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authorHans-Peter Nilsson <hp@axis.com>2004-03-22 04:08:39 +0000
committerHans-Peter Nilsson <hp@axis.com>2004-03-22 04:08:39 +0000
commit6c5bb4c28649830f126412f79cc60cc54afbac0c (patch)
tree91922c39071722f295447778f604901b9cfe6298
parentc076de52c701db25e92415b83c8b21d45cd22671 (diff)
downloadgdb-6c5bb4c28649830f126412f79cc60cc54afbac0c.tar.gz
* elf32-cris.c (cris_elf_relocate_section) <case R_CRIS_16_GOTPLT,
R_CRIS_16_GOTPLT>: Also error if there's no PLT for a symbol not defined by the executable, or defined in a DSO. <eliding run-time relocation of .got>: Initialize GOT entry for a function symbol or ELF_LINK_HASH_NEEDS_PLT statically in an executable. (cris_elf_gc_sweep_hook): Improve fallthrough marking. (elf_cris_try_fold_plt_to_got): Improve head comment. Do not fold a PLT reloc to GOT for an executable. (elf_cris_adjust_dynamic_symbol): Only fold a .got.plt entry with .got for a DSO and explain why. (elf_cris_discard_excess_program_dynamics): Also lose GOT-relocs and unreferenced symbols for which a PLT is defined. Adjust dynamic-symbol pruning correspondingly, to make sure we don't lose a dynamic symbol also defined by a DSO.
-rw-r--r--bfd/ChangeLog18
-rw-r--r--bfd/elf32-cris.c89
2 files changed, 82 insertions, 25 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 50e2f3d6499..595dd3f517c 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,21 @@
+2004-03-22 Hans-Peter Nilsson <hp@axis.com>
+
+ * elf32-cris.c (cris_elf_relocate_section) <case R_CRIS_16_GOTPLT,
+ R_CRIS_16_GOTPLT>: Also error if there's no PLT for a symbol
+ not defined by the executable, or defined in a DSO.
+ <eliding run-time relocation of .got>: Initialize GOT entry for a
+ function symbol or ELF_LINK_HASH_NEEDS_PLT statically in an
+ executable.
+ (cris_elf_gc_sweep_hook): Improve fallthrough marking.
+ (elf_cris_try_fold_plt_to_got): Improve head comment. Do not fold
+ a PLT reloc to GOT for an executable.
+ (elf_cris_adjust_dynamic_symbol): Only fold a .got.plt entry with
+ .got for a DSO and explain why.
+ (elf_cris_discard_excess_program_dynamics): Also lose GOT-relocs
+ and unreferenced symbols for which a PLT is defined. Adjust
+ dynamic-symbol pruning correspondingly, to make sure we don't lose
+ a dynamic symbol also defined by a DSO.
+
2004-03-22 Alan Modra <amodra@bigpond.net.au>
* elf-bfd.h (RELOC_FOR_GLOBAL_SYMBOL): Add input_bfd, input_section
diff --git a/bfd/elf32-cris.c b/bfd/elf32-cris.c
index 18f87f497bd..b8513928e42 100644
--- a/bfd/elf32-cris.c
+++ b/bfd/elf32-cris.c
@@ -960,11 +960,25 @@ cris_elf_relocate_section (output_bfd, info, input_bfd, input_section,
statically linking PIC code, or when using -Bsymbolic. Check
that we instead have a GOT entry as done for us by
elf_cris_adjust_dynamic_symbol, and drop through into the
- ordinary GOT cases. */
- if (h != NULL && h->got.offset == (bfd_vma) -1)
+ ordinary GOT cases. This must not happen for the
+ executable, because any reference it does to a function
+ that is satisfied by a DSO must generate a PLT. We assume
+ these call-specific relocs don't address non-functions. */
+ if (h != NULL
+ && (h->got.offset == (bfd_vma) -1
+ || (!info->shared
+ && !((h->elf_link_hash_flags
+ & ELF_LINK_HASH_DEF_REGULAR) != 0
+ || ((h->elf_link_hash_flags
+ & ELF_LINK_HASH_DEF_DYNAMIC) == 0
+ && h->root.type == bfd_link_hash_undefweak)))))
{
(*_bfd_error_handler)
- (_("%s: No PLT nor GOT for relocation %s against symbol `%s' from %s section"),
+ ((h->got.offset == (bfd_vma) -1)
+ ? _("%s: No PLT nor GOT for relocation %s against\
+ symbol `%s' from %s section")
+ : _("%s: No PLT for relocation %s against\
+ symbol `%s' from %s section"),
bfd_archive_filename (input_bfd),
cris_elf_howto_table[r_type].name,
symname[0] != '\0' ? symname : _("[whose name is lost]"),
@@ -996,18 +1010,25 @@ cris_elf_relocate_section (output_bfd, info, input_bfd, input_section,
if (!elf_hash_table (info)->dynamic_sections_created
|| (! info->shared
- && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))
+ && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)
+ || h->type == STT_FUNC
+ || (h->elf_link_hash_flags
+ & ELF_LINK_HASH_NEEDS_PLT)))
|| (info->shared
&& (info->symbolic || h->dynindx == -1)
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
{
/* This wasn't checked above for ! info->shared, but
- must hold there if we get here; the symbol must be
- defined in the regular program, or be undefweak. */
+ must hold there if we get here; the symbol must
+ be defined in the regular program or be undefweak
+ or be a function or otherwise need a PLT. */
BFD_ASSERT (!elf_hash_table (info)->dynamic_sections_created
|| info->shared
|| (h->elf_link_hash_flags
& ELF_LINK_HASH_DEF_REGULAR) != 0
+ || h->type == STT_FUNC
+ || (h->elf_link_hash_flags
+ & ELF_LINK_HASH_NEEDS_PLT)
|| h->root.type == bfd_link_hash_undefweak);
/* This is actually a static link, or it is a
@@ -1511,12 +1532,15 @@ elf_cris_finish_dynamic_symbol (output_bfd, info, h, sym)
}
}
- /* We don't emit .got relocs for symbols that aren't in the
- dynamic-symbols table for an ordinary program and are either defined
- by the program or are undefined weak symbols. */
+ /* For an ordinary program, we emit .got relocs only for symbols that
+ are in the dynamic-symbols table and are either defined by the
+ program or are undefined weak symbols, or are function symbols
+ where we do not output a PLT: the PLT reloc was output above and all
+ references to the function symbol are redirected to the PLT. */
if (h->got.offset != (bfd_vma) -1
&& (info->shared
|| (h->dynindx != -1
+ && h->plt.offset == (bfd_vma) -1
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
&& h->root.type != bfd_link_hash_undefweak)))
{
@@ -1838,13 +1862,12 @@ cris_elf_gc_sweep_hook (abfd, info, sec, relocs)
r_symndx = ELF32_R_SYM (rel->r_info);
if (r_symndx < symtab_hdr->sh_info)
goto local_got_reloc;
-
+ /* Fall through. */
case R_CRIS_32_PLT_GOTREL:
/* FIXME: We don't garbage-collect away the .got section. */
if (local_got_refcounts != NULL)
local_got_refcounts[-1]--;
/* Fall through. */
-
case R_CRIS_8_PCREL:
case R_CRIS_16_PCREL:
case R_CRIS_32_PCREL:
@@ -1929,16 +1952,22 @@ elf_cris_adjust_gotplt_to_got (h, p)
want to do this:
- When all PLT references are GOTPLT references, and there are GOT
- references. We don't have to generate a PLT at all.
+ references, and this is not the executable. We don't have to
+ generate a PLT at all.
- - When there are both (ordinary) PLT references and GOT references.
+ - When there are both (ordinary) PLT references and GOT references,
+ and this isn't the executable.
We want to make the PLT reference use the ordinary GOT entry rather
- than a run-time dynamically resolved GOTPLT entry (since the GOT
- entry will have to be resolved at startup anyway).
+ than R_CRIS_JUMP_SLOT, a run-time dynamically resolved GOTPLT entry,
+ since the GOT entry will have to be resolved at startup anyway.
Though the latter case is handled when room for the PLT is allocated,
not here.
+ By folding into the GOT, we may need a round-trip to a PLT in the
+ executable for calls, a loss in performance. Still, losing a
+ reloc is a win in size and at least in start-up time.
+
Note that this function is called before symbols are forced local by
version scripts. The differing cases are handled by
elf_cris_hide_symbol. */
@@ -2045,10 +2074,14 @@ elf_cris_adjust_dynamic_symbol (info, h)
info);
}
- /* If there are only GOT references and GOTPLT references to this
- PLT entry, get rid of the PLT. */
- if (! elf_cris_try_fold_plt_to_got ((struct elf_cris_link_hash_entry *)
- h, info))
+ /* If we had a R_CRIS_GLOB_DAT that didn't have to point to a PLT;
+ where a pointer-equivalent symbol was unimportant (i.e. more
+ like R_CRIS_JUMP_SLOT after symbol evaluation) we could get rid
+ of the PLT. We can't for the executable, because the GOT
+ entries will point to the PLT there (and be constant). */
+ if (info->shared
+ && !elf_cris_try_fold_plt_to_got ((struct elf_cris_link_hash_entry*)
+ h, info))
return FALSE;
/* GC or folding may have rendered this entry unused. */
@@ -2086,8 +2119,11 @@ elf_cris_adjust_dynamic_symbol (info, h)
/* If there's already a GOT entry, use that, not a .got.plt. A
GOT field still has a reference count when we get here; it's
- not yet changed to an offset. */
- if (h->got.refcount > 0)
+ not yet changed to an offset. We can't do this for an
+ executable, because then the reloc associated with the PLT
+ would get a non-PLT reloc pointing to the PLT. FIXME: Move
+ this to elf_cris_try_fold_plt_to_got. */
+ if (info->shared && h->got.refcount > 0)
{
h->got.refcount += h->plt.refcount;
@@ -2860,9 +2896,11 @@ elf_cris_discard_excess_program_dynamics (h, inf)
/* If we're not creating a shared library and have a symbol which is
referred to by .got references, but the symbol is defined locally,
- (or rather, not not defined by a DSO) then lose the reloc for the
- .got (don't allocate room for it). */
- if ((h->root.elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0)
+ (or rather, not defined by a DSO) then lose the reloc for the .got
+ (don't allocate room for it). Likewise for relocs for something
+ for which we create a PLT. */
+ if ((h->root.elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
+ || h->root.plt.refcount > 0)
{
if (h->root.got.refcount > 0
/* The size of this section is only valid and in sync with the
@@ -2888,7 +2926,8 @@ elf_cris_discard_excess_program_dynamics (h, inf)
introduce new problems. Of course we don't do this if we're
exporting all dynamic symbols. */
if (! info->export_dynamic
- && (h->root.elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0)
+ && (h->root.elf_link_hash_flags
+ & (ELF_LINK_HASH_DEF_DYNAMIC|ELF_LINK_HASH_REF_DYNAMIC)) == 0)
{
h->root.dynindx = -1;
_bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,