Subject: Re: [PATCH 05/12] powerpc/ftrace: ftrace_graph_caller() needs to save/restore toc

From: Balbir Singh <[email-masked]>
Date: Thu, 25 Feb 2016 11:30:38 +1100

On 25/02/16 01:28, Michael Ellerman wrote:
> Signed-off-by: Michael Ellerman <[email-masked]>
> ---
>  arch/powerpc/kernel/entry_64.S | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> Squash.
>
> diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
> index 2a7313cfbc7d..9e77a2c8f218 100644
> --- a/arch/powerpc/kernel/entry_64.S
> +++ b/arch/powerpc/kernel/entry_64.S
> @@ -1237,6 +1237,11 @@ _GLOBAL(ftrace_graph_caller)
>  	std	r5, 64(r1)
>  	std	r4, 56(r1)
>  	std	r3, 48(r1)
> +
> +	/* Save callee's TOC in the ABI compliant location */
> +	std	r2, 24(r1)
R2_STACK_OFFSET for readability?
> +	ld	r2, PACATOC(r13)	/* get kernel TOC in r2 */
> +
>  	mfctr	r4		/* ftrace_caller has moved local addr here */
>  	std	r4, 40(r1)
>  	mflr	r3		/* ftrace_caller has restored LR from stack */
> @@ -1262,6 +1267,9 @@ _GLOBAL(ftrace_graph_caller)
>  	ld	r4, 56(r1)
>  	ld	r3, 48(r1)
>  
> +	/* Restore callee's TOC */
> +	ld	r2, 24(r1)
> +
>  	addi	r1, r1, 112
>  	mflr	r0
>  	std	r0, LRSAVE(r1)

Reviewed-by: Balbir Singh <[email-masked]>
Balbir Singh.