Don't force use of -fPIE for the dbus-daemon if apparently supported

It's a minor security benefit, but not automatically beneficial (it
enables ASLR, but breaks prelinking, some buggy toolchains, and some gdb
versions). Distributions who know their infrastructure works well can
enable it just as easily via

    ./configure CFLAGS="-fPIE" LDFLAGS="-pie"

without extra support from us, and that's a generic solution applicable to
many packages.

Similarly, don't force libdbus and libdbus-internal to be PIC: libtool
knows better than we do whether that's necessary/beneficial on a
particular platform.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=16621
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=27215
Bug-NB: NB#171940
Reviewed-by: Colin Walters <walters@verbum.org>

diff --git a/bus/Makefile.am b/bus/Makefile.am
index 5cba22babb9c089a00df3a461d03451f2732e7ca..dfb3bc34e58a3f9a8448f723e72be679b7bb5a63 100644 (file)
--- a/bus/Makefile.am
+++ b/bus/Makefile.am
@@ -1,8 +1,9 @@
 configdir=$(sysconfdir)/dbus-1
 dbus_daemon_execdir = $(DBUS_DAEMONDIR)
 
-INCLUDES=-I$(top_srcdir) $(DBUS_BUS_CFLAGS) @PIE_CFLAGS@               \
-       -DDBUS_SYSTEM_CONFIG_FILE=\""$(configdir)/system.conf"\"        \
+INCLUDES = -I$(top_srcdir) \
+       $(DBUS_BUS_CFLAGS) \
+       -DDBUS_SYSTEM_CONFIG_FILE=\""$(configdir)/system.conf"\" \
        -DDBUS_COMPILATION
 
 EFENCE=
@@ -88,7 +89,7 @@ dbus_daemon_LDADD=                                    \
        $(EFENCE)                                       \
        $(DBUS_BUS_LIBS)
 
-dbus_daemon_LDFLAGS=@R_DYNAMIC_LDFLAG@ @SECTION_LDFLAGS@ @PIE_LDFLAGS@
+dbus_daemon_LDFLAGS=@R_DYNAMIC_LDFLAG@ @SECTION_LDFLAGS@
 
 LAUNCH_HELPER_SOURCES=                         \
        $(XML_SOURCES)                          \

diff --git a/configure.ac b/configure.ac
index 075b583224611ff401bc494927b4717db1d771b1..459133c08dffc743b829637e45c6b6fc668d41a2 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1224,30 +1224,6 @@ dnl block.
      ;;
   esac
 
-  case " $CFLAGS " in
-  *[\ \        ]-fPIC[\ \      ]*) ;;
-  *) if test x$dbus_win = xno && cc_supports_flag -fPIC; then
-        PIC_CFLAGS="-fPIC"
-        if ld_supports_flag -z,relro; then
-           PIC_LDFLAGS="-Wl,-z,relro"
-        fi
-     fi
-     ;;
-  esac
-
-  case " $CFLAGS " in
-  *[\ \        ]-fPIE[\ \      ]*) ;;
-  *) if test x$dbus_win = xno && cc_supports_flag -fPIE; then
-        PIE_CFLAGS="-fPIE"
-        if ld_supports_flag -z,relro; then
-           PIE_LDFLAGS="-pie -Wl,-z,relro"
-        else
-           PIE_LDFLAGS="-pie"
-        fi
-     fi
-     ;;
-  esac
-
   ### Disabled warnings, and compiler flag overrides
 
   # Let's just ignore unused for now
@@ -1303,11 +1279,6 @@ dnl block.
   fi
 fi]
 
-AC_SUBST(PIC_CFLAGS)
-AC_SUBST(PIC_LDFLAGS)
-AC_SUBST(PIE_CFLAGS)
-AC_SUBST(PIE_LDFLAGS)
-
 if ld_supports_flag --gc-sections; then
   SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
   CFLAGS="-ffunction-sections -fdata-sections $CFLAGS"

diff --git a/dbus/Makefile.am b/dbus/Makefile.am
index 740def3e39f8a4edd41ccaa64c47081005ce0a48..2e6ca1dea9de9360cde99347e7494a14466c4936 100644 (file)
--- a/dbus/Makefile.am
+++ b/dbus/Makefile.am
@@ -1,9 +1,11 @@
 
 configdir=$(sysconfdir)/dbus-1
 
-INCLUDES=-I$(top_builddir) -I$(top_srcdir) $(DBUS_CLIENT_CFLAGS) @PIC_CFLAGS@ -DDBUS_COMPILATION       \
-       -DDBUS_MACHINE_UUID_FILE=\""$(localstatedir)/lib/dbus/machine-id"\"             \
-       -DDBUS_SYSTEM_CONFIG_FILE=\""$(configdir)/system.conf"\"                        \
+INCLUDES = -I$(top_builddir) -I$(top_srcdir) \
+       $(DBUS_CLIENT_CFLAGS) \
+       -DDBUS_COMPILATION \
+       -DDBUS_MACHINE_UUID_FILE=\""$(localstatedir)/lib/dbus/machine-id"\" \
+       -DDBUS_SYSTEM_CONFIG_FILE=\""$(configdir)/system.conf"\" \
        -DDBUS_SESSION_CONFIG_FILE=\""$(configdir)/session.conf"\"
 
 dbusincludedir=$(includedir)/dbus-1.0/dbus
@@ -261,7 +263,7 @@ noinst_LTLIBRARIES=libdbus-internal.la
 
 libdbus_1_la_CPPFLAGS= -Ddbus_1_EXPORTS
 libdbus_1_la_LIBADD= $(DBUS_CLIENT_LIBS)
-libdbus_1_la_LDFLAGS= $(export_symbols) -version-info $(LT_CURRENT):$(LT_REVISION):$(LT_AGE) -no-undefined @R_DYNAMIC_LDFLAG@ @PIC_LDFLAGS@
+libdbus_1_la_LDFLAGS= $(export_symbols) -version-info $(LT_CURRENT):$(LT_REVISION):$(LT_AGE) -no-undefined @R_DYNAMIC_LDFLAG@
 
 libdbus_internal_la_CPPFLAGS = -DDBUS_STATIC_BUILD
 libdbus_internal_la_LIBADD=$(DBUS_CLIENT_LIBS)