xfsprogs: remove retpoline support

When it came up that xfsprogs was using retpolines by default,
the gcc folks inside Red Hat expressed ... alarm.  I'm not sure
of all the details, but I think the concern was that userspace
support for this is not really quite baked.

Unless/until there is a demonstrated side-channel which would
warrant retpolines here, let's just remove it for now.

Cc: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/configure.ac b/configure.ac
index c2834ab7220248443f1f22e534f9e1b4140924d3..2448416caaa50d37801ee78a9bc5838c09253dc0 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -234,7 +234,6 @@ if test "$enable_lto" = "yes" && test "$have_lto" != "yes"; then
        AC_MSG_ERROR([LTO not supported by compiler.])
 fi
 
-AC_PACKAGE_CHECK_RETPOLINE
 AC_CHECK_SIZEOF([long])
 AC_CHECK_SIZEOF([char *])
 AC_TYPE_UMODE_T

diff --git a/include/builddefs.in b/include/builddefs.in
index defea2c337c7b1625dd62c75c4990f5e868f05db..c5b38b073e1fa66010155957185b85cc03c856b9 100644 (file)
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -151,13 +151,6 @@ LIBICU_CFLAGS = @libicu_CFLAGS@
 SANITIZER_CFLAGS += @addrsan_cflags@ @threadsan_cflags@ @ubsan_cflags@
 SANITIZER_LDFLAGS += @addrsan_ldflags@ @threadsan_ldflags@ @ubsan_ldflags@
 
-# Enable retpolines if available
-HAVE_RETPOLINE = @have_retpoline@
-ifeq ($(HAVE_RETPOLINE),yes)
-OPTIMIZER += @retpoline_cflags@
-LOADERFLAGS += @retpoline_ldflags@
-endif
-
 # Use special ar/ranlib wrappers if we have lto
 HAVE_LTO = @have_lto@
 ifeq ($(HAVE_LTO),yes)

diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
index 268193d765bd4630acc599ca050eb26e4b70db36..7ee4acdd5fd4514b4cdb3ed2e25fe1a8ff11399c 100644 (file)
--- a/m4/package_libcdev.m4
+++ b/m4/package_libcdev.m4
@@ -429,25 +429,3 @@ AC_DEFUN([AC_PACKAGE_CHECK_LTO],
     AC_SUBST(lto_cflags)
     AC_SUBST(lto_ldflags)
   ])
-
-AC_DEFUN([AC_PACKAGE_CHECK_RETPOLINE],
-  [ AC_MSG_CHECKING([if C compiler supports retpoline])
-    OLD_CFLAGS="$CFLAGS"
-    OLD_LDFLAGS="$LDFLAGS"
-    RETPOLINE_FLAGS="-mindirect-branch=thunk"
-    CFLAGS="$CFLAGS $RETPOLINE_FLAGS"
-    LDFLAGS="$LDFLAGS $RETPOLINE_FLAGS"
-    AC_LINK_IFELSE([AC_LANG_PROGRAM([])],
-        [AC_MSG_RESULT([yes])]
-        [retpoline_cflags=$RETPOLINE_FLAGS]
-        [retpoline_ldflags=$RETPOLINE_FLAGS],
-        [AC_MSG_RESULT([no])])
-    if test -n "$retpoline_cflags"; then
-        have_retpoline=yes
-    fi
-    CFLAGS="${OLD_CFLAGS}"
-    LDFLAGS="${OLD_LDFLAGS}"
-    AC_SUBST(have_retpoline)
-    AC_SUBST(retpoline_cflags)
-    AC_SUBST(retpoline_ldflags)
-  ])