configure: Add --enable-sframe option

Enable SFrame stack track information. The --enable-sframe option
allows the glibc build to compile with SFrame stack track
information. Thus, enabling glibc's backtrace to work within glibc.

Signed-off-by: Claudiu Zissulescu <claudiu.zissulescu-ianculescu@oracle.com>
Reviewed-by: DJ Delorie <dj@redhat.com>
Reviewed-by: Sam James <sam@gentoo.org>

INSTALL

@@ -291,6 +291,11 @@ passed to 'configure'.  For example:
 
      Default is to disable fortification.
 
+'--disable-sframe'
+     By default, the GNU C Library is built with '-Wa,--gsframe' if the
+     current GNU 'binutils' supports it.  You may want to use this
+     option if you don't plan to use SFrame stack tracer.
+
    To build the library and related programs, type 'make'.  This will
 produce a lot of output, some of which may look like errors from 'make'
 but aren't.  Look for error messages from 'make' containing '***'.

Makeconfig

@@ -1030,6 +1030,12 @@ endif
 # Filter out 64 bit time_t flags if compiler defines it by default.
 +cflags += $(no-time-bits-source)
 
+# Enable SFrame while compiling for stack backtracing.
+ifeq ($(enable-gsframe),yes)
+as-sframe = -Wa,--gsframe
+endif
++cflags += $(as-sframe)
+
 # Each sysdeps directory can contain header files that both will be
 # used to compile and will be installed.  Each can also contain an
 # include/ subdirectory, whose header files will be used to compile
@@ -1178,7 +1184,7 @@ endif
 ifndef ASFLAGS
 ASFLAGS := $(filter -g% -fdebug-prefix-map=%,$(CFLAGS))
 endif
-override ASFLAGS += -Werror=undef $(ASFLAGS-config) $(asflags-cpu)
+override ASFLAGS += -Werror=undef $(ASFLAGS-config) $(asflags-cpu) $(as-sframe)
 
 move-if-change = $(SHELL) $(..)scripts/move-if-change
 

NEWS

@@ -31,6 +31,10 @@ Major new features:
   glibc.malloc.tcache_max to a larger value (max 4194304).
   Tcache is also significantly faster for small sizes.
 
+* New stack tracer using SFrame.  Introducing --disable-sframe a new
+  configuration flag.  Building glibc using sframe is automatically
+  enabled when the build system supports it.
+
 Deprecated and removed features, and other changes affecting compatibility:
 
 * The glibc.rtld.execstack now supports a compatibility mode to allow

config.make.in

@@ -51,6 +51,7 @@ c++-cstdlib-header = @CXX_CSTDLIB_HEADER@
 c++-cmath-header = @CXX_CMATH_HEADER@
 c++-bits-std_abs-h = @CXX_BITS_STD_ABS_H@
 enable-werror = @enable_werror@
+enable-gsframe = @enable_gsframe@
 
 have-z-execstack = @libc_cv_z_execstack@
 have-no-error-execstack = @libc_cv_no_error_execstack@

configure

@@ -620,6 +620,8 @@ DEFINES
 static_nss
 profile
 libc_cv_multidir
+enable_gsframe
+READELF_SFRAME
 libc_cv_test_x86_have_amx_tile
 test_enable_cet
 libc_cv_test_cc_mprefer_vector_width
@@ -822,6 +824,7 @@ enable_mathvec
 enable_cet
 enable_scv
 enable_fortify_source
+enable_sframe
 with_cpu
 '
       ac_precious_vars='build_alias
@@ -1507,6 +1510,8 @@ Optional Features:
                           Use -D_FORTIFY_SOURCE=[1|2|3] to control code
                           hardening, defaults to highest possible value
                           supported by the build compiler.
+  --disable-sframe        Disable building with SFrame stack trace information
+                          [default=yes if GNU as is 2.41 or older]
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
@@ -4885,6 +4890,16 @@ case "$enable_fortify_source" in
 *) as_fn_error $? "Not a valid argument for --enable-fortify-source: \"$enable_fortify_source\"" "$LINENO" 5;;
 esac
 
+# Check whether --enable-sframe was given.
+if test ${enable_sframe+y}
+then :
+  enableval=$enable_sframe; use_sframe=$enableval
+else case e in #(
+  e) use_sframe=notset ;;
+esac
+fi
+
+
 # We keep the original values in `$config_*' and never modify them, so we
 # can write them unchanged into config.make.  Everything else uses
 # $machine, $vendor, and $os, and changes them whenever convenient.
@@ -9341,6 +9356,120 @@ have-libgcc_s = $libc_cv_have_libgcc_s"
 
 
 
+# Glibc stacktracer supports SFrame v2 or newer
+libc_cv_readelf_version_ok=yes
+# SFrame is supported from 2.41 or higher
+for ac_prog in $READELF
+do
+  # Extract the first word of "$ac_prog", so it can be a program name with args.
+set dummy $ac_prog; ac_word=$2
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_READELF_SFRAME+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if test -n "$READELF_SFRAME"; then
+  ac_cv_prog_READELF_SFRAME="$READELF_SFRAME" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
+    ac_cv_prog_READELF_SFRAME="$ac_prog"
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi ;;
+esac
+fi
+READELF_SFRAME=$ac_cv_prog_READELF_SFRAME
+if test -n "$READELF_SFRAME"; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $READELF_SFRAME" >&5
+printf "%s\n" "$READELF_SFRAME" >&6; }
+else
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+fi
+
+
+  test -n "$READELF_SFRAME" && break
+done
+
+if test -z "$READELF_SFRAME"; then
+  ac_verc_fail=yes
+else
+  # Found it, now check the version.
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking version of $READELF_SFRAME" >&5
+printf %s "checking version of $READELF_SFRAME... " >&6; }
+  ac_prog_version=`$READELF_SFRAME --version 2>&1 | sed -n 's/^.*GNU readelf.* \([0-9][0-9]*\.[0-9.]*\).*$/\1/p'`
+  case $ac_prog_version in
+    '') ac_prog_version="v. ?.??, bad"; ac_verc_fail=yes;;
+    2.4[1-9]*|2.[5-9][0-9]*|[3-9].*|[1-9][0-9][0-9]*)
+       ac_prog_version="$ac_prog_version, ok"; ac_verc_fail=no;;
+    *) ac_prog_version="$ac_prog_version, bad"; ac_verc_fail=yes;;
+
+  esac
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_prog_version" >&5
+printf "%s\n" "$ac_prog_version" >&6; }
+fi
+if test $ac_verc_fail = yes; then
+  libc_cv_readelf_version_ok=no
+fi
+
+
+# Check the current toolchain for SFrame support
+if test $libc_cv_readelf_version_ok = yes; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for SFrame support" >&5
+printf %s "checking for SFrame support... " >&6; }
+if test ${libc_cv_default_sframe+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) cat > conftest.c <<EOF
+int test_function(void)
+{
+  return 42;
+}
+EOF
+  libc_cv_default_sframe=no
+  if ${CC} -c conftest.c -o conftest.o -Wa,--gsframe >/dev/null 2>&1 && \
+     # Check if .sframe section is present and if version > 1
+     $READELF --sframe conftest.o | grep "SFRAME_VER" | grep -qv "VERSION_1"; then
+          libc_cv_default_sframe=yes
+  fi
+  rm -f conftest.c conftest.o
+   ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_default_sframe" >&5
+printf "%s\n" "$libc_cv_default_sframe" >&6; }
+fi
+
+# Prevent enabling sframe on non-supporting toolchains
+enable_gsframe=no
+if test $use_sframe$libc_cv_default_sframe = yesyes || \
+   test $use_sframe$libc_cv_default_sframe = notsetyes; then
+  enable_gsframe=yes
+elif test $use_sframe = yes; then
+   { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in '$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in '$ac_pwd':" >&2;}
+as_fn_error $? "toolchain doesn't support SFrame v2 or higher
+See 'config.log' for more details" "$LINENO" 5; }
+fi
+
+
 # Set the `multidir' variable by grabbing the variable from the compiler.
 # We do it once and save the result in a generated makefile.
 libc_cv_multidir=`${CC-cc} $CFLAGS $CPPFLAGS -print-multi-directory`

configure.ac

@@ -440,6 +440,12 @@ case "$enable_fortify_source" in
 *) AC_MSG_ERROR([Not a valid argument for --enable-fortify-source: "$enable_fortify_source"]);;
 esac
 
+AC_ARG_ENABLE([sframe],
+	      [AS_HELP_STRING([--disable-sframe],
+			     [Disable building with SFrame stack trace information @<:@default=yes if GNU as is 2.41 or older@:>@])],
+	      [use_sframe=$enableval],
+	      [use_sframe=notset])
+
 # We keep the original values in `$config_*' and never modify them, so we
 # can write them unchanged into config.make.  Everything else uses
 # $machine, $vendor, and $os, and changes them whenever convenient.
@@ -2115,6 +2121,44 @@ AC_SUBST(libc_cv_test_cc_mprefer_vector_width)
 AC_SUBST(test_enable_cet)
 AC_SUBST(libc_cv_test_x86_have_amx_tile)
 
+# Glibc stacktracer supports SFrame v2 or newer
+libc_cv_readelf_version_ok=yes
+# SFrame is supported from 2.41 or higher
+AC_CHECK_PROG_VER(READELF_SFRAME, $READELF, --version,
+  [GNU readelf.* \([0-9][0-9]*\.[0-9.]*\)],
+  [2.4[1-9]*|2.[5-9][0-9]*|[3-9].*|[1-9][0-9][0-9]*],
+  libc_cv_readelf_version_ok=no)
+
+# Check the current toolchain for SFrame support
+if test $libc_cv_readelf_version_ok = yes; then
+  AC_CACHE_CHECK([for SFrame support], libc_cv_default_sframe,
+  [dnl
+cat > conftest.c <<EOF
+int test_function(void)
+{
+  return 42;
+}
+EOF
+  libc_cv_default_sframe=no
+  if ${CC} -c conftest.c -o conftest.o -Wa,--gsframe >/dev/null 2>&1 && \
+     # Check if .sframe section is present and if version > 1
+     $READELF --sframe conftest.o | grep "SFRAME_VER" | grep -qv "VERSION_1"; then
+          libc_cv_default_sframe=yes
+  fi
+  rm -f conftest.c conftest.o
+  ])
+fi
+
+# Prevent enabling sframe on non-supporting toolchains
+enable_gsframe=no
+if test $use_sframe$libc_cv_default_sframe = yesyes || \
+   test $use_sframe$libc_cv_default_sframe = notsetyes; then
+  enable_gsframe=yes
+elif test $use_sframe = yes; then
+   AC_MSG_FAILURE([toolchain doesn't support SFrame v2 or higher])
+fi
+AC_SUBST(enable_gsframe)
+
 # Set the `multidir' variable by grabbing the variable from the compiler.
 # We do it once and save the result in a generated makefile.
 libc_cv_multidir=`${CC-cc} $CFLAGS $CPPFLAGS -print-multi-directory`

manual/install.texi

@@ -320,6 +320,11 @@ If not provided, @option{LEVEL} defaults to highest possible value supported by
 the build compiler.
 
 Default is to disable fortification.
+
+@item --disable-sframe
+By default, the GNU C Library is built with @option{-Wa,--gsframe} if
+the current GNU @code{binutils} supports it. You may want to use this
+option if you don't plan to use SFrame stack tracer.
 @end table
 
 To build the library and related programs, type @code{make}.  This will