@@ -276,6 +276,12 @@ if 'CFLAGS' is specified it must enable optimization. For example:
the GNU C Library. The default value refers to the main
bug-reporting information for the GNU C Library.
+'--enable-fortify-source'
+'--enable-fortify-source=LEVEL'
+ Use -D_FORTIFY_SOURCE='LEVEL' to control code hardening, if not
+ provided, 'LEVEL' defaults to highest possible value for your
+ system, based on the supported 'CC' features.
+
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 '***'.
@@ -902,6 +902,11 @@ define elide-stack-protector
$(if $(filter $(@F),$(patsubst %,%$(1),$(2))), $(no-stack-protector))
endef
+# We might want to compile with fortify-source
+ifneq ($(fortify-source),)
++fortify-source=$(fortify-source)
+endif
+
# Some routine can't be fortified like the ones used by fortify
define elide-fortify-source
$(if $(filter $(@F),$(patsubst %,%$(1),$(2))), $(no-fortify-source))
@@ -973,7 +978,9 @@ endif # $(+cflags) == ""
# loader, cannot be fortified. Lastly debug is the fortification routines
# themselves and they cannot be fortified.
do-fortify = $(filter-out elf dlfcn csu debug,$(subdir))
-ifneq ($(do-fortify),$(subdir))
+ifeq ($(do-fortify),$(subdir))
++cflags += $(+fortify-source)
+else
+cflags += $(no-fortify-source)
endif
@@ -48,6 +48,10 @@ Major new features:
* The strlcpy and strlcat functions have been added. They are derived
from OpenBSD, and are expected to be added to a future POSIX version.
+* A new configure option, "--enable-fortify-source", can be used to build GLIBC
+ with _FORTIFY_SOURCE. The level of fortification can either be provided, or
+ is set to the highest value supported by the compiler.
+
Deprecated and removed features, and other changes affecting compatibility:
* In the Linux kernel for the hppa/parisc architecture some of the
@@ -502,9 +506,6 @@ Major new features:
* The audit libraries will avoid unnecessary slowdown if it is not required
PLT tracking (by not implementing the la_pltenter or la_pltexit callbacks).
-* Glibc now supports to be built with _FORTIFY_SOURCE. The value is undefined
- for parts of the library that can't be built with it.
-
Deprecated and removed features, and other changes affecting compatibility:
* On x86-64, the LD_PREFER_MAP_32BIT_EXEC environment variable support
@@ -64,6 +64,7 @@ have-fpie = @libc_cv_fpie@
have-ssp = @libc_cv_ssp@
stack-protector = @stack_protector@
no-stack-protector = @no_stack_protector@
+fortify-source = @fortify_source@
no-fortify-source = @no_fortify_source@
have-selinux = @have_selinux@
have-libaudit = @have_libaudit@
@@ -611,7 +611,10 @@ libc_cv_gcc_unwind_find_fde
libc_extra_cppflags
libc_extra_cflags
libc_cv_cxx_thread_local
+fortify_source
no_fortify_source
+libc_cv_fortify_source
+enable_fortify_source
have_selinux
have_libcap
have_libaudit
@@ -782,6 +785,7 @@ enable_pt_chown
enable_mathvec
enable_cet
enable_scv
+enable_fortify_source
with_cpu
'
ac_precious_vars='build_alias
@@ -1452,6 +1456,10 @@ Optional Features:
(CET), x86 only
--disable-scv syscalls will not use scv instruction, even if the
kernel supports it, powerpc only
+ --enable-fortify-source[=1|2|3]
+ Use -D_FORTIFY_SOURCE=[1|2|3] to control code
+ hardening, defaults to highest possible value for
+ your system
Optional Packages:
--with-PACKAGE[=ARG] use PACKAGE [ARG=yes]
@@ -3717,6 +3725,18 @@ if test "$use_scv" != "no"; then :
fi
+# Check whether --enable-fortify-source was given.
+if test "${enable_fortify_source+set}" = set; then :
+ enableval=$enable_fortify_source; enable_fortify_source=$enableval
+else
+ enable_fortify_source=no
+fi
+
+case "$enable_fortify_source" in
+1|2|3|no|yes) ;;
+*) as_fn_error $? "Not a valid argument for --enable-fortify-source: \"$enable_fortify_source\"" "$LINENO" 5;;
+esac
+
# We keep the original values in `$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.
@@ -6353,8 +6373,65 @@ $as_echo "#define HAVE_LIBCAP 1" >>confdefs.h
fi
+fortify_source=""
no_fortify_source="-Wp,-U_FORTIFY_SOURCE"
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for __builtin_dynamic_object_size" >&5
+$as_echo_n "checking for __builtin_dynamic_object_size... " >&6; }
+if ${libc_cv___builtin_dynamic_object_size+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+int
+main ()
+{
+__builtin_dynamic_object_size("", 0)
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+ libc_cv___builtin_dynamic_object_size=yes
+ if test "$enable_fortify_source" = yes; then :
+ enable_fortify_source=3
+fi
+else
+ libc_cv___builtin_dynamic_object_size=no
+ if test "$enable_fortify_source" = yes; then :
+ enable_fortify_source=2
+fi
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv___builtin_dynamic_object_size" >&5
+$as_echo "$libc_cv___builtin_dynamic_object_size" >&6; }
+
+case $enable_fortify_source in #(
+ 1|2) :
+ libc_cv_fortify_source=yes ;; #(
+ 3) :
+ if test "$libc_cv___builtin_dynamic_object_size" = yes; then :
+ libc_cv_fortify_source=yes
+else
+ as_fn_error $? "Compiler doesn't provide necessary support for _FORTIFY_SOURCE=3" "$LINENO" 5
+fi ;; #(
+ *) :
+ libc_cv_fortify_source=no ;;
+esac
+
+if test "$libc_cv_fortify_source" = yes; then :
+ fortify_source="${no_fortify_source},-D_FORTIFY_SOURCE=${enable_fortify_source}"
+
+fi
+
+
+
+
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the assembler requires one version per symbol" >&5
@@ -466,6 +466,17 @@ AC_ARG_ENABLE([scv],
AS_IF([[test "$use_scv" != "no"]],[AC_DEFINE(USE_PPC_SCV)])
+dnl Build glibc with _FORTIFY_SOURCE
+AC_ARG_ENABLE(fortify-source,
+ AS_HELP_STRING([--enable-fortify-source@<:@=1|2|3@:>@],
+ [Use -D_FORTIFY_SOURCE=[1|2|3] to control code hardening, defaults to highest possible value for your system]),
+ [enable_fortify_source=$enableval],
+ [enable_fortify_source=no])
+case "$enable_fortify_source" in
+1|2|3|no|yes) ;;
+*) AC_MSG_ERROR([Not a valid argument for --enable-fortify-source: "$enable_fortify_source"]);;
+esac
+
# 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 $os, and changes them whenever convenient.
@@ -1559,12 +1570,37 @@ if test "x$have_selinux" = xyes; then
fi
AC_SUBST(have_selinux)
-dnl Create a variable that can be used to control were _FORTIFY_SOURCE is set.
-dnl This will allow users to enable fortification through FLAGS or compiler
-dnl defaults macro definitions.
+dnl Check if we support the requested _FORTIFY_SOURCE level
+dnl If not, then don't use it.
+dnl Note that _FORTIFY_SOURCE may have been set through FLAGS too.
+dnl _FORTIFY_SOURCE value will be selectively disabled for function that can't
+dnl support it
+fortify_source=""
no_fortify_source="-Wp,-U_FORTIFY_SOURCE"
+AC_CACHE_CHECK([for __builtin_dynamic_object_size], [libc_cv___builtin_dynamic_object_size], [
+ AC_LINK_IFELSE([AC_LANG_PROGRAM([], [__builtin_dynamic_object_size("", 0)])],
+ [libc_cv___builtin_dynamic_object_size=yes
+ AS_IF([test "$enable_fortify_source" = yes], [enable_fortify_source=3])],
+ [libc_cv___builtin_dynamic_object_size=no
+ AS_IF([test "$enable_fortify_source" = yes], [enable_fortify_source=2])])
+])
+
+AS_CASE([$enable_fortify_source],
+ [1|2], [libc_cv_fortify_source=yes],
+ [3], [AS_IF([test "$libc_cv___builtin_dynamic_object_size" = yes],
+ [libc_cv_fortify_source=yes],
+ [AC_MSG_ERROR([Compiler doesn't provide necessary support for _FORTIFY_SOURCE=3])])],
+ [libc_cv_fortify_source=no])
+
+AS_IF([test "$libc_cv_fortify_source" = yes],
+ [fortify_source="${no_fortify_source},-D_FORTIFY_SOURCE=${enable_fortify_source}"]
+ )
+
+AC_SUBST(enable_fortify_source)
+AC_SUBST(libc_cv_fortify_source)
AC_SUBST(no_fortify_source)
+AC_SUBST(fortify_source)
dnl Starting with binutils 2.35, GAS can attach multiple symbol versions
dnl to one symbol (PR 23840).
@@ -303,6 +303,12 @@ Specify the URL that users should visit if they wish to report a bug,
to be included in @option{--help} output from programs installed with
@theglibc{}. The default value refers to the main bug-reporting
information for @theglibc{}.
+
+@item --enable-fortify-source
+@itemx --enable-fortify-source=@var{LEVEL}
+Use -D_FORTIFY_SOURCE=@option{LEVEL} to control code hardening, if not
+provided, @option{LEVEL} defaults to highest possible value for your system,
+based on the supported @code{CC} features.
@end table
To build the library and related programs, type @code{make}. This will
@@ -464,7 +464,9 @@ class Context(object):
{'arch': 'i486',
'ccopts': '-m32 -march=i486'},
{'arch': 'i586',
- 'ccopts': '-m32 -march=i586'}])
+ 'ccopts': '-m32 -march=i586'},
+ {'variant': 'enable-fortify-source',
+ 'cfg': ['--enable-fortify-source']}])
self.add_config(arch='x86_64',
os_name='gnu',
gcc_cfg=['--disable-multilib'])
It is now possible to enable fortification through a configure option. The level may be given as parameter, if none is provided, the configure script will determine what is the highest level possible that can be set considering GCC built-ins availability and set it. If level is explicitly set to 3, configure checks if the compiler supports the built-in function necessary for it or raise an error if it isn't. The result of the configure checks is a new variables, ${fortify_source} that can be used to appropriately populate CFLAGS. Updated NEWS and INSTALL. Adding dedicated x86_64 variant that enables the configuration. --- INSTALL | 6 +++ Makeconfig | 9 ++++- NEWS | 7 ++-- config.make.in | 1 + configure | 77 ++++++++++++++++++++++++++++++++++++ configure.ac | 42 ++++++++++++++++++-- manual/install.texi | 6 +++ scripts/build-many-glibcs.py | 4 +- 8 files changed, 144 insertions(+), 8 deletions(-)