From: Yonghong Song <yonghong.song@linux.dev>
To: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
kernel-team@fb.com, Martin KaFai Lau <martin.lau@kernel.org>,
Tejun Heo <tj@kernel.org>
Subject: [PATCH bpf-next v4 08/10] bpf, x86: Create two helpers for some arith operations
Date: Thu, 10 Oct 2024 10:56:33 -0700 [thread overview]
Message-ID: <20241010175633.1898994-1-yonghong.song@linux.dev> (raw)
In-Reply-To: <20241010175552.1895980-1-yonghong.song@linux.dev>
Two helpers are extracted from bpf/x86 jit:
- a helper to handle 'reg1 <op>= reg2' where <op> is add/sub/and/or/xor
- a helper to handle 'reg *= imm'
Both helpers will be used in the subsequent patch.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
---
arch/x86/net/bpf_jit_comp.c | 51 ++++++++++++++++++++++++-------------
1 file changed, 34 insertions(+), 17 deletions(-)
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index a6ba85cec49a..297dd64f4b6a 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1475,6 +1475,37 @@ static void emit_alu_helper_1(u8 **pprog, u8 insn_code, u32 dst_reg, s32 imm32)
*pprog = prog;
}
+/* emit ADD/SUB/AND/OR/XOR 'reg1 <op>= reg2' operations */
+static void emit_alu_helper_2(u8 **pprog, u8 insn_code, u32 dst_reg, u32 src_reg)
+{
+ u8 b2 = 0;
+ u8 *prog = *pprog;
+
+ maybe_emit_mod(&prog, dst_reg, src_reg,
+ BPF_CLASS(insn_code) == BPF_ALU64);
+ b2 = simple_alu_opcodes[BPF_OP(insn_code)];
+ EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg));
+
+ *pprog = prog;
+}
+
+/* emit 'reg *= imm' operations */
+static void emit_alu_helper_3(u8 **pprog, u8 insn_code, u32 dst_reg, s32 imm32)
+{
+ u8 *prog = *pprog;
+
+ maybe_emit_mod(&prog, dst_reg, dst_reg, BPF_CLASS(insn_code) == BPF_ALU64);
+
+ if (is_imm8(imm32))
+ /* imul dst_reg, dst_reg, imm8 */
+ EMIT3(0x6B, add_2reg(0xC0, dst_reg, dst_reg), imm32);
+ else
+ /* imul dst_reg, dst_reg, imm32 */
+ EMIT2_off32(0x69, add_2reg(0xC0, dst_reg, dst_reg), imm32);
+
+ *pprog = prog;
+}
+
static void emit_root_priv_frame_ptr(u8 **pprog, struct bpf_prog *bpf_prog,
u32 orig_stack_depth)
{
@@ -1578,7 +1609,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image
const s32 imm32 = insn->imm;
u32 dst_reg = insn->dst_reg;
u32 src_reg = insn->src_reg;
- u8 b2 = 0, b3 = 0;
+ u8 b3 = 0;
u8 *start_of_ldx;
s64 jmp_offset;
s16 insn_off;
@@ -1606,10 +1637,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image
case BPF_ALU64 | BPF_AND | BPF_X:
case BPF_ALU64 | BPF_OR | BPF_X:
case BPF_ALU64 | BPF_XOR | BPF_X:
- maybe_emit_mod(&prog, dst_reg, src_reg,
- BPF_CLASS(insn->code) == BPF_ALU64);
- b2 = simple_alu_opcodes[BPF_OP(insn->code)];
- EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg));
+ emit_alu_helper_2(&prog, insn->code, dst_reg, src_reg);
break;
case BPF_ALU64 | BPF_MOV | BPF_X:
@@ -1772,18 +1800,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image
case BPF_ALU | BPF_MUL | BPF_K:
case BPF_ALU64 | BPF_MUL | BPF_K:
- maybe_emit_mod(&prog, dst_reg, dst_reg,
- BPF_CLASS(insn->code) == BPF_ALU64);
-
- if (is_imm8(imm32))
- /* imul dst_reg, dst_reg, imm8 */
- EMIT3(0x6B, add_2reg(0xC0, dst_reg, dst_reg),
- imm32);
- else
- /* imul dst_reg, dst_reg, imm32 */
- EMIT2_off32(0x69,
- add_2reg(0xC0, dst_reg, dst_reg),
- imm32);
+ emit_alu_helper_3(&prog, insn->code, dst_reg, imm32);
break;
case BPF_ALU | BPF_MUL | BPF_X:
--
2.43.5
next prev parent reply other threads:[~2024-10-10 17:56 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-10 17:55 [PATCH bpf-next v4 00/10] bpf: Support private stack for bpf progs Yonghong Song
2024-10-10 17:55 ` [PATCH bpf-next v4 01/10] bpf: Allow each subprog having stack size of 512 bytes Yonghong Song
2024-10-10 17:56 ` [PATCH bpf-next v4 02/10] bpf: Mark each subprog with proper private stack modes Yonghong Song
2024-10-10 17:56 ` [PATCH bpf-next v4 03/10] bpf, x86: Refactor func emit_prologue Yonghong Song
2024-10-10 17:56 ` [PATCH bpf-next v4 04/10] bpf, x86: Create a helper for certain "reg <op>= imm" operations Yonghong Song
2024-10-10 17:56 ` [PATCH bpf-next v4 05/10] bpf, x86: Add jit support for private stack Yonghong Song
2024-10-10 17:56 ` [PATCH bpf-next v4 06/10] selftests/bpf: Add private stack tests Yonghong Song
2024-10-10 17:56 ` [PATCH bpf-next v4 07/10] bpf: Support calling non-tailcall bpf prog Yonghong Song
2024-10-10 20:28 ` Alexei Starovoitov
2024-10-11 4:12 ` Yonghong Song
2024-10-15 21:18 ` Tejun Heo
2024-10-15 21:35 ` Alexei Starovoitov
2024-10-10 17:56 ` Yonghong Song [this message]
2024-10-10 20:21 ` [PATCH bpf-next v4 08/10] bpf, x86: Create two helpers for some arith operations Alexei Starovoitov
2024-10-11 4:16 ` Yonghong Song
2024-10-10 17:56 ` [PATCH bpf-next v4 09/10] bpf, x86: Jit support for nested bpf_prog_call Yonghong Song
2024-10-10 20:53 ` Alexei Starovoitov
2024-10-11 4:20 ` Yonghong Song
2024-10-11 4:29 ` Alexei Starovoitov
2024-10-11 15:38 ` Yonghong Song
2024-10-11 15:40 ` Alexei Starovoitov
2024-10-11 16:14 ` Yonghong Song
2024-10-10 17:56 ` [PATCH bpf-next v4 10/10] selftests/bpf: Add tests for bpf_prog_call() Yonghong Song
2024-10-15 21:28 ` [PATCH bpf-next v4 00/10] bpf: Support private stack for bpf progs Tejun Heo
2024-10-15 21:39 ` Alexei Starovoitov
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