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Message-Id: <20230906183320.1959008-5-puranjay12@gmail.com>
Date: Wed, 6 Sep 2023 18:33:16 +0000
From: Puranjay Mohan <puranjay12@...il.com>
To: Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Andrii Nakryiko <andrii@...nel.org>,
Martin KaFai Lau <martin.lau@...ux.dev>,
Song Liu <song@...nel.org>,
Yonghong Song <yonghong.song@...ux.dev>,
John Fastabend <john.fastabend@...il.com>,
KP Singh <kpsingh@...nel.org>,
Stanislav Fomichev <sdf@...gle.com>,
Hao Luo <haoluo@...gle.com>, Jiri Olsa <jolsa@...nel.org>,
Shubham Bansal <illusionist.neo@...il.com>,
Russell King <linux@...linux.org.uk>,
Mykola Lysenko <mykolal@...com>, Shuah Khan <shuah@...nel.org>,
bpf@...r.kernel.org, linux-kselftest@...r.kernel.org,
linux-kernel@...r.kernel.org
Cc: puranjay12@...il.com
Subject: [PATCH bpf-next v2 4/8] arm32, bpf: add support for unconditional bswap instruction
The cpuv4 added a new unconditional bswap instruction with following
behaviour:
BPF_ALU64 | BPF_TO_LE | BPF_END with imm = 16/32/64 means:
dst = bswap16(dst)
dst = bswap32(dst)
dst = bswap64(dst)
As we already support converting to big-endian from little-endian we can
use the same for unconditional bswap. just treat the unconditional scenario
the same as big-endian conversion.
Signed-off-by: Puranjay Mohan <puranjay12@...il.com>
---
arch/arm/net/bpf_jit_32.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index 56ea8022e989..f837db5c71b1 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -1633,8 +1633,10 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
/* dst = htobe(dst) */
case BPF_ALU | BPF_END | BPF_FROM_LE:
case BPF_ALU | BPF_END | BPF_FROM_BE:
+ /* dst = bswap(dst) */
+ case BPF_ALU64 | BPF_END | BPF_TO_LE:
rd = arm_bpf_get_reg64(dst, tmp, ctx);
- if (BPF_SRC(code) == BPF_FROM_LE)
+ if (BPF_SRC(code) == BPF_FROM_LE && BPF_CLASS(code) != BPF_ALU64)
goto emit_bswap_uxt;
switch (imm) {
case 16:
--
2.39.2
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