Fangrui Song <i...@maskray.me> writes:
> For lld, --image-base is the preferred way to set the base address.
> lld does not actually implement -Ttext-segment, but treats it as an alias for
> -Ttext. -Ttext-segment=0x60000000 combined with --no-rosegment can
> create a 1.6GB executable.
>
> Fix the problem by using --image-base for lld. GNU ld and gold will
> still get -Ttext-segment. Also delete the ld --verbose fallback introduced
> in 2013, which is no longer relevant or correct (the default linker
> script has changed).
>
> Signed-off-by: Fangrui Song <i...@maskray.me>
This patch no longer applies cleanly to configure so I couldn't test it.
> ---
> configure | 33 ++++++++++++---------------------
> 1 file changed, 12 insertions(+), 21 deletions(-)
>
> diff --git a/configure b/configure
> index 6099be1d84..2d45af0d09 100755
> --- a/configure
> +++ b/configure
> @@ -6336,43 +6336,34 @@ fi
>
> # Probe for the need for relocating the user-only binary.
> if ( [ "$linux_user" = yes ] || [ "$bsd_user" = yes ] ) && [ "$pie" = no ];
> then
> - textseg_addr=
> + image_base=
> case "$cpu" in
> arm | i386 | ppc* | s390* | sparc* | x86_64 | x32)
> - # ??? Rationale for choosing this address
> - textseg_addr=0x60000000
> + # An arbitrary address that makes it unlikely to collide with user
> + # programs.
> + image_base=0x60000000
The comment probably belongs up above when we define the empty variable
unless it really is specifically about these targets.
Renaming textseg_addr seems like unnecessary churn for this patch.
> ;;
> 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
> + image_base=0x60000000
> ;;
> esac
> - if [ -n "$textseg_addr" ]; then
> + if [ -n "$image_base" ]; 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 ! $ld --verbose >/dev/null 2>&1; then
> + image_base_ldflags="-Wl,--image-base=$image_base"
> + if ! compile_prog "" "$image_base_ldflags"; then
> + image_base_ldflags="-Wl,-Ttext-segment=$image_base"
> + if ! compile_prog "" "$image_base_ldflags"; 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." \
> + "supports neither --image-base nor -Ttext-segment. " \
> "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 =
> $textseg_addr/" > config-host.ld
> - textseg_ldflags="-Wl,-T../config-host.ld"
> fi
> fi
> fi
> @@ -7945,7 +7936,7 @@ if test "$gprof" = "yes" ; then
> fi
>
> if test "$target_linux_user" = "yes" || test "$target_bsd_user" = "yes" ;
> then
> - ldflags="$ldflags $textseg_ldflags"
> + ldflags="$ldflags $image_base_ldflags"
> fi
>
> # Newer kernels on s390 check for an S390_PGSTE program header and
--
Alex Bennée
