Commit f0b5b3d6 authored by Paul Chaignon's avatar Paul Chaignon Committed by Alexei Starovoitov
Browse files

selftests/bpf: Test access from RO map from xdp_store_bytes 



This new test simply checks that helper bpf_xdp_store_bytes can
successfully read from a read-only map.

Signed-off-by: default avatarPaul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/4fdb934a713b2d7cf133288c77f6cfefe9856440.1769875479.git.paul.chaignon@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 6557f156

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

+35 −0
Original line number Diff line number Diff line
@@ -5,6 +5,14 @@ 
#include <bpf/bpf_helpers.h>

#include "bpf_misc.h"



struct {

	__uint(type, BPF_MAP_TYPE_ARRAY);

	__uint(max_entries, 1);

	__type(key, int);

	__type(value, __u64);

	__uint(map_flags, BPF_F_RDONLY_PROG);

} map_array_ro SEC(".maps");



SEC("xdp")

__description("XDP, using ifindex from netdev")

__success __retval(1)
@@ -21,4 +29,31 @@ l0_%=: exit; \ 
	: __clobber_all);

}



SEC("xdp")

__description("XDP, using xdp_store_bytes from RO map")

__success __retval(0)

__naked void xdp_store_bytes_from_ro_map(void)

{

	asm volatile ("					\

	r6 = r1;					\

	r1 = 0;                                         \

	*(u64*)(r10 - 8) = r1;                          \

	r2 = r10;                                       \

	r2 += -8;                                       \

	r1 = %[map_array_ro] ll;                        \

	call %[bpf_map_lookup_elem];                    \

	if r0 == 0 goto l0_%=;                          \

	r1 = r6;					\

	r2 = 0;						\

	r3 = r0;					\

	r4 = 8;						\

	call %[bpf_xdp_store_bytes];			\

l0_%=:	exit;						\

"	:

	: __imm(bpf_map_lookup_elem),

	  __imm(bpf_xdp_store_bytes),

	  __imm_addr(map_array_ro)

	: __clobber_all);

}



char _license[] SEC("license") = "GPL";