Commit 86bf1721 authored by Nicolas Schichan's avatar Nicolas Schichan Committed by David S. Miller
Browse files

test_bpf: add tests checking that JIT/interpreter sets A and X to 0. 



It is mandatory for the JIT or interpreter to reset the A and X
registers to 0 before running the filter. Check that it is the case on
various ALU and JMP instructions.

Signed-off-by: default avatarNicolas Schichan <nschichan@freebox.fr>
Acked-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 08fcb08f

lib/test_bpf.c

+158 −0
Original line number Diff line number Diff line
@@ -4931,6 +4931,164 @@ static struct bpf_test tests[] = { 
		},

		{ {0x40, 0x88ee99ff } },

	},

	/*

	 * verify that the interpreter or JIT correctly sets A and X

	 * to 0.

	 */

	{

		"ADD default X",

		.u.insns = {

			/*

			 * A = 0x42

			 * A = A + X

			 * ret A

			 */

			BPF_STMT(BPF_LD | BPF_IMM, 0x42),

			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),

			BPF_STMT(BPF_RET | BPF_A, 0x0),

		},

		CLASSIC | FLAG_NO_DATA,

		{},

		{ {0x1, 0x42 } },

	},

	{

		"ADD default A",

		.u.insns = {

			/*

			 * A = A + 0x42

			 * ret A

			 */

			BPF_STMT(BPF_ALU | BPF_ADD | BPF_K, 0x42),

			BPF_STMT(BPF_RET | BPF_A, 0x0),

		},

		CLASSIC | FLAG_NO_DATA,

		{},

		{ {0x1, 0x42 } },

	},

	{

		"SUB default X",

		.u.insns = {

			/*

			 * A = 0x66

			 * A = A - X

			 * ret A

			 */

			BPF_STMT(BPF_LD | BPF_IMM, 0x66),

			BPF_STMT(BPF_ALU | BPF_SUB | BPF_X, 0),

			BPF_STMT(BPF_RET | BPF_A, 0x0),

		},

		CLASSIC | FLAG_NO_DATA,

		{},

		{ {0x1, 0x66 } },

	},

	{

		"SUB default A",

		.u.insns = {

			/*

			 * A = A - -0x66

			 * ret A

			 */

			BPF_STMT(BPF_ALU | BPF_SUB | BPF_K, -0x66),

			BPF_STMT(BPF_RET | BPF_A, 0x0),

		},

		CLASSIC | FLAG_NO_DATA,

		{},

		{ {0x1, 0x66 } },

	},

	{

		"MUL default X",

		.u.insns = {

			/*

			 * A = 0x42

			 * A = A * X

			 * ret A

			 */

			BPF_STMT(BPF_LD | BPF_IMM, 0x42),

			BPF_STMT(BPF_ALU | BPF_MUL | BPF_X, 0),

			BPF_STMT(BPF_RET | BPF_A, 0x0),

		},

		CLASSIC | FLAG_NO_DATA,

		{},

		{ {0x1, 0x0 } },

	},

	{

		"MUL default A",

		.u.insns = {

			/*

			 * A = A * 0x66

			 * ret A

			 */

			BPF_STMT(BPF_ALU | BPF_MUL | BPF_K, 0x66),

			BPF_STMT(BPF_RET | BPF_A, 0x0),

		},

		CLASSIC | FLAG_NO_DATA,

		{},

		{ {0x1, 0x0 } },

	},

	{

		"DIV default X",

		.u.insns = {

			/*

			 * A = 0x42

			 * A = A / X ; this halt the filter execution if X is 0

			 * ret 0x42

			 */

			BPF_STMT(BPF_LD | BPF_IMM, 0x42),

			BPF_STMT(BPF_ALU | BPF_DIV | BPF_X, 0),

			BPF_STMT(BPF_RET | BPF_K, 0x42),

		},

		CLASSIC | FLAG_NO_DATA,

		{},

		{ {0x1, 0x0 } },

	},

	{

		"DIV default A",

		.u.insns = {

			/*

			 * A = A / 1

			 * ret A

			 */

			BPF_STMT(BPF_ALU | BPF_DIV | BPF_K, 0x1),

			BPF_STMT(BPF_RET | BPF_A, 0x0),

		},

		CLASSIC | FLAG_NO_DATA,

		{},

		{ {0x1, 0x0 } },

	},

	{

		"JMP EQ default A",

		.u.insns = {

			/*

			 * cmp A, 0x0, 0, 1

			 * ret 0x42

			 * ret 0x66

			 */

			BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x0, 0, 1),

			BPF_STMT(BPF_RET | BPF_K, 0x42),

			BPF_STMT(BPF_RET | BPF_K, 0x66),

		},

		CLASSIC | FLAG_NO_DATA,

		{},

		{ {0x1, 0x42 } },

	},

	{

		"JMP EQ default X",

		.u.insns = {

			/*

			 * A = 0x0

			 * cmp A, X, 0, 1

			 * ret 0x42

			 * ret 0x66

			 */

			BPF_STMT(BPF_LD | BPF_IMM, 0x0),

			BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_X, 0x0, 0, 1),

			BPF_STMT(BPF_RET | BPF_K, 0x42),

			BPF_STMT(BPF_RET | BPF_K, 0x66),

		},

		CLASSIC | FLAG_NO_DATA,

		{},

		{ {0x1, 0x42 } },

	},

};



static struct net_device dev;

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