Messages in this thread | | | Subject | Re: [PATCH v2] loongarch/bpf: Skip speculation barrier opcode, which caused ltp testcase bpf_prog02 to fail | From | Daniel Borkmann <> | Date | Tue, 28 Mar 2023 09:22:24 +0200 |
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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. > > 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> > > --- > Changelog: > v2: > - place it to build_insn > - add printing for skipping bpf_jit the opcode > --- > 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..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.
> default: > pr_err("bpf_jit: unknown opcode %02x\n", code); > return -EINVAL; >
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