From: Andrii Nakryiko andriin@fb.com
[ Upstream commit 29fcb05bbf1a7008900bb9bee347bdbfc7171036 ]
BPF_PROBE_MEM is kernel-internal implmementation details. When dumping BPF instructions to user-space, it needs to be replaced back with BPF_MEM mode.
Fixes: 2a02759ef5f8 ("bpf: Add support for BTF pointers to interpreter") Signed-off-by: Andrii Nakryiko andriin@fb.com Signed-off-by: Alexei Starovoitov ast@kernel.org Link: https://lore.kernel.org/bpf/20200613002115.1632142-1-andriin@fb.com Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/bpf/syscall.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 4e6dee19a668..5d1d24f56d53 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2923,6 +2923,7 @@ static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog) struct bpf_insn *insns; u32 off, type; u64 imm; + u8 code; int i;
insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), @@ -2931,21 +2932,27 @@ static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog) return insns;
for (i = 0; i < prog->len; i++) { - if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) { + code = insns[i].code; + + if (code == (BPF_JMP | BPF_TAIL_CALL)) { insns[i].code = BPF_JMP | BPF_CALL; insns[i].imm = BPF_FUNC_tail_call; /* fall-through */ } - if (insns[i].code == (BPF_JMP | BPF_CALL) || - insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) { - if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) + if (code == (BPF_JMP | BPF_CALL) || + code == (BPF_JMP | BPF_CALL_ARGS)) { + if (code == (BPF_JMP | BPF_CALL_ARGS)) insns[i].code = BPF_JMP | BPF_CALL; if (!bpf_dump_raw_ok()) insns[i].imm = 0; continue; } + if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { + insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; + continue; + }
- if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW)) + if (code != (BPF_LD | BPF_IMM | BPF_DW)) continue;
imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;