Re: [PATCH bpf-next 2/4] selftests/bpf: convenience macro for use with 'asm volatile' blocks

[Yonghong Song <yhs@xxxxxxxx>]

On 12/16/22 6:17 PM, Eduard Zingerman wrote:
> A set of macros useful for writing naked BPF functions using inline
> assembly. E.g. as follows:
>
> struct map_struct {
> 	...
> } map SEC(".maps");
>
> SEC(...)
> __naked int foo_test(void)
> {
> 	asm volatile(
> 		"r0 = 0;"
> 		"*(u64*)(r10 - 8) = r0;"
> 		"r1 = %[map] ll;"
> 		"r2 = r10;"
> 		"r2 += -8;"
> 		"call %[bpf_map_lookup_elem];"
> 		"r0 = 0;"
> 		"exit;"
> 		:
> 		: __imm(bpf_map_lookup_elem),
> 		  __imm_addr(map)
> 		: __clobber_all);
> }
>
> Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>

Acked-by: Yonghong Song <yhs@xxxxxx>