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PowerPC inline PLT call support 

In addition to the existing relocs we need two more to mark all
instructions in the call sequence, PLTCALL on the call itself (plus
the toc restore insn for ppc64), and PLTSEQ on others.  All
relocations in a particular sequence have the same symbol.

Example ppc64 ELFv2 assembly:
 .reloc .,R_PPC64_PLTSEQ,puts
	std 2,24(1)
	addis 12,2,puts@plt@ha	# .reloc .,R_PPC64_PLT16_HA,puts
	ld 12,puts@plt@l(12)	# .reloc .,R_PPC64_PLT16_LO_DS,puts
 .reloc .,R_PPC64_PLTSEQ,puts
	mtctr 12
 .reloc .,R_PPC64_PLTCALL,puts
	bctrl
	ld 2,24(1)

Example ppc32 -fPIC assembly:
	addis 12,30,puts+32768@plt@ha # .reloc .,R_PPC_PLT16_HA,puts+0x8000
	lwz 12,12,puts+32768@plt@l    # .reloc .,R_PPC_PLT16_LO,puts+0x8000
 .reloc .,R_PPC_PLTSEQ,puts+32768
	mtctr 12
 .reloc .,R_PPC_PLTCALL,puts+32768
	bctrl

Marking sequences like this allows the linker to convert them to nops
and a direct call if the target symbol turns out to be local.

When the call is __tls_get_addr, each relocation shown above is paired
with an R_PPC*_TLSLD or R_PPC*_TLSGD reloc to additionally mark the
sequence for possible TLS optimization.  The TLSLD or TLSGD relocs are
emitted first.

include/
	* elf/ppc.h (R_PPC_PLTSEQ, R_PPC_PLTCALL): Define.
	* elf/ppc64.h (R_PPC64_PLTSEQ, R_PPC64_PLTCALL): Define.
bfd/
	* elf32-ppc.c (ppc_elf_howto_raw): Add PLTSEQ and PLTCALL howtos.
	(is_plt_seq_reloc): New function.
	(ppc_elf_check_relocs): Handle PLTSEQ and PLTCALL relocs.
	(ppc_elf_tls_optimize): Handle inline plt call sequence.
	(ppc_elf_relax_section): Handle PLTCALL reloc.
	(ppc_elf_relocate_section): Nop out inline plt call sequence when
	resolving locally.
	* elf64-ppc.c (ppc64_elf_howto_raw): Add R_PPC64_PLTSEQ and
	R_PPC64_PLTCALL entries.  Comment R_PPC64_TOCSAVE.
	(has_tls_get_addr_call): Correct comment.
	(is_branch_reloc): Add PLTCALL.
	(is_plt_seq_reloc): New function.
	(ppc64_elf_check_relocs): Handle PLT16_LO_DS reloc.  Set
	has_tls_reloc for R_PPC64_TLSGD and R_PPC64_TLSLD.  Create plt
	entry for R_PPC64_PLTCALL.
	(ppc64_elf_tls_optimize): Handle inline plt call sequence.
	(ppc_type_of_stub): Handle PLTCALL reloc.
	(toc_adjusting_stub_needed): Likewise.
	(ppc64_elf_relocate_section): Set "can_plt_call" for PLTCALL
	reloc insn.  Nop out inline plt call sequence when resolving
	locally.  Handle __tls_get_addr inline plt call optimization.
elfcpp/
	* powerpc.h (R_POWERPC_PLTSEQ, R_POWERPC_PLTCALL): Define.
gold/
	* powerpc.cc (Target_powerpc::Track_tls::maybe_skip_tls_get_addr_call):
	Handle inline plt sequence relocs.
	(Stub_table::Plt_stub_key::Plt_stub_key): Likewise.
	(Target_powerpc::Scan::reloc_needs_plt_for_ifunc): Likewise.
	(Target_powerpc::Relocate::relocate): Likewise.
This commit is contained in:
Alan Modra 2018-04-09 09:25:10 +09:30
parent 2d7ad24e87
commit 23cedd1dc9
10 changed files with 425 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
bfd/ChangeLog
View File

@ -1,3 +1,27 @@
2018-04-09 Alan Modra <amodra@gmail.com>
* elf32-ppc.c (ppc_elf_howto_raw): Add PLTSEQ and PLTCALL howtos.
(is_plt_seq_reloc): New function.
(ppc_elf_check_relocs): Handle PLTSEQ and PLTCALL relocs.
(ppc_elf_tls_optimize): Handle inline plt call sequence.
(ppc_elf_relax_section): Handle PLTCALL reloc.
(ppc_elf_relocate_section): Nop out inline plt call sequence when
resolving locally.
* elf64-ppc.c (ppc64_elf_howto_raw): Add R_PPC64_PLTSEQ and
R_PPC64_PLTCALL entries. Comment R_PPC64_TOCSAVE.
(has_tls_get_addr_call): Correct comment.
(is_branch_reloc): Add PLTCALL.
(is_plt_seq_reloc): New function.
(ppc64_elf_check_relocs): Handle PLT16_LO_DS reloc. Set
has_tls_reloc for R_PPC64_TLSGD and R_PPC64_TLSLD. Create plt
entry for R_PPC64_PLTCALL.
(ppc64_elf_tls_optimize): Handle inline plt call sequence.
(ppc_type_of_stub): Handle PLTCALL reloc.
(toc_adjusting_stub_needed): Likewise.
(ppc64_elf_relocate_section): Set "can_plt_call" for PLTCALL
reloc insn. Nop out inline plt call sequence when resolving
locally. Handle __tls_get_addr inline plt call optimization.
2018-04-09 Alan Modra <amodra@gmail.com>
* elf64-ppc.c (LOCAL_PLT_ENTRY_SIZE): Define.

148
bfd/elf32-ppc.c
View File

@ -818,6 +818,35 @@ static reloc_howto_type ppc_elf_howto_raw[] = {
0, /* dst_mask */
FALSE), /* pcrel_offset */
/* Marker relocs on inline plt call instructions. */
HOWTO (R_PPC_PLTSEQ,
0, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
32, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_PPC_PLTSEQ", /* name */
FALSE, /* partial_inplace */
0, /* src_mask */
0, /* dst_mask */
FALSE), /* pcrel_offset */
HOWTO (R_PPC_PLTCALL,
0, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
32, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_PPC_PLTCALL", /* name */
FALSE, /* partial_inplace */
0, /* src_mask */
0, /* dst_mask */
FALSE), /* pcrel_offset */
/* Computes the load module index of the load module that contains the
definition of its TLS sym. */
HOWTO (R_PPC_DTPMOD32,
@ -3956,6 +3985,17 @@ is_branch_reloc (enum elf_ppc_reloc_type r_type)
|| r_type == R_PPC_VLE_REL24);
}
/* Relocs on inline plt call sequence insns prior to the call. */
static bfd_boolean
is_plt_seq_reloc (enum elf_ppc_reloc_type r_type)
{
return (r_type == R_PPC_PLT16_HA
|| r_type == R_PPC_PLT16_HI
|| r_type == R_PPC_PLT16_LO
|| r_type == R_PPC_PLTSEQ);
}
static void
bad_shared_reloc (bfd *abfd, enum elf_ppc_reloc_type r_type)
{
@ -4131,6 +4171,9 @@ ppc_elf_check_relocs (bfd *abfd,
return FALSE;
break;
case R_PPC_PLTSEQ:
break;
case R_PPC_GOT_TLSLD16:
case R_PPC_GOT_TLSLD16_LO:
case R_PPC_GOT_TLSLD16_HI:
@ -4310,6 +4353,7 @@ ppc_elf_check_relocs (bfd *abfd,
ppc_elf_tdata (abfd)->makes_plt_call = 1;
/* Fall through */
case R_PPC_PLTCALL:
case R_PPC_PLT32:
case R_PPC_PLTREL32:
case R_PPC_PLT16_LO:
@ -5437,6 +5481,40 @@ ppc_elf_tls_optimize (bfd *obfd ATTRIBUTE_UNUSED,
case R_PPC_TLSGD:
case R_PPC_TLSLD:
if (rel + 1 < relend
&& is_plt_seq_reloc (ELF32_R_TYPE (rel[1].r_info)))
{
if (pass != 0
&& ELF32_R_TYPE (rel[1].r_info) != R_PPC_PLTSEQ)
{
r_type = ELF32_R_TYPE (rel[1].r_info);
r_symndx = ELF32_R_SYM (rel[1].r_info);
if (r_symndx >= symtab_hdr->sh_info)
{
struct elf_link_hash_entry **sym_hashes;
sym_hashes = elf_sym_hashes (ibfd);
h = sym_hashes[r_symndx - symtab_hdr->sh_info];
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (h != NULL)
{
struct plt_entry *ent = NULL;
bfd_vma addend = 0;
if (bfd_link_pic (info))
addend = rel->r_addend;
ent = find_plt_ent (&h->plt.plist,
got2, addend);
if (ent != NULL
&& ent->plt.refcount > 0)
ent->plt.refcount -= 1;
}
}
}
continue;
}
expecting_tls_get_addr = 2;
tls_set = 0;
tls_clear = 0;
@ -5449,8 +5527,7 @@ ppc_elf_tls_optimize (bfd *obfd ATTRIBUTE_UNUSED,
if (pass == 0)
{
if (!expecting_tls_get_addr
|| (expecting_tls_get_addr == 1
&& !sec->has_tls_get_addr_call))
|| !sec->has_tls_get_addr_call)
continue;
if (rel + 1 < relend
@ -5511,7 +5588,8 @@ ppc_elf_tls_optimize (bfd *obfd ATTRIBUTE_UNUSED,
bfd_vma addend = 0;
if (bfd_link_pic (info)
&& ELF32_R_TYPE (rel[1].r_info) == R_PPC_PLTREL24)
&& (ELF32_R_TYPE (rel[1].r_info) == R_PPC_PLTREL24
|| ELF32_R_TYPE (rel[1].r_info) == R_PPC_PLTCALL))
addend = rel[1].r_addend;
ent = find_plt_ent (&htab->tls_get_addr->plt.plist,
got2, addend);
@ -7062,6 +7140,7 @@ ppc_elf_relax_section (bfd *abfd,
case R_PPC_REL24:
case R_PPC_LOCAL24PC:
case R_PPC_PLTREL24:
case R_PPC_PLTCALL:
max_branch_offset = 1 << 25;
break;
@ -7890,7 +7969,7 @@ ppc_elf_relocate_section (bfd *output_bfd,
unsigned long r_symndx;
bfd_vma relocation;
bfd_vma branch_bit, from;
bfd_boolean unresolved_reloc;
bfd_boolean unresolved_reloc, save_unresolved_reloc;
bfd_boolean warned;
unsigned int tls_type, tls_mask, tls_gd;
struct plt_entry **ifunc, **plt_list;
@ -8160,6 +8239,13 @@ ppc_elf_relocate_section (bfd *output_bfd,
unsigned int insn2;
bfd_vma offset = rel->r_offset;
if (is_plt_seq_reloc (ELF32_R_TYPE (rel[1].r_info)))
{
bfd_put_32 (input_bfd, NOP, contents + offset);
rel[1].r_info = ELF32_R_INFO (STN_UNDEF, R_PPC_NONE);
break;
}
if ((tls_mask & TLS_TPRELGD) != 0)
{
/* IE */
@ -8187,6 +8273,13 @@ ppc_elf_relocate_section (bfd *output_bfd,
{
unsigned int insn2;
if (is_plt_seq_reloc (ELF32_R_TYPE (rel[1].r_info)))
{
bfd_put_32 (input_bfd, NOP, contents + rel->r_offset);
rel[1].r_info = ELF32_R_INFO (STN_UNDEF, R_PPC_NONE);
break;
}
for (r_symndx = 0;
r_symndx < symtab_hdr->sh_info;
r_symndx++)
@ -8230,7 +8323,7 @@ ppc_elf_relocate_section (bfd *output_bfd,
case R_PPC_ADDR14_BRNTAKEN:
case R_PPC_REL14_BRNTAKEN:
{
bfd_vma insn;
unsigned int insn;
insn = bfd_get_32 (input_bfd, contents + rel->r_offset);
insn &= ~BRANCH_PREDICT_BIT;
@ -8464,6 +8557,7 @@ ppc_elf_relocate_section (bfd *output_bfd,
}
addend = rel->r_addend;
save_unresolved_reloc = unresolved_reloc;
howto = NULL;
if (r_type < R_PPC_max)
howto = ppc_elf_howto_table[r_type];
@ -9244,6 +9338,8 @@ ppc_elf_relocate_section (bfd *output_bfd,
addend = 0;
break;
case R_PPC_PLTSEQ:
case R_PPC_PLTCALL:
case R_PPC_PLT16_LO:
case R_PPC_PLT16_HI:
case R_PPC_PLT16_HA:
@ -9644,6 +9740,48 @@ ppc_elf_relocate_section (bfd *output_bfd,
goto copy_reloc;
}
switch (r_type)
{
default:
break;
case R_PPC_PLTCALL:
if (unresolved_reloc)
{
bfd_byte *p = contents + rel->r_offset;
unsigned int insn = bfd_get_32 (input_bfd, p);
insn &= 1;
bfd_put_32 (input_bfd, B | insn, p);
unresolved_reloc = save_unresolved_reloc;
r_type = R_PPC_REL24;
howto = ppc_elf_howto_table[r_type];
}
else if (htab->plt_type != PLT_NEW)
info->callbacks->einfo
(_("%P: %H: %s relocation unsupported for bss-plt\n"),
input_bfd, input_section, rel->r_offset,
howto->name);
break;
case R_PPC_PLTSEQ:
case R_PPC_PLT16_HA:
case R_PPC_PLT16_LO:
if (unresolved_reloc)
{
bfd_byte *p = contents + (rel->r_offset & ~3);
bfd_put_32 (input_bfd, NOP, p);
unresolved_reloc = FALSE;
r_type = R_PPC_NONE;
howto = ppc_elf_howto_table[r_type];
}
else if (htab->plt_type != PLT_NEW)
info->callbacks->einfo
(_("%P: %H: %s relocation unsupported for bss-plt\n"),
input_bfd, input_section, rel->r_offset,
howto->name);
break;
}
/* Do any further special processing. */
switch (r_type)
{

208
bfd/elf64-ppc.c
View File

@ -1336,6 +1336,8 @@ static reloc_howto_type ppc64_elf_howto_raw[] =
0, /* dst_mask */
FALSE), /* pcrel_offset */
/* Marker reloc for optimizing r2 save in prologue rather than on
each plt call stub. */
HOWTO (R_PPC64_TOCSAVE,
0, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
@ -1350,6 +1352,35 @@ static reloc_howto_type ppc64_elf_howto_raw[] =
0, /* dst_mask */
FALSE), /* pcrel_offset */
/* Marker relocs on inline plt call instructions. */
HOWTO (R_PPC64_PLTSEQ,
0, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
32, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_PPC64_PLTSEQ", /* name */
FALSE, /* partial_inplace */
0, /* src_mask */
0, /* dst_mask */
FALSE), /* pcrel_offset */
HOWTO (R_PPC64_PLTCALL,
0, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
32, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
bfd_elf_generic_reloc, /* special_function */
"R_PPC64_PLTCALL", /* name */
FALSE, /* partial_inplace */
0, /* src_mask */
0, /* dst_mask */
FALSE), /* pcrel_offset */
/* Computes the load module index of the load module that contains the
definition of its TLS sym. */
HOWTO (R_PPC64_DTPMOD64,
@ -4187,7 +4218,7 @@ struct ppc_link_hash_table
/* Nonzero if this section has TLS related relocations. */
#define has_tls_reloc sec_flg0
/* Nonzero if this section has a call to __tls_get_addr. */
/* Nonzero if this section has an old-style call to __tls_get_addr. */
#define has_tls_get_addr_call sec_flg1
/* Nonzero if this section has any toc or got relocs. */
@ -5430,7 +5461,20 @@ is_branch_reloc (enum elf_ppc64_reloc_type r_type)
|| r_type == R_PPC64_ADDR24
|| r_type == R_PPC64_ADDR14
|| r_type == R_PPC64_ADDR14_BRTAKEN
|| r_type == R_PPC64_ADDR14_BRNTAKEN);
|| r_type == R_PPC64_ADDR14_BRNTAKEN
|| r_type == R_PPC64_PLTCALL);
}
/* Relocs on inline plt call sequence insns prior to the call. */
static bfd_boolean
is_plt_seq_reloc (enum elf_ppc64_reloc_type r_type)
{
return (r_type == R_PPC64_PLT16_HA
|| r_type == R_PPC64_PLT16_HI
|| r_type == R_PPC64_PLT16_LO
|| r_type == R_PPC64_PLT16_LO_DS
|| r_type == R_PPC64_PLTSEQ);
}
/* Look through the relocs for a section during the first phase, and
@ -5777,6 +5821,7 @@ ppc64_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
/* Fall through. */
case R_PPC64_REL24:
case R_PPC64_PLTCALL:
plt_list = ifunc;
if (h != NULL)
{
@ -8583,6 +8628,33 @@ ppc64_elf_tls_optimize (struct bfd_link_info *info)
case R_PPC64_TLSGD:
case R_PPC64_TLSLD:
if (rel + 1 < relend
&& is_plt_seq_reloc (ELF64_R_TYPE (rel[1].r_info)))
{
if (pass != 0
&& ELF64_R_TYPE (rel[1].r_info) != R_PPC64_PLTSEQ)
{
r_symndx = ELF64_R_SYM (rel[1].r_info);
if (!get_sym_h (&h, NULL, NULL, NULL, &locsyms,
r_symndx, ibfd))
goto err_free_rel;
if (h != NULL)
{
struct plt_entry *ent = NULL;
for (ent = h->plt.plist;
ent != NULL;
ent = ent->next)
if (ent->addend == rel[1].r_addend)
break;
if (ent != NULL
&& ent->plt.refcount > 0)
ent->plt.refcount -= 1;
}
}
continue;
}
found_tls_get_addr_arg = 1;
/* Fall through. */
@ -8736,35 +8808,27 @@ ppc64_elf_tls_optimize (struct bfd_link_info *info)
!= (TLS_TLS | TLS_MARK)))
continue;
if (expecting_tls_get_addr && htab->tls_get_addr != NULL)
if (expecting_tls_get_addr)
{
struct plt_entry *ent;
for (ent = htab->tls_get_addr->elf.plt.plist;
ent != NULL;
ent = ent->next)
if (ent->addend == 0)
{
if (ent->plt.refcount > 0)
{
ent->plt.refcount -= 1;
expecting_tls_get_addr = 0;
}
break;
}
}
struct plt_entry *ent = NULL;
if (expecting_tls_get_addr && htab->tls_get_addr_fd != NULL)
{
struct plt_entry *ent;
for (ent = htab->tls_get_addr_fd->elf.plt.plist;
ent != NULL;
ent = ent->next)
if (ent->addend == 0)
{
if (ent->plt.refcount > 0)
ent->plt.refcount -= 1;
if (htab->tls_get_addr != NULL)
for (ent = htab->tls_get_addr->elf.plt.plist;
ent != NULL;
ent = ent->next)
if (ent->addend == 0)
break;
}
if (ent == NULL && htab->tls_get_addr_fd != NULL)
for (ent = htab->tls_get_addr_fd->elf.plt.plist;
ent != NULL;
ent = ent->next)
if (ent->addend == 0)
break;
if (ent != NULL
&& ent->plt.refcount > 0)
ent->plt.refcount -= 1;
}
if (tls_clear == 0)
@ -10504,7 +10568,9 @@ ppc_type_of_stub (asection *input_sec,
/* Determine if a long branch stub is needed. */
max_branch_offset = 1 << 25;
if (r_type != R_PPC64_REL24)
if (r_type == R_PPC64_REL14
|| r_type == R_PPC64_REL14_BRTAKEN
|| r_type == R_PPC64_REL14_BRNTAKEN)
max_branch_offset = 1 << 15;
if (branch_offset + max_branch_offset >= 2 * max_branch_offset - local_off)
@ -11911,7 +11977,8 @@ toc_adjusting_stub_needed (struct bfd_link_info *info, asection *isec)
if (r_type != R_PPC64_REL24
&& r_type != R_PPC64_REL14
&& r_type != R_PPC64_REL14_BRTAKEN
&& r_type != R_PPC64_REL14_BRNTAKEN)
&& r_type != R_PPC64_REL14_BRNTAKEN
&& r_type != R_PPC64_PLTCALL)
continue;
r_symndx = ELF64_R_SYM (rel->r_info);
@ -13721,7 +13788,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
unsigned char tls_mask, tls_gd, tls_type;
unsigned char sym_type;
bfd_vma relocation;
bfd_boolean unresolved_reloc;
bfd_boolean unresolved_reloc, save_unresolved_reloc;
bfd_boolean warned;
enum { DEST_NORMAL, DEST_OPD, DEST_STUB } reloc_dest;
unsigned int insn;
@ -14190,6 +14257,16 @@ ppc64_elf_relocate_section (bfd *output_bfd,
unsigned int insn2;
bfd_vma offset = rel->r_offset;
if (is_plt_seq_reloc (ELF64_R_TYPE (rel[1].r_info)))
{
bfd_put_32 (output_bfd, NOP, contents + offset);
rel[1].r_info = ELF64_R_INFO (STN_UNDEF, R_PPC64_NONE);
break;
}
if (ELF64_R_TYPE (rel[1].r_info) == R_PPC64_PLTCALL)
bfd_put_32 (output_bfd, NOP, contents + offset + 4);
if ((tls_mask & TLS_TPRELGD) != 0)
{
/* IE */
@ -14225,6 +14302,16 @@ ppc64_elf_relocate_section (bfd *output_bfd,
unsigned int insn2;
bfd_vma offset = rel->r_offset;
if (is_plt_seq_reloc (ELF64_R_TYPE (rel[1].r_info)))
{
bfd_put_32 (output_bfd, NOP, contents + offset);
rel[1].r_info = ELF64_R_INFO (STN_UNDEF, R_PPC64_NONE);
break;
}
if (ELF64_R_TYPE (rel[1].r_info) == R_PPC64_PLTCALL)
bfd_put_32 (output_bfd, NOP, contents + offset + 4);
if (toc_symndx)
sec = local_sections[toc_symndx];
for (r_symndx = 0;
@ -14416,6 +14503,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
/* Fall through. */
case R_PPC64_REL24:
case R_PPC64_PLTCALL:
/* Calls to functions with a different TOC, such as calls to
shared objects, need to alter the TOC pointer. This is
done using a linkage stub. A REL24 branching to these
@ -14429,6 +14517,12 @@ ppc64_elf_relocate_section (bfd *output_bfd,
fdh = ppc_follow_link (h->oh);
stub_entry = ppc_get_stub_entry (input_section, sec, fdh, &orig_rel,
htab);
if (r_type == R_PPC64_PLTCALL
&& stub_entry != NULL
&& (stub_entry->stub_type == ppc_stub_plt_call
|| stub_entry->stub_type == ppc_stub_plt_call_r2save))
stub_entry = NULL;
if (stub_entry != NULL
&& (stub_entry->stub_type == ppc_stub_plt_call
|| stub_entry->stub_type == ppc_stub_plt_call_r2save
@ -14461,8 +14555,11 @@ ppc64_elf_relocate_section (bfd *output_bfd,
nop = bfd_get_32 (input_bfd,
contents + rel->r_offset + 4);
if (nop == NOP
|| nop == CROR_151515 || nop == CROR_313131)
if (nop == LD_R2_0R1 + STK_TOC (htab))
can_plt_call = TRUE;
else if (nop == NOP
|| nop == CROR_151515
|| nop == CROR_313131)
{
if (h != NULL
&& (h == htab->tls_get_addr_fd
@ -14656,6 +14753,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
/* Set `addend'. */
tls_type = 0;
save_unresolved_reloc = unresolved_reloc;
switch (r_type)
{
default:
@ -14914,8 +15012,11 @@ ppc64_elf_relocate_section (bfd *output_bfd,
case R_PPC64_PLT16_LO_DS:
case R_PPC64_PLT32:
case R_PPC64_PLT64:
case R_PPC64_PLTSEQ:
case R_PPC64_PLTCALL:
/* Relocation is to the entry for this symbol in the
procedure linkage table. */
unresolved_reloc = TRUE;
{
struct plt_entry **plt_list = NULL;
if (h != NULL)
@ -15368,6 +15469,35 @@ ppc64_elf_relocate_section (bfd *output_bfd,
insn. */
break;
case R_PPC64_PLTCALL:
if (unresolved_reloc)
{
/* No plt entry. Make this into a direct call. */
bfd_byte *p = contents + rel->r_offset;
insn = bfd_get_32 (input_bfd, p);
insn &= 1;
bfd_put_32 (input_bfd, B_DOT | insn, p);
bfd_put_32 (input_bfd, NOP, p + 4);
unresolved_reloc = save_unresolved_reloc;
r_type = R_PPC64_REL24;
}
break;
case R_PPC64_PLTSEQ:
if (unresolved_reloc)
{
unresolved_reloc = FALSE;
goto nop_it;
}
break;
case R_PPC64_PLT16_HA:
if (unresolved_reloc)
{
unresolved_reloc = FALSE;
goto nop_it;
}
/* Fall through. */
case R_PPC64_GOT_TLSLD16_HA:
case R_PPC64_GOT_TLSGD16_HA:
case R_PPC64_GOT_TPREL16_HA:
@ -15377,12 +15507,22 @@ ppc64_elf_relocate_section (bfd *output_bfd,
if (htab->do_toc_opt && relocation + addend + 0x8000 < 0x10000
&& !ppc64_elf_tdata (input_bfd)->unexpected_toc_insn)
{
bfd_byte *p = contents + (rel->r_offset & ~3);
bfd_byte *p;
nop_it:
p = contents + (rel->r_offset & ~3);
bfd_put_32 (input_bfd, NOP, p);
goto copy_reloc;
}
break;
case R_PPC64_PLT16_LO:
case R_PPC64_PLT16_LO_DS:
if (unresolved_reloc)
{
unresolved_reloc = FALSE;
goto nop_it;
}
/* Fall through. */
case R_PPC64_GOT_TLSLD16_LO:
case R_PPC64_GOT_TLSGD16_LO:
case R_PPC64_GOT_TPREL16_LO_DS:

4
elfcpp/ChangeLog
View File

@ -1,3 +1,7 @@
2018-04-09 Alan Modra <amodra@gmail.com>
* powerpc.h (R_POWERPC_PLTSEQ, R_POWERPC_PLTCALL): Define.
2018-03-28 Cary Coutant <ccoutant@gmail.com>
PR gold/22969

2
elfcpp/powerpc.h
View File

@ -179,6 +179,8 @@ enum
R_PPC64_REL24_NOTOC = 116,
R_PPC64_ADDR64_LOCAL = 117,
R_PPC64_ENTRY = 118,
R_POWERPC_PLTSEQ = 119,
R_POWERPC_PLTCALL = 120,
R_PPC_VLE_REL8 = 216,
R_PPC_VLE_REL15 = 217,

8
gold/ChangeLog
View File

@ -1,3 +1,11 @@
2018-04-09 Alan Modra <amodra@gmail.com>
* powerpc.cc (Target_powerpc::Track_tls::maybe_skip_tls_get_addr_call):
Handle inline plt sequence relocs.
(Stub_table::Plt_stub_key::Plt_stub_key): Likewise.
(Target_powerpc::Scan::reloc_needs_plt_for_ifunc): Likewise.
(Target_powerpc::Relocate::relocate): Likewise.
2018-04-09 Alan Modra <amodra@gmail.com>
* powerpc.cc (Target_powerpc::lplt_): New variable.

65
gold/powerpc.cc
View File

@ -78,8 +78,10 @@ struct Stub_table_owner
const Output_section::Input_section* owner;
};
inline bool
is_branch_reloc(unsigned int r_type);
inline bool is_branch_reloc(unsigned int);
template<int size>
inline bool is_plt16_reloc(unsigned int);
// Counter incremented on every Powerpc_relobj constructed.
static uint32_t object_id = 0;
@ -1211,7 +1213,10 @@ class Target_powerpc : public Sized_target<size, big_endian>
unsigned int r_type, const Symbol* gsym)
{
bool is_tls_call = ((r_type == elfcpp::R_POWERPC_REL24
|| r_type == elfcpp::R_PPC_PLTREL24)
|| r_type == elfcpp::R_PPC_PLTREL24
|| is_plt16_reloc<size>(r_type)
|| r_type == elfcpp::R_POWERPC_PLTSEQ
|| r_type == elfcpp::R_POWERPC_PLTCALL)
&& gsym != NULL
&& (gsym == target->tls_get_addr()
|| gsym == target->tls_get_addr_opt()));
@ -4651,7 +4656,8 @@ class Stub_table : public Output_relaxed_input_section
if (size != 32)
this->addend_ = addend;
else if (parameters->options().output_is_position_independent()
&& r_type == elfcpp::R_PPC_PLTREL24)
&& (r_type == elfcpp::R_PPC_PLTREL24
|| r_type == elfcpp::R_POWERPC_PLTCALL))
{
this->addend_ = addend;
if (this->addend_ >= 32768)
@ -4668,7 +4674,8 @@ class Stub_table : public Output_relaxed_input_section
if (size != 32)
this->addend_ = addend;
else if (parameters->options().output_is_position_independent()
&& r_type == elfcpp::R_PPC_PLTREL24)
&& (r_type == elfcpp::R_PPC_PLTREL24
|| r_type == elfcpp::R_POWERPC_PLTCALL))
this->addend_ = addend;
}
@ -6569,6 +6576,8 @@ Target_powerpc<size, big_endian>::Scan::reloc_needs_plt_for_ifunc(
case elfcpp::R_POWERPC_PLT16_HI:
case elfcpp::R_POWERPC_PLT16_HA:
case elfcpp::R_PPC64_PLT16_LO_DS:
case elfcpp::R_POWERPC_PLTSEQ:
case elfcpp::R_POWERPC_PLTCALL:
return true;
break;
@ -6706,6 +6715,8 @@ Target_powerpc<size, big_endian>::Scan::local(
case elfcpp::R_POWERPC_GNU_VTENTRY:
case elfcpp::R_POWERPC_TLS:
case elfcpp::R_PPC64_ENTRY:
case elfcpp::R_POWERPC_PLTSEQ:
case elfcpp::R_POWERPC_PLTCALL:
break;
case elfcpp::R_PPC64_TOC:
@ -7266,6 +7277,8 @@ Target_powerpc<size, big_endian>::Scan::global(
case elfcpp::R_PPC_LOCAL24PC:
case elfcpp::R_POWERPC_TLS:
case elfcpp::R_PPC64_ENTRY:
case elfcpp::R_POWERPC_PLTSEQ:
case elfcpp::R_POWERPC_PLTCALL:
break;
case elfcpp::R_PPC64_TOC:
@ -8495,6 +8508,10 @@ Target_powerpc<size, big_endian>::Relocate::relocate(
Address address,
section_size_type view_size)
{
typedef Powerpc_relocate_functions<size, big_endian> Reloc;
typedef typename elfcpp::Swap<32, big_endian>::Valtype Insn;
typedef typename elfcpp::Rela<size, big_endian> Reltype;
if (view == NULL)
return true;
@ -8513,14 +8530,22 @@ Target_powerpc<size, big_endian>::Relocate::relocate(
// We have already complained.
break;
case Track_tls::SKIP:
if (is_plt16_reloc<size>(r_type)
|| r_type == elfcpp::R_POWERPC_PLTSEQ)
{
Insn* iview = reinterpret_cast<Insn*>(view);
elfcpp::Swap<32, big_endian>::writeval(iview, nop);
}
else if (size == 64 && r_type == elfcpp::R_POWERPC_PLTCALL)
{
Insn* iview = reinterpret_cast<Insn*>(view);
elfcpp::Swap<32, big_endian>::writeval(iview + 1, nop);
}
return true;
case Track_tls::NORMAL:
break;
}
typedef Powerpc_relocate_functions<size, big_endian> Reloc;
typedef typename elfcpp::Swap<32, big_endian>::Valtype Insn;
typedef typename elfcpp::Rela<size, big_endian> Reltype;
// Offset from start of insn to d-field reloc.
const int d_offset = big_endian ? 2 : 0;
@ -8536,6 +8561,8 @@ Target_powerpc<size, big_endian>::Relocate::relocate(
: object->local_has_plt_offset(r_sym));
if (has_plt_offset
&& !is_plt16_reloc<size>(r_type)
&& r_type != elfcpp::R_POWERPC_PLTSEQ
&& r_type != elfcpp::R_POWERPC_PLTCALL
&& (!psymval->is_ifunc_symbol()
|| Scan::reloc_needs_plt_for_ifunc(target, object, r_type, false)))
{
@ -8633,6 +8660,14 @@ Target_powerpc<size, big_endian>::Relocate::relocate(
+ target->got_section()->g_o_t());
}
}
else if (!has_plt_offset
&& (is_plt16_reloc<size>(r_type)
|| r_type == elfcpp::R_POWERPC_PLTSEQ))
{
Insn* iview = reinterpret_cast<Insn*>(view);
elfcpp::Swap<32, big_endian>::writeval(iview, nop);
r_type = elfcpp::R_POWERPC_NONE;
}
else if (r_type == elfcpp::R_POWERPC_GOT16
|| r_type == elfcpp::R_POWERPC_GOT16_LO
|| r_type == elfcpp::R_POWERPC_GOT16_HI
@ -8969,6 +9004,18 @@ Target_powerpc<size, big_endian>::Relocate::relocate(
}
else if (!has_stub_value)
{
if (!has_plt_offset && r_type == elfcpp::R_POWERPC_PLTCALL)
{
// PLTCALL without plt entry => convert to direct call
Insn* iview = reinterpret_cast<Insn*>(view);
Insn insn = elfcpp::Swap<32, big_endian>::readval(iview);
insn = (insn & 1) | b;
elfcpp::Swap<32, big_endian>::writeval(iview, insn);
if (size == 32)
r_type = elfcpp::R_PPC_PLTREL24;
else
r_type = elfcpp::R_POWERPC_REL24;
}
Address addend = 0;
if (!(size == 32
&& (r_type == elfcpp::R_PPC_PLTREL24
@ -9498,6 +9545,8 @@ Target_powerpc<size, big_endian>::Relocate::relocate(
case elfcpp::R_POWERPC_TLS:
case elfcpp::R_POWERPC_GNU_VTINHERIT:
case elfcpp::R_POWERPC_GNU_VTENTRY:
case elfcpp::R_POWERPC_PLTSEQ:
case elfcpp::R_POWERPC_PLTCALL:
break;
case elfcpp::R_PPC64_ADDR64:

5
include/ChangeLog
View File

@ -1,3 +1,8 @@
2018-04-09 Alan Modra <amodra@gmail.com>
* elf/ppc.h (R_PPC_PLTSEQ, R_PPC_PLTCALL): Define.
* elf/ppc64.h (R_PPC64_PLTSEQ, R_PPC64_PLTCALL): Define.
2018-03-28 Renlin Li <renlin.li@arm.com>
PR ld/22970

4
include/elf/ppc.h
View File

@ -134,6 +134,10 @@ START_RELOC_NUMBERS (elf_ppc_reloc_type)
RELOC_NUMBER (R_PPC_EMB_BIT_FLD, 115)
RELOC_NUMBER (R_PPC_EMB_RELSDA, 116)
/* Marker reloc for inline plt call insns. */
RELOC_NUMBER (R_PPC_PLTSEQ, 119)
RELOC_NUMBER (R_PPC_PLTCALL, 120)
/* PowerPC VLE relocations. */
RELOC_NUMBER (R_PPC_VLE_REL8, 216)
RELOC_NUMBER (R_PPC_VLE_REL15, 217)

4
include/elf/ppc64.h
View File

@ -154,6 +154,10 @@ START_RELOC_NUMBERS (elf_ppc64_reloc_type)
RELOC_NUMBER (R_PPC64_ADDR64_LOCAL, 117)
RELOC_NUMBER (R_PPC64_ENTRY, 118)
/* Marker reloc for inline plt call insns. */
RELOC_NUMBER (R_PPC64_PLTSEQ, 119)
RELOC_NUMBER (R_PPC64_PLTCALL, 120)
#ifndef RELOC_MACROS_GEN_FUNC
/* Relocation only used internally by ld. If you need to use these
reloc numbers, you can change them to some other unused value