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

   1 {
   2         "atomic compare-and-exchange smoketest - 64bit",
   3         .insns = {
   4                 /* val = 3; */
   5                 BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
   6                 /* old = atomic_cmpxchg(&val, 2, 4); */
   7                 BPF_MOV64_IMM(BPF_REG_1, 4),
   8                 BPF_MOV64_IMM(BPF_REG_0, 2),
   9                 BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
  10                 /* if (old != 3) exit(2); */
  11                 BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
  12                 BPF_MOV64_IMM(BPF_REG_0, 2),
  13                 BPF_EXIT_INSN(),
  14                 /* if (val != 3) exit(3); */
  15                 BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
  16                 BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
  17                 BPF_MOV64_IMM(BPF_REG_0, 3),
  18                 BPF_EXIT_INSN(),
  19                 /* old = atomic_cmpxchg(&val, 3, 4); */
  20                 BPF_MOV64_IMM(BPF_REG_1, 4),
  21                 BPF_MOV64_IMM(BPF_REG_0, 3),
  22                 BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
  23                 /* if (old != 3) exit(4); */
  24                 BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
  25                 BPF_MOV64_IMM(BPF_REG_0, 4),
  26                 BPF_EXIT_INSN(),
  27                 /* if (val != 4) exit(5); */
  28                 BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
  29                 BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 4, 2),
  30                 BPF_MOV64_IMM(BPF_REG_0, 5),
  31                 BPF_EXIT_INSN(),
  32                 /* exit(0); */
  33                 BPF_MOV64_IMM(BPF_REG_0, 0),
  34                 BPF_EXIT_INSN(),
  35         },
  36         .result = ACCEPT,
  37 },
  38 {
  39         "atomic compare-and-exchange smoketest - 32bit",
  40         .insns = {
  41                 /* val = 3; */
  42                 BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 3),
  43                 /* old = atomic_cmpxchg(&val, 2, 4); */
  44                 BPF_MOV32_IMM(BPF_REG_1, 4),
  45                 BPF_MOV32_IMM(BPF_REG_0, 2),
  46                 BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -4),
  47                 /* if (old != 3) exit(2); */
  48                 BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
  49                 BPF_MOV32_IMM(BPF_REG_0, 2),
  50                 BPF_EXIT_INSN(),
  51                 /* if (val != 3) exit(3); */
  52                 BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -4),
  53                 BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
  54                 BPF_MOV32_IMM(BPF_REG_0, 3),
  55                 BPF_EXIT_INSN(),
  56                 /* old = atomic_cmpxchg(&val, 3, 4); */
  57                 BPF_MOV32_IMM(BPF_REG_1, 4),
  58                 BPF_MOV32_IMM(BPF_REG_0, 3),
  59                 BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -4),
  60                 /* if (old != 3) exit(4); */
  61                 BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
  62                 BPF_MOV32_IMM(BPF_REG_0, 4),
  63                 BPF_EXIT_INSN(),
  64                 /* if (val != 4) exit(5); */
  65                 BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -4),
  66                 BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 4, 2),
  67                 BPF_MOV32_IMM(BPF_REG_0, 5),
  68                 BPF_EXIT_INSN(),
  69                 /* exit(0); */
  70                 BPF_MOV32_IMM(BPF_REG_0, 0),
  71                 BPF_EXIT_INSN(),
  72         },
  73         .result = ACCEPT,
  74 },
  75 {
  76         "Can't use cmpxchg on uninit src reg",
  77         .insns = {
  78                 BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
  79                 BPF_MOV64_IMM(BPF_REG_0, 3),
  80                 BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_2, -8),
  81                 BPF_EXIT_INSN(),
  82         },
  83         .result = REJECT,
  84         .errstr = "!read_ok",
  85 },
  86 {
  87         "Can't use cmpxchg on uninit memory",
  88         .insns = {
  89                 BPF_MOV64_IMM(BPF_REG_0, 3),
  90                 BPF_MOV64_IMM(BPF_REG_2, 4),
  91                 BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_2, -8),
  92                 BPF_EXIT_INSN(),
  93         },
  94         .result = REJECT,
  95         .errstr = "invalid read from stack",
  96 },
  97 {
  98         "BPF_W cmpxchg should zero top 32 bits",
  99         .insns = {
 100                 /* r0 = U64_MAX; */
 101                 BPF_MOV64_IMM(BPF_REG_0, 0),
 102                 BPF_ALU64_IMM(BPF_SUB, BPF_REG_0, 1),
 103                 /* u64 val = r0; */
 104                 BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
 105                 /* r0 = (u32)atomic_cmpxchg((u32 *)&val, r0, 1); */
 106                 BPF_MOV32_IMM(BPF_REG_1, 1),
 107                 BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
 108                 /* r1 = 0x00000000FFFFFFFFull; */
 109                 BPF_MOV64_IMM(BPF_REG_1, 1),
 110                 BPF_ALU64_IMM(BPF_LSH, BPF_REG_1, 32),
 111                 BPF_ALU64_IMM(BPF_SUB, BPF_REG_1, 1),
 112                 /* if (r0 != r1) exit(1); */
 113                 BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_1, 2),
 114                 BPF_MOV32_IMM(BPF_REG_0, 1),
 115                 BPF_EXIT_INSN(),
 116                 /* exit(0); */
 117                 BPF_MOV32_IMM(BPF_REG_0, 0),
 118                 BPF_EXIT_INSN(),
 119         },
 120         .result = ACCEPT,
 121 },