return NULL;
}
+static bfd_boolean
+section_covers_vma (bfd *abfd ATTRIBUTE_UNUSED, asection *section, void *ptr)
+{
+ bfd_vma vma = *(bfd_vma *) ptr;
+ return ((section->flags & SEC_ALLOC) != 0
+ && section->vma <= vma
+ && vma < section->vma + section->size);
+}
+
/* Create synthetic symbols, effectively restoring "dot-symbol" function
- entry syms. */
+ entry syms. Also generate @plt symbols for the glink branch table. */
static long
ppc64_elf_get_synthetic_symtab (bfd *abfd,
symcount = i;
count = 0;
- if (opdsymend == secsymend)
- goto done;
if (relocatable)
{
size_t size;
long relcount;
+ if (opdsymend == secsymend)
+ goto done;
+
slurp_relocs = get_elf_backend_data (abfd)->s->slurp_reloc_table;
relcount = (opd->flags & SEC_RELOC) ? opd->reloc_count : 0;
if (relcount == 0)
}
else
{
+ bfd_boolean (*slurp_relocs) (bfd *, asection *, asymbol **, bfd_boolean);
bfd_byte *contents;
size_t size;
+ long plt_count = 0;
+ bfd_vma glink_vma = 0, resolv_vma = 0;
+ asection *dynamic, *glink = NULL, *relplt = NULL;
+ arelent *p;
if (!bfd_malloc_and_get_section (abfd, opd, &contents))
{
}
}
+ /* Get start of .glink stubs from DT_PPC64_GLINK. */
+ dynamic = bfd_get_section_by_name (abfd, ".dynamic");
+ if (dynamic != NULL)
+ {
+ bfd_byte *dynbuf, *extdyn, *extdynend;
+ size_t extdynsize;
+ void (*swap_dyn_in) (bfd *, const void *, Elf_Internal_Dyn *);
+
+ if (!bfd_malloc_and_get_section (abfd, dynamic, &dynbuf))
+ goto free_contents_and_exit;
+
+ extdynsize = get_elf_backend_data (abfd)->s->sizeof_dyn;
+ swap_dyn_in = get_elf_backend_data (abfd)->s->swap_dyn_in;
+
+ extdyn = dynbuf;
+ extdynend = extdyn + dynamic->size;
+ for (; extdyn < extdynend; extdyn += extdynsize)
+ {
+ Elf_Internal_Dyn dyn;
+ (*swap_dyn_in) (abfd, extdyn, &dyn);
+
+ if (dyn.d_tag == DT_NULL)
+ break;
+
+ if (dyn.d_tag == DT_PPC64_GLINK)
+ {
+ /* The first glink stub starts at offset 32; see comment in
+ ppc64_elf_finish_dynamic_sections. */
+ glink_vma = dyn.d_un.d_val + 32;
+ /* The .glink section usually does not survive the final
+ link; search for the section (usually .text) where the
+ glink stubs now reside. */
+ glink = bfd_sections_find_if (abfd, section_covers_vma,
+ &glink_vma);
+ break;
+ }
+ }
+
+ free (dynbuf);
+ }
+
+ if (glink != NULL)
+ {
+ /* Determine __glink trampoline by reading the relative branch
+ from the first glink stub. */
+ bfd_byte buf[4];
+ if (bfd_get_section_contents (abfd, glink, buf,
+ glink_vma + 4 - glink->vma, 4))
+ {
+ unsigned int insn = bfd_get_32 (abfd, buf);
+ insn ^= B_DOT;
+ if ((insn & ~0x3fffffc) == 0)
+ resolv_vma = glink_vma + 4 + (insn ^ 0x2000000) - 0x2000000;
+ }
+
+ if (resolv_vma)
+ size += sizeof (asymbol) + sizeof ("__glink_PLTresolve");
+ }
+
+ relplt = bfd_get_section_by_name (abfd, ".rela.plt");
+ if (glink != NULL && relplt != NULL)
+ {
+ slurp_relocs = get_elf_backend_data (abfd)->s->slurp_reloc_table;
+ if (! (*slurp_relocs) (abfd, relplt, dyn_syms, TRUE))
+ goto free_contents_and_exit;
+
+ plt_count = relplt->size / sizeof (Elf64_External_Rela);
+ size += plt_count * sizeof (asymbol);
+
+ p = relplt->relocation;
+ for (i = 0; i < plt_count; i++, p++)
+ size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt");
+ }
+
s = *ret = bfd_malloc (size);
if (s == NULL)
goto free_contents_and_exit;
- names = (char *) (s + count);
+ names = (char *) (s + count + plt_count + (resolv_vma != 0));
for (i = secsymend; i < opdsymend; ++i)
{
}
}
free (contents);
+
+ if (glink != NULL && relplt != NULL)
+ {
+ if (resolv_vma)
+ {
+ /* Add a symbol for the main glink trampoline. */
+ memset (s, sizeof *s, 0);
+ s->the_bfd = abfd;
+ s->flags = BSF_GLOBAL;
+ s->section = glink;
+ s->value = resolv_vma - glink->vma;
+ s->name = names;
+ memcpy (names, "__glink_PLTresolve", sizeof ("__glink_PLTresolve"));
+ names += sizeof ("__glink_PLTresolve");
+ s++;
+ count++;
+ }
+
+ /* FIXME: It would be very much nicer to put sym@plt on the
+ stub rather than on the glink branch table entry. The
+ objdump disassembler would then use a sensible symbol
+ name on plt calls. The difficulty in doing so is
+ a) finding the stubs, and,
+ b) matching stubs against plt entries, and,
+ c) there can be multiple stubs for a given plt entry.
+
+ Solving (a) could be done by code scanning, but older
+ ppc64 binaries used different stubs to current code.
+ (b) is the tricky one since you need to known the toc
+ pointer for at least one function that uses a pic stub to
+ be able to calculate the plt address referenced.
+ (c) means gdb would need to set multiple breakpoints (or
+ find the glink branch itself) when setting breakpoints
+ for pending shared library loads. */
+ p = relplt->relocation;
+ for (i = 0; i < plt_count; i++, p++)
+ {
+ size_t len;
+
+ *s = **p->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->section = glink;
+ s->value = glink_vma - glink->vma;
+ s->name = names;
+ s->udata.p = NULL;
+ len = strlen ((*p->sym_ptr_ptr)->name);
+ memcpy (names, (*p->sym_ptr_ptr)->name, len);
+ names += len;
+ memcpy (names, "@plt", sizeof ("@plt"));
+ names += sizeof ("@plt");
+ s++;
+ glink_vma += 8;
+ if (i >= 0x8000)
+ glink_vma += 4;
+ }
+ count += plt_count;
+ }
}
done:
if (htab->emit_stub_syms)
{
struct elf_link_hash_entry *h;
- h = elf_link_hash_lookup (&htab->elf, "__glink", TRUE, FALSE, FALSE);
+ h = elf_link_hash_lookup (&htab->elf, "__glink_PLTresolve",
+ TRUE, FALSE, FALSE);
if (h == NULL)
return FALSE;
if (h->root.type == bfd_link_hash_new)
projects / deliverable / binutils-gdb.git / blobdiff