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[committed, PATCH] x86-64: Also generate unwind info for .plt.bnd
- From: "H.J. Lu" <hongjiu dot lu at intel dot com>
- To: binutils at sourceware dot org
- Date: Thu, 12 Jan 2017 10:35:35 -0800
- Subject: [committed, PATCH] x86-64: Also generate unwind info for .plt.bnd
- Authentication-results: sourceware.org; auth=none
- Reply-to: "H.J. Lu" <hjl dot tools at gmail dot com>
Also generate unwind info for the .plt.bnd section. Sine it is the same
as unwind info for the .plt.got section, we use unwind info for the
.plt.got section to cover the the .plt.bnd section.
bfd/
PR ld/21038
* elf64-x86-64.c (elf_x86_64_link_hash_table): Add
plt_bnd_eh_frame.
(elf_x86_64_check_relocs): Create .eh_frame section for the
.plt.bnd section.
(elf_x86_64_size_dynamic_sections): Allocate and initialize
.eh_frame section for the .plt.bnd section.
(elf_x86_64_finish_dynamic_sections): Adjust .eh_frame section
for the .plt.bnd section.
ld/
PR ld/21038
* testsuite/ld-x86-64/pr21038b.d: Updated.
* testsuite/ld-x86-64/pr21038c.d: New file.
* testsuite/ld-x86-64/pr21038c.s: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run pr21038c.
---
bfd/elf64-x86-64.c | 106 +++++++++++++++++++++++++++-----------
ld/testsuite/ld-x86-64/pr21038b.d | 9 ++++
ld/testsuite/ld-x86-64/pr21038c.d | 90 ++++++++++++++++++++++++++++++++
ld/testsuite/ld-x86-64/pr21038c.s | 9 ++++
ld/testsuite/ld-x86-64/x86-64.exp | 1 +
5 files changed, 185 insertions(+), 30 deletions(-)
create mode 100644 ld/testsuite/ld-x86-64/pr21038c.d
create mode 100644 ld/testsuite/ld-x86-64/pr21038c.s
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 1fb865c..a058eca 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -934,6 +934,7 @@ struct elf_x86_64_link_hash_table
asection *interp;
asection *plt_eh_frame;
asection *plt_bnd;
+ asection *plt_bnd_eh_frame;
asection *plt_got;
asection *plt_got_eh_frame;
@@ -2343,23 +2344,21 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
/* MPX PLT is supported only if elf_x86_64_arch_bed
is used in 64-bit mode. */
if (ABI_64_P (abfd)
- && info->bndplt
- && (get_elf_x86_64_backend_data (abfd)
- == &elf_x86_64_arch_bed))
+ && info->bndplt
+ && (get_elf_x86_64_backend_data (abfd)
+ == &elf_x86_64_arch_bed))
{
elf_x86_64_hash_entry (h)->has_bnd_reloc = 1;
/* Create the second PLT for Intel MPX support. */
if (htab->plt_bnd == NULL)
{
- unsigned int plt_bnd_align;
const struct elf_backend_data *bed;
bed = get_elf_backend_data (info->output_bfd);
BFD_ASSERT (sizeof (elf_x86_64_bnd_plt2_entry) == 8
&& (sizeof (elf_x86_64_bnd_plt2_entry)
== sizeof (elf_x86_64_legacy_plt2_entry)));
- plt_bnd_align = 3;
if (htab->elf.dynobj == NULL)
htab->elf.dynobj = abfd;
@@ -2374,7 +2373,24 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
if (htab->plt_bnd == NULL
|| !bfd_set_section_alignment (htab->elf.dynobj,
htab->plt_bnd,
- plt_bnd_align))
+ 3))
+ goto error_return;
+ }
+
+ if (!info->no_ld_generated_unwind_info
+ && htab->plt_bnd_eh_frame == NULL)
+ {
+ flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY
+ | SEC_HAS_CONTENTS | SEC_IN_MEMORY
+ | SEC_LINKER_CREATED);
+ htab->plt_bnd_eh_frame
+ = bfd_make_section_anyway_with_flags (htab->elf.dynobj,
+ ".eh_frame",
+ flags);
+ if (htab->plt_bnd_eh_frame == NULL
+ || !bfd_set_section_alignment (htab->elf.dynobj,
+ htab->plt_bnd_eh_frame,
+ 3))
goto error_return;
}
}
@@ -3687,6 +3703,7 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd,
bfd_boolean relocs;
bfd *ibfd;
const struct elf_backend_data *bed;
+ const struct elf_x86_64_backend_data *arch_data;
htab = elf_x86_64_hash_table (info);
if (htab == NULL)
@@ -3878,30 +3895,31 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd,
htab->elf.sgotplt->size = 0;
}
+ arch_data = (htab->plt_bnd != NULL
+ ? &elf_x86_64_bnd_arch_bed
+ : get_elf_x86_64_arch_data (bed));
+
if (_bfd_elf_eh_frame_present (info))
{
if (htab->plt_eh_frame != NULL
&& htab->elf.splt != NULL
&& htab->elf.splt->size != 0
&& !bfd_is_abs_section (htab->elf.splt->output_section))
- {
- /* Unwind info for the BND PLT and the normal PLT have the
- same time. */
- const struct elf_x86_64_backend_data *arch_data
- = get_elf_x86_64_arch_data (bed);
- htab->plt_eh_frame->size = arch_data->eh_frame_plt_size;
- }
+ htab->plt_eh_frame->size = arch_data->eh_frame_plt_size;
if (htab->plt_got_eh_frame != NULL
&& htab->plt_got != NULL
&& htab->plt_got->size != 0
&& !bfd_is_abs_section (htab->plt_got->output_section))
- {
- const struct elf_x86_64_backend_data *arch_data
- = get_elf_x86_64_arch_data (bed);
- htab->plt_got_eh_frame->size
- = arch_data->eh_frame_plt_got_size;
- }
+ htab->plt_got_eh_frame->size = arch_data->eh_frame_plt_got_size;
+
+ /* Unwind info for .plt.bnd and .plt.got sections are
+ identical. */
+ if (htab->plt_bnd_eh_frame != NULL
+ && htab->plt_bnd != NULL
+ && htab->plt_bnd->size != 0
+ && !bfd_is_abs_section (htab->plt_bnd->output_section))
+ htab->plt_bnd_eh_frame->size = arch_data->eh_frame_plt_got_size;
}
/* We now have determined the sizes of the various dynamic sections.
@@ -3921,6 +3939,7 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd,
|| s == htab->plt_got
|| s == htab->plt_eh_frame
|| s == htab->plt_got_eh_frame
+ || s == htab->plt_bnd_eh_frame
|| s == htab->elf.sdynbss
|| s == htab->elf.sdynrelro)
{
@@ -3975,13 +3994,6 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd,
if (htab->plt_eh_frame != NULL
&& htab->plt_eh_frame->contents != NULL)
{
- /* Unwind info for the BND PLT and the normal PLT have the same
- size, but different contents. */
- const struct elf_x86_64_backend_data *arch_data
- = (htab->plt_bnd != NULL
- ? &elf_x86_64_bnd_arch_bed
- : get_elf_x86_64_arch_data (bed));
-
memcpy (htab->plt_eh_frame->contents,
arch_data->eh_frame_plt, htab->plt_eh_frame->size);
bfd_put_32 (dynobj, htab->elf.splt->size,
@@ -3991,10 +4003,6 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd,
if (htab->plt_got_eh_frame != NULL
&& htab->plt_got_eh_frame->contents != NULL)
{
- /* Unwind info for .plt.bnd and .plt.got sections are identical. */
- const struct elf_x86_64_backend_data *arch_data
- = get_elf_x86_64_arch_data (bed);
-
memcpy (htab->plt_got_eh_frame->contents,
arch_data->eh_frame_plt_got,
htab->plt_got_eh_frame->size);
@@ -4003,6 +4011,17 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd,
+ PLT_FDE_LEN_OFFSET));
}
+ if (htab->plt_bnd_eh_frame != NULL
+ && htab->plt_bnd_eh_frame->contents != NULL)
+ {
+ memcpy (htab->plt_bnd_eh_frame->contents,
+ arch_data->eh_frame_plt_got,
+ htab->plt_bnd_eh_frame->size);
+ bfd_put_32 (dynobj, htab->plt_bnd->size,
+ (htab->plt_bnd_eh_frame->contents
+ + PLT_FDE_LEN_OFFSET));
+ }
+
if (htab->elf.dynamic_sections_created)
{
/* Add some entries to the .dynamic section. We fill in the
@@ -6495,6 +6514,33 @@ elf_x86_64_finish_dynamic_sections (bfd *output_bfd,
}
}
+ /* Adjust .eh_frame for .plt.bnd section. */
+ if (htab->plt_bnd_eh_frame != NULL
+ && htab->plt_bnd_eh_frame->contents != NULL)
+ {
+ if (htab->plt_bnd != NULL
+ && htab->plt_bnd->size != 0
+ && (htab->plt_bnd->flags & SEC_EXCLUDE) == 0
+ && htab->plt_bnd->output_section != NULL
+ && htab->plt_bnd_eh_frame->output_section != NULL)
+ {
+ bfd_vma plt_start = htab->plt_bnd->output_section->vma;
+ bfd_vma eh_frame_start = htab->plt_bnd_eh_frame->output_section->vma
+ + htab->plt_bnd_eh_frame->output_offset
+ + PLT_FDE_START_OFFSET;
+ bfd_put_signed_32 (dynobj, plt_start - eh_frame_start,
+ htab->plt_bnd_eh_frame->contents
+ + PLT_FDE_START_OFFSET);
+ }
+ if (htab->plt_bnd_eh_frame->sec_info_type == SEC_INFO_TYPE_EH_FRAME)
+ {
+ if (! _bfd_elf_write_section_eh_frame (output_bfd, info,
+ htab->plt_bnd_eh_frame,
+ htab->plt_bnd_eh_frame->contents))
+ return FALSE;
+ }
+ }
+
if (htab->elf.sgot && htab->elf.sgot->size > 0)
elf_section_data (htab->elf.sgot->output_section)->this_hdr.sh_entsize
= GOT_ENTRY_SIZE;
diff --git a/ld/testsuite/ld-x86-64/pr21038b.d b/ld/testsuite/ld-x86-64/pr21038b.d
index 1690d1e..053d908 100644
--- a/ld/testsuite/ld-x86-64/pr21038b.d
+++ b/ld/testsuite/ld-x86-64/pr21038b.d
@@ -40,6 +40,15 @@ Contents of the .eh_frame section:
DW_CFA_nop
DW_CFA_nop
+0+58 0000000000000014 0000005c FDE cie=00000000 pc=0000000000000240..0000000000000248
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+
Disassembly of section .plt:
diff --git a/ld/testsuite/ld-x86-64/pr21038c.d b/ld/testsuite/ld-x86-64/pr21038c.d
new file mode 100644
index 0000000..33ff4ed
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr21038c.d
@@ -0,0 +1,90 @@
+#name: PR ld/21038 (.plt.got and .plt.bnd)
+#as: --64
+#ld: -z bndplt -melf_x86_64 -shared -z relro --ld-generated-unwind-info
+#objdump: -dw -Wf
+
+.*: +file format .*
+
+Contents of the .eh_frame section:
+
+0+ 0000000000000014 00000000 CIE
+ Version: 1
+ Augmentation: "zR"
+ Code alignment factor: 1
+ Data alignment factor: -8
+ Return address column: 16
+ Augmentation data: 1b
+
+ DW_CFA_def_cfa: r7 \(rsp\) ofs 8
+ DW_CFA_offset: r16 \(rip\) at cfa-8
+ DW_CFA_nop
+ DW_CFA_nop
+
+0+18 0000000000000014 0000001c FDE cie=00000000 pc=0000000000000290..00000000000002a1
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+
+0+30 0000000000000024 00000034 FDE cie=00000000 pc=0000000000000260..0000000000000280
+ DW_CFA_def_cfa_offset: 16
+ DW_CFA_advance_loc: 6 to 0000000000000266
+ DW_CFA_def_cfa_offset: 24
+ DW_CFA_advance_loc: 10 to 0000000000000270
+ DW_CFA_def_cfa_expression \(DW_OP_breg7 \(rsp\): 8; DW_OP_breg16 \(rip\): 0; DW_OP_lit15; DW_OP_and; DW_OP_lit5; DW_OP_ge; DW_OP_lit3; DW_OP_shl; DW_OP_plus\)
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+
+0+58 0000000000000014 0000005c FDE cie=00000000 pc=0000000000000288..0000000000000290
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+
+0+70 0000000000000014 00000074 FDE cie=00000000 pc=0000000000000280..0000000000000288
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+ DW_CFA_nop
+
+
+Disassembly of section .plt:
+
+0+260 <.plt>:
+ +[a-f0-9]+: ff 35 a2 0d 20 00 pushq 0x200da2\(%rip\) # 201008 <_GLOBAL_OFFSET_TABLE_\+0x8>
+ +[a-f0-9]+: f2 ff 25 a3 0d 20 00 bnd jmpq \*0x200da3\(%rip\) # 201010 <_GLOBAL_OFFSET_TABLE_\+0x10>
+ +[a-f0-9]+: 0f 1f 00 nopl \(%rax\)
+ +[a-f0-9]+: 68 00 00 00 00 pushq \$0x0
+ +[a-f0-9]+: f2 e9 e5 ff ff ff bnd jmpq 260 <.plt>
+ +[a-f0-9]+: 0f 1f 44 00 00 nopl 0x0\(%rax,%rax,1\)
+
+Disassembly of section .plt.got:
+
+0+280 <.plt.got>:
+ +[a-f0-9]+: f2 ff 25 71 0d 20 00 bnd jmpq \*0x200d71\(%rip\) # 200ff8 <func1>
+ +[a-f0-9]+: 90 nop
+
+Disassembly of section .plt.bnd:
+
+0+288 <func2@plt>:
+ +[a-f0-9]+: f2 ff 25 89 0d 20 00 bnd jmpq \*0x200d89\(%rip\) # 201018 <func2>
+ +[a-f0-9]+: 90 nop
+
+Disassembly of section .text:
+
+0+290 <foo>:
+ +[a-f0-9]+: e8 eb ff ff ff callq 280 <.plt.got>
+ +[a-f0-9]+: e8 ee ff ff ff callq 288 <func2@plt>
+ +[a-f0-9]+: 48 8b 05 57 0d 20 00 mov 0x200d57\(%rip\),%rax # 200ff8 <func1>
+#pass
diff --git a/ld/testsuite/ld-x86-64/pr21038c.s b/ld/testsuite/ld-x86-64/pr21038c.s
new file mode 100644
index 0000000..38fc10d
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr21038c.s
@@ -0,0 +1,9 @@
+ .text
+ .globl foo
+ .type foo, @function
+foo:
+ .cfi_startproc
+ call func1@plt
+ call func2@plt
+ movq func1@GOTPCREL(%rip), %rax
+ .cfi_endproc
diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index ff782a0..8e4e422 100644
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -1023,3 +1023,4 @@ run_dump_test "pr20830a"
run_dump_test "pr20830b"
run_dump_test "pr21038a"
run_dump_test "pr21038b"
+run_dump_test "pr21038c"
--
2.9.3