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@xxxxxxxxxx>
---
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;
