From: Ilya Leoshkevich <iii@linux.ibm.com>
To: bpf@vger.kernel.org, netdev@vger.kernel.org
Cc: gor@linux.ibm.com, heiko.carstens@de.ibm.com,
Ilya Leoshkevich <iii@linux.ibm.com>
Subject: [PATCH bpf] s390/bpf: fix lcgr instruction encoding
Date: Mon, 12 Aug 2019 17:03:32 +0200 [thread overview]
Message-ID: <20190812150332.98109-1-iii@linux.ibm.com> (raw)
"masking, test in bounds 3" fails on s390, because
BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0) ignores the top 32 bits of
BPF_REG_2. The reason is that JIT emits lcgfr instead of lcgr.
The associated comment indicates that the code was intended to emit lcgr
in the first place, it's just that the wrong opcode was used.
Fix by using the correct opcode.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
arch/s390/net/bpf_jit_comp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index e636728ab452..6299156f9738 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -863,7 +863,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
break;
case BPF_ALU64 | BPF_NEG: /* dst = -dst */
/* lcgr %dst,%dst */
- EMIT4(0xb9130000, dst_reg, dst_reg);
+ EMIT4(0xb9030000, dst_reg, dst_reg);
break;
/*
* BPF_FROM_BE/LE
--
2.21.0
next reply other threads:[~2019-08-12 15:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-12 15:03 Ilya Leoshkevich [this message]
2019-08-12 15:46 ` [PATCH bpf] s390/bpf: fix lcgr instruction encoding Vasily Gorbik
2019-08-12 16:06 ` Daniel Borkmann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190812150332.98109-1-iii@linux.ibm.com \
--to=iii@linux.ibm.com \
--cc=bpf@vger.kernel.org \
--cc=gor@linux.ibm.com \
--cc=heiko.carstens@de.ibm.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).