Commit 08de198c authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

selftests/bpf: two scale tests 



Add two tests to check that sequence of 1024 jumps is verifiable.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 3da6e7e4

tools/testing/selftests/bpf/test_verifier.c

+70 −0
Original line number Diff line number Diff line
@@ -208,6 +208,76 @@ static void bpf_fill_rand_ld_dw(struct bpf_test *self) 
	self->retval = (uint32_t)res;

}



/* test the sequence of 1k jumps */

static void bpf_fill_scale1(struct bpf_test *self)

{

	struct bpf_insn *insn = self->fill_insns;

	int i = 0, k = 0;



	insn[i++] = BPF_MOV64_REG(BPF_REG_6, BPF_REG_1);

	/* test to check that the sequence of 1024 jumps is acceptable */

	while (k++ < 1024) {

		insn[i++] = BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,

					 BPF_FUNC_get_prandom_u32);

		insn[i++] = BPF_JMP_IMM(BPF_JGT, BPF_REG_0, bpf_semi_rand_get(), 2);

		insn[i++] = BPF_MOV64_REG(BPF_REG_1, BPF_REG_10);

		insn[i++] = BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6,

					-8 * (k % 64 + 1));

	}

	/* every jump adds 1024 steps to insn_processed, so to stay exactly

	 * within 1m limit add MAX_TEST_INSNS - 1025 MOVs and 1 EXIT

	 */

	while (i < MAX_TEST_INSNS - 1025)

		insn[i++] = BPF_ALU32_IMM(BPF_MOV, BPF_REG_0, 42);

	insn[i] = BPF_EXIT_INSN();

	self->prog_len = i + 1;

	self->retval = 42;

}



/* test the sequence of 1k jumps in inner most function (function depth 8)*/

static void bpf_fill_scale2(struct bpf_test *self)

{

	struct bpf_insn *insn = self->fill_insns;

	int i = 0, k = 0;



#define FUNC_NEST 7

	for (k = 0; k < FUNC_NEST; k++) {

		insn[i++] = BPF_CALL_REL(1);

		insn[i++] = BPF_EXIT_INSN();

	}

	insn[i++] = BPF_MOV64_REG(BPF_REG_6, BPF_REG_1);

	/* test to check that the sequence of 1024 jumps is acceptable */

	while (k++ < 1024) {

		insn[i++] = BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,

					 BPF_FUNC_get_prandom_u32);

		insn[i++] = BPF_JMP_IMM(BPF_JGT, BPF_REG_0, bpf_semi_rand_get(), 2);

		insn[i++] = BPF_MOV64_REG(BPF_REG_1, BPF_REG_10);

		insn[i++] = BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6,

					-8 * (k % (64 - 4 * FUNC_NEST) + 1));

	}

	/* every jump adds 1024 steps to insn_processed, so to stay exactly

	 * within 1m limit add MAX_TEST_INSNS - 1025 MOVs and 1 EXIT

	 */

	while (i < MAX_TEST_INSNS - 1025)

		insn[i++] = BPF_ALU32_IMM(BPF_MOV, BPF_REG_0, 42);

	insn[i] = BPF_EXIT_INSN();

	self->prog_len = i + 1;

	self->retval = 42;

}



static void bpf_fill_scale(struct bpf_test *self)

{

	switch (self->retval) {

	case 1:

		return bpf_fill_scale1(self);

	case 2:

		return bpf_fill_scale2(self);

	default:

		self->prog_len = 0;

		break;

	}

}



/* BPF_SK_LOOKUP contains 13 instructions, if you need to fix up maps */

#define BPF_SK_LOOKUP(func)						\

	/* struct bpf_sock_tuple tuple = {} */				\

tools/testing/selftests/bpf/verifier/scale.c

0 → 100644
+18 −0
Original line number Diff line number Diff line 
{

	"scale: scale test 1",

	.insns = { },

	.data = { },

	.fill_helper = bpf_fill_scale,

	.prog_type = BPF_PROG_TYPE_SCHED_CLS,

	.result = ACCEPT,

	.retval = 1,

},

{

	"scale: scale test 2",

	.insns = { },

	.data = { },

	.fill_helper = bpf_fill_scale,

	.prog_type = BPF_PROG_TYPE_SCHED_CLS,

	.result = ACCEPT,

	.retval = 2,

},