Commit ea2e7ce5 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by David S. Miller

bpf: support 8-byte metafield access

The verifier supported only 4-byte metafields in
struct __sk_buff and struct xdp_md. The metafields in upcoming
struct bpf_perf_event are 8-byte to match register width in struct pt_regs.
Teach verifier to recognize 8-byte metafield access.
The patch doesn't affect safety of sockets and xdp programs.
They check for 4-byte only ctx access before these conditions are hit.
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 569e937e
...@@ -2333,7 +2333,8 @@ static int do_check(struct verifier_env *env) ...@@ -2333,7 +2333,8 @@ static int do_check(struct verifier_env *env)
if (err) if (err)
return err; return err;
if (BPF_SIZE(insn->code) != BPF_W) { if (BPF_SIZE(insn->code) != BPF_W &&
BPF_SIZE(insn->code) != BPF_DW) {
insn_idx++; insn_idx++;
continue; continue;
} }
...@@ -2642,9 +2643,11 @@ static int convert_ctx_accesses(struct verifier_env *env) ...@@ -2642,9 +2643,11 @@ static int convert_ctx_accesses(struct verifier_env *env)
for (i = 0; i < insn_cnt; i++, insn++) { for (i = 0; i < insn_cnt; i++, insn++) {
u32 insn_delta, cnt; u32 insn_delta, cnt;
if (insn->code == (BPF_LDX | BPF_MEM | BPF_W)) if (insn->code == (BPF_LDX | BPF_MEM | BPF_W) ||
insn->code == (BPF_LDX | BPF_MEM | BPF_DW))
type = BPF_READ; type = BPF_READ;
else if (insn->code == (BPF_STX | BPF_MEM | BPF_W)) else if (insn->code == (BPF_STX | BPF_MEM | BPF_W) ||
insn->code == (BPF_STX | BPF_MEM | BPF_DW))
type = BPF_WRITE; type = BPF_WRITE;
else else
continue; continue;
......
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