From 00e6d397103e2acae8261e5e691704b4f4be3b2b Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@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.
Check unsupported files in LIB2ADDNONSHARED or LIB2ADDSHARED.
(iter-items): Add $(LIB2ADDNONSHARED) $(LIB2ADDSHARED).
(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.
* shared-object.mk: Check empty $o.
* config/i386/cpuinfo.c (__cpu_model): Initialize.
(__cpu_indicator_init@GCC_4.8.0): New.
(__cpu_model@GCC_4.8.0): Likewise.
* config/t-slibgcc-elf-ver (HOST_LIBGCC2_CFLAGS ): Add
-DUSE_ELF_SYMVER.
* 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 | 28 ++++++++++++++++++++++++----
libgcc/config/i386/cpuinfo.c | 7 ++++++-
libgcc/config/i386/t-cpuinfo | 3 ++-
libgcc/config/t-slibgcc-elf-ver | 2 ++
libgcc/shared-object.mk | 2 ++
9 files changed, 61 insertions(+), 6 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
@@ -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
new file mode 100644
@@ -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"
new file mode 100644
@@ -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"
new file mode 100644
@@ -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"
@@ -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
@@ -807,12 +815,19 @@ endif
libgcc-objects += $(addsuffix $(objext),$(basename $(notdir $(LIB2ADD))))
libgcc-objects += $(addsuffix $(objext),$(basename $(notdir $(LIB2ADD_ST))))
+# Build LIB2ADDNONSHARED and LIB2ADDSHARED.
+ifneq ($(filter-out %.c %.S %.asm,$(LIB2ADDNONSHARED) $(LIB2ADDSHARED)),)
+$(error Unsupported files in LIB2ADDNONSHARED or LIB2ADDSHARED.)
+endif
+
+libgcc-nonshared-objects += $(addsuffix $(objext),$(basename $(notdir $(LIB2ADDNONSHARED))))
+
c_flags :=
-iter-items := $(LIB2ADD) $(LIB2ADD_ST)
+iter-items := $(LIB2ADD) $(LIB2ADD_ST) $(LIB2ADDNONSHARED) $(LIB2ADDSHARED)
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 +905,9 @@ 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 +921,7 @@ 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 +1067,7 @@ 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 +1135,9 @@ 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
@@ -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 USE_ELF_SYMVER
+__asm__ (".symver __cpu_indicator_init, __cpu_indicator_init@GCC_4.8.0");
+__asm__ (".symver __cpu_model, __cpu_model@GCC_4.8.0");
+#endif
@@ -1 +1,2 @@
-LIB2ADD += $(srcdir)/config/i386/cpuinfo.c
+LIB2ADDSHARED += $(srcdir)/config/i386/cpuinfo.c
+LIB2ADDNONSHARED += $(srcdir)/config/i386/cpuinfo.c
@@ -2,3 +2,5 @@
SHLIB_MKMAP = $(srcdir)/mkmap-symver.awk
SHLIB_MAPFILES = libgcc-std.ver
+
+HOST_LIBGCC2_CFLAGS += -DUSE_ELF_SYMVER
@@ -4,6 +4,7 @@
o := $(firstword $(iter-items))
iter-items := $(filter-out $o,$(iter-items))
+ifneq ($o,)
base := $(basename $(notdir $o))
c_flags-$o := $(c_flags)
@@ -36,3 +37,4 @@ $(base)_s$(objext): $o
$(gcc_s_compile) -c $(as_flags-$<) $<
endif
+endif
--
2.1.0