linux-stable/arch/riscv/net
Pu Lehui d32b2a85ef riscv, bpf: Emit fixed-length instructions for BPF_PSEUDO_FUNC
[ Upstream commit b54b600361 ]

For BPF_PSEUDO_FUNC instruction, verifier will refill imm with
correct addresses of bpf_calls and then run last pass of JIT.
Since the emit_imm of RV64 is variable-length, which will emit
appropriate length instructions accorroding to the imm, it may
broke ctx->offset, and lead to unpredictable problem, such as
inaccurate jump. So let's fix it with fixed-length instructions.

Fixes: 69c087ba62 ("bpf: Add bpf_for_each_map_elem() helper")
Suggested-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Björn Töpel <bjorn@kernel.org>
Acked-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/bpf/20221206091410.1584784-1-pulehui@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-31 13:26:09 +01:00
..
Makefile riscv, bpf: Add RV32G eBPF JIT 2020-03-05 16:13:47 +01:00
bpf_jit.h bpf, riscv: Support riscv jit to provide bpf_line_info 2022-06-02 16:26:01 -07:00
bpf_jit_comp32.c bpf: Change value of MAX_TAIL_CALL_CNT from 32 to 33 2021-11-16 14:03:15 +01:00
bpf_jit_comp64.c riscv, bpf: Emit fixed-length instructions for BPF_PSEUDO_FUNC 2022-12-31 13:26:09 +01:00
bpf_jit_core.c bpf, riscv: Support riscv jit to provide bpf_line_info 2022-06-02 16:26:01 -07:00