Commit a7b76c88 authored by Jiong Wang's avatar Jiong Wang Committed by Alexei Starovoitov
Browse files

bpf: JIT blinds support JMP32 



This patch adds JIT blinds support for JMP32.

Like BPF_JMP_REG/IMM, JMP32 version are needed for building raw bpf insn.
They are added to both include/linux/filter.h and
tools/include/linux/filter.h.

Reviewed-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarJiong Wang <jiong.wang@netronome.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 503a8865

include/linux/filter.h

+20 −0
Original line number Diff line number Diff line
@@ -277,6 +277,26 @@ struct sock_reuseport; 
		.off   = OFF,					\

		.imm   = IMM })



/* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */



#define BPF_JMP32_REG(OP, DST, SRC, OFF)			\

	((struct bpf_insn) {					\

		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_X,	\

		.dst_reg = DST,					\

		.src_reg = SRC,					\

		.off   = OFF,					\

		.imm   = 0 })



/* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */



#define BPF_JMP32_IMM(OP, DST, IMM, OFF)			\

	((struct bpf_insn) {					\

		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_K,	\

		.dst_reg = DST,					\

		.src_reg = 0,					\

		.off   = OFF,					\

		.imm   = IMM })



/* Unconditional jumps, goto pc + off16 */



#define BPF_JMP_A(OFF)						\

kernel/bpf/core.c

+21 −0
Original line number Diff line number Diff line
@@ -949,6 +949,27 @@ static int bpf_jit_blind_insn(const struct bpf_insn *from, 
		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);

		break;



	case BPF_JMP32 | BPF_JEQ  | BPF_K:

	case BPF_JMP32 | BPF_JNE  | BPF_K:

	case BPF_JMP32 | BPF_JGT  | BPF_K:

	case BPF_JMP32 | BPF_JLT  | BPF_K:

	case BPF_JMP32 | BPF_JGE  | BPF_K:

	case BPF_JMP32 | BPF_JLE  | BPF_K:

	case BPF_JMP32 | BPF_JSGT | BPF_K:

	case BPF_JMP32 | BPF_JSLT | BPF_K:

	case BPF_JMP32 | BPF_JSGE | BPF_K:

	case BPF_JMP32 | BPF_JSLE | BPF_K:

	case BPF_JMP32 | BPF_JSET | BPF_K:

		/* Accommodate for extra offset in case of a backjump. */

		off = from->off;

		if (off < 0)

			off -= 2;

		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);

		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);

		*to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,

				      off);

		break;



	case BPF_LD | BPF_IMM | BPF_DW:

		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);

		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);

tools/include/linux/filter.h

+20 −0
Original line number Diff line number Diff line
@@ -199,6 +199,16 @@ 
		.off   = OFF,					\

		.imm   = 0 })



/* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */



#define BPF_JMP32_REG(OP, DST, SRC, OFF)			\

	((struct bpf_insn) {					\

		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_X,	\

		.dst_reg = DST,					\

		.src_reg = SRC,					\

		.off   = OFF,					\

		.imm   = 0 })



/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */



#define BPF_JMP_IMM(OP, DST, IMM, OFF)				\
@@ -209,6 +219,16 @@ 
		.off   = OFF,					\

		.imm   = IMM })



/* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */



#define BPF_JMP32_IMM(OP, DST, IMM, OFF)			\

	((struct bpf_insn) {					\

		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_K,	\

		.dst_reg = DST,					\

		.src_reg = 0,					\

		.off   = OFF,					\

		.imm   = IMM })



/* Unconditional jumps, goto pc + off16 */



#define BPF_JMP_A(OFF)						\

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