From 44c4ea11d335f8d5691e9ea5c38c3187ab568467 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Sun, 14 Jun 2009 22:13:30 +0000
Subject: bfd/
2009-06-14 H.J. Lu <hongjiu.lu@intel.com>
PR ld/10270
* elf32-i386.c (elf_i386_allocate_dynrelocs): Disallow
dynamic IFUNC pointer in non-shared object. Use .got.plt
for IFUNC definition in PIE.
(elf_i386_allocate_dynrelocs): Resolve IFUNC definition in
PIE locally.
* elf64-x86-64.c (elf64_x86_64_allocate_dynrelocs): Disallow
dynamic IFUNC pointer in non-shared object. Use .got.plt
for IFUNC definition in PIE.
(elf64_x86_64_relocate_section): Resolve IFUNC definition in
PIE locally.
ld/testsuite/
2009-06-14 H.J. Lu <hongjiu.lu@intel.com>
PR ld/10270
* ld-ifunc/ifunc-9-x86.d: New.
* ld-ifunc/ifunc-9-x86.s: Likewise.
---
bfd/elf64-x86-64.c | 30 +++++++++++++++++++++++++++---
1 file changed, 27 insertions(+), 3 deletions(-)
(limited to 'bfd/elf64-x86-64.c')
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 27b1cbd..3767a86 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -1982,6 +1982,27 @@ elf64_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
{
asection *plt, *gotplt, *relplt;
+ /* When a shared library references a STT_GNU_IFUNC symbol
+ defined in executable. the .got.plt slot in the shared library
+ will contain address of the .plt slot in the binary and only
+ its .got.plt will contain the resolved function that should be
+ called. Pointer equality won't work correctly. PIE should
+ be used if pointer equality is required here. */
+ if (!info->shared
+ && (h->dynindx != -1
+ || info->export_dynamic)
+ && h->pointer_equality_needed)
+ {
+ info->callbacks->einfo
+ (_("%F%P: dynamic STT_GNU_IFUNC symbool `%s' with pointer "
+ "equality in `%B' can not be used when making an "
+ "executable; recompile with -fPIE and relink with -pie\n"),
+ h->root.root.string,
+ h->root.u.def.section->owner);
+ bfd_set_error (bfd_error_bad_value);
+ return FALSE;
+ }
+
/* Return and discard space for dynamic relocations against it if
it is never referenced in a non-shared object. */
if (!h->ref_regular)
@@ -2049,8 +2070,9 @@ elf64_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
not dynamic.
2. Use .got.plt in a non-shared object if pointer equality
isn't needed.
- 3. Use .got.plt if .got isn't used.
- 4. Otherwise use .got so that it can be shared among different
+ 3. Use .got.plt in PIE.
+ 4. Use .got.plt if .got isn't used.
+ 5. Otherwise use .got so that it can be shared among different
objects at run-time.
We only need to relocate .got entry in shared object. */
if ((info->shared
@@ -2058,6 +2080,7 @@ elf64_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
|| h->forced_local))
|| (!info->shared
&& !h->pointer_equality_needed)
+ || (info->executable && info->shared)
|| htab->sgot == NULL)
{
/* Use .got.plt. */
@@ -2914,7 +2937,8 @@ elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
+ input_section->output_offset);
if (h->dynindx == -1
- || h->forced_local)
+ || h->forced_local
+ || info->executable)
{
/* This symbol is resolved locally. */
outrel.r_info = ELF64_R_INFO (0, R_X86_64_IRELATIVE);
--
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