[OE-core] [PATCH v3 3/6] gcc-runtime: Disable gcc version of libssp

Khem Raj raj.khem at gmail.com
Fri Apr 20 16:33:51 UTC 2018


libssp is implemented fully in glibc as well as in musl
so we really do not need the gcc version of this library
except may be for mingw, where we keep it enabled anyway
gcc in OE is built with the knowledge that C library
already provides libssp implementation, we should therefore
not need the gcc implementation of same.

libssp_nonshared piece is a detail which is needed when gcc
is the compiler, in glibc this is part of libc_nonshared.a
already and libc_nonshared.a is linked always when linking
with -lc becuase libc.so in glibc is actually a linker script

GROUP ( /usr/lib/libc.so.6 /usr/lib/libc_nonshared.a  AS_NEEDED ( /usr/lib/ld-linux-x86-64.so.2 ) )

which automatically links in the needed runtime bits, this however
is not the case for musl, where core SSP APIs are implemented in full
but compiler specific runtime isn't, for this we add a new package
called libssp_nonshared which generate the needed runtime stub
and gcc is already carrying patch to link to libssp_nonshared.a
on musl

This should fix a long standing problem where static PIE executable
were not buildable with OE since it was conflicting SSP implementation
one from C library and the other one from gcc and we end up with
duplicate symbol errors during linking.

Backport a patch from trunk which enhances enable|disable-libssp
to not only disable building libssp but also not emit the gcc
specs to use it for subsequent linking when stack-protector options
are used on compiler cmdline

Signed-off-by: Khem Raj <raj.khem at gmail.com>
---
Changes since v2:
- None

 meta/recipes-devtools/gcc/gcc-7.3.inc         |   7 +-
 ...cc-override-TARGET_LIBC_PROVIDES_SSP.patch | 204 ++++++++++++++++++
 meta/recipes-devtools/gcc/gcc-runtime.inc     |   4 +-
 3 files changed, 212 insertions(+), 3 deletions(-)
 create mode 100644 meta/recipes-devtools/gcc/gcc-7.3/0049-gcc-override-TARGET_LIBC_PROVIDES_SSP.patch

diff --git a/meta/recipes-devtools/gcc/gcc-7.3.inc b/meta/recipes-devtools/gcc/gcc-7.3.inc
index d968c322d2..98e5383b3c 100644
--- a/meta/recipes-devtools/gcc/gcc-7.3.inc
+++ b/meta/recipes-devtools/gcc/gcc-7.3.inc
@@ -72,6 +72,7 @@ SRC_URI = "\
            file://0045-Link-libgcc-using-LDFLAGS-not-just-SHLIB_LDFLAGS.patch \
            file://0047-sync-gcc-stddef.h-with-musl.patch \
            file://0048-gcc-Enable-static-PIE.patch \
+           file://0049-gcc-override-TARGET_LIBC_PROVIDES_SSP.patch \
            file://fix-segmentation-fault-precompiled-hdr.patch \
            file://no-sse-fix-test-case-failures.patch \
            ${BACKPORTS} \
@@ -93,10 +94,12 @@ FORTRAN = ""
 JAVA = ""
 
 LTO = "--enable-lto"
+SSP ?= "--disable-libssp"
+SSP_mingw = "--enable-libssp"
 
 EXTRA_OECONF_BASE = "\
     ${LTO} \
-    --enable-libssp \
+    ${SSP} \
     --enable-libitm \
     --disable-bootstrap \
     --disable-libmudflap \
@@ -120,7 +123,7 @@ EXTRA_OECONF_INITIAL = "\
     --disable-plugin \
     --enable-decimal-float=no \
     --without-isl \
-    gcc_cv_libc_provides_ssp=yes \
+    ${SSP} \
 "
 
 EXTRA_OECONF_PATHS = "\
diff --git a/meta/recipes-devtools/gcc/gcc-7.3/0049-gcc-override-TARGET_LIBC_PROVIDES_SSP.patch b/meta/recipes-devtools/gcc/gcc-7.3/0049-gcc-override-TARGET_LIBC_PROVIDES_SSP.patch
new file mode 100644
index 0000000000..7c53c95c3a
--- /dev/null
+++ b/meta/recipes-devtools/gcc/gcc-7.3/0049-gcc-override-TARGET_LIBC_PROVIDES_SSP.patch
@@ -0,0 +1,204 @@
+From 9815bd97561c778ee0bc0c17f245e88e66570111 Mon Sep 17 00:00:00 2001
+From: sandra <sandra at 138bc75d-0d04-0410-961f-82ee72b054a4>
+Date: Wed, 1 Nov 2017 02:14:19 +0000
+Subject: [PATCH] 2017-10-31  Sandra Loosemore  <sandra at codesourcery.com>
+
+	gcc/
+	* configure.ac (--enable-libssp): New.
+	(gcc_cv_libc_provides_ssp): Check for explicit setting before
+	trying to determine target-specific default.  Adjust indentation.
+	* configure: Regenerated.
+	* doc/install.texi (Configuration): Expand --disable-libssp
+	documentation.
+
+
+git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@254288 138bc75d-0d04-0410-961f-82ee72b054a4
+---
+Signed-off-by: Khem Raj <raj.khem at gmail.com>
+Upstream-Status: Backport [https://patchwork.ozlabs.org/patch/823049/]
+
+ gcc/ChangeLog        |  9 +++++++++
+ gcc/configure        | 26 +++++++++++++++++++++++---
+ gcc/configure.ac     | 24 ++++++++++++++++++++----
+ gcc/doc/install.texi |  3 ++-
+ 4 files changed, 54 insertions(+), 8 deletions(-)
+
+Index: gcc-7.3.0/gcc/configure.ac
+===================================================================
+--- gcc-7.3.0.orig/gcc/configure.ac
++++ gcc-7.3.0/gcc/configure.ac
+@@ -5719,10 +5719,25 @@ if test x$gcc_cv_solaris_crts = xyes; th
+   	    [Define if the system-provided CRTs are present on Solaris.])
+ fi
+ 
++AC_ARG_ENABLE(libssp,
++[AS_HELP_STRING([--enable-libssp], [enable linking against libssp])],
++[case "${enableval}" in
++  yes|no)
++    ;;
++  *)
++    AC_MSG_ERROR([unknown libssp setting $enableval])
++    ;;
++esac], [])
++
+ # Test for stack protector support in target C library.
+ AC_CACHE_CHECK(__stack_chk_fail in target C library,
+-      gcc_cv_libc_provides_ssp,
+-      [gcc_cv_libc_provides_ssp=no
++  gcc_cv_libc_provides_ssp,
++  [gcc_cv_libc_provides_ssp=no
++  if test "x$enable_libssp" = "xno"; then
++    gcc_cv_libc_provides_ssp=yes
++  elif test "x$enable_libssp" = "xyes"; then
++    gcc_cv_libc_provides_ssp=no
++  else
+     case "$target" in
+        *-*-musl*)
+ 	 # All versions of musl provide stack protector
+@@ -5759,8 +5774,9 @@ AC_CACHE_CHECK(__stack_chk_fail in targe
+ 	 AC_CHECK_FUNC(__stack_chk_fail,[gcc_cv_libc_provides_ssp=yes],
+            [echo "no __stack_chk_fail on this target"])
+         ;;
+-  *) gcc_cv_libc_provides_ssp=no ;;
+-    esac])
++       *) gcc_cv_libc_provides_ssp=no ;;
++    esac
++  fi])
+ 
+ if test x$gcc_cv_libc_provides_ssp = xyes; then
+   AC_DEFINE(TARGET_LIBC_PROVIDES_SSP, 1,
+Index: gcc-7.3.0/gcc/doc/install.texi
+===================================================================
+--- gcc-7.3.0.orig/gcc/doc/install.texi
++++ gcc-7.3.0/gcc/doc/install.texi
+@@ -1658,7 +1658,8 @@ not be built.
+ 
+ @item --disable-libssp
+ Specify that the run-time libraries for stack smashing protection
+-should not be built.
++should not be built or linked against.  On many targets library support
++is provided by the C library instead.
+ 
+ @item --disable-libquadmath
+ Specify that the GCC quad-precision math library should not be built.
+Index: gcc-7.3.0/gcc/configure
+===================================================================
+--- gcc-7.3.0.orig/gcc/configure
++++ gcc-7.3.0/gcc/configure
+@@ -940,6 +940,7 @@ enable_fix_cortex_a53_843419
+ with_glibc_version
+ enable_gnu_unique_object
+ enable_linker_build_id
++enable_libssp
+ enable_default_ssp
+ with_long_double_128
+ with_gc
+@@ -1679,6 +1680,7 @@ Optional Features:
+                           extension on glibc systems
+   --enable-linker-build-id
+                           compiler will always pass --build-id to linker
++  --enable-libssp         enable linking against libssp
+   --enable-default-ssp    enable Stack Smashing Protection as default
+   --enable-maintainer-mode
+                           enable make rules and dependencies not useful (and
+@@ -18450,7 +18452,7 @@ else
+   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
+   lt_status=$lt_dlunknown
+   cat > conftest.$ac_ext <<_LT_EOF
+-#line 18436 "configure"
++#line 18455 "configure"
+ #include "confdefs.h"
+ 
+ #if HAVE_DLFCN_H
+@@ -18556,7 +18558,7 @@ else
+   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
+   lt_status=$lt_dlunknown
+   cat > conftest.$ac_ext <<_LT_EOF
+-#line 18542 "configure"
++#line 18561 "configure"
+ #include "confdefs.h"
+ 
+ #if HAVE_DLFCN_H
+@@ -25234,6 +25236,7 @@ $as_echo "#define HAVE_AS_SPARC5_VIS4 1"
+ 
+ fi
+ 
++
+     { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for SPARC6 instructions" >&5
+ $as_echo_n "checking assembler for SPARC6 instructions... " >&6; }
+ if test "${gcc_cv_as_sparc_sparc6+set}" = set; then :
+@@ -25270,6 +25273,7 @@ $as_echo "#define HAVE_AS_SPARC6 1" >>co
+ 
+ fi
+ 
++
+     { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for LEON instructions" >&5
+ $as_echo_n "checking assembler for LEON instructions... " >&6; }
+ if test "${gcc_cv_as_sparc_leon+set}" = set; then :
+@@ -28947,6 +28951,18 @@ $as_echo "#define HAVE_SOLARIS_CRTS 1" >
+ 
+ fi
+ 
++# Check whether --enable-libssp was given.
++if test "${enable_libssp+set}" = set; then :
++  enableval=$enable_libssp; case "${enableval}" in
++  yes|no)
++    ;;
++  *)
++    as_fn_error "unknown libssp setting $enableval" "$LINENO" 5
++    ;;
++esac
++fi
++
++
+ # Test for stack protector support in target C library.
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking __stack_chk_fail in target C library" >&5
+ $as_echo_n "checking __stack_chk_fail in target C library... " >&6; }
+@@ -28954,6 +28970,11 @@ if test "${gcc_cv_libc_provides_ssp+set}
+   $as_echo_n "(cached) " >&6
+ else
+   gcc_cv_libc_provides_ssp=no
++  if test "x$enable_libssp" = "xno"; then
++    gcc_cv_libc_provides_ssp=yes
++  elif test "x$enable_libssp" = "xyes"; then
++    gcc_cv_libc_provides_ssp=no
++  else
+     case "$target" in
+        *-*-musl*)
+ 	 # All versions of musl provide stack protector
+@@ -29001,8 +29022,9 @@ else
+ fi
+ 
+         ;;
+-  *) gcc_cv_libc_provides_ssp=no ;;
++       *) gcc_cv_libc_provides_ssp=no ;;
+     esac
++  fi
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_libc_provides_ssp" >&5
+ $as_echo "$gcc_cv_libc_provides_ssp" >&6; }
+@@ -29037,18 +29059,15 @@ fi
+ 
+ 
+ # Test for <sys/sdt.h> on the target.
+-
+-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking sys/sdt.h in the target C library" >&5
+-$as_echo_n "checking sys/sdt.h in the target C library... " >&6; }
+-have_sys_sdt_h=no
++#GCC_TARGET_TEMPLATE([HAVE_SYS_SDT_H])
++#AC_MSG_CHECKING(sys/sdt.h in the target C library)
++#have_sys_sdt_h=no
+ #if test -f $target_header_dir/sys/sdt.h; then
+ #  have_sys_sdt_h=yes
+-#
+-#$as_echo "#define HAVE_SYS_SDT_H 1" >>confdefs.h
+-#
++#  AC_DEFINE(HAVE_SYS_SDT_H, 1,
++#            [Define if your target C library provides sys/sdt.h])
+ #fi
+-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $have_sys_sdt_h" >&5
+-$as_echo "$have_sys_sdt_h" >&6; }
++#AC_MSG_RESULT($have_sys_sdt_h)
+ 
+ # Check if TFmode long double should be used by default or not.
+ # Some glibc targets used DFmode long double, but with glibc 2.4
diff --git a/meta/recipes-devtools/gcc/gcc-runtime.inc b/meta/recipes-devtools/gcc/gcc-runtime.inc
index 97365a21dc..b4e5539575 100644
--- a/meta/recipes-devtools/gcc/gcc-runtime.inc
+++ b/meta/recipes-devtools/gcc/gcc-runtime.inc
@@ -24,8 +24,10 @@ RUNTIMELIBITM_nios2 = ""
 RUNTIMELIBITM_microblaze = ""
 RUNTIMELIBITM_riscv32 = ""
 RUNTIMELIBITM_riscv64 = ""
+RUNTIMELIBSSP ?= ""
+RUNTIMELIBSSP_mingw ?= "libssp"
 
-RUNTIMETARGET = "libssp libstdc++-v3 libgomp libatomic ${RUNTIMELIBITM} \
+RUNTIMETARGET = "libstdc++-v3 libgomp libatomic ${RUNTIMELIBITM} \
     ${@bb.utils.contains_any('FORTRAN', [',fortran',',f77'], 'libquadmath', '', d)} \
 "
 RUNTIMETARGET_append_x86 = " libmpx"
-- 
2.17.0




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