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Re: x86 .plt and symbol visibility
- To: binutils at sourceware dot cygnus dot com
- Subject: Re: x86 .plt and symbol visibility
- From: Alan Modra <amodra at bigpond dot net dot au>
- Date: Fri, 28 Sep 2001 18:28:47 +0930
- References: <20010928013944.C976@bubble.sa.bigpond.net.au>
On Fri, Sep 28, 2001 at 01:39:44AM +0930, Alan Modra wrote:
> Squashes one obscure bug with the .plt and symbol visibility changes that
> could result in .rel.plt being the wrong size and relocs being written
> past the end of the section.
The same for elf32-hppa.c, except here we wouldn't have the problem with
.rela.plt being the wrong size.
* elf32-hppa.c (elf32_hppa_check_relocs): Update comment since we
no longer allocate here. Localise some vars to blocks where they
are used.
(elf32_hppa_adjust_dynamic_symbol): Correct a comment. Delay
setting of vars until needed.
(allocate_dynrelocs): Don't create a .plt entry without a reloc
when symbol visibilty makes a function local.
(elf32_hppa_finish_dynamic_symbol): Move expressions out of
swap_reloca_out function calls.
(elf32_hppa_relocate_section): Likewies. Comment typo fix.
(elf32_hppa_finish_dynamic_sections): Migrate common code out of
switch statement.
Index: bfd/elf32-hppa.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-hppa.c,v
retrieving revision 1.49
diff -u -p -r1.49 elf32-hppa.c
--- elf32-hppa.c 2001/09/26 09:25:04 1.49
+++ elf32-hppa.c 2001/09/28 08:48:15
@@ -1154,9 +1154,9 @@ elf32_hppa_copy_indirect_symbol (dir, in
}
/* Look through the relocs for a section during the first phase, and
- allocate space in the global offset table or procedure linkage
- table. At this point we haven't necessarily read all the input
- files. */
+ calculate needed space in the global offset table, procedure linkage
+ table, and dynamic reloc sections. At this point we haven't
+ necessarily read all the input files. */
static boolean
elf32_hppa_check_relocs (abfd, info, sec, relocs)
@@ -1165,10 +1165,8 @@ elf32_hppa_check_relocs (abfd, info, sec
asection *sec;
const Elf_Internal_Rela *relocs;
{
- bfd *dynobj;
Elf_Internal_Shdr *symtab_hdr;
struct elf_link_hash_entry **sym_hashes;
- bfd_signed_vma *local_got_refcounts;
const Elf_Internal_Rela *rel;
const Elf_Internal_Rela *rel_end;
struct elf32_hppa_link_hash_table *htab;
@@ -1179,10 +1177,8 @@ elf32_hppa_check_relocs (abfd, info, sec
return true;
htab = hppa_link_hash_table (info);
- dynobj = htab->elf.dynobj;
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
sym_hashes = elf_sym_hashes (abfd);
- local_got_refcounts = elf_local_got_refcounts (abfd);
sreloc = NULL;
stubreloc = NULL;
@@ -1353,12 +1349,11 @@ elf32_hppa_check_relocs (abfd, info, sec
{
/* Allocate space for a GOT entry, as well as a dynamic
relocation for this entry. */
- if (dynobj == NULL)
- htab->elf.dynobj = dynobj = abfd;
-
if (htab->sgot == NULL)
{
- if (! elf32_hppa_create_dynamic_sections (dynobj, info))
+ if (htab->elf.dynobj == NULL)
+ htab->elf.dynobj = abfd;
+ if (!elf32_hppa_create_dynamic_sections (htab->elf.dynobj, info))
return false;
}
@@ -1371,7 +1366,10 @@ elf32_hppa_check_relocs (abfd, info, sec
}
else
{
+ bfd_signed_vma *local_got_refcounts;
+
/* This is a global offset table entry for a local symbol. */
+ local_got_refcounts = elf_local_got_refcounts (abfd);
if (local_got_refcounts == NULL)
{
bfd_size_type size;
@@ -1422,8 +1420,10 @@ elf32_hppa_check_relocs (abfd, info, sec
}
else if (need_entry & PLT_PLABEL)
{
+ bfd_signed_vma *local_got_refcounts;
bfd_signed_vma *local_plt_refcounts;
+ local_got_refcounts = elf_local_got_refcounts (abfd);
if (local_got_refcounts == NULL)
{
bfd_size_type size;
@@ -1501,9 +1501,7 @@ elf32_hppa_check_relocs (abfd, info, sec
if (sreloc == NULL)
{
char *name;
-
- if (dynobj == NULL)
- htab->elf.dynobj = dynobj = abfd;
+ bfd *dynobj;
name = (bfd_elf_string_from_elf_section
(abfd,
@@ -1518,6 +1516,10 @@ elf32_hppa_check_relocs (abfd, info, sec
return false;
}
+ if (htab->elf.dynobj == NULL)
+ htab->elf.dynobj = abfd;
+
+ dynobj = htab->elf.dynobj;
sreloc = bfd_get_section_by_name (dynobj, name);
if (sreloc == NULL)
{
@@ -1547,7 +1549,8 @@ elf32_hppa_check_relocs (abfd, info, sec
if (p == NULL || p->sec != sec)
{
p = ((struct elf32_hppa_dyn_reloc_entry *)
- bfd_alloc (dynobj, (bfd_size_type) sizeof *p));
+ bfd_alloc (htab->elf.dynobj,
+ (bfd_size_type) sizeof *p));
if (p == NULL)
return false;
p->next = h->dyn_relocs;
@@ -1802,14 +1805,11 @@ elf32_hppa_adjust_dynamic_symbol (info,
struct bfd_link_info *info;
struct elf_link_hash_entry *h;
{
- bfd *dynobj;
struct elf32_hppa_link_hash_table *htab;
struct elf32_hppa_link_hash_entry *eh;
struct elf32_hppa_dyn_reloc_entry *p;
asection *s;
-
- htab = hppa_link_hash_table (info);
- dynobj = htab->elf.dynobj;
+ unsigned int power_of_two;
/* If this is a function, put it in the procedure linkage table. We
will fill in the contents of the procedure linkage table later,
@@ -1906,39 +1906,34 @@ elf32_hppa_adjust_dynamic_symbol (info,
both the dynamic object and the regular object will refer to the
same memory location for the variable. */
- s = htab->sdynbss;
+ htab = hppa_link_hash_table (info);
/* We must generate a COPY reloc to tell the dynamic linker to
copy the initial value out of the dynamic object and into the
- runtime process image. We need to remember the offset into the
- .rela.bss section we are going to use. */
+ runtime process image. */
if ((h->root.u.def.section->flags & SEC_ALLOC) != 0)
{
- asection *srel;
-
- srel = htab->srelbss;
- srel->_raw_size += sizeof (Elf32_External_Rela);
+ htab->srelbss->_raw_size += sizeof (Elf32_External_Rela);
h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY;
}
- {
- /* We need to figure out the alignment required for this symbol. I
- have no idea how other ELF linkers handle this. */
- unsigned int power_of_two;
-
- power_of_two = bfd_log2 (h->size);
- if (power_of_two > 3)
- power_of_two = 3;
-
- /* Apply the required alignment. */
- s->_raw_size = BFD_ALIGN (s->_raw_size,
- (bfd_size_type) (1 << power_of_two));
- if (power_of_two > bfd_get_section_alignment (dynobj, s))
- {
- if (! bfd_set_section_alignment (dynobj, s, power_of_two))
- return false;
- }
- }
+ /* We need to figure out the alignment required for this symbol. I
+ have no idea how other ELF linkers handle this. */
+
+ power_of_two = bfd_log2 (h->size);
+ if (power_of_two > 3)
+ power_of_two = 3;
+
+ /* Apply the required alignment. */
+ s = htab->sdynbss;
+ s->_raw_size = BFD_ALIGN (s->_raw_size,
+ (bfd_size_type) (1 << power_of_two));
+ if (power_of_two > bfd_get_section_alignment (htab->elf.dynobj, s))
+ {
+ if (! bfd_set_section_alignment (htab->elf.dynobj, s, power_of_two))
+ return false;
+ }
+
/* Define the symbol as being at this point in the section. */
h->root.u.def.section = s;
h->root.u.def.value = s->_raw_size;
@@ -2010,25 +2005,33 @@ allocate_dynrelocs (h, inf)
return false;
}
- /* Make an entry in the .plt section. */
- s = htab->splt;
- h->plt.offset = s->_raw_size;
- if (PLABEL_PLT_ENTRY_SIZE != PLT_ENTRY_SIZE
- && ((struct elf32_hppa_link_hash_entry *) h)->plabel
- && (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
+ if (((struct elf32_hppa_link_hash_entry *) h)->pic_call
+ || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, info, h))
{
- /* Add some extra space for the dynamic linker to use. */
- s->_raw_size += PLABEL_PLT_ENTRY_SIZE;
+ /* Make an entry in the .plt section. */
+ s = htab->splt;
+ h->plt.offset = s->_raw_size;
+ if (PLABEL_PLT_ENTRY_SIZE != PLT_ENTRY_SIZE
+ && ((struct elf32_hppa_link_hash_entry *) h)->plabel
+ && (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
+ {
+ /* Add some extra space for the dynamic linker to use. */
+ s->_raw_size += PLABEL_PLT_ENTRY_SIZE;
+ }
+ else
+ s->_raw_size += PLT_ENTRY_SIZE;
+
+ if (! ((struct elf32_hppa_link_hash_entry *) h)->pic_call)
+ {
+ /* We also need to make an entry in the .rela.plt section. */
+ htab->srelplt->_raw_size += sizeof (Elf32_External_Rela);
+ htab->need_plt_stub = 1;
+ }
}
else
- s->_raw_size += PLT_ENTRY_SIZE;
-
- if (! ((struct elf32_hppa_link_hash_entry *) h)->pic_call
- && WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, info, h))
{
- /* We also need to make an entry in the .rela.plt section. */
- htab->srelplt->_raw_size += sizeof (Elf32_External_Rela);
- htab->need_plt_stub = 1;
+ h->plt.offset = (bfd_vma) -1;
+ h->elf_link_hash_flags &= ~ELF_LINK_HASH_NEEDS_PLT;
}
}
else
@@ -3531,7 +3534,7 @@ elf32_hppa_relocate_section (output_bfd,
if (info->relocateable)
{
- /* This is a relocateable link. We don't have to change
+ /* This is a relocatable link. We don't have to change
anything, unless the reloc is against a section symbol,
in which case we have to adjust according to where the
section symbol winds up in the output section. */
@@ -3673,17 +3676,16 @@ elf32_hppa_relocate_section (output_bfd,
is zero. */
Elf_Internal_Rela outrel;
asection *srelgot = htab->srelgot;
+ Elf32_External_Rela *loc;
outrel.r_offset = (off
+ htab->sgot->output_offset
+ htab->sgot->output_section->vma);
outrel.r_info = ELF32_R_INFO (0, R_PARISC_DIR32);
outrel.r_addend = relocation;
- bfd_elf32_swap_reloca_out (output_bfd, &outrel,
- ((Elf32_External_Rela *)
- srelgot->contents
- + srelgot->reloc_count));
- ++srelgot->reloc_count;
+ loc = (Elf32_External_Rela *) srelgot->contents;
+ loc += srelgot->reloc_count++;
+ bfd_elf32_swap_reloca_out (output_bfd, &outrel, loc);
}
local_got_offsets[r_symndx] |= 1;
@@ -3765,17 +3767,16 @@ elf32_hppa_relocate_section (output_bfd,
PLT entry. */
Elf_Internal_Rela outrel;
asection *srelplt = htab->srelplt;
+ Elf32_External_Rela *loc;
outrel.r_offset = (off
+ htab->splt->output_offset
+ htab->splt->output_section->vma);
outrel.r_info = ELF32_R_INFO (0, R_PARISC_IPLT);
outrel.r_addend = relocation;
- bfd_elf32_swap_reloca_out (output_bfd, &outrel,
- ((Elf32_External_Rela *)
- srelplt->contents
- + srelplt->reloc_count));
- ++srelplt->reloc_count;
+ loc = (Elf32_External_Rela *) srelplt->contents;
+ loc += srelplt->reloc_count++;
+ bfd_elf32_swap_reloca_out (output_bfd, &outrel, loc);
}
local_plt_offsets[r_symndx] |= 1;
@@ -3926,9 +3927,8 @@ elf32_hppa_relocate_section (output_bfd,
if (sreloc == NULL)
abort ();
- loc = ((Elf32_External_Rela *) sreloc->contents
- + sreloc->reloc_count);
- sreloc->reloc_count += 1;
+ loc = (Elf32_External_Rela *) sreloc->contents;
+ loc += sreloc->reloc_count++;
bfd_elf32_swap_reloca_out (output_bfd, &outrel, loc);
}
break;
@@ -4051,6 +4051,7 @@ elf32_hppa_finish_dynamic_symbol (output
if (! ((struct elf32_hppa_link_hash_entry *) h)->pic_call)
{
Elf_Internal_Rela rel;
+ Elf32_External_Rela *loc;
/* Create a dynamic IPLT relocation for this entry. */
rel.r_offset = (h->plt.offset
@@ -4079,12 +4080,10 @@ elf32_hppa_finish_dynamic_symbol (output
rel.r_addend = value;
}
+ loc = (Elf32_External_Rela *) htab->srelplt->contents;
+ loc += htab->srelplt->reloc_count++;
bfd_elf32_swap_reloca_out (htab->splt->output_section->owner,
- &rel,
- ((Elf32_External_Rela *)
- htab->srelplt->contents
- + htab->srelplt->reloc_count));
- htab->srelplt->reloc_count++;
+ &rel, loc);
}
bfd_put_32 (htab->splt->owner,
@@ -4112,6 +4111,7 @@ elf32_hppa_finish_dynamic_symbol (output
if (h->got.offset != (bfd_vma) -1)
{
Elf_Internal_Rela rel;
+ Elf32_External_Rela *loc;
/* This symbol has an entry in the global offset table. Set it
up. */
@@ -4144,17 +4144,16 @@ elf32_hppa_finish_dynamic_symbol (output
rel.r_addend = 0;
}
- bfd_elf32_swap_reloca_out (output_bfd, &rel,
- ((Elf32_External_Rela *)
- htab->srelgot->contents
- + htab->srelgot->reloc_count));
- ++htab->srelgot->reloc_count;
+ loc = (Elf32_External_Rela *) htab->srelgot->contents;
+ loc += htab->srelgot->reloc_count++;
+ bfd_elf32_swap_reloca_out (output_bfd, &rel, loc);
}
if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0)
{
asection *s;
Elf_Internal_Rela rel;
+ Elf32_External_Rela *loc;
/* This symbol needs a copy reloc. Set it up. */
@@ -4170,10 +4169,8 @@ elf32_hppa_finish_dynamic_symbol (output
+ h->root.u.def.section->output_section->vma);
rel.r_addend = 0;
rel.r_info = ELF32_R_INFO (h->dynindx, R_PARISC_COPY);
- bfd_elf32_swap_reloca_out (output_bfd, &rel,
- ((Elf32_External_Rela *) s->contents
- + s->reloc_count));
- ++s->reloc_count;
+ loc = (Elf32_External_Rela *) s->contents + s->reloc_count++;
+ bfd_elf32_swap_reloca_out (output_bfd, &rel, loc);
}
/* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
@@ -4243,18 +4240,16 @@ elf32_hppa_finish_dynamic_sections (outp
switch (dyn.d_tag)
{
default:
- break;
+ continue;
case DT_PLTGOT:
/* Use PLTGOT to set the GOT register. */
dyn.d_un.d_ptr = elf_gp (output_bfd);
- bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
break;
case DT_JMPREL:
s = htab->srelplt;
dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
- bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
break;
case DT_PLTRELSZ:
@@ -4263,9 +4258,10 @@ elf32_hppa_finish_dynamic_sections (outp
dyn.d_un.d_val = s->_cooked_size;
else
dyn.d_un.d_val = s->_raw_size;
- bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
break;
}
+
+ bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
}
}