[PATCH] powerpc64: Fix calls when r2 is not used [BZ #26173]

[Matheus Castanho]

Hi Tulio,

On 6/25/20 8:02 PM, Tulio Magno Quites Machado Filho via Libc-alpha wrote:
> Teach the linker that __mcount_internal, __sigjmp_save_symbol,
> __syscall_error and __GI_exit do not use r2, so that it does not need to
> recover r2 after the call.
> ---
>  sysdeps/powerpc/powerpc64/ppc-mcount.S                  | 2 +-
>  sysdeps/powerpc/powerpc64/setjmp-common.S               | 2 +-
>  sysdeps/powerpc/powerpc64/sysdep.h                      | 2 +-
>  sysdeps/unix/sysv/linux/powerpc/powerpc64/makecontext.S | 2 +-
>  4 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/sysdeps/powerpc/powerpc64/ppc-mcount.S b/sysdeps/powerpc/powerpc64/ppc-mcount.S
> index f7e9836cae..7b2b3ab908 100644
> --- a/sysdeps/powerpc/powerpc64/ppc-mcount.S
> +++ b/sysdeps/powerpc/powerpc64/ppc-mcount.S
> @@ -29,7 +29,7 @@ ENTRY(_mcount)
>  	cfi_adjust_cfa_offset (FRAME_MIN_SIZE)
>  	cfi_offset (lr, FRAME_LR_SAVE)
>  	ld		 r3, FRAME_LR_SAVE(r11)
> -	bl		 JUMPTARGET(__mcount_internal)
> +	bl		 JUMPTARGET(__mcount_internal@notoc)
Ok.

>  #ifndef SHARED
>  	nop
>  #endif
> diff --git a/sysdeps/powerpc/powerpc64/setjmp-common.S b/sysdeps/powerpc/powerpc64/setjmp-common.S
> index eb37000980..44cc43937e 100644
> --- a/sysdeps/powerpc/powerpc64/setjmp-common.S
> +++ b/sysdeps/powerpc/powerpc64/setjmp-common.S
> @@ -217,7 +217,7 @@ L(no_vmx):
>  	li	r3,0
>  	blr
>  #elif defined SHARED
> -	b	JUMPTARGET (__sigjmp_save_symbol)
> +	b	JUMPTARGET (__sigjmp_save_symbol@notoc)
Ok.

>  #else
>  	mflr	r0
>  	std	r0,FRAME_LR_SAVE(r1)
> diff --git a/sysdeps/powerpc/powerpc64/sysdep.h b/sysdeps/powerpc/powerpc64/sysdep.h
> index d6616ac905..fbddeb492e 100644
> --- a/sysdeps/powerpc/powerpc64/sysdep.h
> +++ b/sysdeps/powerpc/powerpc64/sysdep.h
> @@ -278,7 +278,7 @@ LT_LABELSUFFIX(name,_name_end): ; \
>  
>  #ifdef SHARED
>  #define TAIL_CALL_SYSCALL_ERROR \
> -    b JUMPTARGET(__syscall_error)
> +    b JUMPTARGET(__syscall_error@notoc)
Ok.

>  #else
>  /* Static version might be linked into a large app with a toc exceeding
>     64k.  We can't put a toc adjusting stub on a plain branch, so can't
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/makecontext.S b/sysdeps/unix/sysv/linux/powerpc/powerpc64/makecontext.S
> index e4d4575d68..fd22f8f7ae 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/makecontext.S
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/makecontext.S
> @@ -160,7 +160,7 @@ L(exitcode):
>  	li    r3,-1
>  L(do_exit):
>  #ifdef SHARED
> -	b     JUMPTARGET(__GI_exit);
> +	b     JUMPTARGET(__GI_exit@notoc);
Ok.

>  #else
>  	b     JUMPTARGET(exit);
>  	nop
> 

LGTM.

Thanks,
Matheus Castanho