Check run-time R_X86_64_32 relocation overflow

Since elf_x86_64_check_relocs is called after opening all input files,
we can detect dynamic R_X86_64_32 relocation overflow there.

bfd/

	PR ld/19969
	* elf64-x86-64.c (check_relocs_failed): New.
	(elf_x86_64_need_pic): Moved before elf_x86_64_check_relocs.
	Support relocation agaist local symbol.  Set check_relocs_failed.
	(elf_x86_64_check_relocs): Use elf_x86_64_need_pic.  Check
	R_X86_64_32 relocation overflow.
	(elf_x86_64_relocate_section): Skip if check_relocs failed.
	Update one elf_x86_64_need_pic and remove one elf_x86_64_need_pic.

ld/

	PR ld/19969
	* testsuite/ld-x86-64/pr19969.d: New file.
	* testsuite/ld-x86-64/pr19969a.S: Likewise.
	* testsuite/ld-x86-64/pr19969b.S: Likewise.
	* testsuite/ld-x86-64/x86-64.exp: Run pr19969 tests.
This commit is contained in:
H.J. Lu 2016-04-20 11:10:21 -07:00
parent 6c739336e5
commit 338c190a92
7 changed files with 118 additions and 74 deletions

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@ -1,3 +1,14 @@
2016-04-20 H.J. Lu <hongjiu.lu@intel.com>
PR ld/19969
* elf64-x86-64.c (check_relocs_failed): New.
(elf_x86_64_need_pic): Moved before elf_x86_64_check_relocs.
Support relocation agaist local symbol. Set check_relocs_failed.
(elf_x86_64_check_relocs): Use elf_x86_64_need_pic. Check
R_X86_64_32 relocation overflow.
(elf_x86_64_relocate_section): Skip if check_relocs failed.
Update one elf_x86_64_need_pic and remove one elf_x86_64_need_pic.
2016-04-20 H.J. Lu <hongjiu.lu@intel.com>
* elf32-i386.c (elf_i386_check_relocs): Call

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@ -1587,7 +1587,57 @@ elf_x86_64_tls_transition (struct bfd_link_info *info, bfd *abfd,
/* Rename some of the generic section flags to better document how they
are used here. */
#define need_convert_load sec_flg0
#define need_convert_load sec_flg0
#define check_relocs_failed sec_flg1
static bfd_boolean
elf_x86_64_need_pic (bfd *input_bfd, asection *sec,
struct elf_link_hash_entry *h,
Elf_Internal_Shdr *symtab_hdr,
Elf_Internal_Sym *isym,
reloc_howto_type *howto)
{
const char *v = "";
const char *und = "";
const char *pic = "";
const char *name;
if (h)
{
name = h->root.root.string;
switch (ELF_ST_VISIBILITY (h->other))
{
case STV_HIDDEN:
v = _("hidden symbol ");
break;
case STV_INTERNAL:
v = _("internal symbol ");
break;
case STV_PROTECTED:
v = _("protected symbol ");
break;
default:
v = _("symbol ");
pic = _("; recompile with -fPIC");
break;
}
if (!h->def_regular && !h->def_dynamic)
und = _("undefined ");
}
else
{
name = bfd_elf_sym_name (input_bfd, symtab_hdr, isym, NULL);
pic = _("; recompile with -fPIC");
}
(*_bfd_error_handler) (_("%B: relocation %s against %s%s`%s' can "
"not be used when making a shared object%s"),
input_bfd, howto->name, und, v, name, pic);
bfd_set_error (bfd_error_bad_value);
sec->check_relocs_failed = 1;
return FALSE;
}
/* Look through the relocs for a section during the first phase, and
calculate needed space in the global offset table, procedure
@ -1802,19 +1852,8 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
case R_X86_64_TPOFF32:
if (!bfd_link_executable (info) && ABI_64_P (abfd))
{
if (h)
name = h->root.root.string;
else
name = bfd_elf_sym_name (abfd, symtab_hdr, isym,
NULL);
(*_bfd_error_handler)
(_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
abfd,
x86_64_elf_howto_table[r_type].name, name);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
return elf_x86_64_need_pic (abfd, sec, h, symtab_hdr, isym,
&x86_64_elf_howto_table[r_type]);
if (eh != NULL)
eh->has_got_reloc = 1;
break;
@ -1973,26 +2012,20 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
case R_X86_64_8:
case R_X86_64_16:
case R_X86_64_32S:
/* Let's help debug shared library creation. These relocs
cannot be used in shared libs. Don't error out for
/* Check relocation overflow as these relocs may lead to
run-time relocation overflow. Don't error out for
sections we don't care about, such as debug sections or
non-constant sections, or when relocation overflow check
is disabled. */
when relocation overflow check is disabled. */
if (!info->no_reloc_overflow_check
&& bfd_link_pic (info)
&& (sec->flags & SEC_ALLOC) != 0
&& (sec->flags & SEC_READONLY) != 0)
{
if (h)
name = h->root.root.string;
else
name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL);
(*_bfd_error_handler)
(_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
abfd, x86_64_elf_howto_table[r_type].name, name);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
&& (bfd_link_pic (info)
|| (bfd_link_executable (info)
&& h != NULL
&& !h->def_regular
&& h->def_dynamic
&& (sec->flags & SEC_READONLY) == 0))
&& (sec->flags & SEC_ALLOC) != 0)
return elf_x86_64_need_pic (abfd, sec, h, symtab_hdr, isym,
&x86_64_elf_howto_table[r_type]);
/* Fall through. */
case R_X86_64_PC8:
@ -4040,42 +4073,6 @@ is_32bit_relative_branch (bfd_byte *contents, bfd_vma offset)
&& (contents [offset - 1] & 0xf0) == 0x80));
}
static bfd_boolean
elf_x86_64_need_pic (bfd *input_bfd, struct elf_link_hash_entry *h,
reloc_howto_type *howto)
{
const char *fmt;
const char *v;
const char *pic = "";
switch (ELF_ST_VISIBILITY (h->other))
{
case STV_HIDDEN:
v = _("hidden symbol");
break;
case STV_INTERNAL:
v = _("internal symbol");
break;
case STV_PROTECTED:
v = _("protected symbol");
break;
default:
v = _("symbol");
pic = _("; recompile with -fPIC");
break;
}
if (h->def_regular)
fmt = _("%B: relocation %s against %s `%s' can not be used when making a shared object%s");
else
fmt = _("%B: relocation %s against undefined %s `%s' can not be used when making a shared object%s");
(*_bfd_error_handler) (fmt, input_bfd, howto->name,
v, h->root.root.string, pic);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
/* Relocate an x86_64 ELF section. */
static bfd_boolean
@ -4100,6 +4097,10 @@ elf_x86_64_relocate_section (bfd *output_bfd,
BFD_ASSERT (is_x86_64_elf (input_bfd));
/* Skip if check_relocs failed. */
if (input_section->check_relocs_failed)
return FALSE;
htab = elf_x86_64_hash_table (info);
if (htab == NULL)
return FALSE;
@ -4756,7 +4757,8 @@ elf_x86_64_relocate_section (bfd *output_bfd,
}
if (fail)
return elf_x86_64_need_pic (input_bfd, h, howto);
return elf_x86_64_need_pic (input_bfd, input_section,
h, NULL, NULL, howto);
}
/* Fall through. */
@ -4838,11 +4840,6 @@ direct:
|| SYMBOLIC_BIND (info, h))
|| ! h->def_regular))
{
if ((r_type != R_X86_64_PC64 && r_type != R_X86_64_64)
&& bfd_link_executable (info)
&& h->root.type == bfd_link_hash_undefweak
&& !resolved_to_zero)
return elf_x86_64_need_pic (input_bfd, h, howto);
outrel.r_info = htab->r_info (h->dynindx, r_type);
outrel.r_addend = rel->r_addend;
}

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@ -1,3 +1,11 @@
2016-04-20 H.J. Lu <hongjiu.lu@intel.com>
PR ld/19969
* testsuite/ld-x86-64/pr19969.d: New file.
* testsuite/ld-x86-64/pr19969a.S: Likewise.
* testsuite/ld-x86-64/pr19969b.S: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run pr19969 tests.
2016-04-20 H.J. Lu <hongjiu.lu@intel.com>
* emulparams/elf32_x86_64.sh (CHECK_RELOCS_AFTER_OPEN_INPUT):

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@ -0,0 +1,4 @@
#source: pr19969b.S
#as: --64
#ld: -melf_x86_64 tmpdir/pr19969.so
#error: .*relocation R_X86_64_32 against symbol `foo' can not be used when making a shared object; recompile with -fPIC

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@ -0,0 +1,7 @@
.data
.align 4
.global foo
.type foo, @object
.size foo, 4
foo:
.long -1

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@ -0,0 +1,14 @@
.text
.globl _start
.type _start, @function
_start:
movl foo_p(%rip), %eax
ret
.size _start, .-_start
.globl foo_p
.data
.align 4
.type foo_p, @object
.size foo_p, 4
foo_p:
.long foo

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@ -156,6 +156,8 @@ set x86_64tests {
"--64" { dummy.s } {{readelf {-rW} pr19827.rd}} "pr19827"}
{"Build pr19827.so" "-melf_x86_64 -shared -Bsymbolic" ""
"--64" { pr19827a.S } {{readelf {-rW} pr19827.rd}} "pr19827.so"}
{"Build pr19969.so" "-melf_x86_64 -shared" ""
"--64" { pr19969a.S } {} "pr19969.so"}
}
# So as to avoid rewriting every last test case here in a nacl variant,
@ -262,6 +264,7 @@ run_dump_test "pr19807-2b"
run_dump_test "pr19807-2c"
run_dump_test "pr19807-2d"
run_dump_test "pr19807-2e"
run_dump_test "pr19969"
if { ![istarget "x86_64-*-linux*"] && ![istarget "x86_64-*-nacl*"]} {
return