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authorAlan Modra <amodra@gmail.com>2018-02-05 13:17:52 +1030
committerAlan Modra <amodra@gmail.com>2018-02-07 14:23:08 +1030
commit407aa07cee4d075c8e7996a5e994c02e76f19276 (patch)
tree4d91c369283906fd95e07b6c05b3889d964228c9 /bfd
parented01220cc81fac2f65abde945d9b77b11d004361 (diff)
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Revert "PowerPC PLT speculative execution barriers"
This reverts most of commit 1be5d8d3bb. Left in place are addition of --no-plt-align to some ppc32 ld tests and the ld.texinfo --no-plt-thread-safe fix.
Diffstat (limited to 'bfd')
-rw-r--r--bfd/ChangeLog8
-rw-r--r--bfd/elf32-ppc.c41
-rw-r--r--bfd/elf32-ppc.h3
-rw-r--r--bfd/elf64-ppc.c58
-rw-r--r--bfd/elf64-ppc.h3
5 files changed, 26 insertions, 87 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 4a4167c..6dd9f47 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,11 @@
+2018-02-07 Alan Modra <amodra@gmail.com>
+
+ Revert 2018-01-17 Alan Modra <amodra@gmail.com>
+ * elf32-ppc.c: Remove speculation barrier support.
+ * elf32-ppc.h: Likewise.
+ * elf64-ppc.c: Likewise.
+ * elf64-ppc.h: Likewise.
+
2018-02-06 Jim Wilson <jimw@sifive.com>
* elfnn-riscv.c (riscv_elf_relocate_section): Return TRUE if used
diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c
index 32104a1..092b1ce 100644
--- a/bfd/elf32-ppc.c
+++ b/bfd/elf32-ppc.c
@@ -69,7 +69,7 @@ static bfd_reloc_status_type ppc_elf_unhandled_reloc
/* For new-style .glink and .plt. */
#define GLINK_PLTRESOLVE 16*4
#define GLINK_ENTRY_SIZE(htab, h) \
- (((!htab->params->speculate_indirect_jumps ? 6*4 : 4*4) \
+ ((4*4 \
+ (h != NULL \
&& h == htab->tls_get_addr \
&& !htab->params->no_tls_get_addr_opt ? 8*4 : 0) \
@@ -155,8 +155,6 @@ static const bfd_vma ppc_elf_vxworks_pic_plt0_entry
#define BA 0x48000002
#define BCL_20_31 0x429f0005
#define BCTR 0x4e800420
-#define CRSETEQ 0x4c421242
-#define BEQCTRM 0x4dc20420
#define BEQLR 0x4d820020
#define CMPWI_11_0 0x2c0b0000
#define LIS_11 0x3d600000
@@ -2880,14 +2878,15 @@ ppc_elf_final_write_processing (bfd *abfd, bfd_boolean linker ATTRIBUTE_UNUSED)
static bfd_boolean
is_nonpic_glink_stub (bfd *abfd, asection *glink, bfd_vma off)
{
- bfd_byte buf[3 * 4];
+ bfd_byte buf[4 * 4];
if (!bfd_get_section_contents (abfd, glink, buf, off, sizeof buf))
return FALSE;
return ((bfd_get_32 (abfd, buf + 0) & 0xffff0000) == LIS_11
&& (bfd_get_32 (abfd, buf + 4) & 0xffff0000) == LWZ_11_11
- && bfd_get_32 (abfd, buf + 8) == MTCTR_11);
+ && bfd_get_32 (abfd, buf + 8) == MTCTR_11
+ && bfd_get_32 (abfd, buf + 12) == BCTR);
}
static bfd_boolean
@@ -3366,7 +3365,7 @@ ppc_elf_link_hash_table_create (bfd *abfd)
{
struct ppc_elf_link_hash_table *ret;
static struct ppc_elf_params default_params
- = { PLT_OLD, 0, 1, 0, 1, 0, 0, 12, 0, 0, 0 };
+ = { PLT_OLD, 0, 0, 1, 0, 0, 12, 0, 0, 0 };
ret = bfd_zmalloc (sizeof (struct ppc_elf_link_hash_table));
if (ret == NULL)
@@ -7171,8 +7170,6 @@ ppc_elf_relax_section (bfd *abfd,
size = 4 * ARRAY_SIZE (stub_entry);
insn_offset = 0;
}
- if (!htab->params->speculate_indirect_jumps)
- size += 8;
stub_rtype = R_PPC_RELAX;
if (tsec == htab->elf.splt
|| tsec == htab->glink)
@@ -7454,26 +7451,6 @@ elf_finish_pointer_linker_section (bfd *input_bfd,
#define PPC_HI(v) (((v) >> 16) & 0xffff)
#define PPC_HA(v) PPC_HI ((v) + 0x8000)
-static inline bfd_byte *
-output_bctr (struct ppc_elf_link_hash_table *htab, bfd *obfd, bfd_byte *p)
-{
- if (!htab->params->speculate_indirect_jumps)
- {
- bfd_put_32 (obfd, CRSETEQ, p);
- p += 4;
- bfd_put_32 (obfd, BEQCTRM, p);
- p += 4;
- bfd_put_32 (obfd, B, p);
- p += 4;
- }
- else
- {
- bfd_put_32 (obfd, BCTR, p);
- p += 4;
- }
- return p;
-}
-
static void
write_glink_stub (struct elf_link_hash_entry *h, struct plt_entry *ent,
asection *plt_sec, unsigned char *p,
@@ -7541,7 +7518,8 @@ write_glink_stub (struct elf_link_hash_entry *h, struct plt_entry *ent,
p += 4;
bfd_put_32 (output_bfd, MTCTR_11, p);
p += 4;
- p = output_bctr (htab, output_bfd, p);
+ bfd_put_32 (output_bfd, BCTR, p);
+ p += 4;
while (p < end)
{
bfd_put_32 (output_bfd, htab->params->ppc476_workaround ? BA : NOP, p);
@@ -8979,7 +8957,6 @@ ppc_elf_relocate_section (bfd *output_bfd,
stub = stub_entry;
size = ARRAY_SIZE (stub_entry);
}
- --size;
relocation += addend;
if (bfd_link_relocatable (info))
@@ -9004,7 +8981,6 @@ ppc_elf_relocate_section (bfd *output_bfd,
bfd_put_32 (input_bfd, insn, contents + insn_offset);
insn_offset += 4;
}
- output_bctr (htab, input_bfd, contents + insn_offset);
/* Rewrite the reloc and convert one of the trailing nop
relocs to describe this relocation. */
@@ -10713,7 +10689,8 @@ ppc_elf_finish_dynamic_sections (bfd *output_bfd,
p += 4;
bfd_put_32 (output_bfd, ADD_11_0_11, p);
p += 4;
- p = output_bctr (htab, output_bfd, p);
+ bfd_put_32 (output_bfd, BCTR, p);
+ p += 4;
while (p < endp)
{
bfd_put_32 (output_bfd,
diff --git a/bfd/elf32-ppc.h b/bfd/elf32-ppc.h
index 8977efa..f56d027 100644
--- a/bfd/elf32-ppc.h
+++ b/bfd/elf32-ppc.h
@@ -35,9 +35,6 @@ struct ppc_elf_params
/* Set if individual PLT call stubs should be aligned. */
int plt_stub_align;
- /* Clear if PLT call stubs should use a speculative execution barrier. */
- int speculate_indirect_jumps;
-
/* Whether to emit symbols for stubs. */
int emit_stub_syms;
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index d6ec12f..2d43df89 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -161,10 +161,6 @@ static bfd_vma opd_entry_value
#define LD_R11_0R11 0xe96b0000 /* ld %r11,xxx+16@l(%r11) */
#define BCTR 0x4e800420 /* bctr */
-#define CRSETEQ 0x4c421242 /* crset 4*%cr0+%eq */
-#define BEQCTRM 0x4dc20420 /* beqctr- */
-#define BEQCTRLM 0x4dc20421 /* beqctrl- */
-
#define ADDI_R11_R11 0x396b0000 /* addi %r11,%r11,off@l */
#define ADDIS_R2_R2 0x3c420000 /* addis %r2,%r2,off@ha */
#define ADDI_R2_R2 0x38420000 /* addi %r2,%r2,off@l */
@@ -193,8 +189,7 @@ static bfd_vma opd_entry_value
/* __glink_PLTresolve stub instructions. We enter with the index in R0. */
#define GLINK_PLTRESOLVE_SIZE(htab) \
- (8u + (htab->opd_abi ? 11 * 4 : 14 * 4) \
- + (!htab->params->speculate_indirect_jumps ? 2 * 4 : 0))
+ (8u + (htab->opd_abi ? 11 * 4 : 14 * 4))
/* 0: */
/* .quad plt0-1f */
/* __glink: */
@@ -9886,8 +9881,6 @@ size_global_entry_stubs (struct elf_link_hash_entry *h, void *inf)
unsigned int align_power;
stub_size = 16;
- if (!htab->params->speculate_indirect_jumps)
- stub_size += 8;
stub_off = s->size;
if (htab->params->plt_stub_align >= 0)
align_power = htab->params->plt_stub_align;
@@ -10453,8 +10446,6 @@ plt_stub_size (struct ppc_link_hash_table *htab,
size += 4;
if (PPC_HA (off) != 0)
size += 4;
- if (!htab->params->speculate_indirect_jumps)
- size += 8;
if (htab->opd_abi)
{
size += 4;
@@ -10476,11 +10467,7 @@ plt_stub_size (struct ppc_link_hash_table *htab,
size += 7 * 4;
if (ALWAYS_EMIT_R2SAVE
|| stub_entry->stub_type == ppc_stub_plt_call_r2save)
- {
- size += 6 * 4;
- if (!htab->params->speculate_indirect_jumps)
- size -= 4;
- }
+ size += 6 * 4;
}
return size;
}
@@ -10515,26 +10502,6 @@ plt_stub_pad (struct ppc_link_hash_table *htab,
return 0;
}
-static inline bfd_byte *
-output_bctr (struct ppc_link_hash_table *htab, bfd *obfd, bfd_byte *p)
-{
- if (!htab->params->speculate_indirect_jumps)
- {
- bfd_put_32 (obfd, CRSETEQ, p);
- p += 4;
- bfd_put_32 (obfd, BEQCTRM, p);
- p += 4;
- bfd_put_32 (obfd, B_DOT, p);
- p += 4;
- }
- else
- {
- bfd_put_32 (obfd, BCTR, p);
- p += 4;
- }
- return p;
-}
-
/* Build a .plt call stub. */
static inline bfd_byte *
@@ -10555,7 +10522,6 @@ build_plt_stub (struct ppc_link_hash_table *htab,
if (!ALWAYS_USE_FAKE_DEP
&& plt_load_toc
&& plt_thread_safe
- && htab->params->speculate_indirect_jumps
&& !((stub_entry->h == htab->tls_get_addr_fd
|| stub_entry->h == htab->tls_get_addr)
&& htab->params->tls_get_addr_opt))
@@ -10710,7 +10676,7 @@ build_plt_stub (struct ppc_link_hash_table *htab,
bfd_put_32 (obfd, B_DOT | (cmp_branch_off & 0x3fffffc), p), p += 4;
}
else
- p = output_bctr (htab, obfd, p);
+ bfd_put_32 (obfd, BCTR, p), p += 4;
return p;
}
@@ -10754,13 +10720,7 @@ build_tls_get_addr_stub (struct ppc_link_hash_table *htab,
if (r != NULL)
r[0].r_offset += 2 * 4;
p = build_plt_stub (htab, stub_entry, p, offset, r);
- if (!htab->params->speculate_indirect_jumps)
- {
- p -= 4;
- bfd_put_32 (obfd, BEQCTRLM, p - 4);
- }
- else
- bfd_put_32 (obfd, BCTRL, p - 4);
+ bfd_put_32 (obfd, BCTRL, p - 4);
bfd_put_32 (obfd, LD_R2_0R1 + STK_TOC (htab), p), p += 4;
bfd_put_32 (obfd, LD_R11_0R1 + STK_LINKER (htab), p), p += 4;
@@ -11113,7 +11073,8 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
p += 4;
bfd_put_32 (htab->params->stub_bfd, MTCTR_R12, p);
p += 4;
- p = output_bctr (htab, htab->params->stub_bfd, p);
+ bfd_put_32 (htab->params->stub_bfd, BCTR, p);
+ p += 4;
break;
case ppc_stub_plt_call:
@@ -11446,8 +11407,6 @@ ppc_size_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
if (PPC_LO (r2off) != 0)
size += 4;
}
- if (!htab->params->speculate_indirect_jumps)
- size += 8;
}
else if (info->emitrelocations)
{
@@ -13089,7 +13048,7 @@ build_global_entry_stubs (struct elf_link_hash_entry *h, void *inf)
p += 4;
bfd_put_32 (s->owner, MTCTR_R12, p);
p += 4;
- output_bctr (htab, s->owner, p);
+ bfd_put_32 (s->owner, BCTR, p);
break;
}
return TRUE;
@@ -13218,7 +13177,8 @@ ppc64_elf_build_stubs (struct bfd_link_info *info,
bfd_put_32 (htab->glink->owner, LD_R11_0R11 | 8, p);
p += 4;
}
- p = output_bctr (htab, htab->glink->owner, p);
+ bfd_put_32 (htab->glink->owner, BCTR, p);
+ p += 4;
BFD_ASSERT (p == htab->glink->contents + GLINK_PLTRESOLVE_SIZE (htab));
/* Build the .glink lazy link call stubs. */
diff --git a/bfd/elf64-ppc.h b/bfd/elf64-ppc.h
index b3d4d59..8fa0140 100644
--- a/bfd/elf64-ppc.h
+++ b/bfd/elf64-ppc.h
@@ -51,9 +51,6 @@ struct ppc64_elf_params
/* Set if PLT call stubs for localentry:0 functions should omit r2 save. */
int plt_localentry0;
- /* Clear if PLT call stubs should use a speculative execution barrier. */
- int speculate_indirect_jumps;
-
/* Whether to canonicalize .opd so that there are no overlapping
.opd entries. */
int non_overlapping_opd;