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PATCH: Handle STT_GNU_IFUNC symols when building shared library
- From: "H.J. Lu" <hongjiu dot lu at intel dot com>
- To: binutils at sourceware dot org
- Date: Thu, 6 Jan 2011 10:47:00 -0800
- Subject: PATCH: Handle STT_GNU_IFUNC symols when building shared library
- Reply-to: "H.J. Lu" <hjl dot tools at gmail dot com>
I checked in this patch to properly handle local/global STT_GNU_IFUNC
symols when building shared library.
H.J.
---
bfd/
2012-01-06 H.J. Lu <hongjiu.lu@intel.com>
PR ld/12366
PR ld/12371
* elf-ifunc.c (_bfd_elf_allocate_ifunc_dyn_relocs): Properly
handle symbols marked with regular reference, but not non-GOT
reference when building shared library.
* elf32-i386.c (elf_i386_gc_sweep_hook): Properly handle
local and global STT_GNU_IFUNC symols when building shared
library.
* elf64-x86-64.c (elf_x86_64_gc_sweep_hook): Likewise.
ld/testsuite/
2012-01-06 H.J. Lu <hongjiu.lu@intel.com>
PR ld/12366
PR ld/12371
* ld-ifunc/ifunc-10-i386.s: Add more tests.
* ld-ifunc/ifunc-10-x86-64.s: Likewise.
* ld-ifunc/ifunc-11-i386.s: Likewise.
* ld-ifunc/ifunc-11-x86-64.s: Likewise.
* ld-ifunc/ifunc-12-i386.d: New.
* ld-ifunc/ifunc-12-i386.s: Likewise.
* ld-ifunc/ifunc-12-x86-64.d: Likewise.
* ld-ifunc/ifunc-12-x86-64.s: Likewise.
* ld-ifunc/ifunc-13-i386.d: Likewise.
* ld-ifunc/ifunc-13-x86-64.d: Likewise.
* ld-ifunc/ifunc-13a-i386.s: Likewise.
* ld-ifunc/ifunc-13a-x86-64.s: Likewise.
* ld-ifunc/ifunc-13b-i386.s: Likewise.
* ld-ifunc/ifunc-13b-x86-64.s: Likewise.
diff --git a/bfd/elf-ifunc.c b/bfd/elf-ifunc.c
index 760fc26..17b23c2 100644
--- a/bfd/elf-ifunc.c
+++ b/bfd/elf-ifunc.c
@@ -190,10 +190,29 @@ _bfd_elf_allocate_ifunc_dyn_relocs (struct bfd_link_info *info,
/* Support garbage collection against STT_GNU_IFUNC symbols. */
if (h->plt.refcount <= 0 && h->got.refcount <= 0)
{
- h->got = htab->init_got_offset;
- h->plt = htab->init_plt_offset;
- *head = NULL;
- return TRUE;
+ /* When building shared library, we need to handle the case
+ where it is marked with regular reference, but not non-GOT
+ reference. It may happen if we didn't see STT_GNU_IFUNC
+ symbol at the time when checking relocations. */
+ bfd_size_type count = 0;
+
+ if (info->shared
+ && !h->non_got_ref
+ && h->ref_regular)
+ {
+ for (p = *head; p != NULL; p = p->next)
+ count += p->count;
+ if (count != 0)
+ h->non_got_ref = 1;
+ }
+
+ if (count == 0)
+ {
+ h->got = htab->init_got_offset;
+ h->plt = htab->init_plt_offset;
+ *head = NULL;
+ return TRUE;
+ }
}
/* Return and discard space for dynamic relocations against it if
diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index ae749c6..e9b3933 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -1807,23 +1807,10 @@ elf_i386_gc_sweep_hook (bfd *abfd,
r_symndx = ELF32_R_SYM (rel->r_info);
if (r_symndx >= symtab_hdr->sh_info)
{
- struct elf_i386_link_hash_entry *eh;
- struct elf_dyn_relocs **pp;
- struct elf_dyn_relocs *p;
-
h = sym_hashes[r_symndx - symtab_hdr->sh_info];
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
- eh = (struct elf_i386_link_hash_entry *) h;
-
- for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next)
- if (p->sec == sec)
- {
- /* Everything must go for SEC. */
- *pp = p->next;
- break;
- }
}
else
{
@@ -1843,6 +1830,22 @@ elf_i386_gc_sweep_hook (bfd *abfd,
}
}
+ if (h)
+ {
+ struct elf_i386_link_hash_entry *eh;
+ struct elf_dyn_relocs **pp;
+ struct elf_dyn_relocs *p;
+
+ eh = (struct elf_i386_link_hash_entry *) h;
+ for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next)
+ if (p->sec == sec)
+ {
+ /* Everything must go for SEC. */
+ *pp = p->next;
+ break;
+ }
+ }
+
r_type = ELF32_R_TYPE (rel->r_info);
if (! elf_i386_tls_transition (info, abfd, sec, NULL,
symtab_hdr, sym_hashes,
@@ -1883,7 +1886,8 @@ elf_i386_gc_sweep_hook (bfd *abfd,
case R_386_32:
case R_386_PC32:
- if (info->shared)
+ if (info->shared
+ && (h == NULL || h->type != STT_GNU_IFUNC))
break;
/* Fall through */
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 3dd16ba..ceb1a0a 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -1684,23 +1684,10 @@ elf_x86_64_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info,
r_symndx = htab->r_sym (rel->r_info);
if (r_symndx >= symtab_hdr->sh_info)
{
- struct elf_x86_64_link_hash_entry *eh;
- struct elf_dyn_relocs **pp;
- struct elf_dyn_relocs *p;
-
h = sym_hashes[r_symndx - symtab_hdr->sh_info];
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
- eh = (struct elf_x86_64_link_hash_entry *) h;
-
- for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next)
- if (p->sec == sec)
- {
- /* Everything must go for SEC. */
- *pp = p->next;
- break;
- }
}
else
{
@@ -1720,6 +1707,23 @@ elf_x86_64_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info,
}
}
+ if (h)
+ {
+ struct elf_x86_64_link_hash_entry *eh;
+ struct elf_dyn_relocs **pp;
+ struct elf_dyn_relocs *p;
+
+ eh = (struct elf_x86_64_link_hash_entry *) h;
+
+ for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next)
+ if (p->sec == sec)
+ {
+ /* Everything must go for SEC. */
+ *pp = p->next;
+ break;
+ }
+ }
+
r_type = ELF32_R_TYPE (rel->r_info);
if (! elf_x86_64_tls_transition (info, abfd, sec, NULL,
symtab_hdr, sym_hashes,
@@ -1771,7 +1775,8 @@ elf_x86_64_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info,
case R_X86_64_PC16:
case R_X86_64_PC32:
case R_X86_64_PC64:
- if (info->shared)
+ if (info->shared
+ && (h == NULL || h->type != STT_GNU_IFUNC))
break;
/* Fall thru */
diff --git a/ld/testsuite/ld-ifunc/ifunc-10-i386.s b/ld/testsuite/ld-ifunc/ifunc-10-i386.s
index 8411e81..76c5bef 100644
--- a/ld/testsuite/ld-ifunc/ifunc-10-i386.s
+++ b/ld/testsuite/ld-ifunc/ifunc-10-i386.s
@@ -6,6 +6,8 @@ foo:
movl ifunc@GOTOFF(%ecx), %eax
call ifunc@PLT
call ifunc
+ movl xxx@GOT(%ecx), %eax
+ movl xxx, %eax
ret
.section .text.bar,"ax",@progbits
@@ -18,3 +20,7 @@ bar:
.type ifunc, @gnu_indirect_function
ifunc:
ret
+
+ .section .data.foo,"aw",@progbits
+xxx:
+ .long ifunc
diff --git a/ld/testsuite/ld-ifunc/ifunc-10-x86-64.s b/ld/testsuite/ld-ifunc/ifunc-10-x86-64.s
index ea6f8c2..11e29b5 100644
--- a/ld/testsuite/ld-ifunc/ifunc-10-x86-64.s
+++ b/ld/testsuite/ld-ifunc/ifunc-10-x86-64.s
@@ -6,6 +6,7 @@ foo:
movl ifunc(%rip), %eax
call ifunc@PLT
call ifunc
+ movl xxx(%rip), %eax
ret
.section .text.bar,"ax",@progbits
@@ -18,3 +19,7 @@ bar:
.type ifunc, @gnu_indirect_function
ifunc:
ret
+
+ .section .data.foo,"aw",@progbits
+xxx:
+ .quad ifunc
diff --git a/ld/testsuite/ld-ifunc/ifunc-11-i386.s b/ld/testsuite/ld-ifunc/ifunc-11-i386.s
index 06f5924..e0e4740 100644
--- a/ld/testsuite/ld-ifunc/ifunc-11-i386.s
+++ b/ld/testsuite/ld-ifunc/ifunc-11-i386.s
@@ -3,9 +3,11 @@
foo:
.global foo
movl ifunc@GOT(%ecx), %eax
- movl ifunc@GOTOFF(%ecx), %eax
+ movl ifunc@GOTOFF(%ecx), %eax
call ifunc@PLT
call ifunc
+ movl xxx@GOT(%ecx), %eax
+ movl xxx, %eax
ret
.section .text.bar,"ax",@progbits
@@ -16,6 +18,10 @@ bar:
.section .text.ifunc,"ax",@progbits
.type ifunc, @gnu_indirect_function
- .global ifunc
+ .global ifunc
ifunc:
ret
+
+ .section .data.foo,"aw",@progbits
+xxx:
+ .long ifunc
diff --git a/ld/testsuite/ld-ifunc/ifunc-11-x86-64.s b/ld/testsuite/ld-ifunc/ifunc-11-x86-64.s
index 70d4fbf..8525419 100644
--- a/ld/testsuite/ld-ifunc/ifunc-11-x86-64.s
+++ b/ld/testsuite/ld-ifunc/ifunc-11-x86-64.s
@@ -6,6 +6,7 @@ foo:
movl ifunc(%rip), %eax
call ifunc@PLT
call ifunc
+ movl xxx(%rip), %eax
ret
.section .text.bar,"ax",@progbits
@@ -19,3 +20,7 @@ bar:
.global ifunc
ifunc:
ret
+
+ .section .data.foo,"aw",@progbits
+xxx:
+ .quad ifunc
diff --git a/ld/testsuite/ld-ifunc/ifunc-12-i386.d b/ld/testsuite/ld-ifunc/ifunc-12-i386.d
new file mode 100644
index 0000000..de14181
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-12-i386.d
@@ -0,0 +1,6 @@
+#ld: -shared -m elf_i386 -e bar --gc-sections
+#as: --32
+#readelf: -r --wide
+#target: x86_64-*-* i?86-*-*
+
+There are no relocations in this file.
diff --git a/ld/testsuite/ld-ifunc/ifunc-12-i386.s b/ld/testsuite/ld-ifunc/ifunc-12-i386.s
new file mode 100644
index 0000000..840302f
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-12-i386.s
@@ -0,0 +1,25 @@
+ .section .text.foo,"ax",@progbits
+ .type foo, @function
+foo:
+ movl ifunc@GOT(%ecx), %eax
+ movl ifunc@GOTOFF(%ecx), %eax
+ call ifunc@PLT
+ call ifunc
+ movl xxx@GOT(%ecx), %eax
+ movl xxx, %eax
+ ret
+
+ .section .text.bar,"ax",@progbits
+ .type bar, @function
+bar:
+ .global bar
+ ret
+
+ .section .text.ifunc,"ax",@progbits
+ .type ifunc, @gnu_indirect_function
+ifunc:
+ ret
+
+ .section .data.foo,"aw",@progbits
+xxx:
+ .long ifunc
diff --git a/ld/testsuite/ld-ifunc/ifunc-12-x86-64.d b/ld/testsuite/ld-ifunc/ifunc-12-x86-64.d
new file mode 100644
index 0000000..40f07c3
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-12-x86-64.d
@@ -0,0 +1,6 @@
+#ld: -shared -m elf_x86_64 -e bar --gc-sections
+#as: --64
+#readelf: -r --wide
+#target: x86_64-*-*
+
+There are no relocations in this file.
diff --git a/ld/testsuite/ld-ifunc/ifunc-12-x86-64.s b/ld/testsuite/ld-ifunc/ifunc-12-x86-64.s
new file mode 100644
index 0000000..491684b
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-12-x86-64.s
@@ -0,0 +1,24 @@
+ .section .text.foo,"ax",@progbits
+ .type foo, @function
+foo:
+ movl ifunc@GOTPCREL(%rip), %eax
+ movl ifunc(%rip), %eax
+ call ifunc@PLT
+ call ifunc
+ movl xxx(%rip), %eax
+ ret
+
+ .section .text.bar,"ax",@progbits
+ .type bar, @function
+bar:
+ .global bar
+ ret
+
+ .section .text.ifunc,"ax",@progbits
+ .type ifunc, @gnu_indirect_function
+ifunc:
+ ret
+
+ .section .data.foo,"aw",@progbits
+xxx:
+ .quad ifunc
diff --git a/ld/testsuite/ld-ifunc/ifunc-13-i386.d b/ld/testsuite/ld-ifunc/ifunc-13-i386.d
new file mode 100644
index 0000000..162c3e4
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-13-i386.d
@@ -0,0 +1,19 @@
+#source: ifunc-13a-i386.s
+#source: ifunc-13b-i386.s
+#ld: -shared -m elf_i386 -z nocombreloc
+#as: --32
+#readelf: -r --wide
+#target: x86_64-*-* i?86-*-*
+
+Relocation section '.rel.got' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+#...
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_GLOB_DAT[ ]+ifunc\(\)[ ]+ifunc
+#...
+Relocation section '.rel.ifunc' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_32[ ]+ifunc\(\)[ ]+ifunc
+#...
+Relocation section '.rel.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_JUMP_SLOT[ ]+ifunc\(\)[ ]+ifunc
diff --git a/ld/testsuite/ld-ifunc/ifunc-13-x86-64.d b/ld/testsuite/ld-ifunc/ifunc-13-x86-64.d
new file mode 100644
index 0000000..d0c0647
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-13-x86-64.d
@@ -0,0 +1,18 @@
+#source: ifunc-13a-x86-64.s
+#source: ifunc-13b-x86-64.s
+#ld: -shared -m elf_x86_64 -z nocombreloc
+#as: --64
+#readelf: -r --wide
+#target: x86_64-*-*
+
+Relocation section '.rela.got' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_GLOB_DAT[ ]+ifunc\(\)[ ]+ifunc \+ 0
+#...
+Relocation section '.rela.ifunc' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_64[ ]+ifunc\(\)[ ]+ifunc \+ 0
+#...
+Relocation section '.rela.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_JUMP_SLOT[ ]+ifunc\(\)[ ]+ifunc \+ 0
diff --git a/ld/testsuite/ld-ifunc/ifunc-13a-i386.s b/ld/testsuite/ld-ifunc/ifunc-13a-i386.s
new file mode 100644
index 0000000..eb893af
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-13a-i386.s
@@ -0,0 +1,10 @@
+ .text
+ .type foo, @function
+ .global
+foo:
+ movl xxx@GOT(%ebx), %eax
+ ret
+
+ .data
+xxx:
+ .long ifunc
diff --git a/ld/testsuite/ld-ifunc/ifunc-13a-x86-64.s b/ld/testsuite/ld-ifunc/ifunc-13a-x86-64.s
new file mode 100644
index 0000000..5bfc9e0
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-13a-x86-64.s
@@ -0,0 +1,10 @@
+ .text
+ .type foo, @function
+ .global
+foo:
+ movl xxx(%rip), %eax
+ ret
+
+ .data
+xxx:
+ .quad ifunc
diff --git a/ld/testsuite/ld-ifunc/ifunc-13b-i386.s b/ld/testsuite/ld-ifunc/ifunc-13b-i386.s
new file mode 100644
index 0000000..3560394
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-13b-i386.s
@@ -0,0 +1,5 @@
+ .text
+ .type ifunc, @gnu_indirect_function
+ .globl ifunc
+ifunc:
+ ret
diff --git a/ld/testsuite/ld-ifunc/ifunc-13b-x86-64.s b/ld/testsuite/ld-ifunc/ifunc-13b-x86-64.s
new file mode 100644
index 0000000..3560394
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-13b-x86-64.s
@@ -0,0 +1,5 @@
+ .text
+ .type ifunc, @gnu_indirect_function
+ .globl ifunc
+ifunc:
+ ret