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linux/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c
Brendan Jackman 7960d02ddd selftests/bpf: Some more atomic tests 
Some new verifier tests that hit some important gaps in the parameter
space for atomic ops.

There are already exhaustive tests for the JIT part in
lib/test_bpf.c, but these exercise the verifier too.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211015093318.1273686-1-jackmanb@google.com
2021-10-20 18:09:08 -07:00

160 lines
4.4 KiB
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{
"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",
},
{
"BPF_W cmpxchg should zero top 32 bits",
.insns = {
/* r0 = U64_MAX; */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_0, 1),
/* u64 val = r0; */
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
/* r0 = (u32)atomic_cmpxchg((u32 *)&val, r0, 1); */
BPF_MOV32_IMM(BPF_REG_1, 1),
BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
/* r1 = 0x00000000FFFFFFFFull; */
BPF_MOV64_IMM(BPF_REG_1, 1),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_1, 32),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_1, 1),
/* if (r0 != r1) exit(1); */
BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_1, 2),
BPF_MOV32_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
/* exit(0); */
BPF_MOV32_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"Dest pointer in r0 - fail",
.insns = {
/* val = 0; */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
/* r0 = &val */
BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
/* r0 = atomic_cmpxchg(&val, r0, 1); */
BPF_MOV64_IMM(BPF_REG_1, 1),
BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
/* if (r0 != 0) exit(1); */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
/* exit(0); */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"Dest pointer in r0 - succeed",
.insns = {
/* r0 = &val */
BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
/* val = r0; */
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
/* r0 = atomic_cmpxchg(&val, r0, 0); */
BPF_MOV64_IMM(BPF_REG_1, 0),
BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
/* r1 = *r0 */
BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, -8),
/* exit(0); */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
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