On Sun, Mar 29, 2015 at 7:40 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
> On Sun, Mar 29, 2015 at 7:34 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
>> On Sun, Mar 29, 2015 at 7:25 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
>>> We shouldn't call external function, __cpu_indicator_init, while an object
>>> is being relocated since its .got.plt section hasn't been updated. It
>>> works for non-PIE since no update on .got.plt section is required. This
>>> patch hides __cpu_indicator_init/__cpu_model from linker to force linker
>>> to resolve __cpu_indicator_init/__cpu_model to their hidden definitions
>>> in libgcc.a while providing backward binary compatibility.
>>>
>>> OK for trunk, 4.9 and 4.9 branches?
>>>
>>> Thanks.
>>>
>>>
>>> H.J.
>>> ---
>>> libgcc/
>>>
>>> PR target/65612
>>> * config/i386/cpuinfo.c (__cpu_model): Initialize.
>>> (__cpu_indicator_init@GCC_4.8.0): New.
>>> (__cpu_model@GCC_4.8.0): Likewise.
>>>
>>> gcc/testsuite/
>>>
>>> PR target/65612
>>> * g++.dg/ext/mv18.C: New test.
>>> * g++.dg/ext/mv19.C: Likewise.
>>> * g++.dg/ext/mv20.C: Likewise.
>>
>> It doesn' work for shared C++ library:
>>
>> /export/build/gnu/gcc-x32/release/usr/gcc-5.0.0-x32/bin/g++ -O2 -c
>> -o main.o main.cc
>> /export/build/gnu/gcc-x32/release/usr/gcc-5.0.0-x32/bin/g++ -shared
>> -fPIC -O2 -o libmv20.so mv20.cc
>> /export/build/gnu/gcc-x32/release/usr/gcc-5.0.0-x32/bin/g++ -O2 -o x
>> main.o libmv20.so -Wl,-R,.
>> /usr/local/bin/ld: x: hidden symbol `__cpu_model' in
>> /export/build/gnu/gcc-x32/release/usr/gcc-5.0.0-x32/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.0.0/libgcc.a(cpuinfo.o)
>> is referenced by DSO
>> /usr/local/bin/ld: final link failed: Bad value
>> collect2: error: ld returned 1 exit status
>> Makefile:12: recipe for target 'x' failed
>> make: *** [x] Error 1
>> [hjl@gnu-tools-1 pr65612]$
>>
>> --
>> H.J.
>
> We need something like libgcc_nonshared.a, which contains cpuinfo.o, and
> link together with -lgcc_s when creating executable or DSO.
>
I am testing it on Linux/x86-64. OK for master if regression test
passes?
--
H.J.
--
We shouldn't call external function, __cpu_indicator_init, while an object
is being relocated since its .got.plt section hasn't been updated. It
works for non-PIE since no update on .got.plt section is required. This
patch hides __cpu_indicator_init/__cpu_model from linker to force linker
to resolve __cpu_indicator_init/__cpu_model to their hidden definitions
in libgcc_nonshared.a while providing backward binary compatibility. The
new libgcc_nonshared.a is always linked togther with -lgcc_s and -lgcc.
gcc/
PR target/65612
* gcc.c (init_spec): Add -lgcc_nonshared/libgcc_nonshared.a%s
to -lgcc_s/-lgcc/libgcc.a%s.
gcc/testsuite/
PR target/65612
* g++.dg/ext/mv18.C: New test.
* g++.dg/ext/mv19.C: Likewise.
* g++.dg/ext/mv20.C: Likewise.
libgcc/
PR target/65612
* Makefile.in (LIB2ADDSHARED): New.
(LIB2ADDNONSHARED): Likewise.
(libgcc-nonshared-objects): Likewise.
(libgcc_nonshared.a): Likewise.
(libgcc-s-objects): Add $(LIB2ADDSHARED).
(all): Depend on libgcc_nonshared.a.
($(libgcc-nonshared-objects)): Depend on libgcc_tm.h.
(install-leaf): Install libgcc_nonshared.a.
* config/i386/cpuinfo.c (__cpu_model): Initialize.
(__cpu_indicator_init@GCC_4.8.0): New.
(__cpu_model@GCC_4.8.0): Likewise.
* config/i386/t-cpuinfo (LIB2ADD): Renamed to ...
(LIB2ADDSHARED): This.
From 2dc6879c0c33069a02ae52d494f05603de9fe317 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.to...@gmail.com>
Date: Sun, 29 Mar 2015 18:03:49 -0700
Subject: [PATCH] Hide __cpu_indicator_init/__cpu_model from linker
We shouldn't call external function, __cpu_indicator_init, while an object
is being relocated since its .got.plt section hasn't been updated. It
works for non-PIE since no update on .got.plt section is required. This
patch hides __cpu_indicator_init/__cpu_model from linker to force linker
to resolve __cpu_indicator_init/__cpu_model to their hidden definitions
in libgcc_nonshared.a while providing backward binary compatibility. The
new libgcc_nonshared.a is always linked togther with -lgcc_s and -lgcc.
gcc/
PR target/65612
* gcc.c (init_spec): Add -lgcc_nonshared/libgcc_nonshared.a%s
to -lgcc_s/-lgcc/libgcc.a%s.
gcc/testsuite/
PR target/65612
* g++.dg/ext/mv18.C: New test.
* g++.dg/ext/mv19.C: Likewise.
* g++.dg/ext/mv20.C: Likewise.
libgcc/
PR target/65612
* Makefile.in (LIB2ADDSHARED): New.
(LIB2ADDNONSHARED): Likewise.
(libgcc-nonshared-objects): Likewise.
(libgcc_nonshared.a): Likewise.
(libgcc-s-objects): Add $(LIB2ADDSHARED).
(all): Depend on libgcc_nonshared.a.
($(libgcc-nonshared-objects)): Depend on libgcc_tm.h.
(install-leaf): Install libgcc_nonshared.a.
* config/i386/cpuinfo.c (__cpu_model): Initialize.
(__cpu_indicator_init@GCC_4.8.0): New.
(__cpu_model@GCC_4.8.0): Likewise.
* config/i386/t-cpuinfo (LIB2ADD): Renamed to ...
(LIB2ADDSHARED): This.
(LIB2ADDNONSHARED): New.
---
gcc/gcc.c | 4 ++++
gcc/testsuite/g++.dg/ext/mv18.C | 7 +++++++
gcc/testsuite/g++.dg/ext/mv19.C | 7 +++++++
gcc/testsuite/g++.dg/ext/mv20.C | 7 +++++++
libgcc/Makefile.in | 20 +++++++++++++++++---
libgcc/config/i386/cpuinfo.c | 7 ++++++-
libgcc/config/i386/t-cpuinfo | 3 ++-
7 files changed, 50 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/ext/mv18.C
create mode 100644 gcc/testsuite/g++.dg/ext/mv19.C
create mode 100644 gcc/testsuite/g++.dg/ext/mv20.C
diff --git a/gcc/gcc.c b/gcc/gcc.c
index d956c36..88a8dac 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -1566,11 +1566,13 @@ init_spec (void)
if (in_sep && *p == '-' && strncmp (p, "-lgcc", 5) == 0)
{
init_gcc_specs (&obstack,
+ "-lgcc_nonshared "
"-lgcc_s"
#ifdef USE_LIBUNWIND_EXCEPTIONS
" -lunwind"
#endif
,
+ "-lgcc_nonshared "
"-lgcc",
"-lgcc_eh"
#ifdef USE_LIBUNWIND_EXCEPTIONS
@@ -1591,7 +1593,9 @@ init_spec (void)
/* Ug. We don't know shared library extensions. Hope that
systems that use this form don't do shared libraries. */
init_gcc_specs (&obstack,
+ "libgcc_nonshared.a%s "
"-lgcc_s",
+ "libgcc_nonshared.a%s "
"libgcc.a%s",
"libgcc_eh.a%s"
#ifdef USE_LIBUNWIND_EXCEPTIONS
diff --git a/gcc/testsuite/g++.dg/ext/mv18.C b/gcc/testsuite/g++.dg/ext/mv18.C
new file mode 100644
index 0000000..1f024de
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/mv18.C
@@ -0,0 +1,7 @@
+/* Test case to check if Multiversioning works. */
+/* { dg-do run { target i?86-*-* x86_64-*-* } } */
+/* { dg-require-ifunc "" } */
+/* { dg-require-effective-target pie } */
+/* { dg-options "-O2 -fPIE -pie" } */
+
+#include "mv1.C"
diff --git a/gcc/testsuite/g++.dg/ext/mv19.C b/gcc/testsuite/g++.dg/ext/mv19.C
new file mode 100644
index 0000000..d1ea788
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/mv19.C
@@ -0,0 +1,7 @@
+/* Test case to check if Multiversioning works. */
+/* { dg-do run { target i?86-*-* x86_64-*-* } } */
+/* { dg-require-ifunc "" } */
+/* { dg-require-effective-target pie } */
+/* { dg-options "-O2 -fPIE -pie -march=x86-64" } */
+
+#include "mv14.C"
diff --git a/gcc/testsuite/g++.dg/ext/mv20.C b/gcc/testsuite/g++.dg/ext/mv20.C
new file mode 100644
index 0000000..98f7408
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/mv20.C
@@ -0,0 +1,7 @@
+/* Test case to check if Multiversioning works. */
+/* { dg-do run { target i?86-*-* x86_64-*-* } } */
+/* { dg-require-ifunc "" } */
+/* { dg-require-effective-target pie } */
+/* { dg-options "-O2 -fPIE -pie -march=x86-64" } */
+
+#include "mv15.C"
diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
index 88ddfea..cec4ae0 100644
--- a/libgcc/Makefile.in
+++ b/libgcc/Makefile.in
@@ -261,6 +261,14 @@ LIB2ADD =
# Assembler files should have names ending in `.S'.
LIB2ADD_ST =
+# List of extra C and assembler files to add to shared libgcc2.
+# Assembler files should have names ending in `.S'.
+LIB2ADDSHARED =
+
+# List of extra C and assembler files to add to libgcc_nonshared.a.
+# Assembler files should have names ending in `.S'.
+LIB2ADDNONSHARED =
+
# Specify the directories to be searched for header files.
# Both . and srcdir are used, in that order,
# so that *config.h will be found in the compilation
@@ -806,13 +814,14 @@ endif
libgcc-objects += $(addsuffix $(objext),$(basename $(notdir $(LIB2ADD))))
libgcc-objects += $(addsuffix $(objext),$(basename $(notdir $(LIB2ADD_ST))))
+libgcc-nonshared-objects += $(addsuffix $(objext),$(basename $(notdir $(LIB2ADDNONSHARED))))
c_flags :=
iter-items := $(LIB2ADD) $(LIB2ADD_ST)
include $(iterator)
ifeq ($(enable_shared),yes)
-libgcc-s-objects += $(addsuffix _s$(objext),$(basename $(notdir $(LIB2ADD))))
+libgcc-s-objects += $(addsuffix _s$(objext),$(basename $(notdir $(LIB2ADD) $(LIB2ADDSHARED))))
endif
# Build LIB2ADDEH, LIB2ADDEHSTATIC, and LIB2ADDEHSHARED. If we don't have
@@ -890,8 +899,9 @@ libgcc.a: $(libgcc-objects)
libgcov.a: $(libgcov-objects)
libunwind.a: $(libunwind-objects)
libgcc_eh.a: $(libgcc-eh-objects)
+libgcc_nonshared.a: $(libgcc-nonshared-objects)
-libgcc.a libgcov.a libunwind.a libgcc_eh.a:
+libgcc.a libgcov.a libunwind.a libgcc_eh.a libgcc_nonshared.a:
-rm -f $@
objects="$(objects)"; \
@@ -905,7 +915,7 @@ libgcc.a libgcov.a libunwind.a libgcc_eh.a:
$(RANLIB) $@
-all: libgcc.a libgcov.a
+all: libgcc.a libgcc_nonshared.a libgcov.a
ifneq ($(LIBUNWIND),)
all: libunwind.a
@@ -1051,6 +1061,7 @@ libgcc-extra-parts: $(EXTRA_PARTS)
all: $(extra-parts)
$(libgcc-objects) $(libgcc-s-objects) $(libgcc-eh-objects) \
+ $(libgcc-nonshared-objects) \
$(libgcov-objects) \
$(libunwind-objects) $(libunwind-s-objects) \
$(EXTRA_PARTS): libgcc_tm.h
@@ -1118,6 +1129,9 @@ install-leaf: $(install-shared) $(install-libunwind)
$(INSTALL_DATA) libgcc.a $(DESTDIR)$(inst_libdir)/
chmod 644 $(DESTDIR)$(inst_libdir)/libgcc.a
$(RANLIB) $(DESTDIR)$(inst_libdir)/libgcc.a
+ $(INSTALL_DATA) libgcc_nonshared.a $(DESTDIR)$(inst_libdir)/
+ chmod 644 $(DESTDIR)$(inst_libdir)/libgcc_nonshared.a
+ $(RANLIB) $(DESTDIR)$(inst_libdir)/libgcc_nonshared.a
$(INSTALL_DATA) libgcov.a $(DESTDIR)$(inst_libdir)/
chmod 644 $(DESTDIR)$(inst_libdir)/libgcov.a
$(RANLIB) $(DESTDIR)$(inst_libdir)/libgcov.a
diff --git a/libgcc/config/i386/cpuinfo.c b/libgcc/config/i386/cpuinfo.c
index eaf2f10..9639c8d 100644
--- a/libgcc/config/i386/cpuinfo.c
+++ b/libgcc/config/i386/cpuinfo.c
@@ -109,7 +109,7 @@ struct __processor_model
unsigned int __cpu_type;
unsigned int __cpu_subtype;
unsigned int __cpu_features[1];
-} __cpu_model;
+} __cpu_model = { };
/* Get the specific type of AMD CPU. */
@@ -424,3 +424,8 @@ __cpu_indicator_init (void)
return 0;
}
+
+#if defined SHARED && !defined _WIN32
+__asm__ (".symver __cpu_indicator_init, __cpu_indicator_init@GCC_4.8.0");
+__asm__ (".symver __cpu_model, __cpu_model@GCC_4.8.0");
+#endif
diff --git a/libgcc/config/i386/t-cpuinfo b/libgcc/config/i386/t-cpuinfo
index 31c8db9..8dbe9e6 100644
--- a/libgcc/config/i386/t-cpuinfo
+++ b/libgcc/config/i386/t-cpuinfo
@@ -1 +1,2 @@
-LIB2ADD += $(srcdir)/config/i386/cpuinfo.c
+LIB2ADDSHARED += $(srcdir)/config/i386/cpuinfo.c
+LIB2ADDNONSHARED += $(srcdir)/config/i386/cpuinfo.c
--
1.9.3
