[RESEND PATCH v4 3/8] bpf powerpc: refactor JIT compiler code
From: Hari Bathini <hbathini@linux.ibm.com>
Date: 2021-10-12 12:33:08
Also in:
bpf, linuxppc-dev
Subsystem:
bpf jit for powerpc (32-bit and 64-bit), bpf [general] (safe dynamic programs and tools), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Hari Bathini, Christophe Leroy, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Refactor powerpc LDX JITing code to simplify adding BPF_PROBE_MEM support. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Reviewed-by: Christophe Leroy <redacted> --- Changes in v4: * Dropped the default case in the switch statement for bpf size. * Dropped explicit fallthrough statement for empty switch cases. arch/powerpc/net/bpf_jit_comp32.c | 33 ++++++++++++++++++------------- arch/powerpc/net/bpf_jit_comp64.c | 31 +++++++++++++++++------------ 2 files changed, 37 insertions(+), 27 deletions(-)
diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c
index 903f945601c0..8b2ac1c27f1f 100644
--- a/arch/powerpc/net/bpf_jit_comp32.c
+++ b/arch/powerpc/net/bpf_jit_comp32.c@@ -284,6 +284,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * u32 src_reg = bpf_to_ppc(ctx, insn[i].src_reg); u32 src_reg_h = src_reg - 1; u32 tmp_reg = bpf_to_ppc(ctx, TMP_REG); + u32 size = BPF_SIZE(code); s16 off = insn[i].off; s32 imm = insn[i].imm; bool func_addr_fixed;
@@ -812,23 +813,27 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * * BPF_LDX */ case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */ - EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); - if (!fp->aux->verifier_zext) - EMIT(PPC_RAW_LI(dst_reg_h, 0)); - break; case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */ - EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); - if (!fp->aux->verifier_zext) - EMIT(PPC_RAW_LI(dst_reg_h, 0)); - break; case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */ - EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); - if (!fp->aux->verifier_zext) - EMIT(PPC_RAW_LI(dst_reg_h, 0)); - break; case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */ - EMIT(PPC_RAW_LWZ(dst_reg_h, src_reg, off)); - EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off + 4)); + switch (size) { + case BPF_B: + EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); + break; + case BPF_DW: + EMIT(PPC_RAW_LWZ(dst_reg_h, src_reg, off)); + EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off + 4)); + break; + } + + if (size != BPF_DW && !fp->aux->verifier_zext) + EMIT(PPC_RAW_LI(dst_reg_h, 0)); break; /*
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index b25bf9b11b9d..ad852f15ca61 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c@@ -311,6 +311,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * u32 code = insn[i].code; u32 dst_reg = b2p[insn[i].dst_reg]; u32 src_reg = b2p[insn[i].src_reg]; + u32 size = BPF_SIZE(code); s16 off = insn[i].off; s32 imm = insn[i].imm; bool func_addr_fixed;
@@ -778,25 +779,29 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * */ /* dst = *(u8 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_B: - EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); - if (insn_is_zext(&insn[i + 1])) - addrs[++i] = ctx->idx * 4; - break; /* dst = *(u16 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_H: - EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); - if (insn_is_zext(&insn[i + 1])) - addrs[++i] = ctx->idx * 4; - break; /* dst = *(u32 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_W: - EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); - if (insn_is_zext(&insn[i + 1])) - addrs[++i] = ctx->idx * 4; - break; /* dst = *(u64 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_DW: - PPC_BPF_LL(dst_reg, src_reg, off); + switch (size) { + case BPF_B: + EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); + break; + case BPF_DW: + PPC_BPF_LL(dst_reg, src_reg, off); + break; + } + + if (size != BPF_DW && insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; break; /*
--
2.31.1