0x2718fffe /* subu $24, $24, 2 */
};
-/* The format of subsequent PLT entries. */
+/* The format of the microMIPS first PLT entry in an O32 executable.
+ We rely on v0 ($2) rather than t8 ($24) to contain the address
+ of the GOTPLT entry handled, so this stub may only be used when
+ all the subsequent PLT entries are microMIPS code too.
+
+ The trailing NOP is for alignment and correct disassembly only. */
+static const bfd_vma micromips_o32_exec_plt0_entry[] =
+{
+ 0x7980, 0x0000, /* addiupc $3, (&GOTPLT[0]) - . */
+ 0xff23, 0x0000, /* lw $25, 0($3) */
+ 0x0535, /* subu $2, $2, $3 */
+ 0x2525, /* srl $2, $2, 2 */
+ 0x3302, 0xfffe, /* subu $24, $2, 2 */
+ 0x0dff, /* move $15, $31 */
+ 0x45f9, /* jalrs $25 */
+ 0x0f83, /* move $28, $3 */
+ 0x0c00 /* nop */
+};
+
+/* The format of the microMIPS first PLT entry in an O32 executable
+ in the insn32 mode. */
+static const bfd_vma micromips_insn32_o32_exec_plt0_entry[] =
+{
+ 0x41bc, 0x0000, /* lui $28, %hi(&GOTPLT[0]) */
+ 0xff3c, 0x0000, /* lw $25, %lo(&GOTPLT[0])($28) */
+ 0x339c, 0x0000, /* addiu $28, $28, %lo(&GOTPLT[0]) */
+ 0x0398, 0xc1d0, /* subu $24, $24, $28 */
+ 0x001f, 0x7950, /* move $15, $31 */
+ 0x0318, 0x1040, /* srl $24, $24, 2 */
+ 0x03f9, 0x0f3c, /* jalr $25 */
+ 0x3318, 0xfffe /* subu $24, $24, 2 */
+};
+
+/* The format of subsequent standard PLT entries. */
static const bfd_vma mips_exec_plt_entry[] =
{
0x3c0f0000, /* lui $15, %hi(.got.plt entry) */
0x03200008 /* jr $25 */
};
+/* The format of subsequent MIPS16 o32 PLT entries. We use v0 ($2)
+ and v1 ($3) as temporaries because t8 ($24) and t9 ($25) are not
+ directly addressable. */
+static const bfd_vma mips16_o32_exec_plt_entry[] =
+{
+ 0xb203, /* lw $2, 12($pc) */
+ 0x9a60, /* lw $3, 0($2) */
+ 0x651a, /* move $24, $2 */
+ 0xeb00, /* jr $3 */
+ 0x653b, /* move $25, $3 */
+ 0x6500, /* nop */
+ 0x0000, 0x0000 /* .word (.got.plt entry) */
+};
+
+/* The format of subsequent microMIPS o32 PLT entries. We use v0 ($2)
+ as a temporary because t8 ($24) is not addressable with ADDIUPC. */
+static const bfd_vma micromips_o32_exec_plt_entry[] =
+{
+ 0x7900, 0x0000, /* addiupc $2, (.got.plt entry) - . */
+ 0xff22, 0x0000, /* lw $25, 0($2) */
+ 0x4599, /* jr $25 */
+ 0x0f02 /* move $24, $2 */
+};
+
+/* The format of subsequent microMIPS o32 PLT entries in the insn32 mode. */
+static const bfd_vma micromips_insn32_o32_exec_plt_entry[] =
+{
+ 0x41af, 0x0000, /* lui $15, %hi(.got.plt entry) */
+ 0xff2f, 0x0000, /* lw $25, %lo(.got.plt entry)($15) */
+ 0x0019, 0x0f3c, /* jr $25 */
+ 0x330f, 0x0000 /* addiu $24, $15, %lo(.got.plt entry) */
+};
+
/* The format of the first PLT entry in a VxWorks executable. */
static const bfd_vma mips_vxworks_exec_plt0_entry[] =
{
+ i * 4 * ARRAY_SIZE (mips_exec_plt_entry));
}
+/* Build a table of synthetic symbols to represent the PLT. As with MIPS16
+ and microMIPS PLT slots we may have a many-to-one mapping between .plt
+ and .got.plt and also the slots may be of a different size each we walk
+ the PLT manually fetching instructions and matching them against known
+ patterns. To make things easier standard MIPS slots, if any, always come
+ first. As we don't create proper ELF symbols we use the UDATA.I member
+ of ASYMBOL to carry ISA annotation. The encoding used is the same as
+ with the ST_OTHER member of the ELF symbol. */
+
+long
+_bfd_mips_elf_get_synthetic_symtab (bfd *abfd,
+ long symcount ATTRIBUTE_UNUSED,
+ asymbol **syms ATTRIBUTE_UNUSED,
+ long dynsymcount, asymbol **dynsyms,
+ asymbol **ret)
+{
+ static const char pltname[] = "_PROCEDURE_LINKAGE_TABLE_";
+ static const char microsuffix[] = "@micromipsplt";
+ static const char m16suffix[] = "@mips16plt";
+ static const char mipssuffix[] = "@plt";
+
+ bfd_boolean (*slurp_relocs) (bfd *, asection *, asymbol **, bfd_boolean);
+ const struct elf_backend_data *bed = get_elf_backend_data (abfd);
+ bfd_boolean micromips_p = MICROMIPS_P (abfd);
+ Elf_Internal_Shdr *hdr;
+ bfd_byte *plt_data;
+ bfd_vma plt_offset;
+ unsigned int other;
+ bfd_vma entry_size;
+ bfd_vma plt0_size;
+ asection *relplt;
+ bfd_vma opcode;
+ asection *plt;
+ asymbol *send;
+ size_t size;
+ char *names;
+ long counti;
+ arelent *p;
+ asymbol *s;
+ char *nend;
+ long count;
+ long pi;
+ long i;
+ long n;
+
+ *ret = NULL;
+
+ if ((abfd->flags & (DYNAMIC | EXEC_P)) == 0 || dynsymcount <= 0)
+ return 0;
+
+ relplt = bfd_get_section_by_name (abfd, ".rel.plt");
+ if (relplt == NULL)
+ return 0;
+
+ hdr = &elf_section_data (relplt)->this_hdr;
+ if (hdr->sh_link != elf_dynsymtab (abfd) || hdr->sh_type != SHT_REL)
+ return 0;
+
+ plt = bfd_get_section_by_name (abfd, ".plt");
+ if (plt == NULL)
+ return 0;
+
+ slurp_relocs = get_elf_backend_data (abfd)->s->slurp_reloc_table;
+ if (!(*slurp_relocs) (abfd, relplt, dynsyms, TRUE))
+ return -1;
+ p = relplt->relocation;
+
+ /* Calculating the exact amount of space required for symbols would
+ require two passes over the PLT, so just pessimise assuming two
+ PLT slots per relocation. */
+ count = relplt->size / hdr->sh_entsize;
+ counti = count * bed->s->int_rels_per_ext_rel;
+ size = 2 * count * sizeof (asymbol);
+ size += count * (sizeof (mipssuffix) +
+ (micromips_p ? sizeof (microsuffix) : sizeof (m16suffix)));
+ for (pi = 0; pi < counti; pi += bed->s->int_rels_per_ext_rel)
+ size += 2 * strlen ((*p[pi].sym_ptr_ptr)->name);
+
+ /* Add the size of "_PROCEDURE_LINKAGE_TABLE_" too. */
+ size += sizeof (asymbol) + sizeof (pltname);
+
+ if (!bfd_malloc_and_get_section (abfd, plt, &plt_data))
+ return -1;
+
+ if (plt->size < 16)
+ return -1;
+
+ s = *ret = bfd_malloc (size);
+ if (s == NULL)
+ return -1;
+ send = s + 2 * count + 1;
+
+ names = (char *) send;
+ nend = (char *) s + size;
+ n = 0;
+
+ opcode = bfd_get_micromips_32 (abfd, plt_data + 12);
+ if (opcode == 0x3302fffe)
+ {
+ if (!micromips_p)
+ return -1;
+ plt0_size = 2 * ARRAY_SIZE (micromips_o32_exec_plt0_entry);
+ other = STO_MICROMIPS;
+ }
+ else if (opcode == 0x0398c1d0)
+ {
+ if (!micromips_p)
+ return -1;
+ plt0_size = 2 * ARRAY_SIZE (micromips_insn32_o32_exec_plt0_entry);
+ other = STO_MICROMIPS;
+ }
+ else
+ {
+ plt0_size = 4 * ARRAY_SIZE (mips_o32_exec_plt0_entry);
+ other = 0;
+ }
+
+ s->the_bfd = abfd;
+ s->flags = BSF_SYNTHETIC | BSF_FUNCTION | BSF_LOCAL;
+ s->section = plt;
+ s->value = 0;
+ s->name = names;
+ s->udata.i = other;
+ memcpy (names, pltname, sizeof (pltname));
+ names += sizeof (pltname);
+ ++s, ++n;
+
+ pi = 0;
+ for (plt_offset = plt0_size;
+ plt_offset + 8 <= plt->size && s < send;
+ plt_offset += entry_size)
+ {
+ bfd_vma gotplt_addr;
+ const char *suffix;
+ bfd_vma gotplt_hi;
+ bfd_vma gotplt_lo;
+ size_t suffixlen;
+
+ opcode = bfd_get_micromips_32 (abfd, plt_data + plt_offset + 4);
+
+ /* Check if the second word matches the expected MIPS16 instruction. */
+ if (opcode == 0x651aeb00)
+ {
+ if (micromips_p)
+ return -1;
+ /* Truncated table??? */
+ if (plt_offset + 16 > plt->size)
+ break;
+ gotplt_addr = bfd_get_32 (abfd, plt_data + plt_offset + 12);
+ entry_size = 2 * ARRAY_SIZE (mips16_o32_exec_plt_entry);
+ suffixlen = sizeof (m16suffix);
+ suffix = m16suffix;
+ other = STO_MIPS16;
+ }
+ /* Likewise the expected microMIPS instruction (no insn32 mode). */
+ else if (opcode == 0xff220000)
+ {
+ if (!micromips_p)
+ return -1;
+ gotplt_hi = bfd_get_16 (abfd, plt_data + plt_offset) & 0x7f;
+ gotplt_lo = bfd_get_16 (abfd, plt_data + plt_offset + 2) & 0xffff;
+ gotplt_hi = ((gotplt_hi ^ 0x40) - 0x40) << 18;
+ gotplt_lo <<= 2;
+ gotplt_addr = gotplt_hi + gotplt_lo;
+ gotplt_addr += ((plt->vma + plt_offset) | 3) ^ 3;
+ entry_size = 2 * ARRAY_SIZE (micromips_o32_exec_plt_entry);
+ suffixlen = sizeof (microsuffix);
+ suffix = microsuffix;
+ other = STO_MICROMIPS;
+ }
+ /* Likewise the expected microMIPS instruction (insn32 mode). */
+ else if ((opcode & 0xffff0000) == 0xff2f0000)
+ {
+ gotplt_hi = bfd_get_16 (abfd, plt_data + plt_offset + 2) & 0xffff;
+ gotplt_lo = bfd_get_16 (abfd, plt_data + plt_offset + 6) & 0xffff;
+ gotplt_hi = ((gotplt_hi ^ 0x8000) - 0x8000) << 16;
+ gotplt_lo = (gotplt_lo ^ 0x8000) - 0x8000;
+ gotplt_addr = gotplt_hi + gotplt_lo;
+ entry_size = 2 * ARRAY_SIZE (micromips_insn32_o32_exec_plt_entry);
+ suffixlen = sizeof (microsuffix);
+ suffix = microsuffix;
+ other = STO_MICROMIPS;
+ }
+ /* Otherwise assume standard MIPS code. */
+ else
+ {
+ gotplt_hi = bfd_get_32 (abfd, plt_data + plt_offset) & 0xffff;
+ gotplt_lo = bfd_get_32 (abfd, plt_data + plt_offset + 4) & 0xffff;
+ gotplt_hi = ((gotplt_hi ^ 0x8000) - 0x8000) << 16;
+ gotplt_lo = (gotplt_lo ^ 0x8000) - 0x8000;
+ gotplt_addr = gotplt_hi + gotplt_lo;
+ entry_size = 4 * ARRAY_SIZE (mips_exec_plt_entry);
+ suffixlen = sizeof (mipssuffix);
+ suffix = mipssuffix;
+ other = 0;
+ }
+ /* Truncated table??? */
+ if (plt_offset + entry_size > plt->size)
+ break;
+
+ for (i = 0;
+ i < count && p[pi].address != gotplt_addr;
+ i++, pi = (pi + bed->s->int_rels_per_ext_rel) % counti);
+
+ if (i < count)
+ {
+ size_t namelen;
+ size_t len;
+
+ *s = **p[pi].sym_ptr_ptr;
+ /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL set. Since
+ we are defining a symbol, ensure one of them is set. */
+ if ((s->flags & BSF_LOCAL) == 0)
+ s->flags |= BSF_GLOBAL;
+ s->flags |= BSF_SYNTHETIC;
+ s->section = plt;
+ s->value = plt_offset;
+ s->name = names;
+ s->udata.i = other;
+
+ len = strlen ((*p[pi].sym_ptr_ptr)->name);
+ namelen = len + suffixlen;
+ if (names + namelen > nend)
+ break;
+
+ memcpy (names, (*p[pi].sym_ptr_ptr)->name, len);
+ names += len;
+ memcpy (names, suffix, suffixlen);
+ names += suffixlen;
+
+ ++s, ++n;
+ pi = (pi + bed->s->int_rels_per_ext_rel) % counti;
+ }
+ }
+
+ free (plt_data);
+
+ return n;
+}
+
void
_bfd_mips_post_process_headers (bfd *abfd, struct bfd_link_info *link_info)
{
}
}
+
+/* Check if the given address is the last word of a MIPS16 PLT entry.
+ This word is data and depending on the value it may interfere with
+ disassembly of further PLT entries. We make use of the fact PLT
+ symbols are marked BSF_SYNTHETIC. */
+static bfd_boolean
+is_mips16_plt_tail (struct disassemble_info *info, bfd_vma addr)
+{
+ if (info->symbols
+ && info->symbols[0]
+ && (info->symbols[0]->flags & BSF_SYNTHETIC)
+ && addr == bfd_asymbol_value (info->symbols[0]) + 12)
+ return TRUE;
+
+ return FALSE;
+}
+
/* Disassemble mips16 instructions. */
static int
{
const fprintf_ftype infprintf = info->fprintf_func;
int status;
- bfd_byte buffer[2];
+ bfd_byte buffer[4];
int length;
int insn;
bfd_boolean use_extend;
info->insn_info_valid = 1;
info->branch_delay_insns = 0;
info->data_size = 0;
- info->insn_type = dis_nonbranch;
info->target = 0;
info->target2 = 0;
- status = (*info->read_memory_func) (memaddr, buffer, 2, info);
+ /* Decode PLT entry's GOT slot address word. */
+ if (is_mips16_plt_tail (info, memaddr))
+ {
+ info->insn_type = dis_noninsn;
+ status = (*info->read_memory_func) (memaddr, buffer, 4, info);
+ if (status == 0)
+ {
+ unsigned int gotslot;
+
+ if (info->endian == BFD_ENDIAN_BIG)
+ gotslot = bfd_getb32 (buffer);
+ else
+ gotslot = bfd_getl32 (buffer);
+ infprintf (is, ".word\t0x%x", gotslot);
+
+ return 4;
+ }
+ }
+ else
+ {
+ info->insn_type = dis_nonbranch;
+ status = (*info->read_memory_func) (memaddr, buffer, 2, info);
+ }
if (status != 0)
{
(*info->memory_error_func) (status, memaddr, info);
static bfd_boolean
is_compressed_mode_p (struct disassemble_info *info)
{
- elf_symbol_type *symbol;
- int pos;
int i;
-
- for (i = 0; i < info->num_symbols; i++)
- {
- pos = info->symtab_pos + i;
-
- if (bfd_asymbol_flavour (info->symtab[pos]) != bfd_target_elf_flavour)
- continue;
-
- if (info->symtab[pos]->section != info->section)
- continue;
-
- symbol = (elf_symbol_type *) info->symtab[pos];
- if ((!micromips_ase
- && ELF_ST_IS_MIPS16 (symbol->internal_elf_sym.st_other))
- || (micromips_ase
- && ELF_ST_IS_MICROMIPS (symbol->internal_elf_sym.st_other)))
- return 1;
- }
+ int l;
+
+ for (i = info->symtab_pos, l = i + info->num_symbols; i < l; i++)
+ if (((info->symtab[i])->flags & BSF_SYNTHETIC) != 0
+ && ((!micromips_ase
+ && ELF_ST_IS_MIPS16 ((*info->symbols)->udata.i))
+ || (micromips_ase
+ && ELF_ST_IS_MICROMIPS ((*info->symbols)->udata.i))))
+ return 1;
+ else if (bfd_asymbol_flavour (info->symtab[i]) == bfd_target_elf_flavour
+ && info->symtab[i]->section == info->section)
+ {
+ elf_symbol_type *symbol = (elf_symbol_type *) info->symtab[i];
+ if ((!micromips_ase
+ && ELF_ST_IS_MIPS16 (symbol->internal_elf_sym.st_other))
+ || (micromips_ase
+ && ELF_ST_IS_MICROMIPS (symbol->internal_elf_sym.st_other)))
+ return 1;
+ }
return 0;
}
projects / thirdparty / binutils-gdb.git / commitdiff
