Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 696 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/align.c b/tools/testing/selftests/bpf/prog_tests/align.c
new file mode 100644
index 000000000..8baebb415
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/align.c
@@ -0,0 +1,696 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+
+#define MAX_INSNS	512
+#define MAX_MATCHES	24
+
+struct bpf_reg_match {
+	unsigned int line;
+	const char *match;
+};
+
+struct bpf_align_test {
+	const char *descr;
+	struct bpf_insn	insns[MAX_INSNS];
+	enum {
+		UNDEF,
+		ACCEPT,
+		REJECT
+	} result;
+	enum bpf_prog_type prog_type;
+	/* Matches must be in order of increasing line */
+	struct bpf_reg_match matches[MAX_MATCHES];
+};
+
+static struct bpf_align_test tests[] = {
+	/* Four tests of known constants.  These aren't staggeringly
+	 * interesting since we track exact values now.
+	 */
+	{
+		.descr = "mov",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_3, 2),
+			BPF_MOV64_IMM(BPF_REG_3, 4),
+			BPF_MOV64_IMM(BPF_REG_3, 8),
+			BPF_MOV64_IMM(BPF_REG_3, 16),
+			BPF_MOV64_IMM(BPF_REG_3, 32),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.matches = {
+			{0, "R1=ctx(off=0,imm=0)"},
+			{0, "R10=fp0"},
+			{0, "R3_w=2"},
+			{1, "R3_w=4"},
+			{2, "R3_w=8"},
+			{3, "R3_w=16"},
+			{4, "R3_w=32"},
+		},
+	},
+	{
+		.descr = "shift",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_3, 1),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
+			BPF_ALU64_IMM(BPF_RSH, BPF_REG_3, 4),
+			BPF_MOV64_IMM(BPF_REG_4, 32),
+			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
+			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
+			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
+			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.matches = {
+			{0, "R1=ctx(off=0,imm=0)"},
+			{0, "R10=fp0"},
+			{0, "R3_w=1"},
+			{1, "R3_w=2"},
+			{2, "R3_w=4"},
+			{3, "R3_w=8"},
+			{4, "R3_w=16"},
+			{5, "R3_w=1"},
+			{6, "R4_w=32"},
+			{7, "R4_w=16"},
+			{8, "R4_w=8"},
+			{9, "R4_w=4"},
+			{10, "R4_w=2"},
+		},
+	},
+	{
+		.descr = "addsub",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_3, 4),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 4),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 2),
+			BPF_MOV64_IMM(BPF_REG_4, 8),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 2),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.matches = {
+			{0, "R1=ctx(off=0,imm=0)"},
+			{0, "R10=fp0"},
+			{0, "R3_w=4"},
+			{1, "R3_w=8"},
+			{2, "R3_w=10"},
+			{3, "R4_w=8"},
+			{4, "R4_w=12"},
+			{5, "R4_w=14"},
+		},
+	},
+	{
+		.descr = "mul",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_3, 7),
+			BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 1),
+			BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 2),
+			BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 4),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.matches = {
+			{0, "R1=ctx(off=0,imm=0)"},
+			{0, "R10=fp0"},
+			{0, "R3_w=7"},
+			{1, "R3_w=7"},
+			{2, "R3_w=14"},
+			{3, "R3_w=56"},
+		},
+	},
+
+	/* Tests using unknown values */
+#define PREP_PKT_POINTERS \
+	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, \
+		    offsetof(struct __sk_buff, data)), \
+	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, \
+		    offsetof(struct __sk_buff, data_end))
+
+#define LOAD_UNKNOWN(DST_REG) \
+	PREP_PKT_POINTERS, \
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), \
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8), \
+	BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_0, 1), \
+	BPF_EXIT_INSN(), \
+	BPF_LDX_MEM(BPF_B, DST_REG, BPF_REG_2, 0)
+
+	{
+		.descr = "unknown shift",
+		.insns = {
+			LOAD_UNKNOWN(BPF_REG_3),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
+			LOAD_UNKNOWN(BPF_REG_4),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_4, 5),
+			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
+			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
+			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
+			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.matches = {
+			{6, "R0_w=pkt(off=8,r=8,imm=0)"},
+			{6, "R3_w=scalar(umax=255,var_off=(0x0; 0xff))"},
+			{7, "R3_w=scalar(umax=510,var_off=(0x0; 0x1fe))"},
+			{8, "R3_w=scalar(umax=1020,var_off=(0x0; 0x3fc))"},
+			{9, "R3_w=scalar(umax=2040,var_off=(0x0; 0x7f8))"},
+			{10, "R3_w=scalar(umax=4080,var_off=(0x0; 0xff0))"},
+			{12, "R3_w=pkt_end(off=0,imm=0)"},
+			{17, "R4_w=scalar(umax=255,var_off=(0x0; 0xff))"},
+			{18, "R4_w=scalar(umax=8160,var_off=(0x0; 0x1fe0))"},
+			{19, "R4_w=scalar(umax=4080,var_off=(0x0; 0xff0))"},
+			{20, "R4_w=scalar(umax=2040,var_off=(0x0; 0x7f8))"},
+			{21, "R4_w=scalar(umax=1020,var_off=(0x0; 0x3fc))"},
+			{22, "R4_w=scalar(umax=510,var_off=(0x0; 0x1fe))"},
+		},
+	},
+	{
+		.descr = "unknown mul",
+		.insns = {
+			LOAD_UNKNOWN(BPF_REG_3),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
+			BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 1),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
+			BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 2),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
+			BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 4),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
+			BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 8),
+			BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 2),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.matches = {
+			{6, "R3_w=scalar(umax=255,var_off=(0x0; 0xff))"},
+			{7, "R4_w=scalar(id=1,umax=255,var_off=(0x0; 0xff))"},
+			{8, "R4_w=scalar(umax=255,var_off=(0x0; 0xff))"},
+			{9, "R4_w=scalar(id=1,umax=255,var_off=(0x0; 0xff))"},
+			{10, "R4_w=scalar(umax=510,var_off=(0x0; 0x1fe))"},
+			{11, "R4_w=scalar(id=1,umax=255,var_off=(0x0; 0xff))"},
+			{12, "R4_w=scalar(umax=1020,var_off=(0x0; 0x3fc))"},
+			{13, "R4_w=scalar(id=1,umax=255,var_off=(0x0; 0xff))"},
+			{14, "R4_w=scalar(umax=2040,var_off=(0x0; 0x7f8))"},
+			{15, "R4_w=scalar(umax=4080,var_off=(0x0; 0xff0))"},
+		},
+	},
+	{
+		.descr = "packet const offset",
+		.insns = {
+			PREP_PKT_POINTERS,
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
+
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+
+			/* Skip over ethernet header.  */
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
+			BPF_EXIT_INSN(),
+
+			BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 0),
+			BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 1),
+			BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 2),
+			BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 3),
+			BPF_LDX_MEM(BPF_H, BPF_REG_4, BPF_REG_5, 0),
+			BPF_LDX_MEM(BPF_H, BPF_REG_4, BPF_REG_5, 2),
+			BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),
+
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.matches = {
+			{2, "R5_w=pkt(off=0,r=0,imm=0)"},
+			{4, "R5_w=pkt(off=14,r=0,imm=0)"},
+			{5, "R4_w=pkt(off=14,r=0,imm=0)"},
+			{9, "R2=pkt(off=0,r=18,imm=0)"},
+			{10, "R5=pkt(off=14,r=18,imm=0)"},
+			{10, "R4_w=scalar(umax=255,var_off=(0x0; 0xff))"},
+			{13, "R4_w=scalar(umax=65535,var_off=(0x0; 0xffff))"},
+			{14, "R4_w=scalar(umax=65535,var_off=(0x0; 0xffff))"},
+		},
+	},
+	{
+		.descr = "packet variable offset",
+		.insns = {
+			LOAD_UNKNOWN(BPF_REG_6),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),
+
+			/* First, add a constant to the R5 packet pointer,
+			 * then a variable with a known alignment.
+			 */
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
+			BPF_EXIT_INSN(),
+			BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),
+
+			/* Now, test in the other direction.  Adding first
+			 * the variable offset to R5, then the constant.
+			 */
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
+			BPF_EXIT_INSN(),
+			BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),
+
+			/* Test multiple accumulations of unknown values
+			 * into a packet pointer.
+			 */
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 4),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
+			BPF_EXIT_INSN(),
+			BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),
+
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.matches = {
+			/* Calculated offset in R6 has unknown value, but known
+			 * alignment of 4.
+			 */
+			{6, "R2_w=pkt(off=0,r=8,imm=0)"},
+			{7, "R6_w=scalar(umax=1020,var_off=(0x0; 0x3fc))"},
+			/* Offset is added to packet pointer R5, resulting in
+			 * known fixed offset, and variable offset from R6.
+			 */
+			{11, "R5_w=pkt(id=1,off=14,r=0,umax=1020,var_off=(0x0; 0x3fc))"},
+			/* At the time the word size load is performed from R5,
+			 * it's total offset is NET_IP_ALIGN + reg->off (0) +
+			 * reg->aux_off (14) which is 16.  Then the variable
+			 * offset is considered using reg->aux_off_align which
+			 * is 4 and meets the load's requirements.
+			 */
+			{15, "R4=pkt(id=1,off=18,r=18,umax=1020,var_off=(0x0; 0x3fc))"},
+			{15, "R5=pkt(id=1,off=14,r=18,umax=1020,var_off=(0x0; 0x3fc))"},
+			/* Variable offset is added to R5 packet pointer,
+			 * resulting in auxiliary alignment of 4. To avoid BPF
+			 * verifier's precision backtracking logging
+			 * interfering we also have a no-op R4 = R5
+			 * instruction to validate R5 state. We also check
+			 * that R4 is what it should be in such case.
+			 */
+			{18, "R4_w=pkt(id=2,off=0,r=0,umax=1020,var_off=(0x0; 0x3fc))"},
+			{18, "R5_w=pkt(id=2,off=0,r=0,umax=1020,var_off=(0x0; 0x3fc))"},
+			/* Constant offset is added to R5, resulting in
+			 * reg->off of 14.
+			 */
+			{19, "R5_w=pkt(id=2,off=14,r=0,umax=1020,var_off=(0x0; 0x3fc))"},
+			/* At the time the word size load is performed from R5,
+			 * its total fixed offset is NET_IP_ALIGN + reg->off
+			 * (14) which is 16.  Then the variable offset is 4-byte
+			 * aligned, so the total offset is 4-byte aligned and
+			 * meets the load's requirements.
+			 */
+			{24, "R4=pkt(id=2,off=18,r=18,umax=1020,var_off=(0x0; 0x3fc))"},
+			{24, "R5=pkt(id=2,off=14,r=18,umax=1020,var_off=(0x0; 0x3fc))"},
+			/* Constant offset is added to R5 packet pointer,
+			 * resulting in reg->off value of 14.
+			 */
+			{26, "R5_w=pkt(off=14,r=8"},
+			/* Variable offset is added to R5, resulting in a
+			 * variable offset of (4n). See comment for insn #18
+			 * for R4 = R5 trick.
+			 */
+			{28, "R4_w=pkt(id=3,off=14,r=0,umax=1020,var_off=(0x0; 0x3fc))"},
+			{28, "R5_w=pkt(id=3,off=14,r=0,umax=1020,var_off=(0x0; 0x3fc))"},
+			/* Constant is added to R5 again, setting reg->off to 18. */
+			{29, "R5_w=pkt(id=3,off=18,r=0,umax=1020,var_off=(0x0; 0x3fc))"},
+			/* And once more we add a variable; resulting var_off
+			 * is still (4n), fixed offset is not changed.
+			 * Also, we create a new reg->id.
+			 */
+			{31, "R4_w=pkt(id=4,off=18,r=0,umax=2040,var_off=(0x0; 0x7fc)"},
+			{31, "R5_w=pkt(id=4,off=18,r=0,umax=2040,var_off=(0x0; 0x7fc)"},
+			/* At the time the word size load is performed from R5,
+			 * its total fixed offset is NET_IP_ALIGN + reg->off (18)
+			 * which is 20.  Then the variable offset is (4n), so
+			 * the total offset is 4-byte aligned and meets the
+			 * load's requirements.
+			 */
+			{35, "R4=pkt(id=4,off=22,r=22,umax=2040,var_off=(0x0; 0x7fc)"},
+			{35, "R5=pkt(id=4,off=18,r=22,umax=2040,var_off=(0x0; 0x7fc)"},
+		},
+	},
+	{
+		.descr = "packet variable offset 2",
+		.insns = {
+			/* Create an unknown offset, (4n+2)-aligned */
+			LOAD_UNKNOWN(BPF_REG_6),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 14),
+			/* Add it to the packet pointer */
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
+			/* Check bounds and perform a read */
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
+			BPF_EXIT_INSN(),
+			BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0),
+			/* Make a (4n) offset from the value we just read */
+			BPF_ALU64_IMM(BPF_AND, BPF_REG_6, 0xff),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),
+			/* Add it to the packet pointer */
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
+			/* Check bounds and perform a read */
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
+			BPF_EXIT_INSN(),
+			BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.matches = {
+			/* Calculated offset in R6 has unknown value, but known
+			 * alignment of 4.
+			 */
+			{6, "R2_w=pkt(off=0,r=8,imm=0)"},
+			{7, "R6_w=scalar(umax=1020,var_off=(0x0; 0x3fc))"},
+			/* Adding 14 makes R6 be (4n+2) */
+			{8, "R6_w=scalar(umin=14,umax=1034,var_off=(0x2; 0x7fc))"},
+			/* Packet pointer has (4n+2) offset */
+			{11, "R5_w=pkt(id=1,off=0,r=0,umin=14,umax=1034,var_off=(0x2; 0x7fc)"},
+			{12, "R4=pkt(id=1,off=4,r=0,umin=14,umax=1034,var_off=(0x2; 0x7fc)"},
+			/* At the time the word size load is performed from R5,
+			 * its total fixed offset is NET_IP_ALIGN + reg->off (0)
+			 * which is 2.  Then the variable offset is (4n+2), so
+			 * the total offset is 4-byte aligned and meets the
+			 * load's requirements.
+			 */
+			{15, "R5=pkt(id=1,off=0,r=4,umin=14,umax=1034,var_off=(0x2; 0x7fc)"},
+			/* Newly read value in R6 was shifted left by 2, so has
+			 * known alignment of 4.
+			 */
+			{17, "R6_w=scalar(umax=1020,var_off=(0x0; 0x3fc))"},
+			/* Added (4n) to packet pointer's (4n+2) var_off, giving
+			 * another (4n+2).
+			 */
+			{19, "R5_w=pkt(id=2,off=0,r=0,umin=14,umax=2054,var_off=(0x2; 0xffc)"},
+			{20, "R4=pkt(id=2,off=4,r=0,umin=14,umax=2054,var_off=(0x2; 0xffc)"},
+			/* At the time the word size load is performed from R5,
+			 * its total fixed offset is NET_IP_ALIGN + reg->off (0)
+			 * which is 2.  Then the variable offset is (4n+2), so
+			 * the total offset is 4-byte aligned and meets the
+			 * load's requirements.
+			 */
+			{23, "R5=pkt(id=2,off=0,r=4,umin=14,umax=2054,var_off=(0x2; 0xffc)"},
+		},
+	},
+	{
+		.descr = "dubious pointer arithmetic",
+		.insns = {
+			PREP_PKT_POINTERS,
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			/* (ptr - ptr) << 2 */
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_3),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_5, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_5, 2),
+			/* We have a (4n) value.  Let's make a packet offset
+			 * out of it.  First add 14, to make it a (4n+2)
+			 */
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
+			/* Then make sure it's nonnegative */
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_5, 0, 1),
+			BPF_EXIT_INSN(),
+			/* Add it to packet pointer */
+			BPF_MOV64_REG(BPF_REG_6, BPF_REG_2),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_6, BPF_REG_5),
+			/* Check bounds and perform a read */
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_6),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
+			BPF_EXIT_INSN(),
+			BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_6, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.result = REJECT,
+		.matches = {
+			{3, "R5_w=pkt_end(off=0,imm=0)"},
+			/* (ptr - ptr) << 2 == unknown, (4n) */
+			{5, "R5_w=scalar(smax=9223372036854775804,umax=18446744073709551612,var_off=(0x0; 0xfffffffffffffffc)"},
+			/* (4n) + 14 == (4n+2).  We blow our bounds, because
+			 * the add could overflow.
+			 */
+			{6, "R5_w=scalar(smin=-9223372036854775806,smax=9223372036854775806,umin=2,umax=18446744073709551614,var_off=(0x2; 0xfffffffffffffffc)"},
+			/* Checked s>=0 */
+			{9, "R5=scalar(umin=2,umax=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc)"},
+			/* packet pointer + nonnegative (4n+2) */
+			{11, "R6_w=pkt(id=1,off=0,r=0,umin=2,umax=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc)"},
+			{12, "R4_w=pkt(id=1,off=4,r=0,umin=2,umax=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc)"},
+			/* NET_IP_ALIGN + (4n+2) == (4n), alignment is fine.
+			 * We checked the bounds, but it might have been able
+			 * to overflow if the packet pointer started in the
+			 * upper half of the address space.
+			 * So we did not get a 'range' on R6, and the access
+			 * attempt will fail.
+			 */
+			{15, "R6_w=pkt(id=1,off=0,r=0,umin=2,umax=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc)"},
+		}
+	},
+	{
+		.descr = "variable subtraction",
+		.insns = {
+			/* Create an unknown offset, (4n+2)-aligned */
+			LOAD_UNKNOWN(BPF_REG_6),
+			BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 14),
+			/* Create another unknown, (4n)-aligned, and subtract
+			 * it from the first one
+			 */
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_7, 2),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_6, BPF_REG_7),
+			/* Bounds-check the result */
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_6, 0, 1),
+			BPF_EXIT_INSN(),
+			/* Add it to the packet pointer */
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
+			/* Check bounds and perform a read */
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
+			BPF_EXIT_INSN(),
+			BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.matches = {
+			/* Calculated offset in R6 has unknown value, but known
+			 * alignment of 4.
+			 */
+			{6, "R2_w=pkt(off=0,r=8,imm=0)"},
+			{8, "R6_w=scalar(umax=1020,var_off=(0x0; 0x3fc))"},
+			/* Adding 14 makes R6 be (4n+2) */
+			{9, "R6_w=scalar(umin=14,umax=1034,var_off=(0x2; 0x7fc))"},
+			/* New unknown value in R7 is (4n) */
+			{10, "R7_w=scalar(umax=1020,var_off=(0x0; 0x3fc))"},
+			/* Subtracting it from R6 blows our unsigned bounds */
+			{11, "R6=scalar(smin=-1006,smax=1034,umin=2,umax=18446744073709551614,var_off=(0x2; 0xfffffffffffffffc)"},
+			/* Checked s>= 0 */
+			{14, "R6=scalar(umin=2,umax=1034,var_off=(0x2; 0x7fc))"},
+			/* At the time the word size load is performed from R5,
+			 * its total fixed offset is NET_IP_ALIGN + reg->off (0)
+			 * which is 2.  Then the variable offset is (4n+2), so
+			 * the total offset is 4-byte aligned and meets the
+			 * load's requirements.
+			 */
+			{20, "R5=pkt(id=2,off=0,r=4,umin=2,umax=1034,var_off=(0x2; 0x7fc)"},
+
+		},
+	},
+	{
+		.descr = "pointer variable subtraction",
+		.insns = {
+			/* Create an unknown offset, (4n+2)-aligned and bounded
+			 * to [14,74]
+			 */
+			LOAD_UNKNOWN(BPF_REG_6),
+			BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
+			BPF_ALU64_IMM(BPF_AND, BPF_REG_6, 0xf),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 14),
+			/* Subtract it from the packet pointer */
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_5, BPF_REG_6),
+			/* Create another unknown, (4n)-aligned and >= 74.
+			 * That in fact means >= 76, since 74 % 4 == 2
+			 */
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_7, 2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 76),
+			/* Add it to the packet pointer */
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_7),
+			/* Check bounds and perform a read */
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
+			BPF_EXIT_INSN(),
+			BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.matches = {
+			/* Calculated offset in R6 has unknown value, but known
+			 * alignment of 4.
+			 */
+			{6, "R2_w=pkt(off=0,r=8,imm=0)"},
+			{9, "R6_w=scalar(umax=60,var_off=(0x0; 0x3c))"},
+			/* Adding 14 makes R6 be (4n+2) */
+			{10, "R6_w=scalar(umin=14,umax=74,var_off=(0x2; 0x7c))"},
+			/* Subtracting from packet pointer overflows ubounds */
+			{13, "R5_w=pkt(id=2,off=0,r=8,umin=18446744073709551542,umax=18446744073709551602,var_off=(0xffffffffffffff82; 0x7c)"},
+			/* New unknown value in R7 is (4n), >= 76 */
+			{14, "R7_w=scalar(umin=76,umax=1096,var_off=(0x0; 0x7fc))"},
+			/* Adding it to packet pointer gives nice bounds again */
+			{16, "R5_w=pkt(id=3,off=0,r=0,umin=2,umax=1082,var_off=(0x2; 0x7fc)"},
+			/* At the time the word size load is performed from R5,
+			 * its total fixed offset is NET_IP_ALIGN + reg->off (0)
+			 * which is 2.  Then the variable offset is (4n+2), so
+			 * the total offset is 4-byte aligned and meets the
+			 * load's requirements.
+			 */
+			{20, "R5=pkt(id=3,off=0,r=4,umin=2,umax=1082,var_off=(0x2; 0x7fc)"},
+		},
+	},
+};
+
+static int probe_filter_length(const struct bpf_insn *fp)
+{
+	int len;
+
+	for (len = MAX_INSNS - 1; len > 0; --len)
+		if (fp[len].code != 0 || fp[len].imm != 0)
+			break;
+	return len + 1;
+}
+
+static char bpf_vlog[32768];
+
+static int do_test_single(struct bpf_align_test *test)
+{
+	struct bpf_insn *prog = test->insns;
+	int prog_type = test->prog_type;
+	char bpf_vlog_copy[32768];
+	LIBBPF_OPTS(bpf_prog_load_opts, opts,
+		.prog_flags = BPF_F_STRICT_ALIGNMENT,
+		.log_buf = bpf_vlog,
+		.log_size = sizeof(bpf_vlog),
+		.log_level = 2,
+	);
+	const char *line_ptr;
+	int cur_line = -1;
+	int prog_len, i;
+	int fd_prog;
+	int ret;
+
+	prog_len = probe_filter_length(prog);
+	fd_prog = bpf_prog_load(prog_type ? : BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL",
+				prog, prog_len, &opts);
+	if (fd_prog < 0 && test->result != REJECT) {
+		printf("Failed to load program.\n");
+		printf("%s", bpf_vlog);
+		ret = 1;
+	} else if (fd_prog >= 0 && test->result == REJECT) {
+		printf("Unexpected success to load!\n");
+		printf("%s", bpf_vlog);
+		ret = 1;
+		close(fd_prog);
+	} else {
+		ret = 0;
+		/* We make a local copy so that we can strtok() it */
+		strncpy(bpf_vlog_copy, bpf_vlog, sizeof(bpf_vlog_copy));
+		line_ptr = strtok(bpf_vlog_copy, "\n");
+		for (i = 0; i < MAX_MATCHES; i++) {
+			struct bpf_reg_match m = test->matches[i];
+			int tmp;
+
+			if (!m.match)
+				break;
+			while (line_ptr) {
+				cur_line = -1;
+				sscanf(line_ptr, "%u: ", &cur_line);
+				if (cur_line == -1)
+					sscanf(line_ptr, "from %u to %u: ", &tmp, &cur_line);
+				if (cur_line == m.line)
+					break;
+				line_ptr = strtok(NULL, "\n");
+			}
+			if (!line_ptr) {
+				printf("Failed to find line %u for match: %s\n",
+				       m.line, m.match);
+				ret = 1;
+				printf("%s", bpf_vlog);
+				break;
+			}
+			/* Check the next line as well in case the previous line
+			 * did not have a corresponding bpf insn. Example:
+			 * func#0 @0
+			 * 0: R1=ctx(off=0,imm=0) R10=fp0
+			 * 0: (b7) r3 = 2                 ; R3_w=2
+			 */
+			if (!strstr(line_ptr, m.match)) {
+				cur_line = -1;
+				line_ptr = strtok(NULL, "\n");
+				sscanf(line_ptr, "%u: ", &cur_line);
+			}
+			if (cur_line != m.line || !line_ptr ||
+			    !strstr(line_ptr, m.match)) {
+				printf("Failed to find match %u: %s\n",
+				       m.line, m.match);
+				ret = 1;
+				printf("%s", bpf_vlog);
+				break;
+			}
+		}
+		if (fd_prog >= 0)
+			close(fd_prog);
+	}
+	return ret;
+}
+
+void test_align(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
+		struct bpf_align_test *test = &tests[i];
+
+		if (!test__start_subtest(test->descr))
+			continue;
+
+		ASSERT_OK(do_test_single(test), test->descr);
+	}
+}