Re: [Qemu-devel] [PATCH v2] Fix QEMU build on OpenBSD on x86 archs

[Stefan Weil <sw@weilnetz.de>]

Am 10.12.2013 02:26, schrieb Brad Smith:
> This resolves the build issue with building the ROMs on OpenBSD on x86 archs.
> As of OpenBSD 5.3 the compiler builds PIE binaries by default and thus the
> whole OS/packages and so forth. The ROMs need to have PIE disabled. This
> is my initial attempt at trying to get somehting upstream so that QEMU
> both builds out of the box and to resolve the build issue with the
> buildbots that has been around for awhile. We have a patch in our ports
> tree but it is just the flags hardcoded into the Makefile which obviously
> is not appropriate for upstream.
>
> From the OpenBSD buildbots..
>   Building optionrom/multiboot.img
> ld: multiboot.o: relocation R_X86_64_16 can not be used when making a shared object; recompile with -fPIC
>
>
> Signed-off by: Brad Smith <brad@comstyle.com>
> ---
>
> Changes in v2:
>     * Fix '==' is not portable syntax.
>
>
> diff --git a/configure b/configure
> index 508f6a5..6d84885 100755
> --- a/configure
> +++ b/configure
> @@ -1342,6 +1342,10 @@ EOF
>    if compile_prog "-fPIE -DPIE" "-pie"; then
>      QEMU_CFLAGS="-fPIE -DPIE $QEMU_CFLAGS"
>      LDFLAGS="-pie $LDFLAGS"
> +    if test "$targetos" = OpenBSD; then
> +      CC_NOPIE="-fno-pie"
> +      LD_NOPIE="-nopie"
> +    fi
>      pie="yes"
>      if compile_prog "" "-Wl,-z,relro -Wl,-z,now" ; then
>        LDFLAGS="-Wl,-z,relro -Wl,-z,now $LDFLAGS"
> @@ -4307,6 +4311,8 @@ if test "$gcov" = "yes" ; then
>    echo "CONFIG_GCOV=y" >> $config_host_mak
>    echo "GCOV=$gcov_tool" >> $config_host_mak
>  fi
> +echo "CC_NOPIE=$CC_NOPIE" >> $config_host_mak
> +echo "LD_NOPIE=$LD_NOPIE" >> $config_host_mak
>  
>  # use included Linux headers
>  if test "$linux" = "yes" ; then
> diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile
> index 57d8bd0..0b35000 100644
> --- a/pc-bios/optionrom/Makefile
> +++ b/pc-bios/optionrom/Makefile
> @@ -12,6 +12,7 @@ $(call set-vpath, $(SRC_PATH)/pc-bios/optionrom)
>  CFLAGS := -Wall -Wstrict-prototypes -Werror -fomit-frame-pointer -fno-builtin
>  CFLAGS += -I$(SRC_PATH)
>  CFLAGS += $(call cc-option, $(CFLAGS), -fno-stack-protector)
> +CFLAGS += $(CC_NOPIE)

Would it be possible to add -fno-pie unconditionally here ...


>  QEMU_CFLAGS = $(CFLAGS)
>  
>  build-all: multiboot.bin linuxboot.bin kvmvapic.bin
> @@ -20,7 +21,7 @@ build-all: multiboot.bin linuxboot.bin kvmvapic.bin
>  .SECONDARY:
>  
>  %.img: %.o
> -	$(call quiet-command,$(LD) -Ttext 0 -e _start -s -o $@ $<,"  Building $(TARGET_DIR)$@")
> +	$(call quiet-command,$(LD) $(LD_NOPIE) -Ttext 0 -e _start -s -o $@ $<,"  Building $(TARGET_DIR)$@")
>  


... and use -nopie here? I tried it in my Linux build environment, and
it seems to work.

Then no changes to file configure are needed.

Stefan