linux-stable/tools/testing/selftests/bpf/verifier/bpf_get_stack.c
Dave Marchevsky bdc4e36945 bpf/selftests: Add bpf_get_task_stack retval bounds verifier test
Add a bpf_iter test which feeds bpf_get_task_stack's return value into
seq_write after confirming it's positive. No attempt to bound the value
from above is made.

Load will fail if verifier does not refine retval range based on
buf sz input to bpf_get_task_stack.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210416204704.2816874-3-davemarchevsky@fb.com
2021-04-19 18:23:33 -07:00

87 lines
2.9 KiB
C

{
"bpf_get_stack return R0 within range",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
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_JEQ, BPF_REG_0, 0, 28),
BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_9, sizeof(struct test_val)/2),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
BPF_MOV64_IMM(BPF_REG_3, sizeof(struct test_val)/2),
BPF_MOV64_IMM(BPF_REG_4, 256),
BPF_EMIT_CALL(BPF_FUNC_get_stack),
BPF_MOV64_IMM(BPF_REG_1, 0),
BPF_MOV64_REG(BPF_REG_8, BPF_REG_0),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_8, 32),
BPF_ALU64_IMM(BPF_ARSH, BPF_REG_8, 32),
BPF_JMP_REG(BPF_JSGT, BPF_REG_1, BPF_REG_8, 16),
BPF_ALU64_REG(BPF_SUB, BPF_REG_9, BPF_REG_8),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_8),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_9),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_1, 32),
BPF_ALU64_IMM(BPF_ARSH, BPF_REG_1, 32),
BPF_MOV64_REG(BPF_REG_3, BPF_REG_2),
BPF_ALU64_REG(BPF_ADD, BPF_REG_3, BPF_REG_1),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
BPF_MOV64_IMM(BPF_REG_5, sizeof(struct test_val)/2),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_5),
BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_1, 4),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_MOV64_REG(BPF_REG_3, BPF_REG_9),
BPF_MOV64_IMM(BPF_REG_4, 0),
BPF_EMIT_CALL(BPF_FUNC_get_stack),
BPF_EXIT_INSN(),
},
.fixup_map_hash_48b = { 4 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"bpf_get_task_stack return R0 range is refined",
.insns = {
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_6, 0), // ctx->meta->seq
BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_1, 8), // ctx->task
BPF_LD_MAP_FD(BPF_REG_1, 0), // fixup_map_array_48b
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_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
BPF_MOV64_REG(BPF_REG_9, BPF_REG_0), // keep buf for seq_write
BPF_MOV64_IMM(BPF_REG_3, 48),
BPF_MOV64_IMM(BPF_REG_4, 0),
BPF_EMIT_CALL(BPF_FUNC_get_task_stack),
BPF_JMP_IMM(BPF_JSGT, BPF_REG_0, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_9),
BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
BPF_EMIT_CALL(BPF_FUNC_seq_write),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_TRACING,
.expected_attach_type = BPF_TRACE_ITER,
.kfunc = "task",
.runs = -1, // Don't run, just load
.fixup_map_array_48b = { 3 },
},