Fix MIPS multi-GOT -Bsymbolic link failure
Richard Sandiford
rdsandiford@googlemail.com
Sun Aug 29 18:32:00 GMT 2010
Richard Sandiford <rdsandiford@googlemail.com> writes:
> I might also experiment with generating local GOT entries in this
> case, as mentioned before.
Here's what I had in mind. It means we use local relocations for all
GOT entries in Joseph's testcase, which should be a little more
efficient at load time.
Tested against the binutils testsuite on mips64-linux-gnu, and by
building and testing GCC on the same target. I'll commit it in
a couple of days if there are no objections.
Richard
bfd/
* elfxx-mips.c (mips_got_entry): Adjust commentary.
(mips_elf_create_local_got_entry): If given a symbol, check that it
has been assigned to the local part of the GOT.
(mips_elf_count_got_symbols): Take the bfd_link_info as argument
instead of the master GOT. Put all locally-binding symbols in
the local area.
(mips_elf_make_got_per_bfd): Use global_got_area to decide whether
a symbol lives in the local or global area.
(mips_elf_local_relocation_p): Remove check_forced argument and
retain only the !check_forced behavior.
(mips_elf_calculate_relocation): Adjust call accordingly.
Use global_got_area to decide whether an output relocation
should be local or global. Explicitly decay R_MIPS_GOT_PAGE
into R_MIPS_GOT_DISP where appropriate. Fix selection of
local vs. global semantics for R_MIPS*_26. Remove redundant
reevaluation of what is stored in was_local_p.
(mips_elf_create_dynamic_relocation): Use global_got_area to decide
whether the relocation should be against a global or local symbol.
(mips_elf_lay_out_got): Update the GOT traversal after the above
change to mips_elf_count_got_symbols.
(mips_elf_adjust_addend): Adjust call to mips_elf_local_relocation_p.
(_bfd_mips_elf_relocate_section): Likewise.
(_bfd_mips_elf_finish_dynamic_symbol): Use global_got_area to decide
whether the symbol has a global got entry.
(_bfd_mips_vxworks_finish_dynamic_symbol): Likewise.
Index: bfd/elfxx-mips.c
===================================================================
--- bfd/elfxx-mips.c 2010-08-28 11:55:28.000000000 +0100
+++ bfd/elfxx-mips.c 2010-08-28 18:22:51.000000000 +0100
@@ -53,7 +53,7 @@
(abfd == NULL)
(2) SYMBOL + OFFSET addresses, where SYMBOL is local to an input bfd
(abfd != NULL, symndx >= 0)
- (3) global and forced-local symbols
+ (3) SYMBOL addresses, where SYMBOL is not local to an input bfd
(abfd != NULL, symndx == -1)
Type (3) entries are treated differently for different types of GOT.
@@ -94,8 +94,9 @@ struct mips_got_entry
that should be added to the symbol value. */
bfd_vma addend;
/* If abfd != NULL && symndx == -1, the hash table entry
- corresponding to a global symbol in the got (or, local, if
- h->forced_local). */
+ corresponding to symbol in the GOT. The symbol's entry
+ is in the local area if h->global_got_area is GGA_NONE,
+ otherwise it is in the global area. */
struct mips_elf_link_hash_entry *h;
} d;
@@ -3202,8 +3203,8 @@ mips_elf_got_page (bfd *abfd, bfd *ibfd,
}
/* Find a local GOT entry for an R_MIPS*_GOT16 relocation against VALUE.
- EXTERNAL is true if the relocation was against a global symbol
- that has been forced local. */
+ EXTERNAL is true if the relocation was originally against a global
+ symbol that binds locally. */
static bfd_vma
mips_elf_got16_entry (bfd *abfd, bfd *ibfd, struct bfd_link_info *info,
@@ -3281,11 +3282,9 @@ mips_elf_create_local_got_entry (bfd *ab
BFD_ASSERT (g != NULL);
}
- /* We might have a symbol, H, if it has been forced local. Use the
- global entry then. It doesn't matter whether an entry is local
- or global for TLS, since the dynamic linker does not
- automatically relocate TLS GOT entries. */
- BFD_ASSERT (h == NULL || h->root.forced_local);
+ /* This function shouldn't be called for symbols that live in the global
+ area of the GOT. */
+ BFD_ASSERT (h == NULL || h->global_got_area == GGA_NONE);
if (TLS_RELOC_P (r_type))
{
struct mips_got_entry *p;
@@ -3850,17 +3849,20 @@ mips_elf_resolve_final_got_entries (stru
}
/* A mips_elf_link_hash_traverse callback for which DATA points
- to a mips_got_info. Count the number of type (3) entries. */
+ to the link_info structure. Count the number of type (3) entries
+ in the master GOT. */
static int
mips_elf_count_got_symbols (struct mips_elf_link_hash_entry *h, void *data)
{
+ struct bfd_link_info *info;
struct mips_got_info *g;
- g = (struct mips_got_info *) data;
+ info = (struct bfd_link_info *) data;
+ g = mips_elf_hash_table (info)->got_info;
if (h->global_got_area != GGA_NONE)
{
- if (h->root.forced_local || h->root.dynindx == -1)
+ if (SYMBOL_REFERENCES_LOCAL (info, &h->root))
{
/* We no longer need this entry if it was only used for
relocations; those relocations will be against the
@@ -4010,7 +4012,7 @@ mips_elf_make_got_per_bfd (void **entryp
if (entry->tls_type & GOT_TLS_IE)
g->tls_gotno += 1;
}
- else if (entry->symndx >= 0 || entry->d.h->root.forced_local)
+ else if (entry->symndx >= 0 || entry->d.h->global_got_area == GGA_NONE)
++g->local_gotno;
else
++g->global_gotno;
@@ -4557,17 +4559,15 @@ mips_elf_next_relocation (bfd *abfd ATTR
return NULL;
}
-/* Return whether a relocation is against a local symbol. */
+/* Return whether an input relocation is against a local symbol. */
static bfd_boolean
mips_elf_local_relocation_p (bfd *input_bfd,
const Elf_Internal_Rela *relocation,
- asection **local_sections,
- bfd_boolean check_forced)
+ asection **local_sections)
{
unsigned long r_symndx;
Elf_Internal_Shdr *symtab_hdr;
- struct mips_elf_link_hash_entry *h;
size_t extsymoff;
r_symndx = ELF_R_SYM (input_bfd, relocation->r_info);
@@ -4579,20 +4579,6 @@ mips_elf_local_relocation_p (bfd *input_
if (elf_bad_symtab (input_bfd) && local_sections[r_symndx] != NULL)
return TRUE;
- if (check_forced)
- {
- /* Look up the hash table to check whether the symbol
- was forced local. */
- h = (struct mips_elf_link_hash_entry *)
- elf_sym_hashes (input_bfd) [r_symndx - extsymoff];
- /* Find the real hash-table entry for this symbol. */
- while (h->root.root.type == bfd_link_hash_indirect
- || h->root.root.type == bfd_link_hash_warning)
- h = (struct mips_elf_link_hash_entry *) h->root.root.u.i.link;
- if (h->root.forced_local)
- return TRUE;
- }
-
return FALSE;
}
@@ -4900,7 +4886,7 @@ mips_elf_calculate_relocation (bfd *abfd
used in the array of hash table entries. */
symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
local_p = mips_elf_local_relocation_p (input_bfd, relocation,
- local_sections, FALSE);
+ local_sections);
was_local_p = local_p;
if (! elf_bad_symtab (input_bfd))
extsymoff = symtab_hdr->sh_info;
@@ -5134,8 +5120,7 @@ mips_elf_calculate_relocation (bfd *abfd
|| ((r_type == R_MIPS_26 || r_type == R_MIPS_JALR)
&& target_is_16_bit_code_p));
- local_p = mips_elf_local_relocation_p (input_bfd, relocation,
- local_sections, TRUE);
+ local_p = (h == NULL || h->global_got_area == GGA_NONE);
gp0 = _bfd_get_gp_value (input_bfd);
gp = _bfd_get_gp_value (abfd);
@@ -5145,19 +5130,18 @@ mips_elf_calculate_relocation (bfd *abfd
if (gnu_local_gp_p)
symbol = gp;
+ /* Global R_MIPS_GOT_PAGE relocations are equivalent to R_MIPS_GOT_DISP.
+ The addend is applied by the corresponding R_MIPS_GOT_OFST. */
+ if (r_type == R_MIPS_GOT_PAGE && !local_p)
+ {
+ r_type = R_MIPS_GOT_DISP;
+ addend = 0;
+ }
+
/* If we haven't already determined the GOT offset, oand we're going
to need it, get it now. */
switch (r_type)
{
- case R_MIPS_GOT_PAGE:
- case R_MIPS_GOT_OFST:
- /* We need to decay to GOT_DISP/addend if the symbol doesn't
- bind locally. */
- local_p = local_p || _bfd_elf_symbol_refs_local_p (&h->root, info, 1);
- if (local_p || r_type == R_MIPS_GOT_OFST)
- break;
- /* Fall through. */
-
case R_MIPS16_CALL16:
case R_MIPS16_GOT16:
case R_MIPS_CALL16:
@@ -5193,21 +5177,12 @@ mips_elf_calculate_relocation (bfd *abfd
}
else
{
- /* GOT_PAGE may take a non-zero addend, that is ignored in a
- GOT_PAGE relocation that decays to GOT_DISP because the
- symbol turns out to be global. The addend is then added
- as GOT_OFST. */
- BFD_ASSERT (addend == 0 || r_type == R_MIPS_GOT_PAGE);
+ BFD_ASSERT (addend == 0);
g = mips_elf_global_got_index (dynobj, input_bfd,
&h->root, r_type, info);
if (h->tls_type == GOT_NORMAL
- && (! elf_hash_table(info)->dynamic_sections_created
- || (info->shared
- && (info->symbolic || h->root.forced_local)
- && h->root.def_regular)))
- /* This is a static link or a -Bsymbolic link. The
- symbol is defined locally, or was forced to be local.
- We must initialize this entry in the GOT. */
+ && !elf_hash_table (info)->dynamic_sections_created)
+ /* This is a static link. We must initialize the GOT entry. */
MIPS_ELF_PUT_WORD (dynobj, symbol, htab->sgot->contents + g);
}
}
@@ -5321,7 +5296,7 @@ mips_elf_calculate_relocation (bfd *abfd
mips_elf_perform_relocation. So, we just fall through to the
R_MIPS_26 case here. */
case R_MIPS_26:
- if (local_p)
+ if (was_local_p)
value = ((addend | ((p + 4) & 0xf0000000)) + symbol) >> 2;
else
{
@@ -5447,12 +5422,8 @@ mips_elf_calculate_relocation (bfd *abfd
R_MIPS*_GOT16; every relocation evaluates to "G". */
if (!htab->is_vxworks && local_p)
{
- bfd_boolean forced;
-
- forced = ! mips_elf_local_relocation_p (input_bfd, relocation,
- local_sections, FALSE);
value = mips_elf_got16_entry (abfd, input_bfd, info,
- symbol + addend, forced);
+ symbol + addend, !was_local_p);
if (value == MINUS_ONE)
return bfd_reloc_outofrange;
value
@@ -5467,7 +5438,6 @@ mips_elf_calculate_relocation (bfd *abfd
case R_MIPS_TLS_GOTTPREL:
case R_MIPS_TLS_LDM:
case R_MIPS_GOT_DISP:
- got_disp:
value = g;
overflowed_p = mips_elf_overflow_p (value, 16);
break;
@@ -5502,11 +5472,6 @@ mips_elf_calculate_relocation (bfd *abfd
break;
case R_MIPS_GOT_PAGE:
- /* GOT_PAGE relocations that reference non-local symbols decay
- to GOT_DISP. The corresponding GOT_OFST relocation decays to
- 0. */
- if (! local_p)
- goto got_disp;
value = mips_elf_got_page (abfd, input_bfd, info, symbol + addend, NULL);
if (value == MINUS_ONE)
return bfd_reloc_outofrange;
@@ -5755,7 +5720,7 @@ mips_elf_create_dynamic_relocation (bfd
/* We must now calculate the dynamic symbol table index to use
in the relocation. */
- if (h != NULL && ! SYMBOL_REFERENCES_LOCAL (info, &h->root))
+ if (h != NULL && h->global_got_area != GGA_NONE)
{
indx = h->root.dynindx;
if (SGI_COMPAT (output_bfd))
@@ -8454,7 +8419,7 @@ mips_elf_lay_out_got (bfd *output_bfd, s
return FALSE;
/* Count the number of GOT symbols. */
- mips_elf_link_hash_traverse (htab, mips_elf_count_got_symbols, g);
+ mips_elf_link_hash_traverse (htab, mips_elf_count_got_symbols, info);
/* Calculate the total loadable size of the output. That
will give us the maximum number of GOT_PAGE entries
@@ -8913,7 +8878,7 @@ mips_elf_adjust_addend (bfd *output_bfd,
Elf_Internal_Sym *sym;
asection *sec;
- if (mips_elf_local_relocation_p (input_bfd, rel, local_sections, FALSE))
+ if (mips_elf_local_relocation_p (input_bfd, rel, local_sections))
{
r_type = ELF_R_TYPE (output_bfd, rel->r_info);
if (r_type == R_MIPS16_GPREL
@@ -8983,7 +8948,7 @@ _bfd_mips_elf_relocate_section (bfd *out
r_symndx = ELF_R_SYM (input_bfd, rel->r_info);
symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
- if (mips_elf_local_relocation_p (input_bfd, rel, local_sections, FALSE))
+ if (mips_elf_local_relocation_p (input_bfd, rel, local_sections))
{
sec = local_sections[r_symndx];
h = NULL;
@@ -9048,7 +9013,7 @@ _bfd_mips_elf_relocate_section (bfd *out
if (hi16_reloc_p (r_type)
|| (got16_reloc_p (r_type)
&& mips_elf_local_relocation_p (input_bfd, rel,
- local_sections, FALSE)))
+ local_sections)))
{
if (!mips_elf_add_lo16_rel_addend (input_bfd, rel, relend,
contents, &addend))
@@ -9574,8 +9539,7 @@ _bfd_mips_elf_finish_dynamic_symbol (bfd
/* Run through the global symbol table, creating GOT entries for all
the symbols that need them. */
- if (g->global_gotsym != NULL
- && h->dynindx >= g->global_gotsym->dynindx)
+ if (hmips->global_got_area != GGA_NONE)
{
bfd_vma offset;
bfd_vma value;
@@ -9586,7 +9550,7 @@ _bfd_mips_elf_finish_dynamic_symbol (bfd
MIPS_ELF_PUT_WORD (output_bfd, value, sgot->contents + offset);
}
- if (g->next && h->dynindx != -1 && h->type != STT_TLS)
+ if (hmips->global_got_area != GGA_NONE && g->next && h->type != STT_TLS)
{
struct mips_got_entry e, *p;
bfd_vma entry;
@@ -9752,10 +9716,12 @@ _bfd_mips_vxworks_finish_dynamic_symbol
asection *sgot;
struct mips_got_info *g;
struct mips_elf_link_hash_table *htab;
+ struct mips_elf_link_hash_entry *hmips;
htab = mips_elf_hash_table (info);
BFD_ASSERT (htab != NULL);
dynobj = elf_hash_table (info)->dynobj;
+ hmips = (struct mips_elf_link_hash_entry *) h;
if (h->plt.offset != (bfd_vma) -1)
{
@@ -9861,8 +9827,7 @@ _bfd_mips_vxworks_finish_dynamic_symbol
BFD_ASSERT (g != NULL);
/* See if this symbol has an entry in the GOT. */
- if (g->global_gotsym != NULL
- && h->dynindx >= g->global_gotsym->dynindx)
+ if (hmips->global_got_area != GGA_NONE)
{
bfd_vma offset;
Elf_Internal_Rela outrel;
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