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authorJakub Jelinek <jakub@redhat.com>2011-06-20 13:18:52 +0000
committerJakub Jelinek <jakub@redhat.com>2011-06-20 13:18:52 +0000
commite41b3a13792f24506443962d82207466bf9b9e39 (patch)
tree583e921340ccca5bb5bf50e7833d2e579f575b80 /bfd/elf64-x86-64.c
parentb47d265edba0a7f45ffd3a9952806e124364368b (diff)
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PR ld/12570
include/ * bfdlink.h (struct bfd_link_info): Add no_ld_generated_unwind_info option. ld/ * emultempl/elf32.em (OPTION_LD_GENERATED_UNWIND_INFO, OPTION_NO_LD_GENERATED_UNWIND_INFO): Define. (gld${EMULATION_NAME}_handle_option): Handle --ld-generated-unwind-info and --no-ld-generated-unwind-info. * ld.texinfo (--ld-generated-unwind-info, --no-ld-generated-unwind-info): Document. bfd/ * elf-eh-frame.c (_bfd_elf_parse_eh_frame): Allow no relocations at all for linker created .eh_frame sections. (_bfd_elf_discard_section_eh_frame): Handle linker created .eh_frame sections with no relocations. * elf64-x86-64.c: Include dwarf2.h. (elf_x86_64_eh_frame_plt): New variable. (PLT_CIE_LENGTH, PLT_FDE_LENGTH, PLT_FDE_START_OFFSET, PLT_FDE_LEN_OFFSET): Define. (struct elf_x86_64_link_hash_table): Add plt_eh_frame field. (elf_x86_64_create_dynamic_sections): Create and fill in .eh_frame section for .plt section. (elf_x86_64_size_dynamic_sections): Write .plt section size into .eh_frame FDE covering .plt section. (elf_x86_64_finish_dynamic_sections): Write .plt section start into .eh_frame FDE covering .plt section. Call _bfd_elf_write_section_eh_frame on htab->plt_eh_frame section. (elf_backend_plt_alignment): Define to 4. * elf32-i386.c: Include dwarf2.h. (elf_i386_eh_frame_plt): New variable. (PLT_CIE_LENGTH, PLT_FDE_LENGTH, PLT_FDE_START_OFFSET, PLT_FDE_LEN_OFFSET): Define. (struct elf_i386_link_hash_table): Add plt_eh_frame field. (elf_i386_create_dynamic_sections): Create and fill in .eh_frame section for .plt section. (elf_i386_size_dynamic_sections): Write .plt section size into .eh_frame FDE covering .plt section. (elf_i386_finish_dynamic_sections): Write .plt section start into .eh_frame FDE covering .plt section. Call _bfd_elf_write_section_eh_frame on htab->plt_eh_frame section. (elf_backend_plt_alignment): Define to 4. ld/testsuite/ * ld-x86-64/x86-64.exp: Link some testcases with --no-ld-generated-unwind-info. * ld-x86-64/tlsbin.rd: Add --no-ld-generated-unwind-info to ld comment. * ld-x86-64/tlsdesc.dd: Likewise. * ld-x86-64/tlspic.dd: Likewise. * ld-x86-64/tlsdesc.sd: Likewise. * ld-x86-64/tlspic.rd: Likewise. * ld-x86-64/tlsbindesc.rd: Likewise. * ld-x86-64/tlsbindesc.sd: Likewise. * ld-x86-64/tlsbin.td: Likewise. * ld-x86-64/tlsdesc.pd: Likewise. * ld-x86-64/tlsdesc.td: Likewise. * ld-x86-64/tlsbindesc.dd: Likewise. * ld-x86-64/tlsbin.dd: Likewise. * ld-x86-64/tlsgdesc.rd: Likewise. * ld-x86-64/tlspic.sd: Likewise. * ld-x86-64/tlsbindesc.td: Likewise. * ld-x86-64/tlspic.td: Likewise. * ld-x86-64/tlsbin.sd: Likewise. * ld-x86-64/ilp32-4.d: Likewise. * ld-x86-64/tlsgdesc.dd: Add --no-ld-generated-unwind-info to ld comment. Adjust. * ld-x86-64/tlsdesc.rd: Likewise. * ld-x86-64/tlsgd6.dd: Adjust. * ld-x86-64/tlsgd5.dd: Likewise. * ld-i386/i386.exp: Link some testcases with --no-ld-generated-unwind-info. * ld-i386/tlsbin.rd: Add --no-ld-generated-unwind-info to ld comment.. * ld-i386/tlsdesc.dd: Likewise. * ld-i386/tlspic.dd: Likewise. * ld-i386/tlsdesc.sd: Likewise. * ld-i386/tlsgdesc.dd: Likewise. * ld-i386/tlsnopic.sd: Likewise. * ld-i386/tlspic.rd: Likewise. * ld-i386/tlsdesc.rd: Likewise. * ld-i386/tlsbindesc.rd: Likewise. * ld-i386/tlsbindesc.sd: Likewise. * ld-i386/tlsbin.td: Likewise. * ld-i386/tlsdesc.td: Likewise. * ld-i386/tlsnopic.dd: Likewise. * ld-i386/tlsbindesc.dd: Likewise. * ld-i386/tlsbin.dd: Likewise. * ld-i386/tlsgdesc.rd: Likewise. * ld-i386/tlspic.sd: Likewise. * ld-i386/tlsnopic.rd: Likewise. * ld-i386/tlsbindesc.td: Likewise. * ld-i386/tlspic.td: Likewise. * ld-i386/tlsbin.sd: Likewise.
Diffstat (limited to 'bfd/elf64-x86-64.c')
-rw-r--r--bfd/elf64-x86-64.c94
1 files changed, 94 insertions, 0 deletions
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index a929797..37349f9 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -29,6 +29,7 @@
#include "bfd_stdint.h"
#include "objalloc.h"
#include "hashtab.h"
+#include "dwarf2.h"
#include "elf/x86-64.h"
@@ -528,6 +529,45 @@ static const bfd_byte elf_x86_64_plt_entry[PLT_ENTRY_SIZE] =
0, 0, 0, 0 /* replaced with offset to start of .plt0. */
};
+/* .eh_frame covering the .plt section. */
+
+static const bfd_byte elf_x86_64_eh_frame_plt[] =
+{
+#define PLT_CIE_LENGTH 20
+#define PLT_FDE_LENGTH 36
+#define PLT_FDE_START_OFFSET 4 + PLT_CIE_LENGTH + 8
+#define PLT_FDE_LEN_OFFSET 4 + PLT_CIE_LENGTH + 12
+ PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */
+ 0, 0, 0, 0, /* CIE ID */
+ 1, /* CIE version */
+ 'z', 'R', 0, /* Augmentation string */
+ 1, /* Code alignment factor */
+ 0x78, /* Data alignment factor */
+ 16, /* Return address column */
+ 1, /* Augmentation size */
+ DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */
+ DW_CFA_def_cfa, 7, 8, /* DW_CFA_def_cfa: r7 (rsp) ofs 8 */
+ DW_CFA_offset + 16, 1, /* DW_CFA_offset: r16 (rip) at cfa-8 */
+ DW_CFA_nop, DW_CFA_nop,
+
+ PLT_FDE_LENGTH, 0, 0, 0, /* FDE length */
+ PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */
+ 0, 0, 0, 0, /* R_X86_64_PC32 .plt goes here */
+ 0, 0, 0, 0, /* .plt size goes here */
+ 0, /* Augmentation size */
+ DW_CFA_def_cfa_offset, 16, /* DW_CFA_def_cfa_offset: 16 */
+ DW_CFA_advance_loc + 6, /* DW_CFA_advance_loc: 6 to __PLT__+6 */
+ DW_CFA_def_cfa_offset, 24, /* DW_CFA_def_cfa_offset: 24 */
+ DW_CFA_advance_loc + 10, /* DW_CFA_advance_loc: 10 to __PLT__+16 */
+ DW_CFA_def_cfa_expression, /* DW_CFA_def_cfa_expression */
+ 11, /* Block length */
+ DW_OP_breg7, 8, /* DW_OP_breg7 (rsp): 8 */
+ DW_OP_breg16, 0, /* DW_OP_breg16 (rip): 0 */
+ DW_OP_lit15, DW_OP_and, DW_OP_lit11, DW_OP_ge,
+ DW_OP_lit3, DW_OP_shl, DW_OP_plus,
+ DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop
+};
+
/* x86-64 ELF linker hash entry. */
struct elf_x86_64_link_hash_entry
@@ -601,6 +641,7 @@ struct elf_x86_64_link_hash_table
/* Short-cuts to get to dynamic linker sections. */
asection *sdynbss;
asection *srelbss;
+ asection *plt_eh_frame;
union
{
@@ -847,6 +888,24 @@ elf_x86_64_create_dynamic_sections (bfd *dynobj,
|| (!info->shared && !htab->srelbss))
abort ();
+ if (!info->no_ld_generated_unwind_info
+ && bfd_get_section_by_name (dynobj, ".eh_frame") == NULL
+ && htab->elf.splt != NULL)
+ {
+ flagword flags = get_elf_backend_data (dynobj)->dynamic_sec_flags;
+ htab->plt_eh_frame
+ = bfd_make_section_with_flags (dynobj, ".eh_frame",
+ flags | SEC_READONLY);
+ if (htab->plt_eh_frame == NULL
+ || !bfd_set_section_alignment (dynobj, htab->plt_eh_frame, 3))
+ return FALSE;
+
+ htab->plt_eh_frame->size = sizeof (elf_x86_64_eh_frame_plt);
+ htab->plt_eh_frame->contents
+ = bfd_alloc (dynobj, htab->plt_eh_frame->size);
+ memcpy (htab->plt_eh_frame->contents, elf_x86_64_eh_frame_plt,
+ sizeof (elf_x86_64_eh_frame_plt));
+ }
return TRUE;
}
@@ -2721,6 +2780,13 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd,
return FALSE;
}
+ if (htab->plt_eh_frame != NULL
+ && htab->elf.splt != NULL
+ && htab->elf.splt->size != 0
+ && (htab->elf.splt->flags & SEC_EXCLUDE) == 0)
+ bfd_put_32 (dynobj, htab->elf.splt->size,
+ htab->plt_eh_frame->contents + PLT_FDE_LEN_OFFSET);
+
if (htab->elf.dynamic_sections_created)
{
/* Add some entries to the .dynamic section. We fill in the
@@ -4521,6 +4587,33 @@ elf_x86_64_finish_dynamic_sections (bfd *output_bfd,
GOT_ENTRY_SIZE;
}
+ /* Adjust .eh_frame for .plt section. */
+ if (htab->plt_eh_frame != NULL)
+ {
+ if (htab->elf.splt != NULL
+ && htab->elf.splt->size != 0
+ && (htab->elf.splt->flags & SEC_EXCLUDE) == 0
+ && htab->elf.splt->output_section != NULL
+ && htab->plt_eh_frame->output_section != NULL)
+ {
+ bfd_vma plt_start = htab->elf.splt->output_section->vma;
+ bfd_vma eh_frame_start = htab->plt_eh_frame->output_section->vma
+ + htab->plt_eh_frame->output_offset
+ + PLT_FDE_START_OFFSET;
+ bfd_put_signed_32 (dynobj, plt_start - eh_frame_start,
+ htab->plt_eh_frame->contents
+ + PLT_FDE_START_OFFSET);
+ }
+ if (htab->plt_eh_frame->sec_info_type
+ == ELF_INFO_TYPE_EH_FRAME)
+ {
+ if (! _bfd_elf_write_section_eh_frame (output_bfd, info,
+ htab->plt_eh_frame,
+ htab->plt_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;
@@ -4787,6 +4880,7 @@ static const struct bfd_elf_special_section
#define elf_backend_want_plt_sym 0
#define elf_backend_got_header_size (GOT_ENTRY_SIZE*3)
#define elf_backend_rela_normal 1
+#define elf_backend_plt_alignment 4
#define elf_info_to_howto elf_x86_64_info_to_howto