Commit d99341b3 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: selftest: Trigger a DCE on the whole subprog 



This patch adds a test to trigger the DCE to remove
the whole subprog to ensure the verifier  does not
depend on a stable subprog index.  The DCE is done
by testing a global const.

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211106014020.651638-1-kafai@fb.com
parent 3990ed4c

tools/testing/selftests/bpf/progs/for_each_array_map_elem.c

+12 −0
Original line number Diff line number Diff line
@@ -23,6 +23,16 @@ struct callback_ctx { 
	int output;

};



const volatile int bypass_unused = 1;



static __u64

unused_subprog(struct bpf_map *map, __u32 *key, __u64 *val,

	       struct callback_ctx *data)

{

	data->output = 0;

	return 1;

}



static __u64

check_array_elem(struct bpf_map *map, __u32 *key, __u64 *val,

		 struct callback_ctx *data)
@@ -54,6 +64,8 @@ int test_pkt_access(struct __sk_buff *skb) 


	data.output = 0;

	bpf_for_each_map_elem(&arraymap, check_array_elem, &data, 0);

	if (!bypass_unused)

		bpf_for_each_map_elem(&arraymap, unused_subprog, &data, 0);

	arraymap_output = data.output;



	bpf_for_each_map_elem(&percpu_map, check_percpu_elem, (void *)0, 0);