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authorAndrii Nakryiko <andriin@fb.com>2020-06-12 17:21:15 -0700
committerAlexei Starovoitov <ast@kernel.org>2020-06-12 17:35:38 -0700
commit29fcb05bbf1a7008900bb9bee347bdbfc7171036 (patch)
tree048722952f48b23c5f2e2bf5889776962dae09cf
parentcaf62492f479585296e9d636c798d5ac256b7b04 (diff)
downloadlinux-29fcb05bbf1a7008900bb9bee347bdbfc7171036.tar.gz
bpf: Undo internal BPF_PROBE_MEM in BPF insns dump
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
-rw-r--r--kernel/bpf/syscall.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 4d530b1..e9a3ebc 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3158,6 +3158,7 @@ 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),
@@ -3166,21 +3167,27 @@ 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;