1 /* Machine-dependent ELF dynamic relocation.
2 Parts copied from glibc/sysdeps/xtensa/dl-machine.h
3 Copyright (C) 2001, 2007 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
20 /* Define this if the system uses RELOCA. */
21 #define ELF_USES_RELOCA
25 /* Translate a processor specific dynamic tag to the index
27 #define DT_XTENSA(x) (DT_XTENSA_##x - DT_LOPROC + DT_NUM + OS_NUM)
29 typedef struct xtensa_got_location_struct {
32 } xtensa_got_location;
34 /* Initialization sequence for the GOT. */
35 #define INIT_GOT(GOT_BASE, MODULE) \
37 xtensa_got_location *got_loc; \
38 Elf32_Addr l_addr = MODULE->loadaddr; \
39 Elf32_Addr prev_got_start = 0, prev_got_end = 0; \
42 got_loc = (xtensa_got_location *) \
43 (MODULE->dynamic_info[DT_XTENSA (GOT_LOC_OFF)] + l_addr); \
45 for (x = 0; x < MODULE->dynamic_info[DT_XTENSA (GOT_LOC_SZ)]; x++) \
47 Elf32_Addr got_start, got_end; \
48 got_start = got_loc[x].offset & ~(PAGE_SIZE - 1); \
49 got_end = ((got_loc[x].offset + got_loc[x].length + PAGE_SIZE - 1) \
50 & ~(PAGE_SIZE - 1)); \
51 if (got_end >= prev_got_start && got_start <= prev_got_end) \
53 if (got_end > prev_got_end) \
54 prev_got_end = got_end; \
55 if (got_start < prev_got_start) \
56 prev_got_start = got_start; \
59 else if (prev_got_start != prev_got_end) \
61 _dl_mprotect ((void *)(prev_got_start + l_addr), \
62 prev_got_end - prev_got_start, \
63 PROT_READ | PROT_WRITE | PROT_EXEC); \
65 prev_got_start = got_start; \
66 prev_got_end = got_end; \
69 if (prev_got_start != prev_got_end) \
71 _dl_mprotect ((void *)(prev_got_start + l_addr), \
72 prev_got_end - prev_got_start, \
73 PROT_READ | PROT_WRITE | PROT_EXEC); \
76 /* Fill in first GOT entry according to the ABI. */ \
77 GOT_BASE[0] = (unsigned long) _dl_linux_resolve; \
80 /* Parse dynamic info */
82 #define ARCH_DYNAMIC_INFO(dpnt, dynamic, debug_addr) \
84 if (dpnt->d_tag == DT_XTENSA_GOT_LOC_OFF) \
85 dynamic[DT_XTENSA (GOT_LOC_OFF)] = dpnt->d_un.d_ptr; \
86 else if (dpnt->d_tag == DT_XTENSA_GOT_LOC_SZ) \
87 dynamic[DT_XTENSA (GOT_LOC_SZ)] = dpnt->d_un.d_val; \
90 /* Here we define the magic numbers that this dynamic loader should accept. */
91 #define MAGIC1 EM_XTENSA
94 /* Used for error messages. */
95 #define ELF_TARGET "Xtensa"
97 /* Need bootstrap relocations */
98 #define ARCH_NEEDS_BOOTSTRAP_RELOCS
101 extern unsigned long _dl_linux_resolver (struct elf_resolve *, int);
103 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or
104 TLS variable, so undefined references should not be allowed to define
106 #define elf_machine_type_class(type) \
107 (((type) == R_XTENSA_JMP_SLOT || (type) == R_XTENSA_TLS_TPOFF \
108 || (type) == R_XTENSA_TLSDESC_FN || (type) == R_XTENSA_TLSDESC_ARG) \
109 * ELF_RTYPE_CLASS_PLT)
111 /* Return the link-time address of _DYNAMIC. */
112 static __always_inline Elf32_Addr
113 elf_machine_dynamic (void)
115 /* This function is only used while bootstrapping the runtime linker.
116 The "_DYNAMIC" symbol is always local so its GOT entry will initially
117 contain the link-time address. */
118 return (Elf32_Addr) &_DYNAMIC;
121 /* Return the run-time load address of the shared object. */
122 static __always_inline Elf32_Addr
123 elf_machine_load_address (void)
125 Elf32_Addr addr, tmp;
127 /* At this point, the runtime linker is being bootstrapped and the GOT
128 entry used for ".Lhere" will contain the link address. The CALL0 will
129 produce the dynamic address of ".Lhere" + 3. Thus, the end result is
130 equal to "dynamic_address(.Lhere) - link_address(.Lhere)". */
138 : "=a" (addr), "=a" (tmp));
143 static __always_inline void
144 elf_machine_relative (Elf32_Addr load_off, const Elf32_Addr rel_addr,
145 Elf32_Word relative_count)
147 Elf32_Rela *rpnt = (Elf32_Rela *) rel_addr;
148 while (relative_count--)
150 Elf32_Addr *const reloc_addr = (Elf32_Addr *) (load_off + rpnt->r_offset);
151 *reloc_addr += load_off + rpnt->r_addend;