While for our present .data.read_mostly it may be deemed tolerable that
the name is truncated to .data.re, for the planned .init.trampoline an
abbreviation to .init.tr would end up pretty meaningless. Engage the
long section names extension that GNU ld has had support for already in
2.22 (which we consider the baseline release for xen.efi building).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
Interestingly builds with debug info actually use long section names by
default, at least with recent ld. Or I'm unaware of where we control
that behavior.

--- a/xen/arch/x86/arch.mk
+++ b/xen/arch/x86/arch.mk
@@ -91,7 +91,7 @@ XEN_BUILD_EFI := $(call if-success,$(CC)
                                          -c $(srctree)/$(efi-check).c -o $(efi-check).o,y)
 
 # Check if the linker supports PE.
-EFI_LDFLAGS := $(patsubst -m%,-mi386pep,$(LDFLAGS)) --subsystem=10
+EFI_LDFLAGS := $(patsubst -m%,-mi386pep,$(LDFLAGS)) --subsystem=10 --enable-long-section-names
 LD_PE_check_cmd = $(call ld-option,$(EFI_LDFLAGS) --image-base=0x100000000 -o $(efi-check).efi $(efi-check).o)
 XEN_BUILD_PE := $(LD_PE_check_cmd)

On Mon, Sep 23, 2024 at 4:39 PM Jan Beulich <jbeulich@suse.com> wrote:
>
> While for our present .data.read_mostly it may be deemed tolerable that
> the name is truncated to .data.re, for the planned .init.trampoline an
> abbreviation to .init.tr would end up pretty meaningless. Engage the
> long section names extension that GNU ld has had support for already in
> 2.22 (which we consider the baseline release for xen.efi building).
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> ---
> Interestingly builds with debug info actually use long section names by
> default, at least with recent ld. Or I'm unaware of where we control
> that behavior.
>
> --- a/xen/arch/x86/arch.mk
> +++ b/xen/arch/x86/arch.mk
> @@ -91,7 +91,7 @@ XEN_BUILD_EFI := $(call if-success,$(CC)
>                                           -c $(srctree)/$(efi-check).c -o $(efi-check).o,y)
>
>  # Check if the linker supports PE.
> -EFI_LDFLAGS := $(patsubst -m%,-mi386pep,$(LDFLAGS)) --subsystem=10
> +EFI_LDFLAGS := $(patsubst -m%,-mi386pep,$(LDFLAGS)) --subsystem=10 --enable-long-section-names
>  LD_PE_check_cmd = $(call ld-option,$(EFI_LDFLAGS) --image-base=0x100000000 -o $(efi-check).efi $(efi-check).o)
>  XEN_BUILD_PE := $(LD_PE_check_cmd)
>

Reviewed-by: Frediano Ziglio <frediano.ziglio@cloud.com>


Frediano

On 23/09/2024 4:39 pm, Jan Beulich wrote:
> While for our present .data.read_mostly it may be deemed tolerable that
> the name is truncated to .data.re, for the planned .init.trampoline an
> abbreviation to .init.tr would end up pretty meaningless. Engage the
> long section names extension that GNU ld has had support for already in
> 2.22 (which we consider the baseline release for xen.efi building).
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

It's rather disappointing that this needs enabling explicitly, but oh well.