1#ifndef _DLFCN_H
2#include <dlfcn/dlfcn.h>
3#ifndef _ISOMAC
4#include <link.h> /* For ElfW. */
5#include <stdbool.h>
6
7/* Internally used flag. */
8#define __RTLD_DLOPEN 0x80000000
9#define __RTLD_SPROF 0x40000000
10#define __RTLD_OPENEXEC 0x20000000
11#define __RTLD_CALLMAP 0x10000000
12#define __RTLD_AUDIT 0x08000000
13#define __RTLD_SECURE 0x04000000 /* Apply additional security checks. */
14#define __RTLD_NOIFUNC 0x02000000 /* Suppress calling ifunc functions. */
15
16#define __LM_ID_CALLER -2
17
18#ifdef SHARED
19/* Locally stored program arguments. */
20extern int __dlfcn_argc attribute_hidden;
21extern char **__dlfcn_argv attribute_hidden;
22#else
23/* These variables are defined and initialized in the startup code. */
24extern int __libc_argc attribute_hidden;
25extern char **__libc_argv attribute_hidden;
26
27# define __dlfcn_argc __libc_argc
28# define __dlfcn_argv __libc_argv
29#endif
30
31
32/* Now define the internal interfaces. */
33
34/* Use RTLD_NOW here because:
35 1. In pthread_cancel_init we want to use RTLD_NOW to reduce the stack usage
36 of future cancellation operations, particularly when the target thread
37 is running with a small stack. Likewise for consistency we do the same
38 thing in __libgcc_s_init. RTLD_NOW will rarely make a difference for
39 __libgcc_s_init because unwinding is already in progress, so libgcc_s.so
40 has already been loaded if its unwinder is used (Bug 22636).
41 2. It allows us to provide robust fallback code at dlopen time for
42 incorrectly configured systems that mix old libnss_* modules
43 with newly installed libraries e.g. old libnss_dns.so.2 with new
44 libresolv.so.2. Using RTLD_LAZY here causes a failure at the
45 time the symbol is called and at that point it is much harder to
46 safely return an error (Bug 22766).
47
48 The use of RTLD_NOW also impacts gconv module loading, backtracing
49 (where the unwinder form libgcc_s.so is used), and IDNA functions
50 (which load libidn2), all of which load their respective DSOs on
51 demand, and so should not impact program startup. That is to say
52 that the DSOs are loaded as part of an API call and therefore we
53 will be calling that family of API functions shortly so RTLD_NOW or
54 RTLD_LAZY is not a big difference in performance, but RTLD_NOW has
55 better error handling semantics for the library. */
56#define __libc_dlopen(name) \
57 __libc_dlopen_mode (name, RTLD_NOW | __RTLD_DLOPEN)
58extern void *__libc_dlopen_mode (const char *__name, int __mode);
59extern void *__libc_dlsym (void *__map, const char *__name);
60extern void *__libc_dlvsym (void *map, const char *name, const char *version);
61extern int __libc_dlclose (void *__map);
62libc_hidden_proto (__libc_dlopen_mode)
63libc_hidden_proto (__libc_dlsym)
64libc_hidden_proto (__libc_dlvsym)
65libc_hidden_proto (__libc_dlclose)
66
67/* Locate shared object containing the given address. */
68#ifdef ElfW
69extern int _dl_addr (const void *address, Dl_info *info,
70 struct link_map **mapp, const ElfW(Sym) **symbolp);
71libc_hidden_proto (_dl_addr)
72#endif
73
74struct link_map;
75
76/* Close an object previously opened by _dl_open. */
77extern void _dl_close (void *map) attribute_hidden;
78/* Same as above, but without locking and safety checks for user
79 provided map arguments. */
80extern void _dl_close_worker (struct link_map *map, bool force)
81 attribute_hidden;
82
83/* Look up NAME in shared object HANDLE (which may be RTLD_DEFAULT or
84 RTLD_NEXT). WHO is the calling function, for RTLD_NEXT. Returns
85 the symbol value, which may be NULL. */
86extern void *_dl_sym (void *handle, const char *name, void *who);
87
88/* Look up version VERSION of symbol NAME in shared object HANDLE
89 (which may be RTLD_DEFAULT or RTLD_NEXT). WHO is the calling
90 function, for RTLD_NEXT. Returns the symbol value, which may be
91 NULL. */
92extern void *_dl_vsym (void *handle, const char *name, const char *version,
93 void *who);
94
95/* Helper function for <dlfcn.h> functions. Runs the OPERATE function via
96 _dl_catch_error. Returns zero for success, nonzero for failure; and
97 arranges for `dlerror' to return the error details.
98 ARGS is passed as argument to OPERATE. */
99extern int _dlerror_run (void (*operate) (void *), void *args)
100 attribute_hidden;
101
102#ifdef SHARED
103# define DL_CALLER_DECL /* Nothing */
104# define DL_CALLER RETURN_ADDRESS (0)
105#else
106# define DL_CALLER_DECL , void *dl_caller
107# define DL_CALLER dl_caller
108#endif
109
110struct dlfcn_hook
111{
112 void *(*dlopen) (const char *file, int mode, void *dl_caller);
113 int (*dlclose) (void *handle);
114 void *(*dlsym) (void *handle, const char *name, void *dl_caller);
115 void *(*dlvsym) (void *handle, const char *name, const char *version,
116 void *dl_caller);
117 char *(*dlerror) (void);
118 int (*dladdr) (const void *address, Dl_info *info);
119 int (*dladdr1) (const void *address, Dl_info *info,
120 void **extra_info, int flags);
121 int (*dlinfo) (void *handle, int request, void *arg);
122 void *(*dlmopen) (Lmid_t nsid, const char *file, int mode, void *dl_caller);
123 void *pad[4];
124};
125
126extern struct dlfcn_hook *_dlfcn_hook;
127libdl_hidden_proto (_dlfcn_hook)
128
129extern void *__dlopen (const char *file, int mode DL_CALLER_DECL)
130 attribute_hidden;
131extern void *__dlmopen (Lmid_t nsid, const char *file, int mode DL_CALLER_DECL)
132 attribute_hidden;
133extern int __dlclose (void *handle)
134 attribute_hidden;
135extern void *__dlsym (void *handle, const char *name DL_CALLER_DECL)
136 attribute_hidden;
137extern void *__dlvsym (void *handle, const char *name, const char *version
138 DL_CALLER_DECL)
139 attribute_hidden;
140extern char *__dlerror (void)
141 attribute_hidden;
142extern int __dladdr (const void *address, Dl_info *info)
143 attribute_hidden;
144extern int __dladdr1 (const void *address, Dl_info *info,
145 void **extra_info, int flags)
146 attribute_hidden;
147extern int __dlinfo (void *handle, int request, void *arg) attribute_hidden;
148
149#ifndef SHARED
150struct link_map;
151extern void * __libc_dlsym_private (struct link_map *map, const char *name)
152 attribute_hidden;
153extern void __libc_register_dl_open_hook (struct link_map *map)
154 attribute_hidden;
155extern void __libc_register_dlfcn_hook (struct link_map *map)
156 attribute_hidden;
157#endif
158
159extern void __dlerror_main_freeres (void) attribute_hidden;
160
161#endif
162#endif
163