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PATCH: PR ld/13302: IRELATIVE relocation should come last
- From: "H.J. Lu" <hongjiu dot lu at intel dot com>
- To: binutils at sourceware dot org
- Date: Fri, 21 Oct 2011 08:17:23 -0700
- Subject: PATCH: PR ld/13302: IRELATIVE relocation should come last
- Reply-to: "H.J. Lu" <hjl dot tools at gmail dot com>
Hi,
I checked in this patch to put IRELATIVE relocations after JUMP_SLOT.
H.J.
---
bfd/
2011-10-20 H.J. Lu <hongjiu.lu@intel.com>
PR ld/13302
* elf32-i386.c (elf_i386_link_hash_table): Add next_jump_slot_index
and next_irelative_index.
(elf_i386_link_hash_table_create): Initialize next_jump_slot_index
and next_irelative_index.
(elf_i386_allocate_dynrelocs): Increment reloc_count instead of
next_tls_desc_index.
(elf_i386_size_dynamic_sections): Set next_tls_desc_index and
next_irelative_index from reloc_count.
(elf_i386_finish_dynamic_symbol): Put R_386_IRELATIVE after
R_386_JUMP_SLOT.
* elf64-x86-64.c (elf_x86_64_link_hash_table): Add
next_jump_slot_index and next_irelative_index.
(elf_x86_64_link_hash_table_create): Initialize
next_jump_slot_index and next_irelative_index.
(elf_x86_64_size_dynamic_sections): Set next_irelative_index
from reloc_count.
(elf_x86_64_finish_dynamic_symbol): Put R_X86_64_IRELATIVE after
R_X86_64_JUMP_SLOT.
ld/testsuite/
2011-10-20 H.J. Lu <hongjiu.lu@intel.com>
PR ld/13302
* ld-ifunc/ifunc-16-i386.d: New.
* ld-ifunc/ifunc-16-x86-64.d: Likewise.
* ld-ifunc/ifunc-16-x86.s: Likewise.
diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index 7ef1fc1..c3156bd 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -806,6 +806,12 @@ struct elf_i386_link_hash_table
/* The index of the next unused R_386_TLS_DESC slot in .rel.plt. */
bfd_vma next_tls_desc_index;
+
+ /* The index of the next unused R_386_JUMP_SLOT slot in .rel.plt. */
+ bfd_vma next_jump_slot_index;
+
+ /* The index of the next unused R_386_IRELATIVE slot in .rel.plt. */
+ bfd_vma next_irelative_index;
};
/* Get the i386 ELF linker hash table from a link_info structure. */
@@ -946,6 +952,8 @@ elf_i386_link_hash_table_create (bfd *abfd)
ret->sym_cache.abfd = NULL;
ret->srelplt2 = NULL;
ret->tls_module_base = NULL;
+ ret->next_jump_slot_index = 0;
+ ret->next_irelative_index = 0;
ret->loc_hash_table = htab_try_create (1024,
elf_i386_local_htab_hash,
@@ -2275,7 +2283,7 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
/* We also need to make an entry in the .rel.plt section. */
htab->elf.srelplt->size += sizeof (Elf32_External_Rel);
- htab->next_tls_desc_index++;
+ htab->elf.srelplt->reloc_count++;
if (get_elf_i386_backend_data (info->output_bfd)->is_vxworks
&& !info->shared)
@@ -2700,9 +2708,19 @@ elf_i386_size_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info)
incremented. However, when we reserve space for TLS descriptors,
it's not incremented, so in order to compute the space reserved
for them, it suffices to multiply the reloc count by the jump
- slot size. */
+ slot size.
+
+ PR ld/13302: We start next_irelative_index at the end of .rela.plt
+ so that R_386_IRELATIVE entries come last. */
if (htab->elf.srelplt)
- htab->sgotplt_jump_table_size = htab->next_tls_desc_index * 4;
+ {
+ htab->next_tls_desc_index = htab->elf.srelplt->reloc_count;
+ htab->sgotplt_jump_table_size = htab->next_tls_desc_index * 4;
+ htab->next_irelative_index = htab->elf.srelplt->reloc_count - 1;
+ }
+ else if (htab->elf.irelplt)
+ htab->next_irelative_index = htab->elf.irelplt->reloc_count - 1;
+
if (htab->elf.sgotplt)
{
@@ -4364,13 +4382,13 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd,
if (plt == htab->elf.splt)
{
- plt_index = h->plt.offset / plt_entry_size - 1;
- got_offset = (plt_index + 3) * 4;
+ got_offset = h->plt.offset / plt_entry_size - 1;
+ got_offset = (got_offset + 3) * 4;
}
else
{
- plt_index = h->plt.offset / plt_entry_size;
- got_offset = plt_index * 4;
+ got_offset = h->plt.offset / plt_entry_size;
+ got_offset = got_offset * 4;
}
/* Fill in the entry in the procedure linkage table. */
@@ -4431,18 +4449,6 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd,
+ abed->plt->plt_got_offset);
}
- /* Don't fill PLT entry for static executables. */
- if (plt == htab->elf.splt)
- {
- bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rel),
- plt->contents + h->plt.offset
- + abed->plt->plt_reloc_offset);
- bfd_put_32 (output_bfd, - (h->plt.offset
- + abed->plt->plt_plt_offset + 4),
- plt->contents + h->plt.offset
- + abed->plt->plt_plt_offset);
- }
-
/* Fill in the entry in the global offset table. */
bfd_put_32 (output_bfd,
(plt->output_section->vma
@@ -4470,12 +4476,29 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd,
+ h->root.u.def.section->output_offset),
gotplt->contents + got_offset);
rel.r_info = ELF32_R_INFO (0, R_386_IRELATIVE);
+ /* R_386_IRELATIVE comes last. */
+ plt_index = htab->next_irelative_index--;
}
else
- rel.r_info = ELF32_R_INFO (h->dynindx, R_386_JUMP_SLOT);
+ {
+ rel.r_info = ELF32_R_INFO (h->dynindx, R_386_JUMP_SLOT);
+ plt_index = htab->next_jump_slot_index++;
+ }
loc = relplt->contents + plt_index * sizeof (Elf32_External_Rel);
bfd_elf32_swap_reloc_out (output_bfd, &rel, loc);
+ /* Don't fill PLT entry for static executables. */
+ if (plt == htab->elf.splt)
+ {
+ bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rel),
+ plt->contents + h->plt.offset
+ + abed->plt->plt_reloc_offset);
+ bfd_put_32 (output_bfd, - (h->plt.offset
+ + abed->plt->plt_plt_offset + 4),
+ plt->contents + h->plt.offset
+ + abed->plt->plt_plt_offset);
+ }
+
if (!h->def_regular)
{
/* Mark the symbol as undefined, rather than as defined in
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index e4c3946..a850ce7 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -698,6 +698,11 @@ struct elf_x86_64_link_hash_table
/* The offset into sgot of the GOT entry used by the PLT entry
above. */
bfd_vma tlsdesc_got;
+
+ /* The index of the next R_X86_64_JUMP_SLOT entry in .rela.plt. */
+ bfd_vma next_jump_slot_index;
+ /* The index of the next R_X86_64_IRELATIVE entry in .rela.plt. */
+ bfd_vma next_irelative_index;
};
/* Get the x86-64 ELF linker hash table from a link_info structure. */
@@ -839,6 +844,8 @@ elf_x86_64_link_hash_table_create (bfd *abfd)
ret->tls_ld_got.refcount = 0;
ret->sgotplt_jump_table_size = 0;
ret->tls_module_base = NULL;
+ ret->next_jump_slot_index = 0;
+ ret->next_irelative_index = 0;
if (ABI_64_P (abfd))
{
@@ -2667,10 +2674,18 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd,
incremented. However, when we reserve space for TLS descriptors,
it's not incremented, so in order to compute the space reserved
for them, it suffices to multiply the reloc count by the jump
- slot size. */
+ slot size.
+
+ PR ld/13302: We start next_irelative_index at the end of .rela.plt
+ so that R_X86_64_IRELATIVE entries come last. */
if (htab->elf.srelplt)
- htab->sgotplt_jump_table_size
- = elf_x86_64_compute_jump_table_size (htab);
+ {
+ htab->sgotplt_jump_table_size
+ = elf_x86_64_compute_jump_table_size (htab);
+ htab->next_irelative_index = htab->elf.srelplt->reloc_count - 1;
+ }
+ else if (htab->elf.irelplt)
+ htab->next_irelative_index = htab->elf.irelplt->reloc_count - 1;
if (htab->tlsdesc_plt)
{
@@ -4205,13 +4220,13 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd,
if (plt == htab->elf.splt)
{
- plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1;
- got_offset = (plt_index + 3) * GOT_ENTRY_SIZE;
+ got_offset = h->plt.offset / PLT_ENTRY_SIZE - 1;
+ got_offset = (got_offset + 3) * GOT_ENTRY_SIZE;
}
else
{
- plt_index = h->plt.offset / PLT_ENTRY_SIZE;
- got_offset = plt_index * GOT_ENTRY_SIZE;
+ got_offset = h->plt.offset / PLT_ENTRY_SIZE;
+ got_offset = got_offset * GOT_ENTRY_SIZE;
}
/* Fill in the entry in the procedure linkage table. */
@@ -4233,17 +4248,6 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd,
- 6),
plt->contents + h->plt.offset + 2);
- /* Don't fill PLT entry for static executables. */
- if (plt == htab->elf.splt)
- {
- /* Put relocation index. */
- bfd_put_32 (output_bfd, plt_index,
- plt->contents + h->plt.offset + 7);
- /* Put offset for jmp .PLT0. */
- bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE),
- plt->contents + h->plt.offset + 12);
- }
-
/* Fill in the entry in the global offset table, initially this
points to the pushq instruction in the PLT which is at offset 6. */
bfd_put_64 (output_bfd, (plt->output_section->vma
@@ -4267,11 +4271,25 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd,
rela.r_addend = (h->root.u.def.value
+ h->root.u.def.section->output_section->vma
+ h->root.u.def.section->output_offset);
+ /* R_X86_64_IRELATIVE comes last. */
+ plt_index = htab->next_irelative_index--;
}
else
{
rela.r_info = htab->r_info (h->dynindx, R_X86_64_JUMP_SLOT);
rela.r_addend = 0;
+ plt_index = htab->next_jump_slot_index++;
+ }
+
+ /* Don't fill PLT entry for static executables. */
+ if (plt == htab->elf.splt)
+ {
+ /* Put relocation index. */
+ bfd_put_32 (output_bfd, plt_index,
+ plt->contents + h->plt.offset + 7);
+ /* Put offset for jmp .PLT0. */
+ bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE),
+ plt->contents + h->plt.offset + 12);
}
bed = get_elf_backend_data (output_bfd);
diff --git a/ld/testsuite/ld-ifunc/ifunc-16-i386.d b/ld/testsuite/ld-ifunc/ifunc-16-i386.d
new file mode 100644
index 0000000..8ae3d0a
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-16-i386.d
@@ -0,0 +1,10 @@
+#source: ifunc-16-x86.s
+#ld: -shared -m elf_i386
+#as: --32
+#readelf: -r --wide
+#target: x86_64-*-* i?86-*-*
+
+Relocation section '.rel.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_JUMP_SLOT[ ]+0+[ ]+ifunc
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
diff --git a/ld/testsuite/ld-ifunc/ifunc-16-x86-64.d b/ld/testsuite/ld-ifunc/ifunc-16-x86-64.d
new file mode 100644
index 0000000..d69626d
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-16-x86-64.d
@@ -0,0 +1,10 @@
+#source: ifunc-16-x86.s
+#as: --64
+#ld: -shared -melf_x86_64
+#readelf: -r --wide
+#target: x86_64-*-*
+
+Relocation section '.rela.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_JUMP_SLOT[ ]+0+[ ]+ifunc \+ 0
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
diff --git a/ld/testsuite/ld-ifunc/ifunc-16-x86.s b/ld/testsuite/ld-ifunc/ifunc-16-x86.s
new file mode 100644
index 0000000..fb38253
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-16-x86.s
@@ -0,0 +1,17 @@
+ .text
+ .globl fct
+ .type fct, @gnu_indirect_function
+ .set fct,resolve
+ .hidden int_fct
+ .globl int_fct
+ .set int_fct,fct
+ .p2align 4,,15
+ .type resolve, @function
+resolve:
+ call ifunc@PLT
+ .size resolve, .-resolve
+ .globl g
+ .type g, @function
+g:
+ jmp int_fct@PLT
+ .size g, .-g