linux-stable/tools/testing/selftests/bpf/verifier/atomic_xor.c
Ilya Leoshkevich 45df305268 selftests/bpf: Fix endianness issues in atomic tests
Atomic tests store a DW, but then load it back as a W from the same
address. This doesn't work on big-endian systems, and since the point
of those tests is not testing narrow loads, fix simply by loading a
DW.

Fixes: 98d666d05a ("bpf: Add tests for new BPF atomic operations")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210210020713.77911-1-iii@linux.ibm.com
2021-02-10 11:55:22 -08:00

77 lines
2.3 KiB
C

{
"BPF_ATOMIC XOR without fetch",
.insns = {
/* val = 0x110; */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0x110),
/* atomic_xor(&val, 0x011); */
BPF_MOV64_IMM(BPF_REG_1, 0x011),
BPF_ATOMIC_OP(BPF_DW, BPF_XOR, BPF_REG_10, BPF_REG_1, -8),
/* if (val != 0x101) exit(2); */
BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0x101, 2),
BPF_MOV64_IMM(BPF_REG_0, 2),
BPF_EXIT_INSN(),
/* r1 should not be clobbered, no BPF_FETCH flag */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x011, 1),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"BPF_ATOMIC XOR with fetch",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 123),
/* val = 0x110; */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0x110),
/* old = atomic_fetch_xor(&val, 0x011); */
BPF_MOV64_IMM(BPF_REG_1, 0x011),
BPF_ATOMIC_OP(BPF_DW, BPF_XOR | BPF_FETCH, BPF_REG_10, BPF_REG_1, -8),
/* if (old != 0x110) exit(3); */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x110, 2),
BPF_MOV64_IMM(BPF_REG_0, 3),
BPF_EXIT_INSN(),
/* if (val != 0x101) exit(2); */
BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -8),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x101, 2),
BPF_MOV64_IMM(BPF_REG_1, 2),
BPF_EXIT_INSN(),
/* Check R0 wasn't clobbered (fxor fear of x86 JIT bug) */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 123, 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,
},
{
"BPF_ATOMIC XOR with fetch 32bit",
.insns = {
/* r0 = (s64) -1 */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_0, 1),
/* val = 0x110; */
BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0x110),
/* old = atomic_fetch_xor(&val, 0x011); */
BPF_MOV32_IMM(BPF_REG_1, 0x011),
BPF_ATOMIC_OP(BPF_W, BPF_XOR | BPF_FETCH, BPF_REG_10, BPF_REG_1, -4),
/* if (old != 0x110) exit(3); */
BPF_JMP32_IMM(BPF_JEQ, BPF_REG_1, 0x110, 2),
BPF_MOV32_IMM(BPF_REG_0, 3),
BPF_EXIT_INSN(),
/* if (val != 0x101) exit(2); */
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_10, -4),
BPF_JMP32_IMM(BPF_JEQ, BPF_REG_1, 0x101, 2),
BPF_MOV32_IMM(BPF_REG_1, 2),
BPF_EXIT_INSN(),
/* Check R0 wasn't clobbered (fxor fear of x86 JIT bug)
* It should be -1 so add 1 to get exit code.
*/
BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},