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sourceware.org Git - glibc.git/blob - sysdeps/mips/dl-trampoline.c
1 /* PLT trampoline. MIPS version.
2 Copyright (C) 1996-2001, 2002, 2003, 2004, 2005
3 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5 Contributed by Kazumoto Kojima <kkojima@info.kanagawa-u.ac.jp>.
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public
9 License as published by the Free Software Foundation; either
10 version 2.1 of the License, or (at your option) any later version.
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, write to the Free
19 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
22 /* FIXME: Profiling of shared libraries is not implemented yet. */
28 #include <dl-machine.h>
30 /* Get link map for callers object containing STUB_PC. */
31 static inline struct link_map
*
32 elf_machine_runtime_link_map (ElfW(Addr
) gpreg
, ElfW(Addr
) stub_pc
)
34 extern int _dl_mips_gnu_objects
;
36 /* got[1] is reserved to keep its link map address for the shared
37 object generated by the gnu linker. If all are such objects, we
38 can find the link map from current GPREG simply. If not so, get
39 the link map for caller's object containing STUB_PC. */
41 if (_dl_mips_gnu_objects
)
43 ElfW(Addr
) *got
= elf_mips_got_from_gpreg (gpreg
);
46 g1
= ((ElfW(Word
) *) got
)[1];
48 if ((g1
& ELF_MIPS_GNU_GOT1_MASK
) != 0)
51 (struct link_map
*) (g1
& ~ELF_MIPS_GNU_GOT1_MASK
);
52 ElfW(Addr
) base
, limit
;
53 const ElfW(Phdr
) *p
= l
->l_phdr
;
54 ElfW(Half
) this, nent
= l
->l_phnum
;
56 /* For the common case of a stub being called from the containing
57 object, STUB_PC will point to somewhere within the object that
58 is described by the link map fetched via got[1]. Otherwise we
59 have to scan all maps. */
60 for (this = 0; this < nent
; this++)
62 if (p
[this].p_type
== PT_LOAD
)
64 base
= p
[this].p_vaddr
+ l
->l_addr
;
65 limit
= base
+ p
[this].p_memsz
;
66 if (stub_pc
>= base
&& stub_pc
< limit
)
76 for (nsid
= 0; nsid
< DL_NNS
; ++nsid
)
77 for (l
= GL(dl_ns
)[nsid
]._ns_loaded
; l
!= NULL
; l
= l
->l_next
)
79 ElfW(Addr
) base
, limit
;
80 const ElfW(Phdr
) *p
= l
->l_phdr
;
81 ElfW(Half
) this, nent
= l
->l_phnum
;
83 for (this = 0; this < nent
; ++this)
85 if (p
[this].p_type
== PT_LOAD
)
87 base
= p
[this].p_vaddr
+ l
->l_addr
;
88 limit
= base
+ p
[this].p_memsz
;
89 if (stub_pc
>= base
&& stub_pc
< limit
)
95 _dl_signal_error (0, NULL
, NULL
, "cannot find runtime link map");
99 /* Define mips specific runtime resolver. The function __dl_runtime_resolve
100 is called from assembler function _dl_runtime_resolve which converts
101 special argument registers t7 ($15) and t8 ($24):
102 t7 address to return to the caller of the function
103 t8 index for this function symbol in .dynsym
104 to usual c arguments.
106 Other architectures call fixup from dl-runtime.c in
107 _dl_runtime_resolve. MIPS instead calls __dl_runtime_resolve. We
108 have to use our own version because of the way the got section is
109 treated on MIPS (we've also got ELF_MACHINE_PLT defined). */
111 /* The flag _dl_mips_gnu_objects is set if all dynamic objects are
112 generated by the gnu linker. */
113 int _dl_mips_gnu_objects
= 1;
115 #define VERSYMIDX(sym) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (sym))
117 /* This is called from assembly stubs below which the compiler can't see. */
119 __dl_runtime_resolve (ElfW(Word
), ElfW(Word
), ElfW(Addr
), ElfW(Addr
))
123 __dl_runtime_resolve (ElfW(Word
) sym_index
,
124 ElfW(Word
) return_address
,
125 ElfW(Addr
) old_gpreg
,
128 struct link_map
*l
= elf_machine_runtime_link_map (old_gpreg
, stub_pc
);
129 const ElfW(Sym
) *const symtab
130 = (const ElfW(Sym
) *) D_PTR (l
, l_info
[DT_SYMTAB
]);
131 const char *strtab
= (const void *) D_PTR (l
, l_info
[DT_STRTAB
]);
133 = (ElfW(Addr
) *) D_PTR (l
, l_info
[DT_PLTGOT
]);
134 const ElfW(Word
) local_gotno
135 = (const ElfW(Word
)) l
->l_info
[DT_MIPS (LOCAL_GOTNO
)]->d_un
.d_val
;
136 const ElfW(Word
) gotsym
137 = (const ElfW(Word
)) l
->l_info
[DT_MIPS (GOTSYM
)]->d_un
.d_val
;
138 const ElfW(Sym
) *sym
= &symtab
[sym_index
];
139 struct link_map
*sym_map
;
142 /* FIXME: The symbol versioning stuff is not tested yet. */
143 if (__builtin_expect (ELFW(ST_VISIBILITY
) (sym
->st_other
), 0) == 0)
145 switch (l
->l_info
[VERSYMIDX (DT_VERSYM
)] != NULL
)
149 const ElfW(Half
) *vernum
=
150 (const void *) D_PTR (l
, l_info
[VERSYMIDX (DT_VERSYM
)]);
151 ElfW(Half
) ndx
= vernum
[sym_index
] & 0x7fff;
152 const struct r_found_version
*version
= &l
->l_versions
[ndx
];
154 if (version
->hash
!= 0)
156 sym_map
= _dl_lookup_symbol_x (strtab
+ sym
->st_name
, l
,
157 &sym
, l
->l_scope
, version
,
158 ELF_RTYPE_CLASS_PLT
, 0, 0);
164 sym_map
= _dl_lookup_symbol_x (strtab
+ sym
->st_name
, l
, &sym
,
165 l
->l_scope
, 0, ELF_RTYPE_CLASS_PLT
,
166 DL_LOOKUP_ADD_DEPENDENCY
, 0);
169 /* Currently value contains the base load address of the object
170 that defines sym. Now add in the symbol offset. */
171 value
= (sym
? sym_map
->l_addr
+ sym
->st_value
: 0);
174 /* We already found the symbol. The module (and therefore its load
175 address) is also known. */
176 value
= l
->l_addr
+ sym
->st_value
;
178 /* Apply the relocation with that value. */
179 *(got
+ local_gotno
+ sym_index
- gotsym
) = value
;
184 #if _MIPS_SIM == _ABIO32
185 #define ELF_DL_FRAME_SIZE 40
187 #define ELF_DL_SAVE_ARG_REGS "\
195 #define ELF_DL_RESTORE_ARG_REGS "\
203 #define IFABIO32(X) X
205 #else /* _MIPS_SIM == _ABIN32 || _MIPS_SIM == _ABI64 */
207 #define ELF_DL_FRAME_SIZE 80
209 #define ELF_DL_SAVE_ARG_REGS "\
221 #define ELF_DL_RESTORE_ARG_REGS "\
240 .globl _dl_runtime_resolve\n\
241 .type _dl_runtime_resolve,@function\n\
242 .ent _dl_runtime_resolve\n\
243 _dl_runtime_resolve:\n\
244 .frame $29, " STRINGXP(ELF_DL_FRAME_SIZE
) ", $31\n\
248 # Save arguments and sp value in stack.\n\
249 " STRINGXP(PTR_SUBIU
) " $29, " STRINGXP(ELF_DL_FRAME_SIZE
) "\n\
250 # Modify t9 ($25) so as to point .cpload instruction.\n\
251 " IFABIO32(STRINGXP(PTR_ADDIU
) " $25, 12\n") "\
253 " STRINGXP(SETUP_GP
) "\n\
254 " STRINGXV(SETUP_GP64 (0, _dl_runtime_resolve
)) "\n\
256 # Save slot call pc.\n\
258 " IFABIO32(STRINGXP(CPRESTORE(32))) "\n\
259 " ELF_DL_SAVE_ARG_REGS
"\
264 jal __dl_runtime_resolve\n\
265 " ELF_DL_RESTORE_ARG_REGS
"\
266 " STRINGXP(RESTORE_GP64
) "\n\
267 " STRINGXP(PTR_ADDIU
) " $29, " STRINGXP(ELF_DL_FRAME_SIZE
) "\n\
270 .end _dl_runtime_resolve\n\
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