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Commit 46dd3d7d authored by Luke Nelson's avatar Luke Nelson Committed by Daniel Borkmann
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bpf, riscv: Enable zext optimization for more RV64G ALU ops 



Commit 66d0d5a8 ("riscv: bpf: eliminate zero extension code-gen")
added the new zero-extension optimization for some BPF ALU operations.

Since then, bugs in the JIT that have been fixed in the bpf tree require
this optimization to be added to other operations: commit 1e692f09
("bpf, riscv: clear high 32 bits for ALU32 add/sub/neg/lsh/rsh/arsh"),
and commit fe121ee5 ("bpf, riscv: clear target register high 32-bits
for and/or/xor on ALU32").

Now that these have been merged to bpf-next, the zext optimization can
be enabled for the fixed operations.

Signed-off-by: default avatarLuke Nelson <luke.r.nels@gmail.com>
Cc: Song Liu <liu.song.a23@gmail.com>
Cc: Jiong Wang <jiong.wang@netronome.com>
Cc: Xi Wang <xi.wang@gmail.com>
Acked-by: default avatarBjörn Töpel <bjorn.topel@gmail.com>
Acked-by: default avatarJiong Wang <jiong.wang@netronome.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent aa52bcbe

arch/riscv/net/bpf_jit_comp.c

+8 −8
Original line number Diff line number Diff line
@@ -757,31 +757,31 @@ static int emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, 
	case BPF_ALU | BPF_ADD | BPF_X:

	case BPF_ALU64 | BPF_ADD | BPF_X:

		emit(is64 ? rv_add(rd, rd, rs) : rv_addw(rd, rd, rs), ctx);

		if (!is64)

		if (!is64 && !aux->verifier_zext)

			emit_zext_32(rd, ctx);

		break;

	case BPF_ALU | BPF_SUB | BPF_X:

	case BPF_ALU64 | BPF_SUB | BPF_X:

		emit(is64 ? rv_sub(rd, rd, rs) : rv_subw(rd, rd, rs), ctx);

		if (!is64)

		if (!is64 && !aux->verifier_zext)

			emit_zext_32(rd, ctx);

		break;

	case BPF_ALU | BPF_AND | BPF_X:

	case BPF_ALU64 | BPF_AND | BPF_X:

		emit(rv_and(rd, rd, rs), ctx);

		if (!is64)

		if (!is64 && !aux->verifier_zext)

			emit_zext_32(rd, ctx);

		break;

	case BPF_ALU | BPF_OR | BPF_X:

	case BPF_ALU64 | BPF_OR | BPF_X:

		emit(rv_or(rd, rd, rs), ctx);

		if (!is64)

		if (!is64 && !aux->verifier_zext)

			emit_zext_32(rd, ctx);

		break;

	case BPF_ALU | BPF_XOR | BPF_X:

	case BPF_ALU64 | BPF_XOR | BPF_X:

		emit(rv_xor(rd, rd, rs), ctx);

		if (!is64)

		if (!is64 && !aux->verifier_zext)

			emit_zext_32(rd, ctx);

		break;

	case BPF_ALU | BPF_MUL | BPF_X:
@@ -811,13 +811,13 @@ static int emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, 
	case BPF_ALU | BPF_RSH | BPF_X:

	case BPF_ALU64 | BPF_RSH | BPF_X:

		emit(is64 ? rv_srl(rd, rd, rs) : rv_srlw(rd, rd, rs), ctx);

		if (!is64)

		if (!is64 && !aux->verifier_zext)

			emit_zext_32(rd, ctx);

		break;

	case BPF_ALU | BPF_ARSH | BPF_X:

	case BPF_ALU64 | BPF_ARSH | BPF_X:

		emit(is64 ? rv_sra(rd, rd, rs) : rv_sraw(rd, rd, rs), ctx);

		if (!is64)

		if (!is64 && !aux->verifier_zext)

			emit_zext_32(rd, ctx);

		break;
@@ -826,7 +826,7 @@ static int emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, 
	case BPF_ALU64 | BPF_NEG:

		emit(is64 ? rv_sub(rd, RV_REG_ZERO, rd) :

		     rv_subw(rd, RV_REG_ZERO, rd), ctx);

		if (!is64)

		if (!is64 && !aux->verifier_zext)

			emit_zext_32(rd, ctx);

		break;