Re: [PATCH v2 2/2] powerpc64/bpf: Fix build break for arch_bpf_timed_may_goto

On 30/07/26 11:16 am, Saket Kumar Bhaskar wrote:
> With CONFIG_PPC_KERNEL_PCREL enabled, calling bpf_check_timed_may_goto()
> using a bl instruction results in a link-time failure:
> 
> arch/powerpc/net/bpf_timed_may_goto.o: in function `arch_bpf_timed_may_goto':
> (.text+0x28): call to `bpf_check_timed_may_goto' lacks nop, can't restore toc
> 
> Use CFUNC() macro instead of direct 'bl' to properly annotate the call
> to bpf_check_timed_may_goto(). On PCREL builds, CFUNC() expands to
> 'bl name@notoc', informing the linker that TOC restoration is not
> needed, avoiding the "lacks nop, can't restore toc" linker error.
> 

Reviewed-by: Hari Bathini <[email protected]>

> Fixes: b55b6b9ad76c ("powerpc64/bpf: Add powerpc64 JIT support for timed may_goto")
> Signed-off-by: Saket Kumar Bhaskar <[email protected]>
> Reviewed-by: Christophe Leroy (CS GROUP) <[email protected]>
> ---
>   arch/powerpc/net/bpf_timed_may_goto.S | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/net/bpf_timed_may_goto.S b/arch/powerpc/net/bpf_timed_may_goto.S
> index 6fd8b1c9f4ac..84ecf6fa7f5d 100644
> --- a/arch/powerpc/net/bpf_timed_may_goto.S
> +++ b/arch/powerpc/net/bpf_timed_may_goto.S
> @@ -36,7 +36,7 @@ SYM_FUNC_START(arch_bpf_timed_may_goto)
>   	 * BPF_REG_FP is r31; BPF_REG_AX is r12 (stack offset in bytes).
>   	 */
>   	add     r3, r31, r12
> -	bl      bpf_check_timed_may_goto
> +	bl      CFUNC(bpf_check_timed_may_goto)
>   
>   	/* Put return value back into AX */
>   	mr      r12, r3