALTCHECK	0x00000002	/* alternative system capabilities */
					/*	checked */
#define	FL1_RT_ALTCAP	0x00000004	/* alternative system capabilities */
					/*	should be used */
#define	FL1_RT_CONFSET	0x00000008	/* object was loaded by crle(1) */
#define	FL1_RT_NODEFLIB	0x00000010	/* ignore default library search */
#define	FL1_RT_ENDFILTE	0x00000020	/* filtee terminates filters search */
#define	FL1_RT_DISPREL	0x00000040	/* object has *disp* relocation */
#define	FL1_RT_DTFLAGS	0x00000080	/* DT_FLAGS element exists */
#define	FL1_RT_LDDSTUB	0x00000100	/* identify lddstub */
#define	FL1_RT_NOINIFIN	0x00000200	/* no .init or .fini exists */
#define	FL1_RT_USED	0x00000400	/* symbol referenced from this object */
#define	FL1_RT_SYMBOLIC	0x00000800	/* DF_SYMBOLIC was set - use */
					/*	symbolic sym resolution */
#define	FL1_RT_OBJSFLTR	0x00001000	/* object is acting as a standard */
#define	FL1_RT_OBJAFLTR	0x00002000	/*	or auxiliary filter */
#define	FL1_RT_SYMSFLTR	0x00004000	/* symbol is acting as a standard */
#define	FL1_RT_SYMAFLTR	0x00008000	/*	or auxiliary filter */
#define	MSK_RT_FILTER	0x0000f000	/* mask for all filter possibilities */

#define	FL1_RT_TLSADD	0x00010000	/* objects TLS has been registered */
#define	FL1_RT_TLSSTAT	0x00020000	/* object requires static TLS */
#define	FL1_RT_DIRECT	0x00040000	/* object has DIRECT bindings enabled */
#define	FL1_RT_GLOBAUD	0x00080000	/* establish global auditing */

/*
 * Flags for the tls_modactivity() routine
 */
#define	TM_FLG_MODADD	0x01		/* call tls_modadd() interface */
#define	TM_FLG_MODREM	0x02		/* call tls_modrem() interface */

/*
 * Macros for getting to exposed, link_map data (R_RTLDDB_VERSION <= 2).
 */
#define	ADDR(X)		((X)->rt_public.l_addr)
#define	NAME(X)		((X)->rt_public.l_name)
#define	DYN(X)		((X)->rt_public.l_ld)
#define	NEXT(X)		((X)->rt_public.l_next)
#define	PREV(X)		((X)->rt_public.l_prev)
#define	REFNAME(X)	((X)->rt_public.l_refname)

/*
 * An Rt_map starts with a Link_map, followed by other information.
 * ld.so.1 allocates Rt_map structures, and then casts them to Link_map,
 * and back, depending on context.
 *
 * On some platforms, Rt_map can have a higher alignment requirement
 * than Link_map. On such platforms, the cast from Link_map to Rt_map will
 * draw an E_BAD_PTR_CAST_ALIGN warning from lint. Since we allocate
 * the memory as the higher alignment Rt_map, we know that this is a safe
 * conversion. The LINKMAP_TO_RTMAP macro is used to handle the conversion
 * in a manner that satisfies lint.
 */
#ifdef lint
#define	LINKMAP_TO_RTMAP(X)	(Rt_map *)(void *)(X)
#else
#define	LINKMAP_TO_RTMAP(X)	(Rt_map *)(X)
#endif

/*
 * Convenience macros for the common case of using
 * NEXT()/PREV() and casting the result to (Rt_map *)
 */
#define	NEXT_RT_MAP(X)	LINKMAP_TO_RTMAP(NEXT(X))
#define	PREV_RT_MAP(X)	LINKMAP_TO_RTMAP(PREV(X))

/*
 * Macros for getting to exposed, link_map data (R_RTLDDB_VERSION3).
 */
#define	PATHNAME(X)	((X)->rt_pathname)
#define	PADSTART(X)	((X)->rt_padstart)
#define	PADIMLEN(X)	((X)->rt_padimlen)
#define	MSIZE(X)	((X)->rt_msize)
#define	FLAGS(X)	((X)->rt_flags)
#define	FLAGS1(X)	((X)->rt_flags1)

/*
 * Macros for getting to exposed, link_map data (R_RTLDDB_VERSION4).
 */
#define	TLSMODID(X)	((X)->rt_tlsmodid)

/*
 * Macros for getting to unexposed, link-map data.
 */
#define	LMSIZE(X)	((X)->rt_lmsize)
#define	AFLAGS(X)	((X)->rt_aflags)
#define	ALIAS(X)	((X)->rt_alias)
#define	FPNODE(X)	((X)->rt_fpnode)
#define	INIT(X)		((X)->rt_init)
#define	FINI(X)		((X)->rt_fini)
#define	RPATH(X)	((X)->rt_runpath)
#define	RLIST(X)	((X)->rt_runlist)
#define	DEPENDS(X)	((X)->rt_depends)
#define	CALLERS(X)	((X)->rt_callers)
#define	HANDLES(X)	((X)->rt_handles)
#define	GROUPS(X)	((X)->rt_groups)
#define	FCT(X)		((X)->rt_fct)
#define	SYMINTP(X)	((X)->rt_symintp)
#define	LIST(X)		((X)->rt_list)
#define	OBJFLTRNDX(X)	((X)->rt_objfltrndx)
#define	SYMSFLTRCNT(X)	((X)->rt_symsfltrcnt)
#define	SYMAFLTRCNT(X)	((X)->rt_symafltrcnt)
#define	MODE(X)		((X)->rt_mode)
#define	SORTVAL(X)	((X)->rt_sortval)
#define	CYCGROUP(X)	((X)->rt_cycgroup)
#define	STDEV(X)	((X)->rt_stdev)
#define	STINO(X)	((X)->rt_stino)
#define	ORIGNAME(X)	((X)->rt_origname)
#define	DIRSZ(X)	((X)->rt_dirsz)
#define	COPY_R(X)	((X)->rt_copy.rtc_r)
#define	COPY_S(X)	((X)->rt_copy.rtc_s)
#define	AUDITORS(X)	((X)->rt_auditors)
#define	AUDINFO(X)	((X)->rt_audinfo)
#define	SYMINFO(X)	((X)->rt_syminfo)
#define	INITARRAY(X)	((X)->rt_initarray)
#define	FINIARRAY(X)	((X)->rt_finiarray)
#define	PREINITARRAY(X)	((X)->rt_preinitarray)
#define	MMAPS(X)	((X)->rt_mmaps)
#define	MMAPCNT(X)	((X)->rt_mmapcnt)
#define	INITARRAYSZ(X)	((X)->rt_initarraysz)
#define	FINIARRAYSZ(X)	((X)->rt_finiarraysz)
#define	PREINITARRAYSZ(X) ((X)->rt_preinitarraysz)
#define	DYNINFO(X)	((X)->rt_dyninfo)
#define	DYNINFOCNT(X)	((X)->rt_dyninfocnt)
#define	RELACOUNT(X)	((X)->rt_relacount)
#define	IDX(X)		((X)->rt_idx)
#define	LAZY(X)		((X)->rt_lazy)
#define	CNTL(X)		((X)->rt_cntl)
#define	CAP(X)		((X)->rt_cap)
#define	CAPCHAIN(X)	((X)->rt_capchain)

/*
 * Flags for tsorting.
 */
#define	RT_SORT_FWD	0x01		/* topological sort (.fini) */
#define	RT_SORT_REV	0x02		/* reverse topological sort (.init) */
#define	RT_SORT_DELETE	0x10		/* process FLG_RT_DELETE objects */
					/*	only (called via dlclose()) */
#define	RT_SORT_INTPOSE	0x20		/* process interposer objects */

/*
 * Flags for lookup_sym (and hence find_sym) routines.
 */
#define	LKUP_DEFT	0x0000		/* simple lookup request */
#define	LKUP_SPEC	0x0001		/* special ELF lookup (allows address */
					/*	resolutions to plt[] entries) */
#define	LKUP_LDOT	0x0002		/* indicates the original A_OUT */
					/*	symbol had a leading `.' */
#define	LKUP_FIRST	0x0004		/* lookup symbol in first link map */
					/*	only */
#define	LKUP_COPY	0x0008		/* lookup symbol for a COPY reloc, do */
					/*	not bind to symbol at head */
#define	LKUP_STDRELOC	0x0010		/* lookup originates from a standard */
					/*	relocation (elf_reloc()) */
#define	LKUP_SELF	0x0020		/* lookup symbol in ourself - undef */
					/*	is valid */
#define	LKUP_WEAK	0x0040		/* relocation reference is weak */
#define	LKUP_NEXT	0x0080		/* request originates from RTLD_NEXT */
#define	LKUP_NODESCENT	0x0100		/* don't descend through dependencies */
#define	LKUP_NOFALLBACK	0x0200		/* don't fall back to loading */
					/*	pending lazy dependencies */
#define	LKUP_DIRECT	0x0400		/* direct binding request */
#define	LKUP_SYMNDX	0x0800		/* establish symbol index */
#define	LKUP_SINGLETON	0x1000		/* search for a singleton symbol */
#define	LKUP_STANDARD	0x2000		/* standard lookup - originated from */
					/* 	head link-map element */
#define	LKUP_WORLD	0x4000		/* ensure world lookup */
#define	LKUP_DLSYM	0x8000		/* lookup stems from dlsym() request */

/*
 * For the runtime linker to perform a symbol search, a number of data items
 * related to the search are required.  An Slookup data structure is used to
 * convey this data to lookup_sym(), and in special cases, to other core
 * routines that provide the implementation details for lookup_sym()
 *
 * The symbol name (sl_name), the caller (sl_cmap), and the link-map from which
 * to start the search (sl_imap) are fundamental to the symbol search.  The
 * initial search link-map might get modified by the core routines that provide
 * the implementation details for lookup_sym().  This modification accommodates
 * requirements such as processing a handle, direct binding and interposition.
 * The association between the caller and the potential destination also
 * determines whether the destination is a candidate to search.
 *
 * The lookup identifier (sl_id) is used to identify a runtime linker operation.
 * Within this operation, any lazy loads that fail are not re-examined.  This
 * technique keeps the overhead of processing a failed lazy load to a minimum.
 *
 * Symbol searches that originate from a relocation record are accompanied by
 * the relocation index (sl_rsymndx), the symbol reference (sl_rsym) and
 * possibly the relocation type (sl_rtype).  This data provides for determining
 * lazy loading, direct binding, and special symbol processing requirements
 * such as copy relocations and singleton lookup.
 *
 * The symbols hash value is computed by lookup_sym, and propagated throughout
 * the search engine.  Note, occasionally the Slookup data is passed to a core
 * routine that provides the implementation details for lookup_sym(), ie.
 * elf_find_sym(), in which case the caller must initialize the hash value.
 *
 * The symbols binding information is established by lookup_sym() when the
 * symbols relocation type is supplied.  Weak bindings allow relocations to
 * be set to zero should a symbol lookup fail.
 *
 * The flags allow the caller to control aspects of the search, including the
 * interpretation of copy relocations, etc.  Note, a number of flag settings
 * are established in lookup_sym() from attributes of the symbol reference.
 */
struct slookup {
	const char	*sl_name;	/* symbol name */
	Rt_map		*sl_cmap;	/* callers link-map */
	Rt_map		*sl_imap;	/* initial link-map to search */
	ulong_t		sl_id;		/* identifier for this lookup */
	ulong_t		sl_hash;	/* symbol hash value */
	ulong_t		sl_rsymndx;	/* referencing reloc symndx */
	Sym		*sl_rsym;	/* referencing symbol */
	uchar_t		sl_rtype;	/* relocation type associate with */
					/*    symbol */
	uchar_t		sl_bind;	/* symbols binding (returned) */
	uint_t		sl_flags;	/* lookup flags */
};

#define	SLOOKUP_INIT(sl, name, cmap, imap, id, hash, rsymndx, rsym, rtype, \
    flags) \
	(void) (sl.sl_name = (name), sl.sl_cmap = (cmap), sl.sl_imap = (imap), \
	    sl.sl_id = (id), sl.sl_hash = (hash), sl.sl_rsymndx = (rsymndx), \
	    sl.sl_rsym = (rsym), sl.sl_rtype = (rtype), sl.sl_bind = 0, \
	    sl.sl_flags = (flags))

/*
 * After a symbol lookup has been resolved, the runtime linker needs to retain
 * information regarding the bound definition.  An Sresult data structure is
 * used to provide this information.
 *
 * The symbol name (sr_name) may differ from the original referenced symbol if
 * a symbol capabilities family member has resolved the binding.  The defining
 * object (sr_dmap) indicates the object in which the definition has been found.
 * The symbol table entry (sr_sym) defines the bound symbol definition.
 *
 * Note, a symbol lookup may start with one Sresult buffer, but underlying
 * routines (for example, those that probe filters) might employ their own
 * Sresult buffer.  If a binding is allowed, the latter buffer may get inherited
 * by the former.  Along with this chain of requests, binding info (binfo) and
 * not-found information (in_nfavl), may be passed between all the associated
 * functions.  Hence, the binfo and in_nfavl data is not maintained as part of
 * a Sresult structure.
 */
struct sresult {
	const char	*sr_name;	/* symbol definition name */
	Rt_map		*sr_dmap;	/* defining objects link-map */
	Sym		*sr_sym;	/* symbol table pointer */
};

#define	SRESULT_INIT(sr, name) \
	(void) (sr.sr_name = (name), sr.sr_dmap = NULL, sr.sr_sym = NULL)

/*
 * Define a system capabilities structure for maintaining the various
 * capabilities of the system.  This structure follows the Objcapset definition
 * from libld.h, however the system can only have one platform or machine
 * hardware name, thus this structure is a little simpler.
 */
typedef	struct {
	elfcap_mask_t	sc_hw_1;	/* CA_SUNW_HW_1 capabilities */
	elfcap_mask_t	sc_sf_1;	/* CA_SUNW_SF_1 capabilities */
	elfcap_mask_t	sc_hw_2;	/* CA_SUNW_HW_2 capabilities */
	char		*sc_plat;	/* CA_SUNW_PLAT capability */
	size_t		sc_platsz;	/*	and size */
	char		*sc_mach;	/* CA_SUNW_MACH capability */
	size_t		sc_machsz;	/*	and size */
} Syscapset;

/*
 * Define a number of .plt lookup outcomes, for use in binding diagnostics.
 */
typedef	enum {
	PLT_T_NONE = 0,
	PLT_T_21D,
	PLT_T_24D,
	PLT_T_U32,
	PLT_T_U44,
	PLT_T_FULL,
	PLT_T_FAR,
	PLT_T_NUM			/* Must be last */
} Pltbindtype;

/*
 * Prototypes.
 */
extern ulong_t		ld_entry_cnt;	/* counter bumped on each entry to */
					/*    ld.so.1. */
extern Lm_list		lml_main;	/* main's link map list */
extern Lm_list		lml_rtld;	/* rtld's link map list */
extern Lm_list		*lml_list[];

extern Pltbindtype	elf_plt_write(uintptr_t, uintptr_t, void *, uintptr_t,
			    Xword);
extern Rt_map		*is_so_loaded(Lm_list *, const char *, int *);
extern int		lookup_sym(Slookup *, Sresult *, uint_t *, int *);
extern int		rt_dldump(Rt_map *, const char *, int, Addr);

#ifdef	__cplusplus
}
#endif

#endif /* _RTLD_H */