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authorNick Mathewson <nickm@torproject.org>2013-10-21 13:07:47 -0400
committerNick Mathewson <nickm@torproject.org>2013-10-21 13:07:47 -0400
commit21ac292820da5784cf3c87e77df57b7594071d09 (patch)
tree9d0bad038aeeaef805b7b059be3214d6a0e312b6
parent17d368281ad374908fb019e29f3f012659be010c (diff)
downloadtor-21ac292820da5784cf3c87e77df57b7594071d09.tar.gz
tor-21ac292820da5784cf3c87e77df57b7594071d09.zip
Give a better warning when stack protection breaks linking.
Fix for 9948; patch from Benedikt Gollatz.
-rw-r--r--acinclude.m49
-rw-r--r--changes/bug99486
-rw-r--r--configure.ac11
3 files changed, 25 insertions, 1 deletions
diff --git a/acinclude.m4 b/acinclude.m4
index af1505156c..2943734143 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -43,6 +43,8 @@ AC_DEFUN([TOR_DEFINE_CODEPATH],
])
dnl 1:flags
+dnl 2:also try to link (yes: non-empty string)
+dnl will set yes or no in $tor_can_link_$1 (as modified by AS_VAR_PUSHDEF)
AC_DEFUN([TOR_CHECK_CFLAGS], [
AS_VAR_PUSHDEF([VAR],[tor_cv_cflags_$1])
AC_CACHE_CHECK([whether the compiler accepts $1], VAR, [
@@ -51,6 +53,13 @@ AC_DEFUN([TOR_CHECK_CFLAGS], [
AC_TRY_COMPILE([], [return 0;],
[AS_VAR_SET(VAR,yes)],
[AS_VAR_SET(VAR,no)])
+ if test x$2 != x; then
+ AS_VAR_PUSHDEF([can_link],[tor_can_link_$1])
+ AC_TRY_LINK([], [return 0;],
+ [AS_VAR_SET(can_link,yes)],
+ [AS_VAR_SET(can_link,no)])
+ AS_VAR_POPDEF([can_link])
+ fi
CFLAGS="$tor_saved_CFLAGS"
])
if test x$VAR = xyes; then
diff --git a/changes/bug9948 b/changes/bug9948
new file mode 100644
index 0000000000..6a673c0548
--- /dev/null
+++ b/changes/bug9948
@@ -0,0 +1,6 @@
+ o Minor features (build):
+
+ - Check in configure whether we can link an executable when
+ stack protection is enabled so we can warn the user about a
+ potentially missing libssp. Addresses ticket 9948. Patch
+ from Benedikt Gollatz.
diff --git a/configure.ac b/configure.ac
index 77767c52a6..f1fa8812f8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -589,7 +589,16 @@ if test x$enable_gcc_hardening != xno; then
if test x$have_clang = xyes; then
TOR_CHECK_CFLAGS(-Qunused-arguments)
fi
- TOR_CHECK_CFLAGS(-fstack-protector-all)
+ TOR_CHECK_CFLAGS(-fstack-protector-all, also_link)
+ AS_VAR_PUSHDEF([can_compile], [tor_cv_cflags_-fstack-protector-all])
+ AS_VAR_PUSHDEF([can_link], [tor_can_link_-fstack-protector-all])
+ AS_VAR_IF(can_compile, [yes],
+ AS_VAR_IF(can_link, [yes],
+ [],
+ AC_MSG_ERROR([We tried to build with stack protection; it looks like your compiler supports it but your libc does not provide it. Are you missing libssp? (You can --disable-gcc-hardening to ignore this error.)]))
+ )
+ AS_VAR_POPDEF([can_link])
+ AS_VAR_POPDEF([can_compile])
TOR_CHECK_CFLAGS(-Wstack-protector)
TOR_CHECK_CFLAGS(-fwrapv)
TOR_CHECK_CFLAGS(--param ssp-buffer-size=1)