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91c960b005
A subsequent patch will add additional atomic operations. These new operations will use the same opcode field as the existing XADD, with the immediate discriminating different operations. In preparation, rename the instruction mode BPF_ATOMIC and start calling the zero immediate BPF_ADD. This is possible (doesn't break existing valid BPF progs) because the immediate field is currently reserved MBZ and BPF_ADD is zero. All uses are removed from the tree but the BPF_XADD definition is kept around to avoid breaking builds for people including kernel headers. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20210114181751.768687-5-jackmanb@google.com
98 lines
3.0 KiB
C
98 lines
3.0 KiB
C
{
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"xadd/w check unaligned stack",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
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BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_10, BPF_REG_0, -7),
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BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
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BPF_EXIT_INSN(),
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},
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.result = REJECT,
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.errstr = "misaligned stack access off",
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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},
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{
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"xadd/w check unaligned map",
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.insns = {
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BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
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BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
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BPF_LD_MAP_FD(BPF_REG_1, 0),
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BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
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BPF_EXIT_INSN(),
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BPF_MOV64_IMM(BPF_REG_1, 1),
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BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_0, BPF_REG_1, 3),
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 3),
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BPF_EXIT_INSN(),
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},
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.fixup_map_hash_8b = { 3 },
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.result = REJECT,
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.errstr = "misaligned value access off",
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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},
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{
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"xadd/w check unaligned pkt",
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.insns = {
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BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, offsetof(struct xdp_md, data)),
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BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
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offsetof(struct xdp_md, data_end)),
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BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
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BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_3, 2),
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BPF_MOV64_IMM(BPF_REG_0, 99),
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BPF_JMP_IMM(BPF_JA, 0, 0, 6),
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_ST_MEM(BPF_W, BPF_REG_2, 0, 0),
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BPF_ST_MEM(BPF_W, BPF_REG_2, 3, 0),
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BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_2, BPF_REG_0, 1),
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BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_2, BPF_REG_0, 2),
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 1),
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BPF_EXIT_INSN(),
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},
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.result = REJECT,
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.errstr = "BPF_ATOMIC stores into R2 pkt is not allowed",
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.prog_type = BPF_PROG_TYPE_XDP,
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.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
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},
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{
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"xadd/w check whether src/dst got mangled, 1",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
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BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
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BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
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BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_10, BPF_REG_0, -8),
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BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_10, BPF_REG_0, -8),
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BPF_JMP_REG(BPF_JNE, BPF_REG_6, BPF_REG_0, 3),
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BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_10, 2),
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BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
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BPF_EXIT_INSN(),
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BPF_MOV64_IMM(BPF_REG_0, 42),
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BPF_EXIT_INSN(),
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},
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.result = ACCEPT,
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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.retval = 3,
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},
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{
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"xadd/w check whether src/dst got mangled, 2",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
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BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
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BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -8),
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BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_10, BPF_REG_0, -8),
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BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_10, BPF_REG_0, -8),
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BPF_JMP_REG(BPF_JNE, BPF_REG_6, BPF_REG_0, 3),
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BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_10, 2),
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -8),
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BPF_EXIT_INSN(),
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BPF_MOV64_IMM(BPF_REG_0, 42),
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BPF_EXIT_INSN(),
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},
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.result = ACCEPT,
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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.retval = 3,
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},
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