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[binutils-gdb] x86-64: Force symbol dynamic if it isn't undefined weak
- From: H.J.Lu <hjl at sourceware dot org>
- To: bfd-cvs at sourceware dot org
- Date: 24 Apr 2017 21:40:48 -0000
- Subject: [binutils-gdb] x86-64: Force symbol dynamic if it isn't undefined weak
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=9e9821ddd80c0d0b3dda54d34cc8867f256d4583
commit 9e9821ddd80c0d0b3dda54d34cc8867f256d4583
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Mon Apr 24 14:37:12 2017 -0700
x86-64: Force symbol dynamic if it isn't undefined weak
Force symbol dynamic if it isn't undefined weak. Generate relative
relocation for GOT reference against non-dynamic symbol in PIC to
avoid unnecessary dynamic symbols.
bfd/
* elf64-x86-64.c (elf_x86_64_link_hash_entry): Add
no_finish_dynamic_symbol.
(elf_x86_64_link_hash_newfunc): Set no_finish_dynamic_symbol to
0.
(elf_x86_64_allocate_dynrelocs): If a symbol isn't undefined
weak symbol, don't make it dynamic.
(elf_x86_64_relocate_section): If a symbol isn't dynamic in PIC,
set no_finish_dynamic_symbol and generate R_X86_64_RELATIVE
relocation for GOT reference.
(elf_x86_64_finish_dynamic_symbol): Abort if
no_finish_dynamic_symbol isn't 0.
ld/
* testsuite/ld-x86-64/no-plt.exp: Also check no-plt-1e.nd.
* testsuite/ld-x86-64/no-plt-1e.nd: New file.
Diff:
---
bfd/ChangeLog | 14 ++++++++
bfd/elf64-x86-64.c | 66 +++++++++++++++++++++++++------------
ld/ChangeLog | 5 +++
ld/testsuite/ld-x86-64/no-plt-1e.nd | 7 ++++
ld/testsuite/ld-x86-64/no-plt.exp | 2 +-
5 files changed, 72 insertions(+), 22 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 54e2f0d..b902a76 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,19 @@
2017-04-24 H.J. Lu <hongjiu.lu@intel.com>
+ * elf64-x86-64.c (elf_x86_64_link_hash_entry): Add
+ no_finish_dynamic_symbol.
+ (elf_x86_64_link_hash_newfunc): Set no_finish_dynamic_symbol to
+ 0.
+ (elf_x86_64_allocate_dynrelocs): If a symbol isn't undefined
+ weak symbol, don't make it dynamic.
+ (elf_x86_64_relocate_section): If a symbol isn't dynamic in PIC,
+ set no_finish_dynamic_symbol and generate R_X86_64_RELATIVE
+ relocation for GOT reference.
+ (elf_x86_64_finish_dynamic_symbol): Abort if
+ no_finish_dynamic_symbol isn't 0.
+
+2017-04-24 H.J. Lu <hongjiu.lu@intel.com>
+
PR ld/21402
* elf32-i386.c (elf_i386_allocate_dynrelocs): If a symbol isn't
undefined weak symbol, don't make it dynamic.
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 746b847..965ceb2 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -867,6 +867,9 @@ struct elf_x86_64_link_hash_entry
/* TRUE if symbol has non-GOT/non-PLT relocations in text sections. */
unsigned int has_non_got_reloc : 1;
+ /* Don't call finish_dynamic_symbol on this symbol. */
+ unsigned int no_finish_dynamic_symbol : 1;
+
/* 0: symbol isn't __tls_get_addr.
1: symbol is __tls_get_addr.
2: symbol is unknown. */
@@ -1022,6 +1025,7 @@ elf_x86_64_link_hash_newfunc (struct bfd_hash_entry *entry,
eh->has_bnd_reloc = 0;
eh->has_got_reloc = 0;
eh->has_non_got_reloc = 0;
+ eh->no_finish_dynamic_symbol = 0;
eh->tls_get_addr = 2;
eh->func_pointer_refcount = 0;
eh->plt_bnd.offset = (bfd_vma) -1;
@@ -3218,7 +3222,8 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
&& !h->forced_local
- && !resolved_to_zero)
+ && !resolved_to_zero
+ && h->root.type == bfd_link_hash_undefweak)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
@@ -3338,7 +3343,8 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
&& !h->forced_local
- && !resolved_to_zero)
+ && !resolved_to_zero
+ && h->root.type == bfd_link_hash_undefweak)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
@@ -3475,6 +3481,7 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
if (h->dynindx == -1
&& ! h->forced_local
&& ! resolved_to_zero
+ && h->root.type == bfd_link_hash_undefweak
&& ! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
@@ -4270,6 +4277,7 @@ elf_x86_64_relocate_section (bfd *output_bfd,
asection *base_got, *resolved_plt;
bfd_vma st_size;
bfd_boolean resolved_to_zero;
+ bfd_boolean relative_reloc;
r_type = ELF32_R_TYPE (rel->r_info);
if (r_type == (int) R_X86_64_GNU_VTINHERIT
@@ -4637,6 +4645,7 @@ do_ifunc_pointer:
if (htab->elf.sgot == NULL)
abort ();
+ relative_reloc = FALSE;
if (h != NULL)
{
bfd_boolean dyn;
@@ -4683,6 +4692,17 @@ do_ifunc_pointer:
/* Note that this is harmless for the GOTPLT64 case,
as -1 | 1 still is -1. */
h->got.offset |= 1;
+
+ if (h->dynindx == -1
+ && !h->forced_local
+ && h->root.type != bfd_link_hash_undefweak
+ && bfd_link_pic (info))
+ {
+ /* If this symbol isn't dynamic in PIC,
+ generate R_X86_64_RELATIVE here. */
+ eh->no_finish_dynamic_symbol = 1;
+ relative_reloc = TRUE;
+ }
}
}
else
@@ -4704,30 +4724,32 @@ do_ifunc_pointer:
{
bfd_put_64 (output_bfd, relocation,
base_got->contents + off);
+ local_got_offsets[r_symndx] |= 1;
if (bfd_link_pic (info))
- {
- asection *s;
- Elf_Internal_Rela outrel;
-
- /* We need to generate a R_X86_64_RELATIVE reloc
- for the dynamic linker. */
- s = htab->elf.srelgot;
- if (s == NULL)
- abort ();
-
- outrel.r_offset = (base_got->output_section->vma
- + base_got->output_offset
- + off);
- outrel.r_info = htab->r_info (0, R_X86_64_RELATIVE);
- outrel.r_addend = relocation;
- elf_append_rela (output_bfd, s, &outrel);
- }
-
- local_got_offsets[r_symndx] |= 1;
+ relative_reloc = TRUE;
}
}
+ if (relative_reloc)
+ {
+ asection *s;
+ Elf_Internal_Rela outrel;
+
+ /* We need to generate a R_X86_64_RELATIVE reloc
+ for the dynamic linker. */
+ s = htab->elf.srelgot;
+ if (s == NULL)
+ abort ();
+
+ outrel.r_offset = (base_got->output_section->vma
+ + base_got->output_offset
+ + off);
+ outrel.r_info = htab->r_info (0, R_X86_64_RELATIVE);
+ outrel.r_addend = relocation;
+ elf_append_rela (output_bfd, s, &outrel);
+ }
+
if (off >= (bfd_vma) -2)
abort ();
@@ -5797,6 +5819,8 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd,
: get_elf_x86_64_backend_data (output_bfd));
eh = (struct elf_x86_64_link_hash_entry *) h;
+ if (eh->no_finish_dynamic_symbol)
+ abort ();
/* We keep PLT/GOT entries without dynamic PLT/GOT relocations for
resolved undefined weak symbols in executable so that their
diff --git a/ld/ChangeLog b/ld/ChangeLog
index d40086e..ed3797e 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,5 +1,10 @@
2017-04-24 H.J. Lu <hongjiu.lu@intel.com>
+ * testsuite/ld-x86-64/no-plt.exp: Also check no-plt-1e.nd.
+ * testsuite/ld-x86-64/no-plt-1e.nd: New file.
+
+2017-04-24 H.J. Lu <hongjiu.lu@intel.com>
+
* testsuite/ld-i386/pr12570a.d: Skip for nacl targets.
* testsuite/ld-i386/pr12570b.d: Likewise.
diff --git a/ld/testsuite/ld-x86-64/no-plt-1e.nd b/ld/testsuite/ld-x86-64/no-plt-1e.nd
new file mode 100644
index 0000000..c96760c
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/no-plt-1e.nd
@@ -0,0 +1,7 @@
+#nm: -g -D
+#target: x86_64-*-*
+
+#failif
+#...
+[0-9]+ +T +func
+#...
diff --git a/ld/testsuite/ld-x86-64/no-plt.exp b/ld/testsuite/ld-x86-64/no-plt.exp
index 5b5c817..9cecd03 100644
--- a/ld/testsuite/ld-x86-64/no-plt.exp
+++ b/ld/testsuite/ld-x86-64/no-plt.exp
@@ -111,7 +111,7 @@ run_cc_link_tests [list \
tmpdir/no-plt-func1.o tmpdir/no-plt-extern1.o" \
"" \
{dummy.s} \
- {{readelf -Wr no-plt-1e.rd} {objdump -dwrj.text no-plt-1e.dd}} \
+ {{readelf -Wr no-plt-1e.rd} {nm -gD no-plt-1e.nd} {objdump -dwrj.text no-plt-1e.dd}} \
"no-plt-1e" \
] \
[list \