Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH] loongarch/bpf: Fix bpf load failed with CONFIG_BPF_JIT_ALWAYS_ON, caused by jit (BPF_ST | BPF_NOSPEC) code | From | Daniel Borkmann <> | Date | Mon, 27 Mar 2023 11:29:48 +0200 |
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On 3/26/23 6:40 AM, George Guo wrote: > Here just skip the code(BPF_ST | BPF_NOSPEC) that has no couterpart to the loongarch. > > To verify, use ltp testcase: > > Without this patch: > $ ./bpf_prog02 > ... ... > bpf_common.c:123: TBROK: Failed verification: ??? (524) > > Summary: > passed 0 > failed 0 > broken 1 > skipped 0 > warnings 0 > > With this patch: > $ ./bpf_prog02 > ... ... > Summary: > passed 0 > failed 0 > broken 0 > skipped 0 > warnings 0 > > Signed-off-by: George Guo <guodongtai@kylinos.cn> > --- > arch/loongarch/net/bpf_jit.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c > index 288003a9f0ca..745d344385ed 100644 > --- a/arch/loongarch/net/bpf_jit.c > +++ b/arch/loongarch/net/bpf_jit.c > @@ -1046,6 +1046,11 @@ static int build_body(struct jit_ctx *ctx, bool extra_pass) > if (ctx->image == NULL) > ctx->offset[i] = ctx->idx; > > + /* skip the code that has no couterpart to the host arch */ > + if(insn->code == (BPF_ST | BPF_NOSPEC)) { > + continue; > + }
Small nit, but could we align with other JIT implementations and place it into similar location for consistency? Above looks a bit out of place and it should really be part of build_insn.
diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c index 288003a9f0ca..d586df48ecc6 100644 --- a/arch/loongarch/net/bpf_jit.c +++ b/arch/loongarch/net/bpf_jit.c @@ -1022,6 +1022,10 @@ 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: + break; + default: pr_err("bpf_jit: unknown opcode %02x\n", code); return -EINVAL;
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