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From: Yonghong Song <yhs@fb.com>
To: <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Andrii Nakryiko <andrii@kernel.org>, <bpf@ietf.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Fangrui Song <maskray@google.com>, <kernel-team@fb.com>
Subject: [PATCH bpf-next v3 04/17] bpf: Support new unconditional bswap instruction
Date: Wed, 19 Jul 2023 17:01:24 -0700	[thread overview]
Message-ID: <20230720000124.104276-1-yhs@fb.com> (raw)
In-Reply-To: <20230720000103.99949-1-yhs@fb.com>

The existing 'be' and 'le' insns will do conditional bswap
depends on host endianness. This patch implements
unconditional bswap insns.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 arch/x86/net/bpf_jit_comp.c |  1 +
 kernel/bpf/core.c           | 14 ++++++++++++++
 kernel/bpf/verifier.c       |  7 +++++--
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 031ef3c4185d..4942a4c188b9 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1322,6 +1322,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image
 			break;
 
 		case BPF_ALU | BPF_END | BPF_FROM_BE:
+		case BPF_ALU64 | BPF_END | BPF_FROM_LE:
 			switch (imm32) {
 			case 16:
 				/* Emit 'ror %ax, 8' to swap lower 2 bytes */
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index c37c454b09eb..ad58697cec4b 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1524,6 +1524,7 @@ EXPORT_SYMBOL_GPL(__bpf_call_base);
 	INSN_3(ALU64, DIV,  X),			\
 	INSN_3(ALU64, MOD,  X),			\
 	INSN_2(ALU64, NEG),			\
+	INSN_3(ALU64, END, TO_LE),		\
 	/*   Immediate based. */		\
 	INSN_3(ALU64, ADD,  K),			\
 	INSN_3(ALU64, SUB,  K),			\
@@ -1848,6 +1849,19 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
 			break;
 		}
 		CONT;
+	ALU64_END_TO_LE:
+		switch (IMM) {
+		case 16:
+			DST = (__force u16) __swab16(DST);
+			break;
+		case 32:
+			DST = (__force u32) __swab32(DST);
+			break;
+		case 64:
+			DST = (__force u64) __swab64(DST);
+			break;
+		}
+		CONT;
 
 	/* CALL */
 	JMP_CALL:
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b9be8706bf48..b305f88c2569 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3012,8 +3012,10 @@ static bool is_reg64(struct bpf_verifier_env *env, struct bpf_insn *insn,
 		}
 	}
 
+	if (class == BPF_ALU64 && op == BPF_END && (insn->imm == 16 || insn->imm == 32))
+		return false;
+
 	if (class == BPF_ALU64 || class == BPF_JMP ||
-	    /* BPF_END always use BPF_ALU class. */
 	    (class == BPF_ALU && op == BPF_END && insn->imm == 64))
 		return true;
 
@@ -13076,7 +13078,8 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
 		} else {
 			if (insn->src_reg != BPF_REG_0 || insn->off != 0 ||
 			    (insn->imm != 16 && insn->imm != 32 && insn->imm != 64) ||
-			    BPF_CLASS(insn->code) == BPF_ALU64) {
+			    (BPF_CLASS(insn->code) == BPF_ALU64 &&
+			     BPF_SRC(insn->code) != BPF_TO_LE)) {
 				verbose(env, "BPF_END uses reserved fields\n");
 				return -EINVAL;
 			}
-- 
2.34.1


  parent reply	other threads:[~2023-07-20  0:03 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-20  0:01 [PATCH bpf-next v3 00/17] bpf: Support new insns from cpu v4 Yonghong Song
2023-07-20  0:01 ` [PATCH bpf-next v3 01/17] bpf: Support new sign-extension load insns Yonghong Song
2023-07-20 20:33   ` Eduard Zingerman
2023-07-24  4:03     ` [Bpf] " Yonghong Song
2023-07-24  4:03       ` Yonghong Song
2023-07-20  0:01 ` [PATCH bpf-next v3 02/17] bpf: Support new sign-extension mov insns Yonghong Song
2023-07-20  0:01 ` [PATCH bpf-next v3 03/17] bpf: Handle sign-extenstin ctx member accesses Yonghong Song
2023-07-20  0:01 ` Yonghong Song [this message]
2023-07-20  0:01 ` [PATCH bpf-next v3 05/17] bpf: Support new signed div/mod instructions Yonghong Song
2023-07-20  0:01   ` [Bpf] " Yonghong Song
2023-07-20  0:01 ` [PATCH bpf-next v3 06/17] bpf: Fix jit blinding with new sdiv/smov insns Yonghong Song
2023-07-20  0:01 ` [PATCH bpf-next v3 07/17] bpf: Support new 32bit offset jmp instruction Yonghong Song
2023-07-20  0:01 ` [PATCH bpf-next v3 08/17] bpf: Add kernel/bpftool asm support for new instructions Yonghong Song
2023-07-21 14:36   ` Quentin Monnet
2023-07-21 14:36     ` [Bpf] " Quentin Monnet
2023-07-20  0:01 ` [PATCH bpf-next v3 09/17] selftests/bpf: Fix a test_verifier failure Yonghong Song
2023-07-20  0:01 ` [PATCH bpf-next v3 10/17] selftests/bpf: Add a cpuv4 test runner for cpu=v4 testing Yonghong Song
2023-07-20  0:02 ` [PATCH bpf-next v3 11/17] selftests/bpf: Add unit tests for new sign-extension load insns Yonghong Song
2023-07-20  6:31   ` [Bpf] " Yonghong Song
2023-07-20  6:31     ` Yonghong Song
2023-07-20  6:36     ` [Bpf] " Yonghong Song
2023-07-20  6:36       ` Yonghong Song
2023-07-20  0:02 ` [PATCH bpf-next v3 12/17] selftests/bpf: Add unit tests for new sign-extension mov insns Yonghong Song
2023-07-20  0:02 ` [PATCH bpf-next v3 13/17] selftests/bpf: Add unit tests for new bswap insns Yonghong Song
2023-07-20  0:02 ` [PATCH bpf-next v3 14/17] selftests/bpf: Add unit tests for new sdiv/smod insns Yonghong Song
2023-07-20  0:02 ` [PATCH bpf-next v3 15/17] selftests/bpf: Add unit tests for new gotol insn Yonghong Song
2023-07-20  0:02   ` [Bpf] " Yonghong Song
2023-07-20  0:02 ` [PATCH bpf-next v3 16/17] selftests/bpf: Test ldsx with more complex cases Yonghong Song
2023-07-20  0:02 ` [PATCH bpf-next v3 17/17] docs/bpf: Add documentation for new instructions Yonghong Song
2023-07-20 20:35 ` [PATCH bpf-next v3 00/17] bpf: Support new insns from cpu v4 Eduard Zingerman

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