PATCH: PR ld/14968: Missing R_*_IRELATIVE relocation
H.J. Lu
hongjiu.lu@intel.com
Sun Dec 16 20:35:00 GMT 2012
On Thu, Dec 13, 2012 at 01:08:52PM -0800, H.J. Lu wrote:
> Hi,
>
> I checked in this patch to check local IFUNC calls so that we can
> avoid unnecessary R_*_NONE relocations.
>
>
> H.J.
> ----
> diff --git a/bfd/ChangeLog b/bfd/ChangeLog
> index 5c4ace1..1ff8574 100644
> --- a/bfd/ChangeLog
> +++ b/bfd/ChangeLog
> @@ -1,3 +1,10 @@
> +2012-12-13 H.J. Lu <hongjiu.lu@intel.com>
> +
> + PR ld/14956
> + * elf32-i386.c (elf_i386_adjust_dynamic_symbol): Check local
> + IFUNC calls.
> + * elf64-x86-64.c (elf_x86_64_adjust_dynamic_symbol): Likewise.
> +
> 2012-12-10 Edgar E. Iglesias <edgar.iglesias@gmail.com>
>
> * reloc.c (MICROBLAZE): Document new relocations
> diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
> index 1b04a6e..bb41302 100644
> --- a/bfd/elf32-i386.c
> +++ b/bfd/elf32-i386.c
> @@ -2066,10 +2066,39 @@ elf_i386_adjust_dynamic_symbol (struct bfd_link_info *info,
> {
> struct elf_i386_link_hash_table *htab;
> asection *s;
> + struct elf_i386_link_hash_entry *eh;
> + struct elf_dyn_relocs *p;
>
> /* STT_GNU_IFUNC symbol must go through PLT. */
> if (h->type == STT_GNU_IFUNC)
> {
> + /* Check local STT_GNU_IFUNC calls. */
> + if (h->ref_regular
> + && SYMBOL_CALLS_LOCAL (info, h))
> + {
> + bfd_size_type pc_count = 0;
> + struct elf_dyn_relocs **pp;
> +
> + eh = (struct elf_i386_link_hash_entry *) h;
> + for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
> + {
> + pc_count += p->pc_count;
> + p->count -= p->pc_count;
> + p->pc_count = 0;
> + if (p->count == 0)
> + *pp = p->next;
> + else
> + pp = &p->next;
> + }
> +
> + if (pc_count)
> + {
> + h->needs_plt = 1;
> + h->plt.refcount += 1;
> + h->non_got_ref = 1;
> + }
> + }
> +
> if (h->plt.refcount <= 0)
> {
> h->plt.offset = (bfd_vma) -1;
The above patch has a hole. All local IFUNC references, including
non-call references, must go though local PLT. I checked in this
patch to fix it.
H.J.
----
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 87cc9d7..070acb4 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,6 +1,13 @@
+2012-12-16 H.J. Lu <hongjiu.lu@intel.com>
+
+ PR ld/14968
+ * elf32-i386.c (elf_i386_adjust_dynamic_symbol): Also check
+ local IFUNC references.
+ * elf64-x86-64.c (elf_x86_64_adjust_dynamic_symbol): Likewise.
+
2012-12-14 Tom Tromey <tromey@redhat.com>
- * elf.c (elfcore_grok_note) <NT_FILE>: New case.
+ * elf.c (elfcore_grok_note) <NT_FILE>: New case.
2012-12-13 H.J. Lu <hongjiu.lu@intel.com>
diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index bb41302..a188cec 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -2072,11 +2072,12 @@ elf_i386_adjust_dynamic_symbol (struct bfd_link_info *info,
/* STT_GNU_IFUNC symbol must go through PLT. */
if (h->type == STT_GNU_IFUNC)
{
- /* Check local STT_GNU_IFUNC calls. */
+ /* All local STT_GNU_IFUNC references must be treate as local
+ calls via local PLT. */
if (h->ref_regular
&& SYMBOL_CALLS_LOCAL (info, h))
{
- bfd_size_type pc_count = 0;
+ bfd_size_type pc_count = 0, count = 0;
struct elf_dyn_relocs **pp;
eh = (struct elf_i386_link_hash_entry *) h;
@@ -2085,13 +2086,14 @@ elf_i386_adjust_dynamic_symbol (struct bfd_link_info *info,
pc_count += p->pc_count;
p->count -= p->pc_count;
p->pc_count = 0;
+ count += p->count;
if (p->count == 0)
*pp = p->next;
else
pp = &p->next;
}
- if (pc_count)
+ if (pc_count || count)
{
h->needs_plt = 1;
h->plt.refcount += 1;
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index ec38ddc..283681c 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -2140,11 +2140,12 @@ elf_x86_64_adjust_dynamic_symbol (struct bfd_link_info *info,
/* STT_GNU_IFUNC symbol must go through PLT. */
if (h->type == STT_GNU_IFUNC)
{
- /* Check local STT_GNU_IFUNC calls. */
+ /* All local STT_GNU_IFUNC references must be treate as local
+ calls via local PLT. */
if (h->ref_regular
&& SYMBOL_CALLS_LOCAL (info, h))
{
- bfd_size_type pc_count = 0;
+ bfd_size_type pc_count = 0, count = 0;
struct elf_dyn_relocs **pp;
eh = (struct elf_x86_64_link_hash_entry *) h;
@@ -2153,13 +2154,14 @@ elf_x86_64_adjust_dynamic_symbol (struct bfd_link_info *info,
pc_count += p->pc_count;
p->count -= p->pc_count;
p->pc_count = 0;
+ count += p->count;
if (p->count == 0)
*pp = p->next;
else
pp = &p->next;
}
- if (pc_count)
+ if (pc_count || count)
{
h->needs_plt = 1;
h->plt.refcount += 1;
diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index 7ae4014..7a2cb17 100644
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,3 +1,19 @@
+2012-12-16 H.J. Lu <hongjiu.lu@intel.com>
+
+ PR ld/14968
+ * ld-ifunc/ifunc-18a-i386.d: New file.
+ * ld-ifunc/ifunc-18a-x86-64.d: Likewise.
+ * ld-ifunc/ifunc-18a.s: Likewise.
+ * ld-ifunc/ifunc-18b-i386.d: Likewise.
+ * ld-ifunc/ifunc-18b-x86-64.d: Likewise.
+ * ld-ifunc/ifunc-18b.s: Likewise.
+ * ld-ifunc/ifunc-19a-i386.d: Likewise.
+ * ld-ifunc/ifunc-19a-x86-64.d: Likewise.
+ * ld-ifunc/ifunc-19a.s: Likewise.
+ * ld-ifunc/ifunc-19b-i386.d: Likewise.
+ * ld-ifunc/ifunc-19b-x86-64.d: Likewise.
+ * ld-ifunc/ifunc-19b.s: Likewise.
+
2012-12-15 Thomas Schwinge <thomas@codesourcery.com>
* ld-elf/elf.exp (stack exec, stack size): Run for any GNU target.
diff --git a/ld/testsuite/ld-ifunc/ifunc-18a-i386.d b/ld/testsuite/ld-ifunc/ifunc-18a-i386.d
new file mode 100644
index 0000000..10490b1
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-18a-i386.d
@@ -0,0 +1,15 @@
+#source: ifunc-18a.s
+#source: ifunc-18b.s
+#ld: -shared -m elf_i386 -z nocombreloc
+#as: --32
+#readelf: -r --wide
+#target: x86_64-*-* i?86-*-*
+
+Relocation section '.rel.ifunc' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
+
+Relocation section '.rel.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
diff --git a/ld/testsuite/ld-ifunc/ifunc-18a-x86-64.d b/ld/testsuite/ld-ifunc/ifunc-18a-x86-64.d
new file mode 100644
index 0000000..0d600eb
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-18a-x86-64.d
@@ -0,0 +1,15 @@
+#source: ifunc-18a.s
+#source: ifunc-18b.s
+#as: --64
+#ld: -shared -melf_x86_64 -z nocombreloc
+#readelf: -r --wide
+#target: x86_64-*-*
+
+Relocation section '.rela.ifunc' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
+
+Relocation section '.rela.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
diff --git a/ld/testsuite/ld-ifunc/ifunc-18a.s b/ld/testsuite/ld-ifunc/ifunc-18a.s
new file mode 100644
index 0000000..c29c121
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-18a.s
@@ -0,0 +1,5 @@
+ .section .data.rel,"aw",@progbits
+ .globl foo_ptrt
+ .type foo_ptr, @object
+foo_ptr:
+ .dc.a foo
diff --git a/ld/testsuite/ld-ifunc/ifunc-18b-i386.d b/ld/testsuite/ld-ifunc/ifunc-18b-i386.d
new file mode 100644
index 0000000..a5eda94
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-18b-i386.d
@@ -0,0 +1,15 @@
+#source: ifunc-18b.s
+#source: ifunc-18a.s
+#ld: -shared -m elf_i386 -z nocombreloc
+#as: --32
+#readelf: -r --wide
+#target: x86_64-*-* i?86-*-*
+
+Relocation section '.rel.ifunc' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
+
+Relocation section '.rel.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
diff --git a/ld/testsuite/ld-ifunc/ifunc-18b-x86-64.d b/ld/testsuite/ld-ifunc/ifunc-18b-x86-64.d
new file mode 100644
index 0000000..8dfebfb
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-18b-x86-64.d
@@ -0,0 +1,15 @@
+#source: ifunc-18b.s
+#source: ifunc-18a.s
+#as: --64
+#ld: -shared -melf_x86_64 -z nocombreloc
+#readelf: -r --wide
+#target: x86_64-*-*
+
+Relocation section '.rela.ifunc' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
+
+Relocation section '.rela.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
diff --git a/ld/testsuite/ld-ifunc/ifunc-18b.s b/ld/testsuite/ld-ifunc/ifunc-18b.s
new file mode 100644
index 0000000..fece413
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-18b.s
@@ -0,0 +1,15 @@
+ .text
+ .type foo, %gnu_indirect_function
+ .hidden foo
+ .globl foo
+foo:
+ ret
+ .size foo, .-foo
+ .globl bar
+bar:
+ jmp foo1@PLT
+ ret
+ .size bar, .-bar
+ .hidden foo1
+ .globl foo1
+ foo1 = foo
diff --git a/ld/testsuite/ld-ifunc/ifunc-19a-i386.d b/ld/testsuite/ld-ifunc/ifunc-19a-i386.d
new file mode 100644
index 0000000..8319bfc
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-19a-i386.d
@@ -0,0 +1,14 @@
+#source: ifunc-19a.s
+#source: ifunc-19b.s
+#ld: -shared -m elf_i386 -z nocombreloc
+#as: --32
+#readelf: -r --wide
+#target: x86_64-*-* i?86-*-*
+
+Relocation section '.rel.ifunc' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
+
+Relocation section '.rel.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
diff --git a/ld/testsuite/ld-ifunc/ifunc-19a-x86-64.d b/ld/testsuite/ld-ifunc/ifunc-19a-x86-64.d
new file mode 100644
index 0000000..fe576d2
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-19a-x86-64.d
@@ -0,0 +1,14 @@
+#source: ifunc-19a.s
+#source: ifunc-19b.s
+#as: --64
+#ld: -shared -melf_x86_64 -z nocombreloc
+#readelf: -r --wide
+#target: x86_64-*-*
+
+Relocation section '.rela.ifunc' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
+
+Relocation section '.rela.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
diff --git a/ld/testsuite/ld-ifunc/ifunc-19a.s b/ld/testsuite/ld-ifunc/ifunc-19a.s
new file mode 100644
index 0000000..3a3d0cd
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-19a.s
@@ -0,0 +1,5 @@
+ .section .data.rel,"aw",@progbits
+ .globl foo_ptrt
+ .type foo_ptr, @object
+foo_ptr:
+ .dc.a foo1
diff --git a/ld/testsuite/ld-ifunc/ifunc-19b-i386.d b/ld/testsuite/ld-ifunc/ifunc-19b-i386.d
new file mode 100644
index 0000000..5bb8170
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-19b-i386.d
@@ -0,0 +1,14 @@
+#source: ifunc-19b.s
+#source: ifunc-19a.s
+#ld: -shared -m elf_i386 -z nocombreloc
+#as: --32
+#readelf: -r --wide
+#target: x86_64-*-* i?86-*-*
+
+Relocation section '.rel.ifunc' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
+
+Relocation section '.rel.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
diff --git a/ld/testsuite/ld-ifunc/ifunc-19b-x86-64.d b/ld/testsuite/ld-ifunc/ifunc-19b-x86-64.d
new file mode 100644
index 0000000..35fa328
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-19b-x86-64.d
@@ -0,0 +1,14 @@
+#source: ifunc-19b.s
+#source: ifunc-19a.s
+#as: --64
+#ld: -shared -melf_x86_64 -z nocombreloc
+#readelf: -r --wide
+#target: x86_64-*-*
+
+Relocation section '.rela.ifunc' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
+
+Relocation section '.rela.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
diff --git a/ld/testsuite/ld-ifunc/ifunc-19b.s b/ld/testsuite/ld-ifunc/ifunc-19b.s
new file mode 100644
index 0000000..fece413
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc-19b.s
@@ -0,0 +1,15 @@
+ .text
+ .type foo, %gnu_indirect_function
+ .hidden foo
+ .globl foo
+foo:
+ ret
+ .size foo, .-foo
+ .globl bar
+bar:
+ jmp foo1@PLT
+ ret
+ .size bar, .-bar
+ .hidden foo1
+ .globl foo1
+ foo1 = foo
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