Re: [PATCH 1/7] configure: Drop adjustment of textseg

[Thomas Huth]

On 18/12/2019 04.19, Richard Henderson wrote:
> This adjustment was random and unnecessary.  The user mode
> startup code in probe_guest_base() will choose a value for
> guest_base that allows the host qemu binary to not conflict
> with the guest binary.
> 
> With modern distributions, this isn't even used, as the default
> is PIE, which does the same job in a more portable way.
> 
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  configure | 47 -----------------------------------------------
>  1 file changed, 47 deletions(-)
> 
> diff --git a/configure b/configure
> index 84b413dbfc..255ac432af 100755
> --- a/configure
> +++ b/configure
> @@ -6292,49 +6292,6 @@ if test "$cpu" = "s390x" ; then
>    fi
>  fi
>  
> -# Probe for the need for relocating the user-only binary.
> -if ( [ "$linux_user" = yes ] || [ "$bsd_user" = yes ] ) && [ "$pie" = no ]; 
> then
> -  textseg_addr=
> -  case "$cpu" in
> -    arm | i386 | ppc* | s390* | sparc* | x86_64 | x32)
> -      # ??? Rationale for choosing this address
> -      textseg_addr=0x60000000
> -      ;;
> -    mips)
> -      # A 256M aligned address, high in the address space, with enough
> -      # room for the code_gen_buffer above it before the stack.
> -      textseg_addr=0x60000000
> -      ;;
> -  esac
> -  if [ -n "$textseg_addr" ]; then
> -    cat > $TMPC <<EOF
> -    int main(void) { return 0; }
> -EOF
> -    textseg_ldflags="-Wl,-Ttext-segment=$textseg_addr"
> -    if ! compile_prog "" "$textseg_ldflags"; then
> -      # In case ld does not support -Ttext-segment, edit the default linker
> -      # script via sed to set the .text start addr.  This is needed on 
> FreeBSD
> -      # at least.
> -      if ! $ld --verbose >/dev/null 2>&1; then
> -        error_exit \
> -            "We need to link the QEMU user mode binaries at a" \
> -            "specific text address. Unfortunately your linker" \
> -            "doesn't support either the -Ttext-segment option or" \
> -            "printing the default linker script with --verbose." \
> -            "If you don't want the user mode binaries, pass the" \
> -            "--disable-user option to configure."
> -      fi
> -
> -      $ld --verbose | sed \
> -        -e '1,/==================================================/d' \
> -        -e '/==================================================/,$d' \
> -        -e "s/[.] = [0-9a-fx]* [+] SIZEOF_HEADERS/. = $textseg_addr + 
> SIZEOF_HEADERS/" \
> -        -e "s/__executable_start = [0-9a-fx]*/__executable_start = 
> $textseg_addr/" > config-host.ld
> -      textseg_ldflags="-Wl,-T../config-host.ld"

config-host.ld is mentioned one more time in the main "Makefile" ... I
think you could remove it from there now, too.

With such a hunk added:

Reviewed-by: Thomas Huth <address@hidden>