bpf, tests: Add tests for BPF_LDX/BPF_STX with different offsets

This patch adds tests to verify the behavior of BPF_LDX/BPF_STX +
BPF_B/BPF_H/BPF_W/BPF_DW with negative offset, small positive offset,
large positive offset, and misaligned offset.

Tested on both big-endian and little-endian arm64 qemu, result:

 test_bpf: Summary: 1026 PASSED, 0 FAILED, [1014/1014 JIT'ed]']
 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [8/8 JIT'ed]
 test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220321152852.2334294-5-xukuohai@huawei.com

1 files changed, 281 insertions, 4 deletions

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 0c5cb2d6436a..aa0c7c68b2be 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -53,6 +53,7 @@
 #define FLAG_EXPECTED_FAIL	BIT(1)
 #define FLAG_SKB_FRAG		BIT(2)
 #define FLAG_VERIFIER_ZEXT	BIT(3)
+#define FLAG_LARGE_MEM		BIT(4)
 
 enum {
 	CLASSIC  = BIT(6),	/* Old BPF instructions only. */
@@ -7838,7 +7839,7 @@ static struct bpf_test tests[] = {
 	},
 	/* BPF_LDX_MEM B/H/W/DW */
 	{
-		"BPF_LDX_MEM | BPF_B",
+		"BPF_LDX_MEM | BPF_B, base",
 		.u.insns_int = {
 			BPF_LD_IMM64(R1, 0x0102030405060708ULL),
 			BPF_LD_IMM64(R2, 0x0000000000000008ULL),
@@ -7878,7 +7879,56 @@ static struct bpf_test tests[] = {
 		.stack_depth = 8,
 	},
 	{
-		"BPF_LDX_MEM | BPF_H",
+		"BPF_LDX_MEM | BPF_B, negative offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_LD_IMM64(R3, 0x0000000000000088ULL),
+			BPF_ALU64_IMM(BPF_ADD, R1, 512),
+			BPF_STX_MEM(BPF_B, R1, R2, -256),
+			BPF_LDX_MEM(BPF_B, R0, R1, -256),
+			BPF_JMP_REG(BPF_JNE, R0, R3, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 512, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_B, small positive offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_LD_IMM64(R3, 0x0000000000000088ULL),
+			BPF_STX_MEM(BPF_B, R1, R2, 256),
+			BPF_LDX_MEM(BPF_B, R0, R1, 256),
+			BPF_JMP_REG(BPF_JNE, R0, R3, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 512, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_B, large positive offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_LD_IMM64(R3, 0x0000000000000088ULL),
+			BPF_STX_MEM(BPF_B, R1, R2, 4096),
+			BPF_LDX_MEM(BPF_B, R0, R1, 4096),
+			BPF_JMP_REG(BPF_JNE, R0, R3, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 4096 + 16, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_H, base",
 		.u.insns_int = {
 			BPF_LD_IMM64(R1, 0x0102030405060708ULL),
 			BPF_LD_IMM64(R2, 0x0000000000000708ULL),
@@ -7918,7 +7968,72 @@ static struct bpf_test tests[] = {
 		.stack_depth = 8,
 	},
 	{
-		"BPF_LDX_MEM | BPF_W",
+		"BPF_LDX_MEM | BPF_H, negative offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_LD_IMM64(R3, 0x0000000000008788ULL),
+			BPF_ALU64_IMM(BPF_ADD, R1, 512),
+			BPF_STX_MEM(BPF_H, R1, R2, -256),
+			BPF_LDX_MEM(BPF_H, R0, R1, -256),
+			BPF_JMP_REG(BPF_JNE, R0, R3, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 512, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_H, small positive offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_LD_IMM64(R3, 0x0000000000008788ULL),
+			BPF_STX_MEM(BPF_H, R1, R2, 256),
+			BPF_LDX_MEM(BPF_H, R0, R1, 256),
+			BPF_JMP_REG(BPF_JNE, R0, R3, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 512, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_H, large positive offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_LD_IMM64(R3, 0x0000000000008788ULL),
+			BPF_STX_MEM(BPF_H, R1, R2, 8192),
+			BPF_LDX_MEM(BPF_H, R0, R1, 8192),
+			BPF_JMP_REG(BPF_JNE, R0, R3, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 8192 + 16, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_H, unaligned positive offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_LD_IMM64(R3, 0x0000000000008788ULL),
+			BPF_STX_MEM(BPF_H, R1, R2, 13),
+			BPF_LDX_MEM(BPF_H, R0, R1, 13),
+			BPF_JMP_REG(BPF_JNE, R0, R3, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 32, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_W, base",
 		.u.insns_int = {
 			BPF_LD_IMM64(R1, 0x0102030405060708ULL),
 			BPF_LD_IMM64(R2, 0x0000000005060708ULL),
@@ -7957,6 +8072,162 @@ static struct bpf_test tests[] = {
 		{ { 0, 0 } },
 		.stack_depth = 8,
 	},
+	{
+		"BPF_LDX_MEM | BPF_W, negative offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_LD_IMM64(R3, 0x0000000085868788ULL),
+			BPF_ALU64_IMM(BPF_ADD, R1, 512),
+			BPF_STX_MEM(BPF_W, R1, R2, -256),
+			BPF_LDX_MEM(BPF_W, R0, R1, -256),
+			BPF_JMP_REG(BPF_JNE, R0, R3, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 512, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_W, small positive offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_LD_IMM64(R3, 0x0000000085868788ULL),
+			BPF_STX_MEM(BPF_W, R1, R2, 256),
+			BPF_LDX_MEM(BPF_W, R0, R1, 256),
+			BPF_JMP_REG(BPF_JNE, R0, R3, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 512, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_W, large positive offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_LD_IMM64(R3, 0x0000000085868788ULL),
+			BPF_STX_MEM(BPF_W, R1, R2, 16384),
+			BPF_LDX_MEM(BPF_W, R0, R1, 16384),
+			BPF_JMP_REG(BPF_JNE, R0, R3, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 16384 + 16, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_W, unaligned positive offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_LD_IMM64(R3, 0x0000000085868788ULL),
+			BPF_STX_MEM(BPF_W, R1, R2, 13),
+			BPF_LDX_MEM(BPF_W, R0, R1, 13),
+			BPF_JMP_REG(BPF_JNE, R0, R3, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 32, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_DW, base",
+		.u.insns_int = {
+			BPF_LD_IMM64(R1, 0x0102030405060708ULL),
+			BPF_STX_MEM(BPF_DW, R10, R1, -8),
+			BPF_LDX_MEM(BPF_DW, R0, R10, -8),
+			BPF_JMP_REG(BPF_JNE, R0, R1, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL,
+		{ },
+		{ { 0, 0 } },
+		.stack_depth = 8,
+	},
+	{
+		"BPF_LDX_MEM | BPF_DW, MSB set",
+		.u.insns_int = {
+			BPF_LD_IMM64(R1, 0x8182838485868788ULL),
+			BPF_STX_MEM(BPF_DW, R10, R1, -8),
+			BPF_LDX_MEM(BPF_DW, R0, R10, -8),
+			BPF_JMP_REG(BPF_JNE, R0, R1, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL,
+		{ },
+		{ { 0, 0 } },
+		.stack_depth = 8,
+	},
+	{
+		"BPF_LDX_MEM | BPF_DW, negative offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_ALU64_IMM(BPF_ADD, R1, 512),
+			BPF_STX_MEM(BPF_DW, R1, R2, -256),
+			BPF_LDX_MEM(BPF_DW, R0, R1, -256),
+			BPF_JMP_REG(BPF_JNE, R0, R2, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 512, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_DW, small positive offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_STX_MEM(BPF_DW, R1, R2, 256),
+			BPF_LDX_MEM(BPF_DW, R0, R1, 256),
+			BPF_JMP_REG(BPF_JNE, R0, R2, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 512, 0 } },
+		.stack_depth = 8,
+	},
+	{
+		"BPF_LDX_MEM | BPF_DW, large positive offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_STX_MEM(BPF_DW, R1, R2, 32760),
+			BPF_LDX_MEM(BPF_DW, R0, R1, 32760),
+			BPF_JMP_REG(BPF_JNE, R0, R2, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 32768, 0 } },
+		.stack_depth = 0,
+	},
+	{
+		"BPF_LDX_MEM | BPF_DW, unaligned positive offset",
+		.u.insns_int = {
+			BPF_LD_IMM64(R2, 0x8182838485868788ULL),
+			BPF_STX_MEM(BPF_DW, R1, R2, 13),
+			BPF_LDX_MEM(BPF_DW, R0, R1, 13),
+			BPF_JMP_REG(BPF_JNE, R0, R2, 1),
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_EXIT_INSN(),
+		},
+		INTERNAL | FLAG_LARGE_MEM,
+		{ },
+		{ { 32, 0 } },
+		.stack_depth = 0,
+	},
 	/* BPF_STX_MEM B/H/W/DW */
 	{
 		"BPF_STX_MEM | BPF_B",
@@ -14094,6 +14365,9 @@ static void *generate_test_data(struct bpf_test *test, int sub)
 	if (test->aux & FLAG_NO_DATA)
 		return NULL;
 
+	if (test->aux & FLAG_LARGE_MEM)
+		return kmalloc(test->test[sub].data_size, GFP_KERNEL);
+
 	/* Test case expects an skb, so populate one. Various
 	 * subtests generate skbs of different sizes based on
 	 * the same data.
@@ -14137,7 +14411,10 @@ static void release_test_data(const struct bpf_test *test, void *data)
 	if (test->aux & FLAG_NO_DATA)
 		return;
 
-	kfree_skb(data);
+	if (test->aux & FLAG_LARGE_MEM)
+		kfree(data);
+	else
+		kfree_skb(data);
 }
 
 static int filter_length(int which)