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|
/*
* 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 (c) 1995, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2017, Joyent, Inc.
* Copyright 2022 Oxide Computer Company
*/
#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 */
Alist *lm_aud_cookies; /* local auditor cookies */
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_aud_cookies;
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_ACTAUDIT 0x00000004 /* audit activity posted */
#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_STARTREL 0x00000400 /* relocation started */
#define LML_FLG_ATEXIT 0x00000800 /* atexit processing */
#define LML_FLG_OBJADDED 0x00001000 /* object(s) added */
#define LML_FLG_OBJDELETED 0x00002000 /* object(s) deleted */
#define LML_FLG_OBJREEVAL 0x00004000 /* existing object(s) needs */
/* tsort reevaluation */
#define LML_FLG_INTRPOSETSORT 0x00008000 /* interpose tsorting done */
#define LML_FLG_AUDITNOTIFY 0x00010000 /* audit consistent required */
#define LML_FLG_GROUPSEXIST 0x00020000 /* 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_NOAUDIT 0x00000004 /* auditing 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;
const char *di_name;
} 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_REGISTER 0x00040 /* .dynamic entry for DT_REGISTER */
#define FLG_DI_IGNORE 0x00080 /* .dynamic entry should be ignored */
#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_DEFERRED 0x00400 /* deferred needed entry, preceded by */
/* DF_P1_DEFERRED (DT_POSFLAG_1) */
#define FLG_DI_LAZYFAIL 0x01000 /* the lazy loading of this entry */
/* failed */
#define FLG_DI_LDD_DONE 0x02000 /* entry has been processed (ldd) */
#define FLG_DI_DEF_DONE 0x04000 /* entry has been processed (dlinfo) */
/*
* 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; /* .init_array table */
Addr *rt_finiarray; /* .fini_array table */
Addr *rt_preinitarray; /* .preinit_array table */
mmapobj_result_t *rt_mmaps; /* array of mapping information */
uint_t rt_mmapcnt; /* and associated number */
uint_t rt_initarraysz; /* size of .init_array table */
uint_t rt_finiarraysz; /* size of .fini_array table */
uint_t rt_preinitarraysz; /* size of .preinit_array 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_ */
Rt_cond rt_cv; /* for waiting on flags changes */
Rt_lock rt_lock; /* for coordinating flags changes */
/* address of _init */
thread_t rt_init_thread; /* thread id in this lm's _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(3C)'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 */
#define FL1_RT_DEPAUD 0x00100000 /* audit library from DT_DEPAUDIT */
/*
* 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) */
/* 0x2 was previously used as part of a.out support */
#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.
*
* Note, the amd64 version of elf_rtbndr assumes that the sc_hw_1 value is at
* offset zero and sc_hw_2 is at offset 8. If you are changing this structure
* in a way that invalidates this, you need to update that code.
*/
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 */
elfcap_mask_t sc_hw_3; /* CA_SUNW_HW_3 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 */
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