Commit d4ff9ee2 authored by Johan Almbladh's avatar Johan Almbladh Committed by Daniel Borkmann
Browse files

bpf/tests: Add JMP tests with small offsets 



This patch adds a set of tests for JMP to verify that the JITed jump
offset is calculated correctly. We pretend that the verifier has inserted
any zero extensions to make the jump-over operations JIT to one
instruction each, in order to control the exact JITed jump offset.

Signed-off-by: default avatarJohan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210914091842.4186267-10-johan.almbladh@anyfinetworks.com
parent 27cc6dac

lib/test_bpf.c

+71 −0
Original line number Diff line number Diff line
@@ -10709,6 +10709,77 @@ static struct bpf_test tests[] = { 
		.fill_helper = bpf_fill_jmp32_jsle_reg,

		.nr_testruns = NR_PATTERN_RUNS,

	},

	/* Short relative jumps */

	{

		"Short relative jump: offset=0",

		.u.insns_int = {

			BPF_ALU64_IMM(BPF_MOV, R0, 0),

			BPF_JMP_IMM(BPF_JEQ, R0, 0, 0),

			BPF_EXIT_INSN(),

			BPF_ALU32_IMM(BPF_MOV, R0, -1),

		},

		INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,

		{ },

		{ { 0, 0 } },

	},

	{

		"Short relative jump: offset=1",

		.u.insns_int = {

			BPF_ALU64_IMM(BPF_MOV, R0, 0),

			BPF_JMP_IMM(BPF_JEQ, R0, 0, 1),

			BPF_ALU32_IMM(BPF_ADD, R0, 1),

			BPF_EXIT_INSN(),

			BPF_ALU32_IMM(BPF_MOV, R0, -1),

		},

		INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,

		{ },

		{ { 0, 0 } },

	},

	{

		"Short relative jump: offset=2",

		.u.insns_int = {

			BPF_ALU64_IMM(BPF_MOV, R0, 0),

			BPF_JMP_IMM(BPF_JEQ, R0, 0, 2),

			BPF_ALU32_IMM(BPF_ADD, R0, 1),

			BPF_ALU32_IMM(BPF_ADD, R0, 1),

			BPF_EXIT_INSN(),

			BPF_ALU32_IMM(BPF_MOV, R0, -1),

		},

		INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,

		{ },

		{ { 0, 0 } },

	},

	{

		"Short relative jump: offset=3",

		.u.insns_int = {

			BPF_ALU64_IMM(BPF_MOV, R0, 0),

			BPF_JMP_IMM(BPF_JEQ, R0, 0, 3),

			BPF_ALU32_IMM(BPF_ADD, R0, 1),

			BPF_ALU32_IMM(BPF_ADD, R0, 1),

			BPF_ALU32_IMM(BPF_ADD, R0, 1),

			BPF_EXIT_INSN(),

			BPF_ALU32_IMM(BPF_MOV, R0, -1),

		},

		INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,

		{ },

		{ { 0, 0 } },

	},

	{

		"Short relative jump: offset=4",

		.u.insns_int = {

			BPF_ALU64_IMM(BPF_MOV, R0, 0),

			BPF_JMP_IMM(BPF_JEQ, R0, 0, 4),

			BPF_ALU32_IMM(BPF_ADD, R0, 1),

			BPF_ALU32_IMM(BPF_ADD, R0, 1),

			BPF_ALU32_IMM(BPF_ADD, R0, 1),

			BPF_ALU32_IMM(BPF_ADD, R0, 1),

			BPF_EXIT_INSN(),

			BPF_ALU32_IMM(BPF_MOV, R0, -1),

		},

		INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,

		{ },

		{ { 0, 0 } },

	},

	/* Staggered jump sequences, immediate */

	{

		"Staggered jumps: JMP_JA",