net: filter: add slot overlapping test with fully filled M[]

Also add a test for the scratch memory store that first fills
all slots and then sucessively reads all of them back adding
up to A, and eventually returning A. This and the previous
M[] test with alternating fill/spill will detect possible JIT
errors on M[].

Suggested-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

lib/test_bpf.c

@@ -1493,7 +1493,7 @@ static struct bpf_test tests[] = {
 		{ },
 	},
 	{	/* Mainly checking JIT here. */
-		"M[]: STX + LDX",
+		"M[]: alt STX + LDX",
 		.u.insns = {
 			BPF_STMT(BPF_LDX | BPF_IMM, 100),
 			BPF_STMT(BPF_STX, 0),
@@ -1582,6 +1582,79 @@ static struct bpf_test tests[] = {
 		{ },
 		{ { 0, 116 } },
 	},
+	{	/* Mainly checking JIT here. */
+		"M[]: full STX + full LDX",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xbadfeedb),
+			BPF_STMT(BPF_STX, 0),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xecabedae),
+			BPF_STMT(BPF_STX, 1),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xafccfeaf),
+			BPF_STMT(BPF_STX, 2),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xbffdcedc),
+			BPF_STMT(BPF_STX, 3),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xfbbbdccb),
+			BPF_STMT(BPF_STX, 4),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xfbabcbda),
+			BPF_STMT(BPF_STX, 5),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xaedecbdb),
+			BPF_STMT(BPF_STX, 6),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xadebbade),
+			BPF_STMT(BPF_STX, 7),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xfcfcfaec),
+			BPF_STMT(BPF_STX, 8),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xbcdddbdc),
+			BPF_STMT(BPF_STX, 9),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xfeefdfac),
+			BPF_STMT(BPF_STX, 10),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xcddcdeea),
+			BPF_STMT(BPF_STX, 11),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xaccfaebb),
+			BPF_STMT(BPF_STX, 12),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xbdcccdcf),
+			BPF_STMT(BPF_STX, 13),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xaaedecde),
+			BPF_STMT(BPF_STX, 14),
+			BPF_STMT(BPF_LDX | BPF_IMM, 0xfaeacdad),
+			BPF_STMT(BPF_STX, 15),
+			BPF_STMT(BPF_LDX | BPF_MEM, 0),
+			BPF_STMT(BPF_MISC | BPF_TXA, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 1),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 2),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 3),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 4),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 5),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 6),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 7),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 8),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 9),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 10),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 11),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 12),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 13),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 14),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_LDX | BPF_MEM, 15),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_RET | BPF_A, 0),
+		},
+		CLASSIC | FLAG_NO_DATA,
+		{ },
+		{ { 0, 0x2a5a5e5 } },
+	},
 };
 
 static struct net_device dev;