On 2023/3/28 15:22, Daniel Borkmann wrote:
On 3/28/23 9:13 AM, George Guo wrote:
Here just skip the opcode(BPF_ST | BPF_NOSPEC) that has no couterpart
to the loongarch.
<snip>
diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
index 288003a9f0ca..d3c6b1c4ccbb 100644
--- a/arch/loongarch/net/bpf_jit.c
+++ b/arch/loongarch/net/bpf_jit.c
@@ -1022,6 +1022,11 @@ static int build_insn(const struct bpf_insn
*insn, struct jit_ctx *ctx, bool ext
emit_atomic(insn, ctx);
break;
+ /* Speculation barrier */
+ case BPF_ST | BPF_NOSPEC:
+ pr_info_once("bpf_jit: skip speculation barrier opcode
%0x2x\n", code);
+ break;
Thanks that looks better. Question to LoongArch folks (Cc): There is no
equivalent
to a speculation barrier here, correct? Either way, I think the
pr_info_once() can
just be removed given there is little value for a users to have this in
the kernel
log. I can take care of this while applying, that's fine.
I can confirm there's currently no speculation barrier equivalent on
lonogarch. (Loongson says there are builtin mitigations for Spectre-V1
and V2 on their chips, and AFAIK efforts to port the exploits to
mips/loongarch have all failed a few years ago.)
And yes I'd agree with removing the warning altogether. Thanks for the
reviews!
Acked-by: WANG Xuerui <git@xxxxxxxxxx>
default:
pr_err("bpf_jit: unknown opcode %02x\n", code);
return -EINVAL;
--
WANG "xen0n" Xuerui
Linux/LoongArch mailing list: https://lore.kernel.org/loongarch/
