diff options
| author | Nick Mathewson <nickm@torproject.org> | 2016-04-12 18:59:40 -0400 |
|---|---|---|
| committer | Nick Mathewson <nickm@torproject.org> | 2016-05-12 11:21:28 -0400 |
| commit | ce854a8d22d5056cc1a47a0d4d4251f93a0c667c (patch) | |
| tree | 52579eb2bff509a54933805655a70f4091e7b4c0 /acinclude.m4 | |
| parent | bd34edc18d6e21f5ba7bddf5a7ebe6582e8dc639 (diff) | |
| download | tor-ce854a8d22d5056cc1a47a0d4d4251f93a0c667c.tar.gz tor-ce854a8d22d5056cc1a47a0d4d4251f93a0c667c.zip | |
Add -ftrapv to gcc-hardening ... mostly!
We know there are overflows in curve25519-donna-c32, so we'll have
to have that one be fwrapv.
Only apply the asan, ubsan, and trapv options to the code that does
not need to run in constant time. Those options introduce branches
to the code they instrument.
(These introduced branches should never actually be taken, so it
might _still_ be constant time after all, but branch predictors are
complicated enough that I'm not really confident here. Let's aim for
safety.)
Closes 17983.
Diffstat (limited to 'acinclude.m4')
| -rw-r--r-- | acinclude.m4 | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/acinclude.m4 b/acinclude.m4 index 7b1aab2f99..4b9f0953e9 100644 --- a/acinclude.m4 +++ b/acinclude.m4 @@ -42,10 +42,11 @@ AC_DEFUN([TOR_DEFINE_CODEPATH], AC_SUBST(TOR_LDFLAGS_$2) ]) -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], [ +dnl 1: flags +dnl 2: try to link too if this is nonempty. +dnl 3: what to do on success compiling +dnl 4: what to do on failure compiling +AC_DEFUN([TOR_TRY_COMPILE_WITH_CFLAGS], [ AS_VAR_PUSHDEF([VAR],[tor_cv_cflags_$1]) AC_CACHE_CHECK([whether the compiler accepts $1], VAR, [ tor_saved_CFLAGS="$CFLAGS" @@ -63,12 +64,21 @@ AC_DEFUN([TOR_CHECK_CFLAGS], [ CFLAGS="$tor_saved_CFLAGS" ]) if test x$VAR = xyes; then - CFLAGS="$CFLAGS $1" + $3 + else + $4 fi AS_VAR_POPDEF([VAR]) ]) 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], [ + TOR_TRY_COMPILE_WITH_CFLAGS($1, $2, CFLAGS="$CFLAGS $1", /bin/true) +]) + +dnl 1:flags dnl 2:extra ldflags dnl 3:extra libraries AC_DEFUN([TOR_CHECK_LDFLAGS], [ |