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Re: [committed, PATCH] x86: Add GENERATE_RELATIVE_RELOC_P
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: binutils at sourceware dot org
- Date: Fri, 6 Oct 2017 00:33:44 -0700
- Subject: Re: [committed, PATCH] x86: Add GENERATE_RELATIVE_RELOC_P
- Authentication-results: sourceware.org; auth=none
- References: <20171006073219.GA25790@gmail.com>
On Fri, Oct 06, 2017 at 12:32:19AM -0700, H.J. Lu wrote:
> Add GENERATE_RELATIVE_RELOC_P which returns TRUE if dynamic relative
> relocation should be generated.
>
> * elfxx-x86.h (GENERATE_RELATIVE_RELOC_P): New.
> * elf32-i386.c (elf_i386_relocate_section): Use it.
> * elf64-x86-64.c (elf_x86_64_relocate_section): Likewise.
Here is the actual change.
H.J.
---
Add GENERATE_RELATIVE_RELOC_P which returns TRUE if dynamic relative
relocation should be generated.
* elfxx-x86.h (GENERATE_RELATIVE_RELOC_P): New.
* elf32-i386.c (elf_i386_relocate_section): Use it.
* elf64-x86-64.c (elf_x86_64_relocate_section): Likewise.
---
bfd/ChangeLog | 6 ++++++
bfd/elf32-i386.c | 5 +----
bfd/elf64-x86-64.c | 5 +----
bfd/elfxx-x86.h | 12 ++++++++++++
4 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index b43cdfac9b..afd14b8740 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,11 @@
2017-10-06 H.J. Lu <hongjiu.lu@intel.com>
+ * elfxx-x86.h (GENERATE_RELATIVE_RELOC_P): New.
+ * elf32-i386.c (elf_i386_relocate_section): Use it.
+ * elf64-x86-64.c (elf_x86_64_relocate_section): Likewise.
+
+2017-10-06 H.J. Lu <hongjiu.lu@intel.com>
+
* elfxx-x86.h (RESOLVED_LOCALLY_P): New.
* elf32-i386.c (elf_i386_relocate_section): Use it.
* elf64-x86-64.c (elf_x86_64_relocate_section): Likewise.
diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index 25d349ce00..198732cec3 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -2531,10 +2531,7 @@ r_386_got32:
htab->elf.sgot->contents + off);
h->got.offset |= 1;
- if (h->dynindx == -1
- && !h->forced_local
- && h->root.type != bfd_link_hash_undefweak
- && bfd_link_pic (info))
+ if (GENERATE_RELATIVE_RELOC_P (info, h))
{
/* PR ld/21402: If this symbol isn't dynamic
in PIC, generate R_386_RELATIVE here. */
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 5a9e3fd614..d443551b44 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -2797,10 +2797,7 @@ do_ifunc_pointer:
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 (GENERATE_RELATIVE_RELOC_P (info, h))
{
/* If this symbol isn't dynamic in PIC,
generate R_X86_64_RELATIVE here. */
diff --git a/bfd/elfxx-x86.h b/bfd/elfxx-x86.h
index 317c86ea75..02a388a368 100644
--- a/bfd/elfxx-x86.h
+++ b/bfd/elfxx-x86.h
@@ -124,6 +124,18 @@
|| (ELF_ST_VISIBILITY ((H)->other) \
&& (H)->root.type == bfd_link_hash_undefweak))
+/* TRUE if relative relocation should be generated. GOT reference to
+ global symbol in PIC will lead to dynamic symbol. It becomes a
+ problem when "time" or "times" is defined as a variable in an
+ executable, clashing with functions of the same name in libc. If a
+ symbol isn't undefined weak symbol, don't make it dynamic in PIC and
+ generate relative relocation. */
+#define GENERATE_RELATIVE_RELOC_P(INFO, H) \
+ ((H)->dynindx == -1 \
+ && !(H)->forced_local \
+ && (H)->root.type != bfd_link_hash_undefweak \
+ && bfd_link_pic (INFO))
+
/* TRUE if TLS IE->LE transition is OK. */
#define TLS_TRANSITION_IE_TO_LE_P(INFO, H, TLS_TYPE) \
(bfd_link_executable (INFO) \
--
2.13.6