Re: [PATCH] powerpc/vdso: Fix build of VDSO32 with pcrel

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Hi Maddy,

ping ?

Christophe

Le 12/05/2025 à 20:14, Christophe Leroy a écrit :
> Building vdso32 on power10 with pcrel leads to following errors:
> 
> 	  VDSO32A arch/powerpc/kernel/vdso/gettimeofday-32.o
> 	arch/powerpc/kernel/vdso/gettimeofday.S: Assembler messages:
> 	arch/powerpc/kernel/vdso/gettimeofday.S:40: Error: syntax error; found `@', expected `,'
> 	arch/powerpc/kernel/vdso/gettimeofday.S:71:  Info: macro invoked from here
> 	arch/powerpc/kernel/vdso/gettimeofday.S:40: Error: junk at end of line: `@notoc'
> 	arch/powerpc/kernel/vdso/gettimeofday.S:71:  Info: macro invoked from here
> 	 ...
> 	make[2]: *** [arch/powerpc/kernel/vdso/Makefile:85: arch/powerpc/kernel/vdso/gettimeofday-32.o] Error 1
> 	make[1]: *** [arch/powerpc/Makefile:388: vdso_prepare] Error 2
> 
> Once the above is fixed, the following happens:
> 
> 	  VDSO32C arch/powerpc/kernel/vdso/vgettimeofday-32.o
> 	cc1: error: '-mpcrel' requires '-mcmodel=medium'
> 	make[2]: *** [arch/powerpc/kernel/vdso/Makefile:89: arch/powerpc/kernel/vdso/vgettimeofday-32.o] Error 1
> 	make[1]: *** [arch/powerpc/Makefile:388: vdso_prepare] Error 2
> 	make: *** [Makefile:251: __sub-make] Error 2
> 
> Make sure pcrel version of CFUNC() macro is used only for powerpc64
> builds and remove -mpcrel for powerpc32 builds.
> 
> Fixes: 7e3a68be42e1 ("powerpc/64: vmlinux support building with PCREL addresing")
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>   arch/powerpc/include/asm/ppc_asm.h | 2 +-
>   arch/powerpc/kernel/vdso/Makefile  | 2 +-
>   2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
> index 02897f4b0dbf..b891910fce8a 100644
> --- a/arch/powerpc/include/asm/ppc_asm.h
> +++ b/arch/powerpc/include/asm/ppc_asm.h
> @@ -183,7 +183,7 @@
>   /*
>    * Used to name C functions called from asm
>    */
> -#ifdef CONFIG_PPC_KERNEL_PCREL
> +#if defined(__powerpc64__) && defined(CONFIG_PPC_KERNEL_PCREL)
>   #define CFUNC(name) name@notoc
>   #else
>   #define CFUNC(name) name
> diff --git a/arch/powerpc/kernel/vdso/Makefile b/arch/powerpc/kernel/vdso/Makefile
> index e8824f933326..8834dfe9d727 100644
> --- a/arch/powerpc/kernel/vdso/Makefile
> +++ b/arch/powerpc/kernel/vdso/Makefile
> @@ -53,7 +53,7 @@ ldflags-$(CONFIG_LD_ORPHAN_WARN) += -Wl,--orphan-handling=$(CONFIG_LD_ORPHAN_WAR
>   ldflags-y += $(filter-out $(CC_AUTO_VAR_INIT_ZERO_ENABLER) $(CC_FLAGS_FTRACE) -Wa$(comma)%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
>   
>   CC32FLAGS := -m32
> -CC32FLAGSREMOVE := -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
> +CC32FLAGSREMOVE := -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc -mpcrel
>   ifdef CONFIG_CC_IS_CLANG
>   # This flag is supported by clang for 64-bit but not 32-bit so it will cause
>   # an unused command line flag warning for this file.