+2015-09-01 H.J. Lu <hongjiu.lu@intel.com>
+
+ PR ld/18900
+ * elf32-i386.c (elf_i386_link_hash_entry): Add
+ func_pointer_refcount.
+ (elf_i386_link_hash_newfunc): Clear func_pointer_refcount.
+ (elf_i386_get_local_sym_hash): Likewise.
+ (elf_i386_copy_indirect_symbol): Also copy
+ func_pointer_refcount.
+ (elf_i386_check_relocs): Increment func_pointer_refcount.
+ (elf_i386_gc_sweep_hook): Decrement func_pointer_refcount.
+ (elf_i386_allocate_dynrelocs): Don't create the PLT entry if
+ there are only function pointer relocations which can be
+ resolved at run-time. Keep dynanamic relocations for run-time
+ function pointer initialization.
+ (elf_i386_relocate_section): Copy dynamic function pointer
+ relocations.
+ * elf64-x86-64.c (elf_x86_64_link_hash_entry): Add
+ func_pointer_refcount.
+ (elf_x86_64_link_hash_newfunc): Clear func_pointer_refcount.
+ (elf_x86_64_get_local_sym_hash): Likewise.
+ (elf_x86_64_copy_indirect_symbol): Also copy
+ func_pointer_refcount.
+ (elf_x86_64_check_relocs): Increment func_pointer_refcount.
+ (elf_x86_64_gc_sweep_hook): Decrement func_pointer_refcount.
+ (elf_x86_64_allocate_dynrelocs): Don't create the PLT entry if
+ there are only function pointer relocations which can be
+ resolved at run-time. Keep dynanamic relocations for run-time
+ function pointer initialization.
+ (elf_x86_64_relocate_section): Copy dynamic function pointer
+ relocations.
+
2015-09-01 Alan Modra <amodra@gmail.com>
* elf64-ppc.c (ppc64_elf_maybe_function_sym): Adjust symbol value
/* Symbol is referenced by R_386_GOTOFF relocation. */
unsigned int gotoff_ref : 1;
+ /* Reference count of C/C++ function pointer relocations in read-write
+ section which can be resolved at run-time. */
+ bfd_signed_vma func_pointer_refcount;
+
/* Information about the GOT PLT entry. Filled when there are both
GOT and PLT relocations against the same function. */
union gotplt_union plt_got;
eh->dyn_relocs = NULL;
eh->tls_type = GOT_UNKNOWN;
eh->gotoff_ref = 0;
+ eh->func_pointer_refcount = 0;
eh->plt_got.offset = (bfd_vma) -1;
eh->tlsdesc_got = (bfd_vma) -1;
}
ret->elf.indx = sec->id;
ret->elf.dynstr_index = ELF32_R_SYM (rel->r_info);
ret->elf.dynindx = -1;
+ ret->func_pointer_refcount = 0;
ret->plt_got.offset = (bfd_vma) -1;
*slot = ret;
}
dir->pointer_equality_needed |= ind->pointer_equality_needed;
}
else
- _bfd_elf_link_hash_copy_indirect (info, dir, ind);
+ {
+ if (eind->func_pointer_refcount > 0)
+ {
+ edir->func_pointer_refcount += eind->func_pointer_refcount;
+ eind->func_pointer_refcount = 0;
+ }
+
+ _bfd_elf_link_hash_copy_indirect (info, dir, ind);
+ }
}
/* Return TRUE if the TLS access code sequence support transition
refers to is in a shared lib. */
h->plt.refcount += 1;
if (r_type != R_386_PC32)
- h->pointer_equality_needed = 1;
+ {
+ h->pointer_equality_needed = 1;
+ /* R_386_32 can be resolved at run-time. */
+ if (r_type == R_386_32
+ && (sec->flags & SEC_READONLY) == 0)
+ eh->func_pointer_refcount += 1;
+ }
}
size_reloc = FALSE;
{
if (h->plt.refcount > 0)
h->plt.refcount -= 1;
+ if (r_type == R_386_32
+ && (sec->flags & SEC_READONLY) == 0)
+ {
+ struct elf_i386_link_hash_entry *eh
+ = (struct elf_i386_link_hash_entry *) h;
+ if (eh->func_pointer_refcount > 0)
+ eh->func_pointer_refcount -= 1;
+ }
}
break;
plt_entry_size = GET_PLT_ENTRY_SIZE (info->output_bfd);
+ /* Clear the reference count of function pointer relocations if
+ symbol isn't a normal function. */
+ if (h->type != STT_FUNC)
+ eh->func_pointer_refcount = 0;
+
/* We can't use the GOT PLT if pointer equality is needed since
finish_dynamic_symbol won't clear symbol value and the dynamic
linker won't update the GOT slot. We will get into an infinite
return _bfd_elf_allocate_ifunc_dyn_relocs (info, h, &eh->dyn_relocs,
plt_entry_size,
plt_entry_size, 4);
+ /* Don't create the PLT entry if there are only function pointer
+ relocations which can be resolved at run-time. */
else if (htab->elf.dynamic_sections_created
- && (h->plt.refcount > 0 || eh->plt_got.refcount > 0))
+ && (h->plt.refcount > eh->func_pointer_refcount
+ || eh->plt_got.refcount > 0))
{
bfd_boolean use_plt_got;
+ /* Clear the reference count of function pointer relocations
+ if PLT is used. */
+ eh->func_pointer_refcount = 0;
+
if ((info->flags & DF_BIND_NOW) && !h->pointer_equality_needed)
{
/* Don't use the regular PLT for DF_BIND_NOW. */
{
/* For the non-shared case, discard space for relocs against
symbols which turn out to need copy relocs or are not
- dynamic. */
+ dynamic. Keep dynamic relocations for run-time function
+ pointer initialization. */
- if (!h->non_got_ref
+ if ((!h->non_got_ref || eh->func_pointer_refcount > 0)
&& ((h->def_dynamic
&& !h->def_regular)
|| (htab->elf.dynamic_sections_created
}
eh->dyn_relocs = NULL;
+ eh->func_pointer_refcount = 0;
keep: ;
}
}
}
+ eh = (struct elf_i386_link_hash_entry *) h;
switch (r_type)
{
case R_386_GOT32:
if (h == NULL)
break;
- eh = (struct elf_i386_link_hash_entry *) h;
if ((h->plt.offset == (bfd_vma) -1
&& eh->plt_got.offset == (bfd_vma) -1)
|| htab->elf.splt == NULL)
|| is_vxworks_tls)
break;
+ /* Copy dynamic function pointer relocations. */
if ((bfd_link_pic (info)
&& (h == NULL
|| ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
&& !bfd_link_pic (info)
&& h != NULL
&& h->dynindx != -1
- && !h->non_got_ref
+ && (!h->non_got_ref || eh->func_pointer_refcount > 0)
&& ((h->def_dynamic
&& !h->def_regular)
|| h->root.type == bfd_link_hash_undefweak
/* TRUE if symbol has at least one BND relocation. */
unsigned int has_bnd_reloc : 1;
+ /* Reference count of C/C++ function pointer relocations in read-write
+ section which can be resolved at run-time. */
+ bfd_signed_vma func_pointer_refcount;
+
/* Information about the GOT PLT entry. Filled when there are both
GOT and PLT relocations against the same function. */
union gotplt_union plt_got;
eh->tls_type = GOT_UNKNOWN;
eh->needs_copy = 0;
eh->has_bnd_reloc = 0;
+ eh->func_pointer_refcount = 0;
eh->plt_bnd.offset = (bfd_vma) -1;
eh->plt_got.offset = (bfd_vma) -1;
eh->tlsdesc_got = (bfd_vma) -1;
ret->elf.indx = sec->id;
ret->elf.dynstr_index = htab->r_sym (rel->r_info);
ret->elf.dynindx = -1;
+ ret->func_pointer_refcount = 0;
ret->plt_got.offset = (bfd_vma) -1;
*slot = ret;
}
dir->pointer_equality_needed |= ind->pointer_equality_needed;
}
else
- _bfd_elf_link_hash_copy_indirect (info, dir, ind);
+ {
+ if (eind->func_pointer_refcount > 0)
+ {
+ edir->func_pointer_refcount += eind->func_pointer_refcount;
+ eind->func_pointer_refcount = 0;
+ }
+
+ _bfd_elf_link_hash_copy_indirect (info, dir, ind);
+ }
}
static bfd_boolean
if (r_type != R_X86_64_PC32
&& r_type != R_X86_64_PC32_BND
&& r_type != R_X86_64_PC64)
- h->pointer_equality_needed = 1;
+ {
+ h->pointer_equality_needed = 1;
+ /* At run-time, R_X86_64_64 can be resolved for both
+ x86-64 and x32. But R_X86_64_32 and R_X86_64_32S
+ can only be resolved for x32. */
+ if ((sec->flags & SEC_READONLY) == 0
+ && (r_type == R_X86_64_64
+ || (!ABI_64_P (abfd)
+ && (r_type == R_X86_64_32
+ || r_type == R_X86_64_32S))))
+ {
+ struct elf_x86_64_link_hash_entry *eh
+ = (struct elf_x86_64_link_hash_entry *) h;
+ eh->func_pointer_refcount += 1;
+ }
+ }
}
size_reloc = FALSE;
unsigned long r_symndx;
unsigned int r_type;
struct elf_link_hash_entry *h = NULL;
+ bfd_boolean pointer_reloc;
r_symndx = htab->r_sym (rel->r_info);
if (r_symndx >= symtab_hdr->sh_info)
rel, relend, h, r_symndx))
return FALSE;
+ pointer_reloc = FALSE;
switch (r_type)
{
case R_X86_64_TLSLD:
}
break;
- case R_X86_64_8:
- case R_X86_64_16:
case R_X86_64_32:
- case R_X86_64_64:
case R_X86_64_32S:
+ pointer_reloc = !ABI_64_P (abfd);
+ goto pointer;
+
+ case R_X86_64_64:
+ pointer_reloc = TRUE;
+ case R_X86_64_8:
+ case R_X86_64_16:
case R_X86_64_PC8:
case R_X86_64_PC16:
case R_X86_64_PC32:
case R_X86_64_PC64:
case R_X86_64_SIZE32:
case R_X86_64_SIZE64:
+pointer:
if (bfd_link_pic (info)
&& (h == NULL || h->type != STT_GNU_IFUNC))
break;
{
if (h->plt.refcount > 0)
h->plt.refcount -= 1;
+ if (pointer_reloc && (sec->flags & SEC_READONLY) == 0)
+ {
+ struct elf_x86_64_link_hash_entry *eh
+ = (struct elf_x86_64_link_hash_entry *) h;
+ if (eh->func_pointer_refcount > 0)
+ eh->func_pointer_refcount -= 1;
+ }
}
break;
eh->plt_got.refcount = 1;
}
+ /* Clear the reference count of function pointer relocations if
+ symbol isn't a normal function. */
+ if (h->type != STT_FUNC)
+ eh->func_pointer_refcount = 0;
+
/* Since STT_GNU_IFUNC symbol must go through PLT, we handle it
here if it is defined and referenced in a non-shared object. */
if (h->type == STT_GNU_IFUNC
else
return FALSE;
}
+ /* Don't create the PLT entry if there are only function pointer
+ relocations which can be resolved at run-time. */
else if (htab->elf.dynamic_sections_created
- && (h->plt.refcount > 0 || eh->plt_got.refcount > 0))
+ && (h->plt.refcount > eh->func_pointer_refcount
+ || eh->plt_got.refcount > 0))
{
bfd_boolean use_plt_got;
+ /* Clear the reference count of function pointer relocations
+ if PLT is used. */
+ eh->func_pointer_refcount = 0;
+
if ((info->flags & DF_BIND_NOW) && !h->pointer_equality_needed)
{
/* Don't use the regular PLT for DF_BIND_NOW. */
{
/* For the non-shared case, discard space for relocs against
symbols which turn out to need copy relocs or are not
- dynamic. */
+ dynamic. Keep dynamic relocations for run-time function
+ pointer initialization. */
- if (!h->non_got_ref
+ if ((!h->non_got_ref || eh->func_pointer_refcount > 0)
&& ((h->def_dynamic
&& !h->def_regular)
|| (htab->elf.dynamic_sections_created
}
eh->dyn_relocs = NULL;
+ eh->func_pointer_refcount = 0;
keep: ;
}
/* Don't copy a pc-relative relocation into the output file
if the symbol needs copy reloc or the symbol is undefined
- when building executable. */
+ when building executable. Copy dynamic function pointer
+ relocations. */
if ((bfd_link_pic (info)
&& !(bfd_link_executable (info)
&& h != NULL
&& !bfd_link_pic (info)
&& h != NULL
&& h->dynindx != -1
- && !h->non_got_ref
+ && (!h->non_got_ref || eh->func_pointer_refcount > 0)
&& ((h->def_dynamic
&& !h->def_regular)
|| h->root.type == bfd_link_hash_undefweak
+2015-09-01 H.J. Lu <hongjiu.lu@intel.com>
+
+ PR ld/18900
+ * ld-i386/i386.exp: Run tests for PR ld/18900.
+ * ld-x86-64/x86-64.exp: Likewise.
+ * ld-i386/pr18900.out: New file.
+ * ld-i386/pr18900a.c: Likewise.
+ * ld-i386/pr18900a.c: Likewise.
+ * ld-i386/pr18900a.rd: Likewise.
+ * ld-i386/pr18900b.c: Likewise.
+ * ld-i386/pr18900b.rd: Likewise.
+ * ld-i386/pr18900c.c: Likewise.
+ * ld-x86-64/pr18900.out: Likewise.
+ * ld-x86-64/pr18900a.c: Likewise.
+ * ld-x86-64/pr18900a.rd: Likewise.
+ * ld-x86-64/pr18900b.c: Likewise.
+ * ld-x86-64/pr18900b.rd: Likewise.
+ * ld-x86-64/pr18900c.c: Likewise.
+ * ld-x86-64/mpx3.dd: Updated.
+
2015-08-27 Alan Modra <amodra@gmail.com>
* ld-powerpc/relocsort.s, * ld-powerpc/relocsort.d: New test.
{{readelf {-Wr} pr17827.rd}} \
"pr17827" \
] \
+ [list \
+ "Build pr18900.so" \
+ "-shared" \
+ "-fPIC" \
+ { pr18900a.c } \
+ "" \
+ "pr18900.so" \
+ ] \
+ [list \
+ "Build pr18900a" \
+ "tmpdir/pr18900.so" \
+ "" \
+ { pr18900b.c pr18900c.c } \
+ {{readelf {-Wrd} pr18900a.rd}} \
+ "pr18900a" \
+ ] \
+ [list \
+ "Build pr18900b" \
+ "tmpdir/pr18900.so" \
+ "" \
+ { pr18900b.c pr18900c.c } \
+ {{readelf {-Wrd} pr18900b.rd}} \
+ "pr18900b" \
+ ] \
]
run_ld_link_exec_tests [] [list \
"pr17689ver" \
"pr17689.out" \
] \
+ [list \
+ "Run pr18900" \
+ "tmpdir/pr18900.so" \
+ "" \
+ { pr18900b.c pr18900c.c } \
+ "pr18900" \
+ "pr18900.out" \
+ ] \
]
}
--- /dev/null
+OK
+OK
+OK
+OK
--- /dev/null
+#include <stdio.h>
+
+void
+foo (void)
+{
+ printf ("OK\n");
+}
+
+void *
+bar (void)
+{
+ foo ();
+ return &foo;
+}
--- /dev/null
+#failif
+#...
+.*\(TEXTREL\).*
+#...
--- /dev/null
+extern void abort (void);
+extern void foo (void);
+extern void *bar (void);
+
+typedef void (*func_p) (void);
+
+extern const func_p p1;
+
+func_p p2 = &foo;
+func_p p3 = &foo;
+
+int
+main ()
+{
+ void *p = bar ();
+ p1 ();
+ p2 ();
+ p3 ();
+ if (p != p1)
+ abort ();
+ return 0;
+}
--- /dev/null
+#failif
+#...
+[0-9a-f ]+R_386_JUMP_SLOT[0-9a-f ]+foo
+#...
--- /dev/null
+extern void foo (void);
+
+typedef void (*func_p) (void);
+
+func_p p1 = &foo;
Disassembly of section .plt:
-0+400290 <.plt>:
-[ ]*[a-f0-9]+: ff 35 6a 01 20 00 pushq 0x20016a\(%rip\) # 600400 <_GLOBAL_OFFSET_TABLE_\+0x8>
-[ ]*[a-f0-9]+: f2 ff 25 6b 01 20 00 bnd jmpq \*0x20016b\(%rip\) # 600408 <_GLOBAL_OFFSET_TABLE_\+0x10>
+0+[a-f0-9]+ <.plt>:
+[ ]*[a-f0-9]+: ff ([0-9a-f]{2} ){5} pushq 0x[a-f0-9]+\(%rip\) # [a-f0-9]+ <_GLOBAL_OFFSET_TABLE_\+0x8>
+[ ]*[a-f0-9]+: f2 ff ([0-9a-f]{2} ){5} bnd jmpq \*0x[a-f0-9]+\(%rip\) # [a-f0-9]+ <_GLOBAL_OFFSET_TABLE_\+0x10>
[ ]*[a-f0-9]+: 0f 1f 00 nopl \(%rax\)
[ ]*[a-f0-9]+: 68 00 00 00 00 pushq \$0x0
-[ ]*[a-f0-9]+: f2 e9 e5 ff ff ff bnd jmpq 400290 <call1@plt-0x30>
-[ ]*[a-f0-9]+: 0f 1f 44 00 00 nopl 0x0\(%rax,%rax,1\)
-[ ]*[a-f0-9]+: 68 01 00 00 00 pushq \$0x1
-[ ]*[a-f0-9]+: f2 e9 d5 ff ff ff bnd jmpq 400290 <call1@plt-0x30>
+[ ]*[a-f0-9]+: f2 e9 ([0-9a-f]{2} ){4} bnd jmpq [a-f0-9]+ <call1@plt-0x20>
[ ]*[a-f0-9]+: 0f 1f 44 00 00 nopl 0x0\(%rax,%rax,1\)
Disassembly of section .plt.bnd:
-0+4002c0 <call1@plt>:
-[ ]*[a-f0-9]+: f2 ff 25 49 01 20 00 bnd jmpq \*0x200149\(%rip\) # 600410 <_GLOBAL_OFFSET_TABLE_\+0x18>
-[ ]*[a-f0-9]+: 90 nop
-
-0+4002c8 <call2@plt>:
-[ ]*[a-f0-9]+: f2 ff 25 49 01 20 00 bnd jmpq \*0x200149\(%rip\) # 600418 <_GLOBAL_OFFSET_TABLE_\+0x20>
+0+[a-f0-9]+ <call1@plt>:
+[ ]*[a-f0-9]+: f2 ff ([0-9a-f]{2} ){5} bnd jmpq \*0x[a-f0-9]+\(%rip\) # [a-f0-9]+ <_GLOBAL_OFFSET_TABLE_\+0x18>
[ ]*[a-f0-9]+: 90 nop
Disassembly of section .text:
-0+4002d0 <_start>:
-[ ]*[a-f0-9]+: bf c0 02 40 00 mov \$0x4002c0,%edi
+0+[a-f0-9]+ <_start>:
+[ ]*[a-f0-9]+: bf ([0-9a-f]{2} ){4} mov \$0x[a-f0-9]+,%edi
[ ]*[a-f0-9]+: f2 ff d7 bnd callq \*%rdi
-[ ]*[a-f0-9]+: 48 8b 3d 41 01 20 00 mov 0x200141\(%rip\),%rdi # 600420 <func>
+[ ]*[a-f0-9]+: 48 8b ([0-9a-f]{2} ){5} mov 0x[a-f0-9]+\(%rip\),%rdi # [a-f0-9]+ <func>
[ ]*[a-f0-9]+: f2 ff d7 bnd callq \*%rdi
[ ]*[a-f0-9]+: c3 retq
#pass
--- /dev/null
+OK
+OK
+OK
+OK
--- /dev/null
+#include <stdio.h>
+
+void
+foo (void)
+{
+ printf ("OK\n");
+}
+
+void *
+bar (void)
+{
+ foo ();
+ return &foo;
+}
--- /dev/null
+#failif
+#...
+.*\(TEXTREL\).*
+#...
--- /dev/null
+extern void abort (void);
+extern void foo (void);
+extern void *bar (void);
+
+typedef void (*func_p) (void);
+
+extern const func_p p1;
+
+func_p p2 = &foo;
+func_p p3 = &foo;
+
+int
+main ()
+{
+ void *p = bar ();
+ p1 ();
+ p2 ();
+ p3 ();
+ if (p != p1)
+ abort ();
+ return 0;
+}
--- /dev/null
+#failif
+#...
+[0-9a-f ]+R_X86_64_JUMP_SLOT[0-9a-f ]+foo \+ 0
+#...
--- /dev/null
+extern void foo (void);
+
+typedef void (*func_p) (void);
+
+func_p p1 = &foo;
{{readelf {-Wr} pr17827.rd}} \
"pr17827" \
] \
+ [list \
+ "Build pr18900.so" \
+ "-shared" \
+ "-fPIC" \
+ { pr18900a.c } \
+ "" \
+ "pr18900.so" \
+ ] \
+ [list \
+ "Build pr18900a" \
+ "tmpdir/pr18900.so" \
+ "" \
+ { pr18900b.c pr18900c.c } \
+ {{readelf {-Wrd} pr18900a.rd}} \
+ "pr18900a" \
+ ] \
+ [list \
+ "Build pr18900b" \
+ "tmpdir/pr18900.so" \
+ "" \
+ { pr18900b.c pr18900c.c } \
+ {{readelf {-Wrd} pr18900b.rd}} \
+ "pr18900b" \
+ ] \
]
run_ld_link_exec_tests [] [list \
"pr17689now" \
"pr17689.out" \
] \
+ [list \
+ "Run pr18900" \
+ "tmpdir/pr18900.so" \
+ "" \
+ { pr18900b.c pr18900c.c } \
+ "pr18900" \
+ "pr18900.out" \
+ ] \
]
if { [istarget "x86_64-*-linux*"] \
projects / binutils-gdb.git / commitdiff