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[PATCH] x86-64: Add TLSDESC fields to elf_x86_lazy_plt_layout
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Binutils <binutils at sourceware dot org>
- Date: Mon, 28 May 2018 10:56:00 -0700
- Subject: [PATCH] x86-64: Add TLSDESC fields to elf_x86_lazy_plt_layout
On Sat, Mar 24, 2018 at 8:45 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> The TLSDESC entry in a lazy procedure linkage table is called indirectly
> with "callq *(%rax)". This patch adds an ENDBR64 to support indirect
> branch tracking in Intel CET. The TLSDESC PLT entry now looks like:
>
> 0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */
> 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
> 0xff, 0x25, 16, 0, 0, 0 /* jmpq *GOT+TDG(%rip) */
>
> The BND prefix isn't needed since MPX isn't used for TLSDESC.
>
> I will check it into master branch and backport it to 2.30 branch.
>
>
> H.J.
> ---
> bfd/
>
> PR ld/23000
> * elf64-x86-64.c (elf_x86_64_finish_dynamic_sections): Add
> ENDBR64 to the TLSDESC PLT entry.
>
> ld/
> PR ld/23000
> * testsuite/ld-x86-64/tlsdesc.pd: Updated.
>
I am checking in this patch to fix
FAIL: TLS descriptor -fpic -shared transitions
for x86_64-nacl. I will backport it to 2.30 branch.
--
H.J.
From 92e68c1d65f844c0027f471a0c9e1722d781ef7d Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Mon, 28 May 2018 10:46:16 -0700
Subject: [PATCH] x86-64: Add TLSDESC fields to elf_x86_lazy_plt_layout
ENDBR64 is added to the special TLSDESC entry, which is similar to the
PLT0 entry, in the x86-64 lazy procedure linkage table to support Intel
CET. The NaCl PLT is different from the normal PLT. This patch adds
plt_tlsdesc_entry, plt_tlsdesc_entry_size, plt_tlsdesc_got1_offset,
plt_tlsdesc_got2_offset, plt_tlsdesc_got1_insn_end and
plt_tlsdesc_got2_insn_end to elf_x86_lazy_plt_layout to support both
normal and NaCl TLSDESC entries. This fixed
FAIL: TLS descriptor -fpic -shared transitions
for x86_64-nacl.
* elf32-i386.c (elf_i386_lazy_plt): Add plt_tlsdesc_entry,
plt_tlsdesc_entry_size, plt_tlsdesc_got1_offset,
plt_tlsdesc_got2_offset, plt_tlsdesc_got1_insn_end and
plt_tlsdesc_got2_insn_end for TLSDESC entry.
(elf_i386_lazy_ibt_plt): Likewise.
(elf_i386_nacl_plt): Likewise.
* elf64-x86-64.c (tlsdesc_plt_entry): Moved and renamed to ...
(elf_x86_64_tlsdesc_plt_entry): This.
(elf_x86_64_lazy_plt): Add plt_tlsdesc_entry,
plt_tlsdesc_entry_size, plt_tlsdesc_got1_offset,
plt_tlsdesc_got2_offset, plt_tlsdesc_got1_insn_end and
plt_tlsdesc_got2_insn_end for TLSDESC entry.
(elf_x86_64_lazy_bnd_plt): Likewise.
(elf_x86_64_lazy_ibt_plt): Likewise.
(elf_x32_lazy_ibt_plt): Likewise.
(elf_x86_64_nacl_plt): Likewise.
(elf_x86_64_finish_dynamic_sections): Use plt_tlsdesc_entry,
plt_tlsdesc_entry_size, plt_tlsdesc_got1_offset,
plt_tlsdesc_got2_offset, plt_tlsdesc_got1_insn_end and
plt_tlsdesc_got2_insn_end to update TLSDESC entry.
* elfxx-x86.h (elf_x86_lazy_plt_layout): Update comments.
Add plt_tlsdesc_entry, plt_tlsdesc_entry_size,
plt_tlsdesc_got1_offset, plt_tlsdesc_got2_offset,
plt_tlsdesc_got1_insn_end and plt_tlsdesc_got2_insn_end.
(elf_x86_non_lazy_plt_layout): Update comments.
(elf_x86_plt_layout): Likewise.
---
bfd/ChangeLog | 29 +++++++++++++++++++++++
bfd/elf32-i386.c | 18 ++++++++++++++
bfd/elf64-x86-64.c | 58 +++++++++++++++++++++++++++++++++++-----------
bfd/elfxx-x86.h | 33 ++++++++++++++++++--------
4 files changed, 115 insertions(+), 23 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index f190b9f3be..5e1724b5f2 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,32 @@
+2018-05-28 H.J. Lu <hongjiu.lu@intel.com>
+
+ * elf32-i386.c (elf_i386_lazy_plt): Add plt_tlsdesc_entry,
+ plt_tlsdesc_entry_size, plt_tlsdesc_got1_offset,
+ plt_tlsdesc_got2_offset, plt_tlsdesc_got1_insn_end and
+ plt_tlsdesc_got2_insn_end for TLSDESC entry.
+ (elf_i386_lazy_ibt_plt): Likewise.
+ (elf_i386_nacl_plt): Likewise.
+ * elf64-x86-64.c (tlsdesc_plt_entry): Moved and renamed to ...
+ (elf_x86_64_tlsdesc_plt_entry): This.
+ (elf_x86_64_lazy_plt): Add plt_tlsdesc_entry,
+ plt_tlsdesc_entry_size, plt_tlsdesc_got1_offset,
+ plt_tlsdesc_got2_offset, plt_tlsdesc_got1_insn_end and
+ plt_tlsdesc_got2_insn_end for TLSDESC entry.
+ (elf_x86_64_lazy_bnd_plt): Likewise.
+ (elf_x86_64_lazy_ibt_plt): Likewise.
+ (elf_x32_lazy_ibt_plt): Likewise.
+ (elf_x86_64_nacl_plt): Likewise.
+ (elf_x86_64_finish_dynamic_sections): Use plt_tlsdesc_entry,
+ plt_tlsdesc_entry_size, plt_tlsdesc_got1_offset,
+ plt_tlsdesc_got2_offset, plt_tlsdesc_got1_insn_end and
+ plt_tlsdesc_got2_insn_end to update TLSDESC entry.
+ * elfxx-x86.h (elf_x86_lazy_plt_layout): Update comments.
+ Add plt_tlsdesc_entry, plt_tlsdesc_entry_size,
+ plt_tlsdesc_got1_offset, plt_tlsdesc_got2_offset,
+ plt_tlsdesc_got1_insn_end and plt_tlsdesc_got2_insn_end.
+ (elf_x86_non_lazy_plt_layout): Update comments.
+ (elf_x86_plt_layout): Likewise.
+
2018-05-28 H.J. Lu <hongjiu.lu@intel.com>
PR ld/23238
diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index 3dd709a10e..49797dcbfa 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -766,6 +766,12 @@ static const struct elf_x86_lazy_plt_layout elf_i386_lazy_plt =
sizeof (elf_i386_lazy_plt0_entry), /* plt0_entry_size */
elf_i386_lazy_plt_entry, /* plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
+ NULL, /* plt_tlsdesc_entry */
+ 0, /* plt_tlsdesc_entry_size*/
+ 0, /* plt_tlsdesc_got1_offset */
+ 0, /* plt_tlsdesc_got2_offset */
+ 0, /* plt_tlsdesc_got1_insn_end */
+ 0, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
8, /* plt0_got2_offset */
0, /* plt0_got2_insn_end */
@@ -798,6 +804,12 @@ static const struct elf_x86_lazy_plt_layout elf_i386_lazy_ibt_plt =
sizeof (elf_i386_lazy_ibt_plt0_entry), /* plt0_entry_size */
elf_i386_lazy_ibt_plt_entry, /* plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
+ NULL, /* plt_tlsdesc_entry */
+ 0, /* plt_tlsdesc_entry_size*/
+ 0, /* plt_tlsdesc_got1_offset */
+ 0, /* plt_tlsdesc_got2_offset */
+ 0, /* plt_tlsdesc_got1_insn_end */
+ 0, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
8, /* plt0_got2_offset */
0, /* plt0_got2_insn_end */
@@ -4728,6 +4740,12 @@ static const struct elf_x86_lazy_plt_layout elf_i386_nacl_plt =
sizeof (elf_i386_nacl_plt0_entry), /* plt0_entry_size */
elf_i386_nacl_plt_entry, /* plt_entry */
NACL_PLT_ENTRY_SIZE, /* plt_entry_size */
+ NULL, /* plt_tlsdesc_entry */
+ 0, /* plt_tlsdesc_entry_size*/
+ 0, /* plt_tlsdesc_got1_offset */
+ 0, /* plt_tlsdesc_got2_offset */
+ 0, /* plt_tlsdesc_got1_insn_end */
+ 0, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
8, /* plt0_got2_offset */
0, /* plt0_got2_insn_end */
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index e5a4dbcd51..4349561f3c 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -660,6 +660,14 @@ static const bfd_byte elf_x32_non_lazy_ibt_plt_entry[LAZY_PLT_ENTRY_SIZE] =
0x66, 0x0f, 0x1f, 0x44, 0x00, 0x00 /* nopw 0x0(%rax,%rax,1) */
};
+/* The TLSDESC entry in a lazy procedure linkage table. */
+static const bfd_byte elf_x86_64_tlsdesc_plt_entry[LAZY_PLT_ENTRY_SIZE] =
+{
+ 0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */
+ 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
+ 0xff, 0x25, 16, 0, 0, 0 /* jmpq *GOT+TDG(%rip) */
+};
+
/* .eh_frame covering the lazy .plt section. */
static const bfd_byte elf_x86_64_eh_frame_lazy_plt[] =
@@ -834,6 +842,12 @@ static const struct elf_x86_lazy_plt_layout elf_x86_64_lazy_plt =
LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */
elf_x86_64_lazy_plt_entry, /* plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
+ elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */
+ LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */
+ 6, /* plt_tlsdesc_got1_offset */
+ 12, /* plt_tlsdesc_got2_offset */
+ 10, /* plt_tlsdesc_got1_insn_end */
+ 16, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
8, /* plt0_got2_offset */
12, /* plt0_got2_insn_end */
@@ -866,6 +880,12 @@ static const struct elf_x86_lazy_plt_layout elf_x86_64_lazy_bnd_plt =
LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */
elf_x86_64_lazy_bnd_plt_entry, /* plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
+ elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */
+ LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */
+ 6, /* plt_tlsdesc_got1_offset */
+ 12, /* plt_tlsdesc_got2_offset */
+ 10, /* plt_tlsdesc_got1_insn_end */
+ 16, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
1+8, /* plt0_got2_offset */
1+12, /* plt0_got2_insn_end */
@@ -898,6 +918,12 @@ static const struct elf_x86_lazy_plt_layout elf_x86_64_lazy_ibt_plt =
LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */
elf_x86_64_lazy_ibt_plt_entry, /* plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
+ elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */
+ LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */
+ 6, /* plt_tlsdesc_got1_offset */
+ 12, /* plt_tlsdesc_got2_offset */
+ 10, /* plt_tlsdesc_got1_insn_end */
+ 16, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
1+8, /* plt0_got2_offset */
1+12, /* plt0_got2_insn_end */
@@ -919,6 +945,12 @@ static const struct elf_x86_lazy_plt_layout elf_x32_lazy_ibt_plt =
LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */
elf_x32_lazy_ibt_plt_entry, /* plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
+ elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */
+ LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */
+ 6, /* plt_tlsdesc_got1_offset */
+ 12, /* plt_tlsdesc_got2_offset */
+ 10, /* plt_tlsdesc_got1_insn_end */
+ 16, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
8, /* plt0_got2_offset */
12, /* plt0_got2_insn_end */
@@ -4417,19 +4449,12 @@ elf_x86_64_finish_dynamic_sections (bfd *output_bfd,
if (htab->tlsdesc_plt)
{
- /* The TLSDESC entry in a lazy procedure linkage table. */
- static const bfd_byte tlsdesc_plt_entry[LAZY_PLT_ENTRY_SIZE] =
- {
- 0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */
- 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
- 0xff, 0x25, 16, 0, 0, 0 /* jmpq *GOT+TDG(%rip) */
- };
-
bfd_put_64 (output_bfd, (bfd_vma) 0,
htab->elf.sgot->contents + htab->tlsdesc_got);
memcpy (htab->elf.splt->contents + htab->tlsdesc_plt,
- tlsdesc_plt_entry, LAZY_PLT_ENTRY_SIZE);
+ htab->lazy_plt->plt_tlsdesc_entry,
+ htab->lazy_plt->plt_tlsdesc_entry_size);
/* Add offset for pushq GOT+8(%rip), since ENDBR64 uses 4
bytes and the instruction uses 6 bytes, subtract these
@@ -4441,10 +4466,10 @@ elf_x86_64_finish_dynamic_sections (bfd *output_bfd,
- htab->elf.splt->output_section->vma
- htab->elf.splt->output_offset
- htab->tlsdesc_plt
- - 4 - 6),
+ - htab->lazy_plt->plt_tlsdesc_got1_insn_end),
(htab->elf.splt->contents
+ htab->tlsdesc_plt
- + 4 + 2));
+ + htab->lazy_plt->plt_tlsdesc_got1_offset));
/* Add offset for indirect branch via GOT+TDG, where TDG
stands for htab->tlsdesc_got, subtracting the offset
to the end of that instruction. */
@@ -4455,9 +4480,10 @@ elf_x86_64_finish_dynamic_sections (bfd *output_bfd,
- htab->elf.splt->output_section->vma
- htab->elf.splt->output_offset
- htab->tlsdesc_plt
- - 4 - 6 - 6),
+ - htab->lazy_plt->plt_tlsdesc_got2_insn_end),
(htab->elf.splt->contents
- + htab->tlsdesc_plt + 4 + 6 + 2));
+ + htab->tlsdesc_plt
+ + htab->lazy_plt->plt_tlsdesc_got2_offset));
}
}
@@ -5246,6 +5272,12 @@ static const struct elf_x86_lazy_plt_layout elf_x86_64_nacl_plt =
NACL_PLT_ENTRY_SIZE, /* plt0_entry_size */
elf_x86_64_nacl_plt_entry, /* plt_entry */
NACL_PLT_ENTRY_SIZE, /* plt_entry_size */
+ elf_x86_64_nacl_plt0_entry, /* plt_tlsdesc_entry */
+ NACL_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */
+ 2, /* plt_tlsdesc_got1_offset */
+ 9, /* plt_tlsdesc_got2_offset */
+ 6, /* plt_tlsdesc_got1_insn_end */
+ 13, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
9, /* plt0_got2_offset */
13, /* plt0_got2_insn_end */
diff --git a/bfd/elfxx-x86.h b/bfd/elfxx-x86.h
index 8f67c23a9f..6a5609467d 100644
--- a/bfd/elfxx-x86.h
+++ b/bfd/elfxx-x86.h
@@ -285,16 +285,30 @@ struct elf_x86_link_hash_entry
struct elf_x86_lazy_plt_layout
{
- /* The first entry in an absolute lazy procedure linkage table looks
- like this. */
+ /* The first entry in a lazy procedure linkage table looks like this. */
const bfd_byte *plt0_entry;
unsigned int plt0_entry_size; /* Size of PLT0 entry. */
- /* Later entries in an absolute lazy procedure linkage table look
- like this. */
+ /* Later entries in a lazy procedure linkage table look like this. */
const bfd_byte *plt_entry;
unsigned int plt_entry_size; /* Size of each PLT entry. */
+ /* The TLSDESC entry in a lazy procedure linkage table looks like
+ this. This is for x86-64 only. */
+ const bfd_byte *plt_tlsdesc_entry;
+ unsigned int plt_tlsdesc_entry_size; /* Size of TLSDESC entry. */
+
+ /* Offsets into the TLSDESC entry that are to be replaced with
+ GOT+8 and GOT+TDG. These are for x86-64 only. */
+ unsigned int plt_tlsdesc_got1_offset;
+ unsigned int plt_tlsdesc_got2_offset;
+
+ /* Offset of the end of the PC-relative instructions containing
+ plt_tlsdesc_got1_offset and plt_tlsdesc_got2_offset. These
+ are for x86-64 only. */
+ unsigned int plt_tlsdesc_got1_insn_end;
+ unsigned int plt_tlsdesc_got2_insn_end;
+
/* Offsets into plt0_entry that are to be replaced with GOT[1] and
GOT[2]. */
unsigned int plt0_got1_offset;
@@ -336,10 +350,11 @@ struct elf_x86_lazy_plt_layout
struct elf_x86_non_lazy_plt_layout
{
- /* Entries in an absolute non-lazy procedure linkage table look like
- this. */
+ /* Entries in a non-lazy procedure linkage table look like this. */
const bfd_byte *plt_entry;
- /* Entries in a PIC non-lazy procedure linkage table look like this. */
+ /* Entries in a PIC non-lazy procedure linkage table look like this.
+ This is only used for i386 where absolute PLT and PIC PLT are
+ different. */
const bfd_byte *pic_plt_entry;
unsigned int plt_entry_size; /* Size of each PLT entry. */
@@ -358,9 +373,7 @@ struct elf_x86_non_lazy_plt_layout
struct elf_x86_plt_layout
{
- /* The first entry in a lazy procedure linkage table looks like this.
- This is only used for i386 where absolute PLT0 and PIC PLT0 are
- different. */
+ /* The first entry in a lazy procedure linkage table looks like this. */
const bfd_byte *plt0_entry;
/* Entries in a procedure linkage table look like this. */
const bfd_byte *plt_entry;
--
2.17.0