selftests/bpf: Add verifier tests for xor operation

Added some test_verifier bounds check test cases for
xor operations.
  $ ./test_verifier
  ...
  #78/u bounds check for reg = 0, reg xor 1 OK
  #78/p bounds check for reg = 0, reg xor 1 OK
  #79/u bounds check for reg32 = 0, reg32 xor 1 OK
  #79/p bounds check for reg32 = 0, reg32 xor 1 OK
  #80/u bounds check for reg = 2, reg xor 3 OK
  #80/p bounds check for reg = 2, reg xor 3 OK
  #81/u bounds check for reg = any, reg xor 3 OK
  #81/p bounds check for reg = any, reg xor 3 OK
  #82/u bounds check for reg32 = any, reg32 xor 3 OK
  #82/p bounds check for reg32 = any, reg32 xor 3 OK
  #83/u bounds check for reg > 0, reg xor 3 OK
  #83/p bounds check for reg > 0, reg xor 3 OK
  #84/u bounds check for reg32 > 0, reg32 xor 3 OK
  #84/p bounds check for reg32 > 0, reg32 xor 3 OK
  ...
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200825064609.2018077-1-yhs@fb.com

tools/testing/selftests/bpf/verifier/bounds.c

@@ -557,3 +557,149 @@
 	.result = ACCEPT,
 	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 },
+{
+	"bounds check for reg = 0, reg xor 1",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_XOR, BPF_REG_1, 1),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 8),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_hash_8b = { 3 },
+	.result = ACCEPT,
+},
+{
+	"bounds check for reg32 = 0, reg32 xor 1",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_MOV32_IMM(BPF_REG_1, 0),
+	BPF_ALU32_IMM(BPF_XOR, BPF_REG_1, 1),
+	BPF_JMP32_IMM(BPF_JNE, BPF_REG_1, 0, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 8),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_hash_8b = { 3 },
+	.result = ACCEPT,
+},
+{
+	"bounds check for reg = 2, reg xor 3",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_IMM(BPF_REG_1, 2),
+	BPF_ALU64_IMM(BPF_XOR, BPF_REG_1, 3),
+	BPF_JMP_IMM(BPF_JGT, BPF_REG_1, 0, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 8),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_hash_8b = { 3 },
+	.result = ACCEPT,
+},
+{
+	"bounds check for reg = any, reg xor 3",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0),
+	BPF_ALU64_IMM(BPF_XOR, BPF_REG_1, 3),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 8),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_hash_8b = { 3 },
+	.result = REJECT,
+	.errstr = "invalid access to map value",
+	.errstr_unpriv = "invalid access to map value",
+},
+{
+	"bounds check for reg32 = any, reg32 xor 3",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0),
+	BPF_ALU32_IMM(BPF_XOR, BPF_REG_1, 3),
+	BPF_JMP32_IMM(BPF_JNE, BPF_REG_1, 0, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 8),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_hash_8b = { 3 },
+	.result = REJECT,
+	.errstr = "invalid access to map value",
+	.errstr_unpriv = "invalid access to map value",
+},
+{
+	"bounds check for reg > 0, reg xor 3",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0),
+	BPF_JMP_IMM(BPF_JLE, BPF_REG_1, 0, 3),
+	BPF_ALU64_IMM(BPF_XOR, BPF_REG_1, 3),
+	BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 8),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_hash_8b = { 3 },
+	.result = ACCEPT,
+},
+{
+	"bounds check for reg32 > 0, reg32 xor 3",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0),
+	BPF_JMP32_IMM(BPF_JLE, BPF_REG_1, 0, 3),
+	BPF_ALU32_IMM(BPF_XOR, BPF_REG_1, 3),
+	BPF_JMP32_IMM(BPF_JGE, BPF_REG_1, 0, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 8),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_hash_8b = { 3 },
+	.result = ACCEPT,
+},