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Commit fcd1c917 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by Alexei Starovoitov
Browse files

bpf: add couple of test cases for signed extended imms 

Add a couple of test cases for interpreter and JIT that are
related to an issue we faced some time ago in Cilium [1],
which is fixed in LLVM with commit e53750e1e086 ("bpf: fix
bug on silently truncating 64-bit immediate").

Test cases were run-time checking kernel to behave as intended
which should also provide some guidance for current or new
JITs in case they should trip over this. Added for cBPF and
eBPF.

  [1] https://github.com/cilium/cilium/pull/2162



Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 205c3807

lib/test_bpf.c

+104 −0
Original line number Diff line number Diff line
@@ -6109,6 +6109,110 @@ static struct bpf_test tests[] = { 
		{ { ETH_HLEN, 42 } },

		.fill_helper = bpf_fill_ld_abs_vlan_push_pop2,

	},

	/* Checking interpreter vs JIT wrt signed extended imms. */

	{

		"JNE signed compare, test 1",

		.u.insns_int = {

			BPF_ALU32_IMM(BPF_MOV, R1, 0xfefbbc12),

			BPF_ALU32_IMM(BPF_MOV, R3, 0xffff0000),

			BPF_MOV64_REG(R2, R1),

			BPF_ALU64_REG(BPF_AND, R2, R3),

			BPF_ALU32_IMM(BPF_MOV, R0, 1),

			BPF_JMP_IMM(BPF_JNE, R2, -17104896, 1),

			BPF_ALU32_IMM(BPF_MOV, R0, 2),

			BPF_EXIT_INSN(),

		},

		INTERNAL,

		{ },

		{ { 0, 1 } },

	},

	{

		"JNE signed compare, test 2",

		.u.insns_int = {

			BPF_ALU32_IMM(BPF_MOV, R1, 0xfefbbc12),

			BPF_ALU32_IMM(BPF_MOV, R3, 0xffff0000),

			BPF_MOV64_REG(R2, R1),

			BPF_ALU64_REG(BPF_AND, R2, R3),

			BPF_ALU32_IMM(BPF_MOV, R0, 1),

			BPF_JMP_IMM(BPF_JNE, R2, 0xfefb0000, 1),

			BPF_ALU32_IMM(BPF_MOV, R0, 2),

			BPF_EXIT_INSN(),

		},

		INTERNAL,

		{ },

		{ { 0, 1 } },

	},

	{

		"JNE signed compare, test 3",

		.u.insns_int = {

			BPF_ALU32_IMM(BPF_MOV, R1, 0xfefbbc12),

			BPF_ALU32_IMM(BPF_MOV, R3, 0xffff0000),

			BPF_ALU32_IMM(BPF_MOV, R4, 0xfefb0000),

			BPF_MOV64_REG(R2, R1),

			BPF_ALU64_REG(BPF_AND, R2, R3),

			BPF_ALU32_IMM(BPF_MOV, R0, 1),

			BPF_JMP_REG(BPF_JNE, R2, R4, 1),

			BPF_ALU32_IMM(BPF_MOV, R0, 2),

			BPF_EXIT_INSN(),

		},

		INTERNAL,

		{ },

		{ { 0, 2 } },

	},

	{

		"JNE signed compare, test 4",

		.u.insns_int = {

			BPF_LD_IMM64(R1, -17104896),

			BPF_ALU32_IMM(BPF_MOV, R0, 1),

			BPF_JMP_IMM(BPF_JNE, R1, -17104896, 1),

			BPF_ALU32_IMM(BPF_MOV, R0, 2),

			BPF_EXIT_INSN(),

		},

		INTERNAL,

		{ },

		{ { 0, 2 } },

	},

	{

		"JNE signed compare, test 5",

		.u.insns_int = {

			BPF_LD_IMM64(R1, 0xfefb0000),

			BPF_ALU32_IMM(BPF_MOV, R0, 1),

			BPF_JMP_IMM(BPF_JNE, R1, 0xfefb0000, 1),

			BPF_ALU32_IMM(BPF_MOV, R0, 2),

			BPF_EXIT_INSN(),

		},

		INTERNAL,

		{ },

		{ { 0, 1 } },

	},

	{

		"JNE signed compare, test 6",

		.u.insns_int = {

			BPF_LD_IMM64(R1, 0x7efb0000),

			BPF_ALU32_IMM(BPF_MOV, R0, 1),

			BPF_JMP_IMM(BPF_JNE, R1, 0x7efb0000, 1),

			BPF_ALU32_IMM(BPF_MOV, R0, 2),

			BPF_EXIT_INSN(),

		},

		INTERNAL,

		{ },

		{ { 0, 2 } },

	},

	{

		"JNE signed compare, test 7",

		.u.insns = {

			BPF_STMT(BPF_LD | BPF_IMM, 0xffff0000),

			BPF_STMT(BPF_MISC | BPF_TAX, 0),

			BPF_STMT(BPF_LD | BPF_IMM, 0xfefbbc12),

			BPF_STMT(BPF_ALU | BPF_AND | BPF_X, 0),

			BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0xfefb0000, 1, 0),

			BPF_STMT(BPF_RET | BPF_K, 1),

			BPF_STMT(BPF_RET | BPF_K, 2),

		},

		CLASSIC | FLAG_NO_DATA,

		{},

		{ { 0, 2 } },

	},

};



static struct net_device dev;