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. */ |
20 | extern int __dlfcn_argc attribute_hidden; |
21 | extern char **__dlfcn_argv attribute_hidden; |
22 | #else |
23 | /* These variables are defined and initialized in the startup code. */ |
24 | extern int __libc_argc attribute_hidden; |
25 | extern 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 with newly |
43 | installed libraries e.g. old libnss_nis.so.2 with new libnsl.so.1. Using |
44 | RTLD_LAZY here causes a failure at the time the symbol is called and at |
45 | that point it is much harder to safely return an error (Bug 22766). |
46 | |
47 | The use of RTLD_NOW also impacts gconv module loading, backtracing |
48 | (where the unwinder form libgcc_s.so is used), and IDNA functions |
49 | (which load libidn2), all of which load their respective DSOs on |
50 | demand, and so should not impact program startup. That is to say |
51 | that the DSOs are loaded as part of an API call and therefore we |
52 | will be calling that family of API functions shortly so RTLD_NOW or |
53 | RTLD_LAZY is not a big difference in performance, but RTLD_NOW has |
54 | better error handling semantics for the library. */ |
55 | #define __libc_dlopen(name) \ |
56 | __libc_dlopen_mode (name, RTLD_NOW | __RTLD_DLOPEN) |
57 | extern void *__libc_dlopen_mode (const char *__name, int __mode); |
58 | extern void *__libc_dlsym (void *__map, const char *__name); |
59 | extern void *__libc_dlvsym (void *map, const char *name, const char *version); |
60 | extern int __libc_dlclose (void *__map); |
61 | libc_hidden_proto (__libc_dlopen_mode) |
62 | libc_hidden_proto (__libc_dlsym) |
63 | libc_hidden_proto (__libc_dlvsym) |
64 | libc_hidden_proto (__libc_dlclose) |
65 | |
66 | /* Locate shared object containing the given address. */ |
67 | #ifdef ElfW |
68 | extern int _dl_addr (const void *address, Dl_info *info, |
69 | struct link_map **mapp, const ElfW(Sym) **symbolp); |
70 | libc_hidden_proto (_dl_addr) |
71 | #endif |
72 | |
73 | struct link_map; |
74 | |
75 | /* Close an object previously opened by _dl_open. */ |
76 | extern void _dl_close (void *map) attribute_hidden; |
77 | /* Same as above, but without locking and safety checks for user |
78 | provided map arguments. */ |
79 | extern void _dl_close_worker (struct link_map *map, bool force) |
80 | attribute_hidden; |
81 | |
82 | /* Look up NAME in shared object HANDLE (which may be RTLD_DEFAULT or |
83 | RTLD_NEXT). WHO is the calling function, for RTLD_NEXT. Returns |
84 | the symbol value, which may be NULL. */ |
85 | extern void *_dl_sym (void *handle, const char *name, void *who); |
86 | |
87 | /* Look up version VERSION of symbol NAME in shared object HANDLE |
88 | (which may be RTLD_DEFAULT or RTLD_NEXT). WHO is the calling |
89 | function, for RTLD_NEXT. Returns the symbol value, which may be |
90 | NULL. */ |
91 | extern void *_dl_vsym (void *handle, const char *name, const char *version, |
92 | void *who); |
93 | |
94 | /* Helper function for <dlfcn.h> functions. Runs the OPERATE function via |
95 | _dl_catch_error. Returns zero for success, nonzero for failure; and |
96 | arranges for `dlerror' to return the error details. |
97 | ARGS is passed as argument to OPERATE. */ |
98 | extern int _dlerror_run (void (*operate) (void *), void *args) |
99 | attribute_hidden; |
100 | |
101 | #ifdef SHARED |
102 | # define DL_CALLER_DECL /* Nothing */ |
103 | # define DL_CALLER RETURN_ADDRESS (0) |
104 | #else |
105 | # define DL_CALLER_DECL , void *dl_caller |
106 | # define DL_CALLER dl_caller |
107 | #endif |
108 | |
109 | struct dlfcn_hook |
110 | { |
111 | void *(*dlopen) (const char *file, int mode, void *dl_caller); |
112 | int (*dlclose) (void *handle); |
113 | void *(*dlsym) (void *handle, const char *name, void *dl_caller); |
114 | void *(*dlvsym) (void *handle, const char *name, const char *version, |
115 | void *dl_caller); |
116 | char *(*dlerror) (void); |
117 | int (*dladdr) (const void *address, Dl_info *info); |
118 | int (*dladdr1) (const void *address, Dl_info *info, |
119 | void **, int flags); |
120 | int (*dlinfo) (void *handle, int request, void *arg); |
121 | void *(*dlmopen) (Lmid_t nsid, const char *file, int mode, void *dl_caller); |
122 | void *pad[4]; |
123 | }; |
124 | |
125 | extern struct dlfcn_hook *_dlfcn_hook; |
126 | libdl_hidden_proto (_dlfcn_hook) |
127 | |
128 | extern void *__dlopen (const char *file, int mode DL_CALLER_DECL) |
129 | attribute_hidden; |
130 | extern void *__dlmopen (Lmid_t nsid, const char *file, int mode DL_CALLER_DECL) |
131 | attribute_hidden; |
132 | extern int __dlclose (void *handle) |
133 | attribute_hidden; |
134 | extern void *__dlsym (void *handle, const char *name DL_CALLER_DECL) |
135 | attribute_hidden; |
136 | extern void *__dlvsym (void *handle, const char *name, const char *version |
137 | DL_CALLER_DECL) |
138 | attribute_hidden; |
139 | extern char *__dlerror (void) |
140 | attribute_hidden; |
141 | extern int __dladdr (const void *address, Dl_info *info) |
142 | attribute_hidden; |
143 | extern int __dladdr1 (const void *address, Dl_info *info, |
144 | void **, int flags) |
145 | attribute_hidden; |
146 | extern int __dlinfo (void *handle, int request, void *arg) attribute_hidden; |
147 | |
148 | #ifndef SHARED |
149 | struct link_map; |
150 | extern void * __libc_dlsym_private (struct link_map *map, const char *name) |
151 | attribute_hidden; |
152 | extern void __libc_register_dl_open_hook (struct link_map *map) |
153 | attribute_hidden; |
154 | extern void __libc_register_dlfcn_hook (struct link_map *map) |
155 | attribute_hidden; |
156 | #endif |
157 | |
158 | extern void __dlerror_main_freeres (void) attribute_hidden; |
159 | |
160 | #endif |
161 | #endif |
162 | |