Commit 3d06d816 authored by Pu Lehui's avatar Pu Lehui Committed by Alexei Starovoitov
Browse files

riscv, bpf: Support sign-extension load insns 



Add Support sign-extension load instructions for RV64.

Signed-off-by: default avatarPu Lehui <pulehui@huawei.com>
Acked-by: default avatarBjörn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20230824095001.3408573-3-pulehui@huaweicloud.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 469fb2c3

arch/riscv/net/bpf_jit.h

+10 −0
Original line number Diff line number Diff line
@@ -501,6 +501,16 @@ static inline u32 rv_ble(u8 rs1, u8 rs2, u16 imm12_1) 
	return rv_bge(rs2, rs1, imm12_1);

}



static inline u32 rv_lb(u8 rd, u16 imm11_0, u8 rs1)

{

	return rv_i_insn(imm11_0, rs1, 0, rd, 0x03);

}



static inline u32 rv_lh(u8 rd, u16 imm11_0, u8 rs1)

{

	return rv_i_insn(imm11_0, rs1, 1, rd, 0x03);

}



static inline u32 rv_lw(u8 rd, u16 imm11_0, u8 rs1)

{

	return rv_i_insn(imm11_0, rs1, 2, rd, 0x03);

arch/riscv/net/bpf_jit_comp64.c

+38 −8
Original line number Diff line number Diff line
@@ -580,7 +580,8 @@ static int add_exception_handler(const struct bpf_insn *insn, 
	unsigned long pc;

	off_t offset;



	if (!ctx->insns || !ctx->prog->aux->extable || BPF_MODE(insn->code) != BPF_PROBE_MEM)

	if (!ctx->insns || !ctx->prog->aux->extable ||

	    (BPF_MODE(insn->code) != BPF_PROBE_MEM && BPF_MODE(insn->code) != BPF_PROBE_MEMSX))

		return 0;



	if (WARN_ON_ONCE(ctx->nexentries >= ctx->prog->aux->num_exentries))
@@ -1486,7 +1487,7 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, 
		return 1;

	}



	/* LDX: dst = *(size *)(src + off) */

	/* LDX: dst = *(unsigned size *)(src + off) */

	case BPF_LDX | BPF_MEM | BPF_B:

	case BPF_LDX | BPF_MEM | BPF_H:

	case BPF_LDX | BPF_MEM | BPF_W:
@@ -1495,13 +1496,27 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, 
	case BPF_LDX | BPF_PROBE_MEM | BPF_H:

	case BPF_LDX | BPF_PROBE_MEM | BPF_W:

	case BPF_LDX | BPF_PROBE_MEM | BPF_DW:

	/* LDSX: dst = *(signed size *)(src + off) */

	case BPF_LDX | BPF_MEMSX | BPF_B:

	case BPF_LDX | BPF_MEMSX | BPF_H:

	case BPF_LDX | BPF_MEMSX | BPF_W:

	case BPF_LDX | BPF_PROBE_MEMSX | BPF_B:

	case BPF_LDX | BPF_PROBE_MEMSX | BPF_H:

	case BPF_LDX | BPF_PROBE_MEMSX | BPF_W:

	{

		int insn_len, insns_start;

		bool sign_ext;



		sign_ext = BPF_MODE(insn->code) == BPF_MEMSX ||

			   BPF_MODE(insn->code) == BPF_PROBE_MEMSX;



		switch (BPF_SIZE(code)) {

		case BPF_B:

			if (is_12b_int(off)) {

				insns_start = ctx->ninsns;

				if (sign_ext)

					emit(rv_lb(rd, off, rs), ctx);

				else

					emit(rv_lbu(rd, off, rs), ctx);

				insn_len = ctx->ninsns - insns_start;

				break;
@@ -1510,12 +1525,18 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, 
			emit_imm(RV_REG_T1, off, ctx);

			emit_add(RV_REG_T1, RV_REG_T1, rs, ctx);

			insns_start = ctx->ninsns;

			if (sign_ext)

				emit(rv_lb(rd, 0, RV_REG_T1), ctx);

			else

				emit(rv_lbu(rd, 0, RV_REG_T1), ctx);

			insn_len = ctx->ninsns - insns_start;

			break;

		case BPF_H:

			if (is_12b_int(off)) {

				insns_start = ctx->ninsns;

				if (sign_ext)

					emit(rv_lh(rd, off, rs), ctx);

				else

					emit(rv_lhu(rd, off, rs), ctx);

				insn_len = ctx->ninsns - insns_start;

				break;
@@ -1524,12 +1545,18 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, 
			emit_imm(RV_REG_T1, off, ctx);

			emit_add(RV_REG_T1, RV_REG_T1, rs, ctx);

			insns_start = ctx->ninsns;

			if (sign_ext)

				emit(rv_lh(rd, 0, RV_REG_T1), ctx);

			else

				emit(rv_lhu(rd, 0, RV_REG_T1), ctx);

			insn_len = ctx->ninsns - insns_start;

			break;

		case BPF_W:

			if (is_12b_int(off)) {

				insns_start = ctx->ninsns;

				if (sign_ext)

					emit(rv_lw(rd, off, rs), ctx);

				else

					emit(rv_lwu(rd, off, rs), ctx);

				insn_len = ctx->ninsns - insns_start;

				break;
@@ -1538,6 +1565,9 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, 
			emit_imm(RV_REG_T1, off, ctx);

			emit_add(RV_REG_T1, RV_REG_T1, rs, ctx);

			insns_start = ctx->ninsns;

			if (sign_ext)

				emit(rv_lw(rd, 0, RV_REG_T1), ctx);

			else

				emit(rv_lwu(rd, 0, RV_REG_T1), ctx);

			insn_len = ctx->ninsns - insns_start;

			break;