BZ#10375: Configure magic to use -fno-stack-protector if needed.

diff --git a/ChangeLog b/ChangeLog
index cde01738514f22a39a014160023fed0bca473e65..ecfdebcc135847b86fed87a461c219f1c2d94afe 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2012-05-16  Roland McGrath  <roland@hack.frob.com>
 
+       [BZ #10375]
+       * configure.in (NM): Add AC_CHECK_TOOL for it.
+       (libc_extra_cflags): New substituted variable.
+       Check for -fstack-protector being used implicitly.
+       * configure: Regenerated.
+       * config.make.in (config-extra-cflags): New variable,
+       gets @libc_extra_cflags@.
+       * Makeconfig (CFLAGS): Add $(config-extra-cflags) near the front.
+
        [BZ #10375]
        * configure.in: Check for _FORTIFY_SOURCE being predefined.
        (CPPUNDEFS): New substituted variable; add -U_FORTIFY_SOURCE if needed.

diff --git a/Makeconfig b/Makeconfig
index b81594f077cafae9d46b8bdd87f2623f7ed0d04a..3a09764dfafc0e8cbdb63e9cfbad5c2048a3877d 100644 (file)
--- a/Makeconfig
+++ b/Makeconfig
@@ -668,7 +668,7 @@ CPPFLAGS = $(CPPUNDEFS) $(CPPFLAGS-config) $($(subdir)-CPPFLAGS) \
           $(foreach lib,$(libof-$(basename $(@F))) \
                         $(libof-$(<F)) $(libof-$(@F)),$(CPPFLAGS-$(lib))) \
           $(CPPFLAGS-$(<F)) $(CPPFLAGS-$(@F)) $(CPPFLAGS-$(basename $(@F)))
-override CFLAGS        = -std=gnu99 $(gnu89-inline-CFLAGS) \
+override CFLAGS        = -std=gnu99 $(gnu89-inline-CFLAGS) $(config-extra-cflags) \
                  $(filter-out %frame-pointer,$(+cflags)) $(+gccwarn-c) \
                  $(sysdep-CFLAGS) $(CFLAGS-$(suffix $@)) $(CFLAGS-$(<F)) \
                  $(CFLAGS-$(@F)) \

diff --git a/NEWS b/NEWS
index dc0f11ae1c377f58cc400fa6881794a13eabd258..8d98497032acaf7f7cc037522f67fe6cde37e995 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -14,20 +14,20 @@ Version 2.16
   3440, 3748, 3768, 3866, 3868, 3906, 3976, 3992, 4026, 4108, 4596, 4822,
   5077, 5461, 5805, 5993, 6471, 6486, 6578, 6649, 6730, 6770, 6794, 6884,
   6890, 6894, 6895, 6907, 6911, 6959, 7064, 9739, 9902, 10110, 10135, 10140,
-  10153, 10210, 10254, 10346, 10545, 10716, 11174, 11322, 11365, 11451,
-  11494, 11521, 11677, 11837, 11959, 12047, 12097, 12193, 12297, 12298,
-  12301, 12340, 12354, 13058, 13361, 13525, 13526, 13527, 13528, 13529,
-  13530, 13531, 13532, 13533, 13547, 13551, 13552, 13553, 13555, 13556,
-  13559, 13563, 13566, 13583, 13592, 13594, 13613, 13618, 13637, 13656,
-  13658, 13673, 13691, 13695, 13704, 13705, 13706, 13726, 13738, 13739,
-  13750, 13758, 13760, 13761, 13775, 13786, 13787, 13792, 13806, 13824,
-  13840, 13841, 13844, 13846, 13851, 13852, 13854, 13871, 13872, 13873,
-  13879, 13883, 13884, 13885, 13886, 13892, 13895, 13908, 13910, 13911,
-  13912, 13913, 13914, 13915, 13916, 13917, 13918, 13919, 13920, 13921,
-  13922, 13923, 13924, 13926, 13927, 13928, 13938, 13941, 13942, 13954,
-  13955, 13956, 13963, 13967, 13970, 13973, 13979, 13983, 13986, 14012,
-  14027, 14033, 14034, 14040, 14043, 14044, 14049, 14053, 14055, 14064,
-  14080, 14083, 14103, 14104, 14109
+  10153, 10210, 10254, 10346, 10375 10545, 10716, 11174, 11322, 11365,
+  11451, 11494, 11521, 11677, 11837, 11959, 12047, 12097, 12193, 12297,
+  12298, 12301, 12340, 12354, 13058, 13361, 13525, 13526, 13527, 13528,
+  13529, 13530, 13531, 13532, 13533, 13547, 13551, 13552, 13553, 13555,
+  13556, 13559, 13563, 13566, 13583, 13592, 13594, 13613, 13618, 13637,
+  13656, 13658, 13673, 13691, 13695, 13704, 13705, 13706, 13726, 13738,
+  13739, 13750, 13758, 13760, 13761, 13775, 13786, 13787, 13792, 13806,
+  13824, 13840, 13841, 13844, 13846, 13851, 13852, 13854, 13871, 13872,
+  13873, 13879, 13883, 13884, 13885, 13886, 13892, 13895, 13908, 13910,
+  13911, 13912, 13913, 13914, 13915, 13916, 13917, 13918, 13919, 13920,
+  13921, 13922, 13923, 13924, 13926, 13927, 13928, 13938, 13941, 13942,
+  13954, 13955, 13956, 13963, 13967, 13970, 13973, 13979, 13983, 13986,
+  14012, 14027, 14033, 14034, 14040, 14043, 14044, 14049, 14053, 14055,
+  14064, 14080, 14083, 14103, 14104, 14109
 
 * ISO C11 support:
 

diff --git a/config.make.in b/config.make.in
index 4fa26081ffac4d96d59bdefe9afeda169687bef2..f0db19929b5d9f6d1c887c4ff281a1a29fdb19ce 100644 (file)
--- a/config.make.in
+++ b/config.make.in
@@ -34,6 +34,7 @@ config-sysdirs = @sysnames@
 cflags-cpu = @libc_cv_cc_submachine@
 asflags-cpu = @libc_cv_cc_submachine@
 
+config-extra-cflags = @libc_extra_cflags@
 config-cflags-sse4 = @libc_cv_cc_sse4@
 config-cflags-avx = @libc_cv_cc_avx@
 config-cflags-sse2avx = @libc_cv_cc_sse2avx@

diff --git a/configure b/configure
index c295277e406c0d845a94dd1a31d5e3dd56781622..f23c40f99d5889b1f9b59df6ecd64160fa6148d1 100755 (executable)
--- a/configure
+++ b/configure
@@ -632,6 +632,7 @@ libc_cv_localedir
 libc_cv_slibdir
 old_glibc_headers
 libc_cv_gcc_unwind_find_fde
+libc_extra_cflags
 CPPUNDEFS
 sizeof_long_double
 EGREP
@@ -666,6 +667,7 @@ libc_cv_gcc_static_libgcc
 CXX_SYSINCLUDES
 SYSINCLUDES
 AUTOCONF
+NM
 READELF
 SED
 MAKEINFO
@@ -5154,6 +5156,98 @@ else
   READELF="$ac_cv_prog_READELF"
 fi
 
+if test -n "$ac_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}nm", so it can be a program name with args.
+set dummy ${ac_tool_prefix}nm; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_NM+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$NM"; then
+  ac_cv_prog_NM="$NM" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_prog_NM="${ac_tool_prefix}nm"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+NM=$ac_cv_prog_NM
+if test -n "$NM"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $NM" >&5
+$as_echo "$NM" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+fi
+if test -z "$ac_cv_prog_NM"; then
+  ac_ct_NM=$NM
+  # Extract the first word of "nm", so it can be a program name with args.
+set dummy nm; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_ac_ct_NM+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$ac_ct_NM"; then
+  ac_cv_prog_ac_ct_NM="$ac_ct_NM" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_prog_ac_ct_NM="nm"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+ac_ct_NM=$ac_cv_prog_ac_ct_NM
+if test -n "$ac_ct_NM"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_NM" >&5
+$as_echo "$ac_ct_NM" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+  if test "x$ac_ct_NM" = x; then
+    NM="false"
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    NM=$ac_ct_NM
+  fi
+else
+  NM="$ac_cv_prog_NM"
+fi
+
 
 for ac_prog in autoconf
 do
@@ -7577,6 +7671,51 @@ if test $libc_cv_predef_fortify_source = yes; then
 fi
 
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CC implicitly enables -fstack-protector" >&5
+$as_echo_n "checking whether $CC implicitly enables -fstack-protector... " >&6; }
+if ${libc_cv_predef_stack_protector+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+extern void foobar (char *);
+int
+main ()
+{
+char large_array[2048]; foobar (large_array);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+libc_undefs=`$NM -u conftest.o |
+  LC_ALL=C $AWK '$1 == "U" { print $2 | "sort -u"; next } { exit(1) }' \
+    2>&5` || {
+  as_fn_error $? "confusing output from $NM -u" "$LINENO" 5
+}
+echo >&5 "libc_undefs='$libc_undefs'"
+case "$libc_undefs" in
+foobar) libc_cv_predef_stack_protector=no ;;
+'__stack_chk_fail
+foobar') libc_cv_predef_stack_protector=yes ;;
+*) as_fn_error $? "unexpected symbols in test: $libc_undefs" "$LINENO" 5 ;;
+esac
+else
+  as_fn_error $? "test compilation failed" "$LINENO" 5
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_predef_stack_protector" >&5
+$as_echo "$libc_cv_predef_stack_protector" >&6; }
+libc_extra_cflags=
+if test $libc_cv_predef_stack_protector = yes; then
+  libc_extra_cflags=-fno-stack-protector
+fi
+
+
 ### End of automated tests.
 ### Now run sysdeps configure fragments.
 

diff --git a/configure.in b/configure.in
index 0916e9ec5c064c4cf0bc4f0474f1a893cc5f674f..a9ee7334d6340a2fc0c4ae3448d275bb664d9fe9 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -927,6 +927,7 @@ AC_CHECK_PROG_VER(SED, sed, --version,
   SED=: aux_missing="$aux_missing sed")
 
 AC_CHECK_TOOL(READELF, readelf, false)
+AC_CHECK_TOOL(NM, nm, false)
 
 AC_CHECK_PROGS(AUTOCONF, autoconf, no)
 case "x$AUTOCONF" in
@@ -2052,6 +2053,39 @@ if test $libc_cv_predef_fortify_source = yes; then
 fi
 AC_SUBST(CPPUNDEFS)
 
+dnl Check for silly hacked compilers inserting -fstack-protector.
+dnl This breaks badly for the early startup code we compile, since
+dnl the compiled code can refer to a magic machine-dependent location
+dnl for the canary value before we have sufficient setup for that to
+dnl work.  It's also questionable to build all of libc with this flag
+dnl even when you're doing that for most applications you build, since
+dnl libc's code is so heavily-used and performance-sensitive.  If we
+dnl ever really want to make that work, it should be enabled explicitly
+dnl in the libc build, not inherited from implicit compiler settings.
+AC_CACHE_CHECK([whether $CC implicitly enables -fstack-protector],
+              libc_cv_predef_stack_protector, [
+AC_TRY_COMPILE([extern void foobar (char *);],
+              [char large_array[2048]; foobar (large_array);], [
+libc_undefs=`$NM -u conftest.o |
+  LC_ALL=C $AWK '$1 == "U" { print $2 | "sort -u"; next } { exit(1) }' \
+    2>&AS_MESSAGE_LOG_FD` || {
+  AC_MSG_ERROR([confusing output from $NM -u])
+}
+echo >&AS_MESSAGE_LOG_FD "libc_undefs='$libc_undefs'"
+case "$libc_undefs" in
+foobar) libc_cv_predef_stack_protector=no ;;
+'__stack_chk_fail
+foobar') libc_cv_predef_stack_protector=yes ;;
+*) AC_MSG_ERROR([unexpected symbols in test: $libc_undefs]) ;;
+esac],
+              [AC_MSG_ERROR([test compilation failed])])
+])
+libc_extra_cflags=
+if test $libc_cv_predef_stack_protector = yes; then
+  libc_extra_cflags=-fno-stack-protector
+fi
+AC_SUBST(libc_extra_cflags)
+
 ### End of automated tests.
 ### Now run sysdeps configure fragments.