1 files changed, 96 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c b/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c
new file mode 100644
index 000000000000..2efd8bcf57a1
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c
@@ -0,0 +1,96 @@
+{
+	"atomic compare-and-exchange smoketest - 64bit",
+	.insns = {
+		/* val = 3; */
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
+		/* old = atomic_cmpxchg(&val, 2, 4); */
+		BPF_MOV64_IMM(BPF_REG_1, 4),
+		BPF_MOV64_IMM(BPF_REG_0, 2),
+		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
+		/* if (old != 3) exit(2); */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 2),
+		BPF_EXIT_INSN(),
+		/* if (val != 3) exit(3); */
+		BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 3),
+		BPF_EXIT_INSN(),
+		/* old = atomic_cmpxchg(&val, 3, 4); */
+		BPF_MOV64_IMM(BPF_REG_1, 4),
+		BPF_MOV64_IMM(BPF_REG_0, 3),
+		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
+		/* if (old != 3) exit(4); */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 4),
+		BPF_EXIT_INSN(),
+		/* if (val != 4) exit(5); */
+		BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 4, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 5),
+		BPF_EXIT_INSN(),
+		/* exit(0); */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"atomic compare-and-exchange smoketest - 32bit",
+	.insns = {
+		/* val = 3; */
+		BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 3),
+		/* old = atomic_cmpxchg(&val, 2, 4); */
+		BPF_MOV32_IMM(BPF_REG_1, 4),
+		BPF_MOV32_IMM(BPF_REG_0, 2),
+		BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -4),
+		/* if (old != 3) exit(2); */
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 2),
+		BPF_EXIT_INSN(),
+		/* if (val != 3) exit(3); */
+		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -4),
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 3),
+		BPF_EXIT_INSN(),
+		/* old = atomic_cmpxchg(&val, 3, 4); */
+		BPF_MOV32_IMM(BPF_REG_1, 4),
+		BPF_MOV32_IMM(BPF_REG_0, 3),
+		BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -4),
+		/* if (old != 3) exit(4); */
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 4),
+		BPF_EXIT_INSN(),
+		/* if (val != 4) exit(5); */
+		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -4),
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 4, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 5),
+		BPF_EXIT_INSN(),
+		/* exit(0); */
+		BPF_MOV32_IMM(BPF_REG_0, 0),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"Can't use cmpxchg on uninit src reg",
+	.insns = {
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
+		BPF_MOV64_IMM(BPF_REG_0, 3),
+		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_2, -8),
+		BPF_EXIT_INSN(),
+	},
+	.result = REJECT,
+	.errstr = "!read_ok",
+},
+{
+	"Can't use cmpxchg on uninit memory",
+	.insns = {
+		BPF_MOV64_IMM(BPF_REG_0, 3),
+		BPF_MOV64_IMM(BPF_REG_2, 4),
+		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_2, -8),
+		BPF_EXIT_INSN(),
+	},
+	.result = REJECT,
+	.errstr = "invalid read from stack",
+},