l4/pkg/uclibc/lib/contrib/uclibc/ldso/ldso/mips/dl-sysdep.h

   1 /* vi: set sw=8 ts=8: */
   2
   3 /*
   4  * Various assembly language/system dependent hacks that are required
   5  * so that we can minimize the amount of platform specific code.
   6  */
   7
   8 /* Define this if the system uses RELOCA.  */
   9 #undef ELF_USES_RELOCA
  10 #include <elf.h>
  11
  12 #ifdef __mips64 /* from glibc sysdeps/mips/elf/ldsodefs.h 1.4 */
  13 /* The 64-bit MIPS ELF ABI uses an unusual reloc format.  Each
  14    relocation entry specifies up to three actual relocations, all at
  15    the same address.  The first relocation which required a symbol
  16    uses the symbol in the r_sym field.  The second relocation which
  17    requires a symbol uses the symbol in the r_ssym field.  If all
  18    three relocations require a symbol, the third one uses a zero
  19    value.
  20
  21    We define these structures in internal headers because we're not
  22    sure we want to make them part of the ABI yet.  Eventually, some of
  23    this may move into elf/elf.h.  */
  24
  25 /* An entry in a 64 bit SHT_REL section.  */
  26
  27 typedef struct
  28 {
  29   Elf32_Word    r_sym;          /* Symbol index */
  30   unsigned char r_ssym;         /* Special symbol for 2nd relocation */
  31   unsigned char r_type3;        /* 3rd relocation type */
  32   unsigned char r_type2;        /* 2nd relocation type */
  33   unsigned char r_type1;        /* 1st relocation type */
  34 } _Elf64_Mips_R_Info;
  35
  36 typedef union
  37 {
  38   Elf64_Xword   r_info_number;
  39   _Elf64_Mips_R_Info r_info_fields;
  40 } _Elf64_Mips_R_Info_union;
  41
  42 typedef struct
  43 {
  44   Elf64_Addr    r_offset;               /* Address */
  45   _Elf64_Mips_R_Info_union r_info;      /* Relocation type and symbol index */
  46 } Elf64_Mips_Rel;
  47
  48 typedef struct
  49 {
  50   Elf64_Addr    r_offset;               /* Address */
  51   _Elf64_Mips_R_Info_union r_info;      /* Relocation type and symbol index */
  52   Elf64_Sxword  r_addend;               /* Addend */
  53 } Elf64_Mips_Rela;
  54
  55 #define ELF64_MIPS_R_SYM(i) \
  56   ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym)
  57 #define ELF64_MIPS_R_TYPE(i) \
  58   (((_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1 \
  59    | ((Elf32_Word)(__extension__ (_Elf64_Mips_R_Info_union)(i) \
  60                    ).r_info_fields.r_type2 << 8) \
  61    | ((Elf32_Word)(__extension__ (_Elf64_Mips_R_Info_union)(i) \
  62                    ).r_info_fields.r_type3 << 16) \
  63    | ((Elf32_Word)(__extension__ (_Elf64_Mips_R_Info_union)(i) \
  64                    ).r_info_fields.r_ssym << 24))
  65 #define ELF64_MIPS_R_INFO(sym, type) \
  66   (__extension__ (_Elf64_Mips_R_Info_union) \
  67    (__extension__ (_Elf64_Mips_R_Info) \
  68    { (sym), ELF64_MIPS_R_SSYM (type), \
  69        ELF64_MIPS_R_TYPE3 (type), \
  70        ELF64_MIPS_R_TYPE2 (type), \
  71        ELF64_MIPS_R_TYPE1 (type) \
  72    }).r_info_number)
  73 /* These macros decompose the value returned by ELF64_MIPS_R_TYPE, and
  74    compose it back into a value that it can be used as an argument to
  75    ELF64_MIPS_R_INFO.  */
  76 #define ELF64_MIPS_R_SSYM(i) (((i) >> 24) & 0xff)
  77 #define ELF64_MIPS_R_TYPE3(i) (((i) >> 16) & 0xff)
  78 #define ELF64_MIPS_R_TYPE2(i) (((i) >> 8) & 0xff)
  79 #define ELF64_MIPS_R_TYPE1(i) ((i) & 0xff)
  80 #define ELF64_MIPS_R_TYPEENC(type1, type2, type3, ssym) \
  81   ((type1) \
  82    | ((Elf32_Word)(type2) << 8) \
  83    | ((Elf32_Word)(type3) << 16) \
  84    | ((Elf32_Word)(ssym) << 24))
  85
  86 #undef ELF64_R_SYM
  87 #define ELF64_R_SYM(i) ELF64_MIPS_R_SYM (i)
  88 #undef ELF64_R_TYPE
  89 #define ELF64_R_TYPE(i) ELF64_MIPS_R_TYPE (i)
  90 #undef ELF64_R_INFO
  91 #define ELF64_R_INFO(sym, type) ELF64_MIPS_R_INFO ((sym), (type))
  92 #endif  /* __mips64 */
  93
  94 #include <link.h>
  95
  96 #define ARCH_NUM 4
  97 #define DT_MIPS_GOTSYM_IDX      (DT_NUM + OS_NUM)
  98 #define DT_MIPS_LOCAL_GOTNO_IDX (DT_NUM + OS_NUM +1)
  99 #define DT_MIPS_SYMTABNO_IDX    (DT_NUM + OS_NUM +2)
 100 #define DT_MIPS_PLTGOT_IDX      (DT_NUM + OS_NUM +3)
 101
 102 #define ARCH_DYNAMIC_INFO(dpnt,  dynamic, debug_addr) \
 103 do { \
 104 if (dpnt->d_tag == DT_MIPS_GOTSYM) \
 105      dynamic[DT_MIPS_GOTSYM_IDX] = dpnt->d_un.d_val; \
 106 else if (dpnt->d_tag == DT_MIPS_LOCAL_GOTNO) \
 107      dynamic[DT_MIPS_LOCAL_GOTNO_IDX] = dpnt->d_un.d_val; \
 108 else if (dpnt->d_tag == DT_MIPS_SYMTABNO) \
 109      dynamic[DT_MIPS_SYMTABNO_IDX] = dpnt->d_un.d_val; \
 110 else if (dpnt->d_tag == DT_MIPS_PLTGOT) \
 111      dynamic[DT_MIPS_PLTGOT_IDX] = dpnt->d_un.d_val; \
 112 else if ((dpnt->d_tag == DT_MIPS_RLD_MAP) && (dpnt->d_un.d_ptr)) \
 113      *(ElfW(Addr) *)(dpnt->d_un.d_ptr) =  (ElfW(Addr)) debug_addr; \
 114 } while (0)
 115
 116 /* Initialization sequence for the application/library GOT.  */
 117 #define INIT_GOT(GOT_BASE,MODULE)                                               \
 118 do {                                                                            \
 119         unsigned long idx;                                                      \
 120         unsigned long *pltgot;                                                  \
 121                                                                                 \
 122         /* Check if this is the dynamic linker itself */                        \
 123         if (MODULE->libtype == program_interpreter)                             \
 124                 continue;                                                       \
 125                                                                                 \
 126         /* Fill in first two GOT entries according to the ABI */                \
 127         GOT_BASE[0] = (unsigned long) _dl_runtime_resolve;                      \
 128         GOT_BASE[1] = (unsigned long) MODULE;                                   \
 129                                                                                 \
 130         pltgot = MODULE->dynamic_info[DT_MIPS_PLTGOT_IDX];                      \
 131         if (pltgot) {                                                           \
 132                 pltgot[0] = (unsigned long) _dl_runtime_pltresolve;             \
 133                 pltgot[1] = (unsigned long) MODULE;                             \
 134         }                                                                       \
 135                                                                                 \
 136         /* Add load address displacement to all local GOT entries */            \
 137         idx = 2;                                                                        \
 138         while (idx < MODULE->dynamic_info[DT_MIPS_LOCAL_GOTNO_IDX])             \
 139                 GOT_BASE[idx++] += (unsigned long) MODULE->loadaddr;            \
 140                                                                                 \
 141 } while (0)
 142
 143
 144 /* Here we define the magic numbers that this dynamic loader should accept */
 145 #define MAGIC1 EM_MIPS
 146 #define MAGIC2 EM_MIPS_RS3_LE
 147
 148
 149 /* Used for error messages */
 150 #define ELF_TARGET "MIPS"
 151
 152 /* Need bootstrap relocations */
 153 #define ARCH_NEEDS_BOOTSTRAP_RELOCS
 154
 155 unsigned long __dl_runtime_resolve(unsigned long sym_index,
 156         unsigned long old_gpreg);
 157
 158 struct elf_resolve;
 159 void _dl_perform_mips_global_got_relocations(struct elf_resolve *tpnt, int lazy);
 160
 161 /* 4096 bytes alignment */
 162 #if _MIPS_SIM == _MIPS_SIM_ABI64
 163 #define OFFS_ALIGN (0x10000000000UL-0x1000)
 164 #endif  /* O32 || N32 */
 165
 166 #if defined USE_TLS
 167 # if _MIPS_SIM == _MIPS_SIM_ABI64
 168 # define elf_machine_type_class(type)                                   \
 169   ((((type) == R_MIPS_JUMP_SLOT || (type) == R_MIPS_TLS_DTPMOD64        \
 170      || (type) == R_MIPS_TLS_DTPREL64 || (type) == R_MIPS_TLS_TPREL64)  \
 171     * ELF_RTYPE_CLASS_PLT)                                              \
 172    | (((type) == R_MIPS_COPY) * ELF_RTYPE_CLASS_COPY))
 173 # else
 174 # define elf_machine_type_class(type)                                   \
 175   ((((type) == R_MIPS_JUMP_SLOT || (type) == R_MIPS_TLS_DTPMOD32        \
 176      || (type) == R_MIPS_TLS_DTPREL32 || (type) == R_MIPS_TLS_TPREL32)  \
 177     * ELF_RTYPE_CLASS_PLT)                                              \
 178    | (((type) == R_MIPS_COPY) * ELF_RTYPE_CLASS_COPY))
 179 # endif /* _MIPS_SIM == _MIPS_SIM_ABI64 */
 180 #else
 181 #define elf_machine_type_class(type)                                    \
 182   ((((type) == R_MIPS_JUMP_SLOT) * ELF_RTYPE_CLASS_PLT)                 \
 183    | (((type) == R_MIPS_COPY) * ELF_RTYPE_CLASS_COPY))
 184 #endif /* USE_TLS */
 185
 186 #define OFFSET_GP_GOT 0x7ff0
 187
 188 static __always_inline ElfW(Addr) *
 189 elf_mips_got_from_gpreg (ElfW(Addr) gpreg)
 190 {
 191         /* FIXME: the offset of gp from GOT may be system-dependent. */
 192         return (ElfW(Addr) *) (gpreg - OFFSET_GP_GOT);
 193 }
 194
 195 /* Return the link-time address of _DYNAMIC.  Conveniently, this is the
 196    first element of the GOT.  This must be inlined in a function which
 197    uses global data.  We assume its $gp points to the primary GOT.  */
 198 static __always_inline ElfW(Addr)
 199 elf_machine_dynamic (void)
 200 {
 201         register ElfW(Addr) gp __asm__ ("$28");
 202         return *elf_mips_got_from_gpreg (gp);
 203 }
 204
 205 #define STRINGXP(X) __STRING(X)
 206 #define STRINGXV(X) STRINGV_(X)
 207 #define STRINGV_(...) # __VA_ARGS__
 208 #if _MIPS_SIM == _MIPS_SIM_ABI64
 209 #define PTR_LA               dla
 210 #define PTR_SUBU     dsubu
 211 #else
 212 #define PTR_LA               la
 213 #define PTR_SUBU     subu
 214 #endif
 215
 216 /* Return the run-time load address of the shared object.  */
 217 static __always_inline ElfW(Addr)
 218 elf_machine_load_address (void)
 219 {
 220         ElfW(Addr) addr;
 221         __asm__ ("        .set noreorder\n"
 222              "        " STRINGXP (PTR_LA) " %0, 0f\n"
 223              "        bltzal $0, 0f\n"
 224              "        nop\n"
 225              "0:      " STRINGXP (PTR_SUBU) " %0, $31, %0\n"
 226              "        .set reorder\n"
 227              :        "=r" (addr)
 228              :        /* No inputs */
 229              :        "$31");
 230         return addr;
 231 }
 232
 233 static __always_inline void
 234 elf_machine_relative (ElfW(Addr) load_off, const ElfW(Addr) rel_addr,
 235                       ElfW(Word) relative_count)
 236 {
 237         /* No RELATIVE relocs in MIPS? */
 238 }
 239
 240 #ifdef __mips64
 241 #define DL_MALLOC_ALIGN 8       /* N64/N32 needs 8 byte alignment */
 242 #endif