Re: [PATCH bpf-next v5 10/11] selftests/bpf: Add inline-asm and subprog tests for R0:R2 returns

[Yonghong Song <yonghong.song@linux.dev>]

On 8/14/26 6:03 PM, Eduard Zingerman wrote:
> On Thu, 2026-08-13 at 13:03 -0700, Yonghong Song wrote:
>
> ...
>
>> diff --git a/tools/testing/selftests/bpf/progs/aggregate_ret_func.c b/tools/testing/selftests/bpf/progs/aggregate_ret_func.c
>> new file mode 100644
>> index 000000000000..cfb21bcf704b
>> --- /dev/null
>> +++ b/tools/testing/selftests/bpf/progs/aggregate_ret_func.c
> ...
>
>> +struct ptr_pair {
>> +	void *p;
>> +	__u64 x;
>> +};
>> +
>> +static __naked __noinline struct ptr_pair static_ret_ptr_pair(void)
>> +{
>> +	asm volatile (
>> +	"r0 = 0;"
>> +	"r2 = r1;"
>> +	"exit;"
>> +	);
>> +}
>> +
>> +SEC("tc")
>> +__load_if_JITed()
>> +__success __retval(0)
>> +__naked int aggregate_ret_static_ptr_pair(void)
> This test is redundant, already covered by a previous patch.

Ack.

>
>> +{
>> +	asm volatile (
>> +	"call %[static_ret_ptr_pair];"
>> +	"r1 = *(u32 *)(r2 + 0);"	/* deref the returned ctx pointer */
>> +	"r0 = 0;"
>> +	"exit;"
>> +	:
>> +	: __imm(static_ret_ptr_pair)
>> +	: __clobber_all);
>> +}
>> +
>> +char _license[] SEC("license") = "GPL";
> ...
>
>> diff --git a/tools/testing/selftests/bpf/progs/aggregate_ret_kfunc_c.c b/tools/testing/selftests/bpf/progs/aggregate_ret_kfunc_c.c
>> index b66576307f73..2c1889fc28ef 100644
>> --- a/tools/testing/selftests/bpf/progs/aggregate_ret_kfunc_c.c
>> +++ b/tools/testing/selftests/bpf/progs/aggregate_ret_kfunc_c.c
>> @@ -50,6 +50,66 @@ int aggregate_ret_kfunc_struct_c_test(struct __sk_buff *skb)
>> +int aggregate_ret_kfunc_li_c_test(struct __sk_buff *skb)
> ...
>> +int aggregate_ret_kfunc_ii_c_test(struct __sk_buff *skb)
> ...
>> +int aggregate_ret_kfunc_uu_c_test(struct __sk_buff *skb)
> I don't think three tests above a warranted, the previous patch
> already tested returning 16-byte structs. Maybe a test with a small
> structs of two ints, but I'd skip even that.
> This would drop a ton of code from the back of the patch.

Ack. Will do.

>
> ...