[PATCH] powerpc/boot: Allow text relocations for pseries wrapper with binutils 2.46+

[PATCH] powerpc/boot: Allow text relocations for pseries wrapper with binutils 2.46+

[Amit Machhiwal]

Binutils 2.46 changed the default linker behavior from '-z notext' to
'-z text', which treats dynamic relocations in read-only segments as
errors rather than warnings. This causes the pseries boot wrapper build
to fail with:

  /usr/bin/ld.bfd: arch/powerpc/boot/wrapper.a(crt0.o): warning:
    relocation against `_platform_stack_top' in read-only section `.text'
  /usr/bin/ld.bfd: error: read-only segment has dynamic relocations

The pseries wrapper uses '-pie' to create position-independent code.
However, crt0.S contains a pointer to '_platform_stack_top' in the .text
section, which requires a dynamic relocation at runtime. This creates
DT_TEXTREL (text relocations), which were allowed by default in binutils
2.45 and earlier (via implicit '-z notext') but are now rejected by
binutils 2.46+.

Add '-z notext' linker flag to explicitly allow text relocations for
the pseries platform, similar to what is already done for the epapr
platform. This restores the previous behavior and allows the boot
wrapper to build successfully with binutils 2.46+.

Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
---
 arch/powerpc/boot/wrapper | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/boot/wrapper b/arch/powerpc/boot/wrapper
index 1efd1206fcab..25321ce262e8 100755
--- a/arch/powerpc/boot/wrapper
+++ b/arch/powerpc/boot/wrapper
@@ -262,6 +262,7 @@ pseries)
     if [ "$format" != "elf32ppc" ]; then
 	link_address=
 	pie=-pie
+	notext='-z notext'
     fi
     make_space=n
     ;;

base-commit: e7ae89a0c97ce2b68b0983cd01eda67cf373517d
-- 
2.50.1 (Apple Git-155)

Re: [PATCH] powerpc/boot: Allow text relocations for pseries wrapper with binutils 2.46+

[Anushree Mathur]

On 25/05/26 9:46 PM, Amit Machhiwal wrote:
> Binutils 2.46 changed the default linker behavior from '-z notext' to
> '-z text', which treats dynamic relocations in read-only segments as
> errors rather than warnings. This causes the pseries boot wrapper build
> to fail with:
>
>    /usr/bin/ld.bfd: arch/powerpc/boot/wrapper.a(crt0.o): warning:
>      relocation against `_platform_stack_top' in read-only section `.text'
>    /usr/bin/ld.bfd: error: read-only segment has dynamic relocations
>
> The pseries wrapper uses '-pie' to create position-independent code.
> However, crt0.S contains a pointer to '_platform_stack_top' in the .text
> section, which requires a dynamic relocation at runtime. This creates
> DT_TEXTREL (text relocations), which were allowed by default in binutils
> 2.45 and earlier (via implicit '-z notext') but are now rejected by
> binutils 2.46+.
>
> Add '-z notext' linker flag to explicitly allow text relocations for
> the pseries platform, similar to what is already done for the epapr
> platform. This restores the previous behavior and allows the boot
> wrapper to build successfully with binutils 2.46+.
>
> Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
> ---
>   arch/powerpc/boot/wrapper | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/arch/powerpc/boot/wrapper b/arch/powerpc/boot/wrapper
> index 1efd1206fcab..25321ce262e8 100755
> --- a/arch/powerpc/boot/wrapper
> +++ b/arch/powerpc/boot/wrapper
> @@ -262,6 +262,7 @@ pseries)
>       if [ "$format" != "elf32ppc" ]; then
>   	link_address=
>   	pie=-pie
> +	notext='-z notext'
>       fi
>       make_space=n
>       ;;
>
> base-commit: e7ae89a0c97ce2b68b0983cd01eda67cf373517d
Hi Amit,
I have tested this patch and it has fixed the kernel build issue. Here 
is my analysis:

i) Without applying the patch:

Kernel build failed with below error -

   CC [M]  drivers/net/usb/r8152.mod.o
   CC [M]  drivers/net/usb/hso.mod.o
   CC [M]  drivers/net/usb/lan78xx.mod.o
   CC [M]  drivers/net/usb/asix.mod.o
   CC [M]  drivers/net/usb/ax88179_178a.mod.o
/usr/bin/ld.bfd: arch/powerpc/boot/wrapper.a(crt0.o): warning: 
relocation against `_platform_stack_top' in read-only section `.text'
/usr/bin/ld.bfd: error: read-only segment has dynamic relocations
make[2]: *** [arch/powerpc/boot/Makefile:386: 
arch/powerpc/boot/zImage.pseries] Error 1
   CC [M]  drivers/net/usb/cdc_ether.mod.o
make[1]: *** [arch/powerpc/Makefile:236: zImage] Error 2
make[1]: *** Waiting for unfinished jobs....

ii) After applying the patch :

Kernel build got successful.

Please feel free to add:

Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>

Thank you!
Anushree Mathur