xref: /linux/arch/powerpc/net/bpf_jit_comp64.c (revision 0e9ab8e4d44ae9d9aaf213bfd2c90bbe7289337b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * bpf_jit_comp64.c: eBPF JIT compiler
4  *
5  * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
6  *		  IBM Corporation
7  *
8  * Based on the powerpc classic BPF JIT compiler by Matt Evans
9  */
10 #include <linux/moduleloader.h>
11 #include <asm/cacheflush.h>
12 #include <asm/asm-compat.h>
13 #include <linux/netdevice.h>
14 #include <linux/filter.h>
15 #include <linux/if_vlan.h>
16 #include <asm/kprobes.h>
17 #include <linux/bpf.h>
18 #include <asm/security_features.h>
19 
20 #include "bpf_jit.h"
21 
22 /*
23  * Stack layout:
24  * Ensure the top half (upto local_tmp_var) stays consistent
25  * with our redzone usage.
26  *
27  *		[	prev sp		] <-------------
28  *		[   nv gpr save area	] 5*8		|
29  *		[    tail_call_cnt	] 8		|
30  *		[    local_tmp_var	] 16		|
31  * fp (r31) -->	[   ebpf stack space	] upto 512	|
32  *		[     frame header	] 32/112	|
33  * sp (r1) --->	[    stack pointer	] --------------
34  */
35 
36 /* for gpr non volatile registers BPG_REG_6 to 10 */
37 #define BPF_PPC_STACK_SAVE	(5*8)
38 /* for bpf JIT code internal usage */
39 #define BPF_PPC_STACK_LOCALS	24
40 /* stack frame excluding BPF stack, ensure this is quadword aligned */
41 #define BPF_PPC_STACKFRAME	(STACK_FRAME_MIN_SIZE + \
42 				 BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE)
43 
44 /* BPF register usage */
45 #define TMP_REG_1	(MAX_BPF_JIT_REG + 0)
46 #define TMP_REG_2	(MAX_BPF_JIT_REG + 1)
47 
48 /* BPF to ppc register mappings */
49 void bpf_jit_init_reg_mapping(struct codegen_context *ctx)
50 {
51 	/* function return value */
52 	ctx->b2p[BPF_REG_0] = _R8;
53 	/* function arguments */
54 	ctx->b2p[BPF_REG_1] = _R3;
55 	ctx->b2p[BPF_REG_2] = _R4;
56 	ctx->b2p[BPF_REG_3] = _R5;
57 	ctx->b2p[BPF_REG_4] = _R6;
58 	ctx->b2p[BPF_REG_5] = _R7;
59 	/* non volatile registers */
60 	ctx->b2p[BPF_REG_6] = _R27;
61 	ctx->b2p[BPF_REG_7] = _R28;
62 	ctx->b2p[BPF_REG_8] = _R29;
63 	ctx->b2p[BPF_REG_9] = _R30;
64 	/* frame pointer aka BPF_REG_10 */
65 	ctx->b2p[BPF_REG_FP] = _R31;
66 	/* eBPF jit internal registers */
67 	ctx->b2p[BPF_REG_AX] = _R12;
68 	ctx->b2p[TMP_REG_1] = _R9;
69 	ctx->b2p[TMP_REG_2] = _R10;
70 }
71 
72 /* PPC NVR range -- update this if we ever use NVRs below r27 */
73 #define BPF_PPC_NVR_MIN		_R27
74 
75 static inline bool bpf_has_stack_frame(struct codegen_context *ctx)
76 {
77 	/*
78 	 * We only need a stack frame if:
79 	 * - we call other functions (kernel helpers), or
80 	 * - the bpf program uses its stack area
81 	 * The latter condition is deduced from the usage of BPF_REG_FP
82 	 */
83 	return ctx->seen & SEEN_FUNC || bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP));
84 }
85 
86 /*
87  * When not setting up our own stackframe, the redzone usage is:
88  *
89  *		[	prev sp		] <-------------
90  *		[	  ...       	] 		|
91  * sp (r1) --->	[    stack pointer	] --------------
92  *		[   nv gpr save area	] 5*8
93  *		[    tail_call_cnt	] 8
94  *		[    local_tmp_var	] 16
95  *		[   unused red zone	] 208 bytes protected
96  */
97 static int bpf_jit_stack_local(struct codegen_context *ctx)
98 {
99 	if (bpf_has_stack_frame(ctx))
100 		return STACK_FRAME_MIN_SIZE + ctx->stack_size;
101 	else
102 		return -(BPF_PPC_STACK_SAVE + 24);
103 }
104 
105 static int bpf_jit_stack_tailcallcnt(struct codegen_context *ctx)
106 {
107 	return bpf_jit_stack_local(ctx) + 16;
108 }
109 
110 static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
111 {
112 	if (reg >= BPF_PPC_NVR_MIN && reg < 32)
113 		return (bpf_has_stack_frame(ctx) ?
114 			(BPF_PPC_STACKFRAME + ctx->stack_size) : 0)
115 				- (8 * (32 - reg));
116 
117 	pr_err("BPF JIT is asking about unknown registers");
118 	BUG();
119 }
120 
121 void bpf_jit_realloc_regs(struct codegen_context *ctx)
122 {
123 }
124 
125 void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
126 {
127 	int i;
128 
129 	if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
130 		EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc)));
131 
132 	/*
133 	 * Initialize tail_call_cnt if we do tail calls.
134 	 * Otherwise, put in NOPs so that it can be skipped when we are
135 	 * invoked through a tail call.
136 	 */
137 	if (ctx->seen & SEEN_TAILCALL) {
138 		EMIT(PPC_RAW_LI(bpf_to_ppc(TMP_REG_1), 0));
139 		/* this goes in the redzone */
140 		EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, -(BPF_PPC_STACK_SAVE + 8)));
141 	} else {
142 		EMIT(PPC_RAW_NOP());
143 		EMIT(PPC_RAW_NOP());
144 	}
145 
146 	if (bpf_has_stack_frame(ctx)) {
147 		/*
148 		 * We need a stack frame, but we don't necessarily need to
149 		 * save/restore LR unless we call other functions
150 		 */
151 		if (ctx->seen & SEEN_FUNC) {
152 			EMIT(PPC_RAW_MFLR(_R0));
153 			EMIT(PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF));
154 		}
155 
156 		EMIT(PPC_RAW_STDU(_R1, _R1, -(BPF_PPC_STACKFRAME + ctx->stack_size)));
157 	}
158 
159 	/*
160 	 * Back up non-volatile regs -- BPF registers 6-10
161 	 * If we haven't created our own stack frame, we save these
162 	 * in the protected zone below the previous stack frame
163 	 */
164 	for (i = BPF_REG_6; i <= BPF_REG_10; i++)
165 		if (bpf_is_seen_register(ctx, bpf_to_ppc(i)))
166 			EMIT(PPC_RAW_STD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i))));
167 
168 	/* Setup frame pointer to point to the bpf stack area */
169 	if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP)))
170 		EMIT(PPC_RAW_ADDI(bpf_to_ppc(BPF_REG_FP), _R1,
171 				STACK_FRAME_MIN_SIZE + ctx->stack_size));
172 }
173 
174 static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx)
175 {
176 	int i;
177 
178 	/* Restore NVRs */
179 	for (i = BPF_REG_6; i <= BPF_REG_10; i++)
180 		if (bpf_is_seen_register(ctx, bpf_to_ppc(i)))
181 			EMIT(PPC_RAW_LD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i))));
182 
183 	/* Tear down our stack frame */
184 	if (bpf_has_stack_frame(ctx)) {
185 		EMIT(PPC_RAW_ADDI(_R1, _R1, BPF_PPC_STACKFRAME + ctx->stack_size));
186 		if (ctx->seen & SEEN_FUNC) {
187 			EMIT(PPC_RAW_LD(_R0, _R1, PPC_LR_STKOFF));
188 			EMIT(PPC_RAW_MTLR(_R0));
189 		}
190 	}
191 }
192 
193 void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
194 {
195 	bpf_jit_emit_common_epilogue(image, ctx);
196 
197 	/* Move result to r3 */
198 	EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_0)));
199 
200 	EMIT(PPC_RAW_BLR());
201 }
202 
203 static int bpf_jit_emit_func_call_hlp(u32 *image, struct codegen_context *ctx, u64 func)
204 {
205 	unsigned long func_addr = func ? ppc_function_entry((void *)func) : 0;
206 	long reladdr;
207 
208 	if (WARN_ON_ONCE(!core_kernel_text(func_addr)))
209 		return -EINVAL;
210 
211 	reladdr = func_addr - kernel_toc_addr();
212 	if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
213 		pr_err("eBPF: address of %ps out of range of kernel_toc.\n", (void *)func);
214 		return -ERANGE;
215 	}
216 
217 	EMIT(PPC_RAW_ADDIS(_R12, _R2, PPC_HA(reladdr)));
218 	EMIT(PPC_RAW_ADDI(_R12, _R12, PPC_LO(reladdr)));
219 	EMIT(PPC_RAW_MTCTR(_R12));
220 	EMIT(PPC_RAW_BCTRL());
221 
222 	return 0;
223 }
224 
225 int bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func)
226 {
227 	unsigned int i, ctx_idx = ctx->idx;
228 
229 	if (WARN_ON_ONCE(func && is_module_text_address(func)))
230 		return -EINVAL;
231 
232 	/* skip past descriptor if elf v1 */
233 	func += FUNCTION_DESCR_SIZE;
234 
235 	/* Load function address into r12 */
236 	PPC_LI64(_R12, func);
237 
238 	/* For bpf-to-bpf function calls, the callee's address is unknown
239 	 * until the last extra pass. As seen above, we use PPC_LI64() to
240 	 * load the callee's address, but this may optimize the number of
241 	 * instructions required based on the nature of the address.
242 	 *
243 	 * Since we don't want the number of instructions emitted to increase,
244 	 * we pad the optimized PPC_LI64() call with NOPs to guarantee that
245 	 * we always have a five-instruction sequence, which is the maximum
246 	 * that PPC_LI64() can emit.
247 	 */
248 	if (!image)
249 		for (i = ctx->idx - ctx_idx; i < 5; i++)
250 			EMIT(PPC_RAW_NOP());
251 
252 	EMIT(PPC_RAW_MTCTR(_R12));
253 	EMIT(PPC_RAW_BCTRL());
254 
255 	return 0;
256 }
257 
258 static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out)
259 {
260 	/*
261 	 * By now, the eBPF program has already setup parameters in r3, r4 and r5
262 	 * r3/BPF_REG_1 - pointer to ctx -- passed as is to the next bpf program
263 	 * r4/BPF_REG_2 - pointer to bpf_array
264 	 * r5/BPF_REG_3 - index in bpf_array
265 	 */
266 	int b2p_bpf_array = bpf_to_ppc(BPF_REG_2);
267 	int b2p_index = bpf_to_ppc(BPF_REG_3);
268 	int bpf_tailcall_prologue_size = 8;
269 
270 	if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
271 		bpf_tailcall_prologue_size += 4; /* skip past the toc load */
272 
273 	/*
274 	 * if (index >= array->map.max_entries)
275 	 *   goto out;
276 	 */
277 	EMIT(PPC_RAW_LWZ(bpf_to_ppc(TMP_REG_1), b2p_bpf_array, offsetof(struct bpf_array, map.max_entries)));
278 	EMIT(PPC_RAW_RLWINM(b2p_index, b2p_index, 0, 0, 31));
279 	EMIT(PPC_RAW_CMPLW(b2p_index, bpf_to_ppc(TMP_REG_1)));
280 	PPC_BCC_SHORT(COND_GE, out);
281 
282 	/*
283 	 * if (tail_call_cnt >= MAX_TAIL_CALL_CNT)
284 	 *   goto out;
285 	 */
286 	EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx)));
287 	EMIT(PPC_RAW_CMPLWI(bpf_to_ppc(TMP_REG_1), MAX_TAIL_CALL_CNT));
288 	PPC_BCC_SHORT(COND_GE, out);
289 
290 	/*
291 	 * tail_call_cnt++;
292 	 */
293 	EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), 1));
294 	EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx)));
295 
296 	/* prog = array->ptrs[index]; */
297 	EMIT(PPC_RAW_MULI(bpf_to_ppc(TMP_REG_1), b2p_index, 8));
298 	EMIT(PPC_RAW_ADD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), b2p_bpf_array));
299 	EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_array, ptrs)));
300 
301 	/*
302 	 * if (prog == NULL)
303 	 *   goto out;
304 	 */
305 	EMIT(PPC_RAW_CMPLDI(bpf_to_ppc(TMP_REG_1), 0));
306 	PPC_BCC_SHORT(COND_EQ, out);
307 
308 	/* goto *(prog->bpf_func + prologue_size); */
309 	EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_prog, bpf_func)));
310 	EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1),
311 			FUNCTION_DESCR_SIZE + bpf_tailcall_prologue_size));
312 	EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_1)));
313 
314 	/* tear down stack, restore NVRs, ... */
315 	bpf_jit_emit_common_epilogue(image, ctx);
316 
317 	EMIT(PPC_RAW_BCTR());
318 
319 	/* out: */
320 	return 0;
321 }
322 
323 /*
324  * We spill into the redzone always, even if the bpf program has its own stackframe.
325  * Offsets hardcoded based on BPF_PPC_STACK_SAVE -- see bpf_jit_stack_local()
326  */
327 void bpf_stf_barrier(void);
328 
329 asm (
330 "		.global bpf_stf_barrier		;"
331 "	bpf_stf_barrier:			;"
332 "		std	21,-64(1)		;"
333 "		std	22,-56(1)		;"
334 "		sync				;"
335 "		ld	21,-64(1)		;"
336 "		ld	22,-56(1)		;"
337 "		ori	31,31,0			;"
338 "		.rept 14			;"
339 "		b	1f			;"
340 "	1:					;"
341 "		.endr				;"
342 "		blr				;"
343 );
344 
345 /* Assemble the body code between the prologue & epilogue */
346 int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx,
347 		       u32 *addrs, int pass, bool extra_pass)
348 {
349 	enum stf_barrier_type stf_barrier = stf_barrier_type_get();
350 	const struct bpf_insn *insn = fp->insnsi;
351 	int flen = fp->len;
352 	int i, ret;
353 
354 	/* Start of epilogue code - will only be valid 2nd pass onwards */
355 	u32 exit_addr = addrs[flen];
356 
357 	for (i = 0; i < flen; i++) {
358 		u32 code = insn[i].code;
359 		u32 dst_reg = bpf_to_ppc(insn[i].dst_reg);
360 		u32 src_reg = bpf_to_ppc(insn[i].src_reg);
361 		u32 size = BPF_SIZE(code);
362 		u32 tmp1_reg = bpf_to_ppc(TMP_REG_1);
363 		u32 tmp2_reg = bpf_to_ppc(TMP_REG_2);
364 		u32 save_reg, ret_reg;
365 		s16 off = insn[i].off;
366 		s32 imm = insn[i].imm;
367 		bool func_addr_fixed;
368 		u64 func_addr;
369 		u64 imm64;
370 		u32 true_cond;
371 		u32 tmp_idx;
372 		int j;
373 
374 		/*
375 		 * addrs[] maps a BPF bytecode address into a real offset from
376 		 * the start of the body code.
377 		 */
378 		addrs[i] = ctx->idx * 4;
379 
380 		/*
381 		 * As an optimization, we note down which non-volatile registers
382 		 * are used so that we can only save/restore those in our
383 		 * prologue and epilogue. We do this here regardless of whether
384 		 * the actual BPF instruction uses src/dst registers or not
385 		 * (for instance, BPF_CALL does not use them). The expectation
386 		 * is that those instructions will have src_reg/dst_reg set to
387 		 * 0. Even otherwise, we just lose some prologue/epilogue
388 		 * optimization but everything else should work without
389 		 * any issues.
390 		 */
391 		if (dst_reg >= BPF_PPC_NVR_MIN && dst_reg < 32)
392 			bpf_set_seen_register(ctx, dst_reg);
393 		if (src_reg >= BPF_PPC_NVR_MIN && src_reg < 32)
394 			bpf_set_seen_register(ctx, src_reg);
395 
396 		switch (code) {
397 		/*
398 		 * Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG
399 		 */
400 		case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */
401 		case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */
402 			EMIT(PPC_RAW_ADD(dst_reg, dst_reg, src_reg));
403 			goto bpf_alu32_trunc;
404 		case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */
405 		case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */
406 			EMIT(PPC_RAW_SUB(dst_reg, dst_reg, src_reg));
407 			goto bpf_alu32_trunc;
408 		case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */
409 		case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */
410 			if (!imm) {
411 				goto bpf_alu32_trunc;
412 			} else if (imm >= -32768 && imm < 32768) {
413 				EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(imm)));
414 			} else {
415 				PPC_LI32(tmp1_reg, imm);
416 				EMIT(PPC_RAW_ADD(dst_reg, dst_reg, tmp1_reg));
417 			}
418 			goto bpf_alu32_trunc;
419 		case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */
420 		case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */
421 			if (!imm) {
422 				goto bpf_alu32_trunc;
423 			} else if (imm > -32768 && imm <= 32768) {
424 				EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(-imm)));
425 			} else {
426 				PPC_LI32(tmp1_reg, imm);
427 				EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
428 			}
429 			goto bpf_alu32_trunc;
430 		case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */
431 		case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */
432 			if (BPF_CLASS(code) == BPF_ALU)
433 				EMIT(PPC_RAW_MULW(dst_reg, dst_reg, src_reg));
434 			else
435 				EMIT(PPC_RAW_MULD(dst_reg, dst_reg, src_reg));
436 			goto bpf_alu32_trunc;
437 		case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */
438 		case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */
439 			if (imm >= -32768 && imm < 32768)
440 				EMIT(PPC_RAW_MULI(dst_reg, dst_reg, IMM_L(imm)));
441 			else {
442 				PPC_LI32(tmp1_reg, imm);
443 				if (BPF_CLASS(code) == BPF_ALU)
444 					EMIT(PPC_RAW_MULW(dst_reg, dst_reg, tmp1_reg));
445 				else
446 					EMIT(PPC_RAW_MULD(dst_reg, dst_reg, tmp1_reg));
447 			}
448 			goto bpf_alu32_trunc;
449 		case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */
450 		case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */
451 			if (BPF_OP(code) == BPF_MOD) {
452 				EMIT(PPC_RAW_DIVWU(tmp1_reg, dst_reg, src_reg));
453 				EMIT(PPC_RAW_MULW(tmp1_reg, src_reg, tmp1_reg));
454 				EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
455 			} else
456 				EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, src_reg));
457 			goto bpf_alu32_trunc;
458 		case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */
459 		case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */
460 			if (BPF_OP(code) == BPF_MOD) {
461 				EMIT(PPC_RAW_DIVDU(tmp1_reg, dst_reg, src_reg));
462 				EMIT(PPC_RAW_MULD(tmp1_reg, src_reg, tmp1_reg));
463 				EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
464 			} else
465 				EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, src_reg));
466 			break;
467 		case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */
468 		case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */
469 		case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */
470 		case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */
471 			if (imm == 0)
472 				return -EINVAL;
473 			if (imm == 1) {
474 				if (BPF_OP(code) == BPF_DIV) {
475 					goto bpf_alu32_trunc;
476 				} else {
477 					EMIT(PPC_RAW_LI(dst_reg, 0));
478 					break;
479 				}
480 			}
481 
482 			PPC_LI32(tmp1_reg, imm);
483 			switch (BPF_CLASS(code)) {
484 			case BPF_ALU:
485 				if (BPF_OP(code) == BPF_MOD) {
486 					EMIT(PPC_RAW_DIVWU(tmp2_reg, dst_reg, tmp1_reg));
487 					EMIT(PPC_RAW_MULW(tmp1_reg, tmp1_reg, tmp2_reg));
488 					EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
489 				} else
490 					EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, tmp1_reg));
491 				break;
492 			case BPF_ALU64:
493 				if (BPF_OP(code) == BPF_MOD) {
494 					EMIT(PPC_RAW_DIVDU(tmp2_reg, dst_reg, tmp1_reg));
495 					EMIT(PPC_RAW_MULD(tmp1_reg, tmp1_reg, tmp2_reg));
496 					EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
497 				} else
498 					EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, tmp1_reg));
499 				break;
500 			}
501 			goto bpf_alu32_trunc;
502 		case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */
503 		case BPF_ALU64 | BPF_NEG: /* dst = -dst */
504 			EMIT(PPC_RAW_NEG(dst_reg, dst_reg));
505 			goto bpf_alu32_trunc;
506 
507 		/*
508 		 * Logical operations: AND/OR/XOR/[A]LSH/[A]RSH
509 		 */
510 		case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */
511 		case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
512 			EMIT(PPC_RAW_AND(dst_reg, dst_reg, src_reg));
513 			goto bpf_alu32_trunc;
514 		case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */
515 		case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
516 			if (!IMM_H(imm))
517 				EMIT(PPC_RAW_ANDI(dst_reg, dst_reg, IMM_L(imm)));
518 			else {
519 				/* Sign-extended */
520 				PPC_LI32(tmp1_reg, imm);
521 				EMIT(PPC_RAW_AND(dst_reg, dst_reg, tmp1_reg));
522 			}
523 			goto bpf_alu32_trunc;
524 		case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
525 		case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
526 			EMIT(PPC_RAW_OR(dst_reg, dst_reg, src_reg));
527 			goto bpf_alu32_trunc;
528 		case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */
529 		case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */
530 			if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
531 				/* Sign-extended */
532 				PPC_LI32(tmp1_reg, imm);
533 				EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp1_reg));
534 			} else {
535 				if (IMM_L(imm))
536 					EMIT(PPC_RAW_ORI(dst_reg, dst_reg, IMM_L(imm)));
537 				if (IMM_H(imm))
538 					EMIT(PPC_RAW_ORIS(dst_reg, dst_reg, IMM_H(imm)));
539 			}
540 			goto bpf_alu32_trunc;
541 		case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */
542 		case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */
543 			EMIT(PPC_RAW_XOR(dst_reg, dst_reg, src_reg));
544 			goto bpf_alu32_trunc;
545 		case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */
546 		case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */
547 			if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
548 				/* Sign-extended */
549 				PPC_LI32(tmp1_reg, imm);
550 				EMIT(PPC_RAW_XOR(dst_reg, dst_reg, tmp1_reg));
551 			} else {
552 				if (IMM_L(imm))
553 					EMIT(PPC_RAW_XORI(dst_reg, dst_reg, IMM_L(imm)));
554 				if (IMM_H(imm))
555 					EMIT(PPC_RAW_XORIS(dst_reg, dst_reg, IMM_H(imm)));
556 			}
557 			goto bpf_alu32_trunc;
558 		case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */
559 			/* slw clears top 32 bits */
560 			EMIT(PPC_RAW_SLW(dst_reg, dst_reg, src_reg));
561 			/* skip zero extension move, but set address map. */
562 			if (insn_is_zext(&insn[i + 1]))
563 				addrs[++i] = ctx->idx * 4;
564 			break;
565 		case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */
566 			EMIT(PPC_RAW_SLD(dst_reg, dst_reg, src_reg));
567 			break;
568 		case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<== (u32) imm */
569 			/* with imm 0, we still need to clear top 32 bits */
570 			EMIT(PPC_RAW_SLWI(dst_reg, dst_reg, imm));
571 			if (insn_is_zext(&insn[i + 1]))
572 				addrs[++i] = ctx->idx * 4;
573 			break;
574 		case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<== imm */
575 			if (imm != 0)
576 				EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, imm));
577 			break;
578 		case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */
579 			EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg));
580 			if (insn_is_zext(&insn[i + 1]))
581 				addrs[++i] = ctx->idx * 4;
582 			break;
583 		case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */
584 			EMIT(PPC_RAW_SRD(dst_reg, dst_reg, src_reg));
585 			break;
586 		case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */
587 			EMIT(PPC_RAW_SRWI(dst_reg, dst_reg, imm));
588 			if (insn_is_zext(&insn[i + 1]))
589 				addrs[++i] = ctx->idx * 4;
590 			break;
591 		case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */
592 			if (imm != 0)
593 				EMIT(PPC_RAW_SRDI(dst_reg, dst_reg, imm));
594 			break;
595 		case BPF_ALU | BPF_ARSH | BPF_X: /* (s32) dst >>= src */
596 			EMIT(PPC_RAW_SRAW(dst_reg, dst_reg, src_reg));
597 			goto bpf_alu32_trunc;
598 		case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */
599 			EMIT(PPC_RAW_SRAD(dst_reg, dst_reg, src_reg));
600 			break;
601 		case BPF_ALU | BPF_ARSH | BPF_K: /* (s32) dst >>= imm */
602 			EMIT(PPC_RAW_SRAWI(dst_reg, dst_reg, imm));
603 			goto bpf_alu32_trunc;
604 		case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */
605 			if (imm != 0)
606 				EMIT(PPC_RAW_SRADI(dst_reg, dst_reg, imm));
607 			break;
608 
609 		/*
610 		 * MOV
611 		 */
612 		case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */
613 		case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
614 			if (imm == 1) {
615 				/* special mov32 for zext */
616 				EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31));
617 				break;
618 			}
619 			EMIT(PPC_RAW_MR(dst_reg, src_reg));
620 			goto bpf_alu32_trunc;
621 		case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */
622 		case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */
623 			PPC_LI32(dst_reg, imm);
624 			if (imm < 0)
625 				goto bpf_alu32_trunc;
626 			else if (insn_is_zext(&insn[i + 1]))
627 				addrs[++i] = ctx->idx * 4;
628 			break;
629 
630 bpf_alu32_trunc:
631 		/* Truncate to 32-bits */
632 		if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext)
633 			EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31));
634 		break;
635 
636 		/*
637 		 * BPF_FROM_BE/LE
638 		 */
639 		case BPF_ALU | BPF_END | BPF_FROM_LE:
640 		case BPF_ALU | BPF_END | BPF_FROM_BE:
641 #ifdef __BIG_ENDIAN__
642 			if (BPF_SRC(code) == BPF_FROM_BE)
643 				goto emit_clear;
644 #else /* !__BIG_ENDIAN__ */
645 			if (BPF_SRC(code) == BPF_FROM_LE)
646 				goto emit_clear;
647 #endif
648 			switch (imm) {
649 			case 16:
650 				/* Rotate 8 bits left & mask with 0x0000ff00 */
651 				EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 16, 23));
652 				/* Rotate 8 bits right & insert LSB to reg */
653 				EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 24, 31));
654 				/* Move result back to dst_reg */
655 				EMIT(PPC_RAW_MR(dst_reg, tmp1_reg));
656 				break;
657 			case 32:
658 				/*
659 				 * Rotate word left by 8 bits:
660 				 * 2 bytes are already in their final position
661 				 * -- byte 2 and 4 (of bytes 1, 2, 3 and 4)
662 				 */
663 				EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 0, 31));
664 				/* Rotate 24 bits and insert byte 1 */
665 				EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 0, 7));
666 				/* Rotate 24 bits and insert byte 3 */
667 				EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 16, 23));
668 				EMIT(PPC_RAW_MR(dst_reg, tmp1_reg));
669 				break;
670 			case 64:
671 				/* Store the value to stack and then use byte-reverse loads */
672 				EMIT(PPC_RAW_STD(dst_reg, _R1, bpf_jit_stack_local(ctx)));
673 				EMIT(PPC_RAW_ADDI(tmp1_reg, _R1, bpf_jit_stack_local(ctx)));
674 				if (cpu_has_feature(CPU_FTR_ARCH_206)) {
675 					EMIT(PPC_RAW_LDBRX(dst_reg, 0, tmp1_reg));
676 				} else {
677 					EMIT(PPC_RAW_LWBRX(dst_reg, 0, tmp1_reg));
678 					if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN))
679 						EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, 32));
680 					EMIT(PPC_RAW_LI(tmp2_reg, 4));
681 					EMIT(PPC_RAW_LWBRX(tmp2_reg, tmp2_reg, tmp1_reg));
682 					if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
683 						EMIT(PPC_RAW_SLDI(tmp2_reg, tmp2_reg, 32));
684 					EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp2_reg));
685 				}
686 				break;
687 			}
688 			break;
689 
690 emit_clear:
691 			switch (imm) {
692 			case 16:
693 				/* zero-extend 16 bits into 64 bits */
694 				EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 48));
695 				if (insn_is_zext(&insn[i + 1]))
696 					addrs[++i] = ctx->idx * 4;
697 				break;
698 			case 32:
699 				if (!fp->aux->verifier_zext)
700 					/* zero-extend 32 bits into 64 bits */
701 					EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 32));
702 				break;
703 			case 64:
704 				/* nop */
705 				break;
706 			}
707 			break;
708 
709 		/*
710 		 * BPF_ST NOSPEC (speculation barrier)
711 		 */
712 		case BPF_ST | BPF_NOSPEC:
713 			if (!security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) ||
714 					!security_ftr_enabled(SEC_FTR_STF_BARRIER))
715 				break;
716 
717 			switch (stf_barrier) {
718 			case STF_BARRIER_EIEIO:
719 				EMIT(PPC_RAW_EIEIO() | 0x02000000);
720 				break;
721 			case STF_BARRIER_SYNC_ORI:
722 				EMIT(PPC_RAW_SYNC());
723 				EMIT(PPC_RAW_LD(tmp1_reg, _R13, 0));
724 				EMIT(PPC_RAW_ORI(_R31, _R31, 0));
725 				break;
726 			case STF_BARRIER_FALLBACK:
727 				ctx->seen |= SEEN_FUNC;
728 				PPC_LI64(_R12, dereference_kernel_function_descriptor(bpf_stf_barrier));
729 				EMIT(PPC_RAW_MTCTR(_R12));
730 				EMIT(PPC_RAW_BCTRL());
731 				break;
732 			case STF_BARRIER_NONE:
733 				break;
734 			}
735 			break;
736 
737 		/*
738 		 * BPF_ST(X)
739 		 */
740 		case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */
741 		case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
742 			if (BPF_CLASS(code) == BPF_ST) {
743 				EMIT(PPC_RAW_LI(tmp1_reg, imm));
744 				src_reg = tmp1_reg;
745 			}
746 			EMIT(PPC_RAW_STB(src_reg, dst_reg, off));
747 			break;
748 		case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
749 		case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
750 			if (BPF_CLASS(code) == BPF_ST) {
751 				EMIT(PPC_RAW_LI(tmp1_reg, imm));
752 				src_reg = tmp1_reg;
753 			}
754 			EMIT(PPC_RAW_STH(src_reg, dst_reg, off));
755 			break;
756 		case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
757 		case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
758 			if (BPF_CLASS(code) == BPF_ST) {
759 				PPC_LI32(tmp1_reg, imm);
760 				src_reg = tmp1_reg;
761 			}
762 			EMIT(PPC_RAW_STW(src_reg, dst_reg, off));
763 			break;
764 		case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
765 		case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
766 			if (BPF_CLASS(code) == BPF_ST) {
767 				PPC_LI32(tmp1_reg, imm);
768 				src_reg = tmp1_reg;
769 			}
770 			if (off % 4) {
771 				EMIT(PPC_RAW_LI(tmp2_reg, off));
772 				EMIT(PPC_RAW_STDX(src_reg, dst_reg, tmp2_reg));
773 			} else {
774 				EMIT(PPC_RAW_STD(src_reg, dst_reg, off));
775 			}
776 			break;
777 
778 		/*
779 		 * BPF_STX ATOMIC (atomic ops)
780 		 */
781 		case BPF_STX | BPF_ATOMIC | BPF_W:
782 		case BPF_STX | BPF_ATOMIC | BPF_DW:
783 			save_reg = tmp2_reg;
784 			ret_reg = src_reg;
785 
786 			/* Get offset into TMP_REG_1 */
787 			EMIT(PPC_RAW_LI(tmp1_reg, off));
788 			tmp_idx = ctx->idx * 4;
789 			/* load value from memory into TMP_REG_2 */
790 			if (size == BPF_DW)
791 				EMIT(PPC_RAW_LDARX(tmp2_reg, tmp1_reg, dst_reg, 0));
792 			else
793 				EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0));
794 
795 			/* Save old value in _R0 */
796 			if (imm & BPF_FETCH)
797 				EMIT(PPC_RAW_MR(_R0, tmp2_reg));
798 
799 			switch (imm) {
800 			case BPF_ADD:
801 			case BPF_ADD | BPF_FETCH:
802 				EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg));
803 				break;
804 			case BPF_AND:
805 			case BPF_AND | BPF_FETCH:
806 				EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg));
807 				break;
808 			case BPF_OR:
809 			case BPF_OR | BPF_FETCH:
810 				EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg));
811 				break;
812 			case BPF_XOR:
813 			case BPF_XOR | BPF_FETCH:
814 				EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg));
815 				break;
816 			case BPF_CMPXCHG:
817 				/*
818 				 * Return old value in BPF_REG_0 for BPF_CMPXCHG &
819 				 * in src_reg for other cases.
820 				 */
821 				ret_reg = bpf_to_ppc(BPF_REG_0);
822 
823 				/* Compare with old value in BPF_R0 */
824 				if (size == BPF_DW)
825 					EMIT(PPC_RAW_CMPD(bpf_to_ppc(BPF_REG_0), tmp2_reg));
826 				else
827 					EMIT(PPC_RAW_CMPW(bpf_to_ppc(BPF_REG_0), tmp2_reg));
828 				/* Don't set if different from old value */
829 				PPC_BCC_SHORT(COND_NE, (ctx->idx + 3) * 4);
830 				fallthrough;
831 			case BPF_XCHG:
832 				save_reg = src_reg;
833 				break;
834 			default:
835 				pr_err_ratelimited(
836 					"eBPF filter atomic op code %02x (@%d) unsupported\n",
837 					code, i);
838 				return -EOPNOTSUPP;
839 			}
840 
841 			/* store new value */
842 			if (size == BPF_DW)
843 				EMIT(PPC_RAW_STDCX(save_reg, tmp1_reg, dst_reg));
844 			else
845 				EMIT(PPC_RAW_STWCX(save_reg, tmp1_reg, dst_reg));
846 			/* we're done if this succeeded */
847 			PPC_BCC_SHORT(COND_NE, tmp_idx);
848 
849 			if (imm & BPF_FETCH) {
850 				EMIT(PPC_RAW_MR(ret_reg, _R0));
851 				/*
852 				 * Skip unnecessary zero-extension for 32-bit cmpxchg.
853 				 * For context, see commit 39491867ace5.
854 				 */
855 				if (size != BPF_DW && imm == BPF_CMPXCHG &&
856 				    insn_is_zext(&insn[i + 1]))
857 					addrs[++i] = ctx->idx * 4;
858 			}
859 			break;
860 
861 		/*
862 		 * BPF_LDX
863 		 */
864 		/* dst = *(u8 *)(ul) (src + off) */
865 		case BPF_LDX | BPF_MEM | BPF_B:
866 		case BPF_LDX | BPF_PROBE_MEM | BPF_B:
867 		/* dst = *(u16 *)(ul) (src + off) */
868 		case BPF_LDX | BPF_MEM | BPF_H:
869 		case BPF_LDX | BPF_PROBE_MEM | BPF_H:
870 		/* dst = *(u32 *)(ul) (src + off) */
871 		case BPF_LDX | BPF_MEM | BPF_W:
872 		case BPF_LDX | BPF_PROBE_MEM | BPF_W:
873 		/* dst = *(u64 *)(ul) (src + off) */
874 		case BPF_LDX | BPF_MEM | BPF_DW:
875 		case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
876 			/*
877 			 * As PTR_TO_BTF_ID that uses BPF_PROBE_MEM mode could either be a valid
878 			 * kernel pointer or NULL but not a userspace address, execute BPF_PROBE_MEM
879 			 * load only if addr is kernel address (see is_kernel_addr()), otherwise
880 			 * set dst_reg=0 and move on.
881 			 */
882 			if (BPF_MODE(code) == BPF_PROBE_MEM) {
883 				EMIT(PPC_RAW_ADDI(tmp1_reg, src_reg, off));
884 				if (IS_ENABLED(CONFIG_PPC_BOOK3E_64))
885 					PPC_LI64(tmp2_reg, 0x8000000000000000ul);
886 				else /* BOOK3S_64 */
887 					PPC_LI64(tmp2_reg, PAGE_OFFSET);
888 				EMIT(PPC_RAW_CMPLD(tmp1_reg, tmp2_reg));
889 				PPC_BCC_SHORT(COND_GT, (ctx->idx + 3) * 4);
890 				EMIT(PPC_RAW_LI(dst_reg, 0));
891 				/*
892 				 * Check if 'off' is word aligned for BPF_DW, because
893 				 * we might generate two instructions.
894 				 */
895 				if (BPF_SIZE(code) == BPF_DW && (off & 3))
896 					PPC_JMP((ctx->idx + 3) * 4);
897 				else
898 					PPC_JMP((ctx->idx + 2) * 4);
899 			}
900 
901 			switch (size) {
902 			case BPF_B:
903 				EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off));
904 				break;
905 			case BPF_H:
906 				EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off));
907 				break;
908 			case BPF_W:
909 				EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off));
910 				break;
911 			case BPF_DW:
912 				if (off % 4) {
913 					EMIT(PPC_RAW_LI(tmp1_reg, off));
914 					EMIT(PPC_RAW_LDX(dst_reg, src_reg, tmp1_reg));
915 				} else {
916 					EMIT(PPC_RAW_LD(dst_reg, src_reg, off));
917 				}
918 				break;
919 			}
920 
921 			if (size != BPF_DW && insn_is_zext(&insn[i + 1]))
922 				addrs[++i] = ctx->idx * 4;
923 
924 			if (BPF_MODE(code) == BPF_PROBE_MEM) {
925 				ret = bpf_add_extable_entry(fp, image, pass, ctx, ctx->idx - 1,
926 							    4, dst_reg);
927 				if (ret)
928 					return ret;
929 			}
930 			break;
931 
932 		/*
933 		 * Doubleword load
934 		 * 16 byte instruction that uses two 'struct bpf_insn'
935 		 */
936 		case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
937 			imm64 = ((u64)(u32) insn[i].imm) |
938 				    (((u64)(u32) insn[i+1].imm) << 32);
939 			tmp_idx = ctx->idx;
940 			PPC_LI64(dst_reg, imm64);
941 			/* padding to allow full 5 instructions for later patching */
942 			if (!image)
943 				for (j = ctx->idx - tmp_idx; j < 5; j++)
944 					EMIT(PPC_RAW_NOP());
945 			/* Adjust for two bpf instructions */
946 			addrs[++i] = ctx->idx * 4;
947 			break;
948 
949 		/*
950 		 * Return/Exit
951 		 */
952 		case BPF_JMP | BPF_EXIT:
953 			/*
954 			 * If this isn't the very last instruction, branch to
955 			 * the epilogue. If we _are_ the last instruction,
956 			 * we'll just fall through to the epilogue.
957 			 */
958 			if (i != flen - 1) {
959 				ret = bpf_jit_emit_exit_insn(image, ctx, tmp1_reg, exit_addr);
960 				if (ret)
961 					return ret;
962 			}
963 			/* else fall through to the epilogue */
964 			break;
965 
966 		/*
967 		 * Call kernel helper or bpf function
968 		 */
969 		case BPF_JMP | BPF_CALL:
970 			ctx->seen |= SEEN_FUNC;
971 
972 			ret = bpf_jit_get_func_addr(fp, &insn[i], extra_pass,
973 						    &func_addr, &func_addr_fixed);
974 			if (ret < 0)
975 				return ret;
976 
977 			if (func_addr_fixed)
978 				ret = bpf_jit_emit_func_call_hlp(image, ctx, func_addr);
979 			else
980 				ret = bpf_jit_emit_func_call_rel(image, ctx, func_addr);
981 
982 			if (ret)
983 				return ret;
984 
985 			/* move return value from r3 to BPF_REG_0 */
986 			EMIT(PPC_RAW_MR(bpf_to_ppc(BPF_REG_0), _R3));
987 			break;
988 
989 		/*
990 		 * Jumps and branches
991 		 */
992 		case BPF_JMP | BPF_JA:
993 			PPC_JMP(addrs[i + 1 + off]);
994 			break;
995 
996 		case BPF_JMP | BPF_JGT | BPF_K:
997 		case BPF_JMP | BPF_JGT | BPF_X:
998 		case BPF_JMP | BPF_JSGT | BPF_K:
999 		case BPF_JMP | BPF_JSGT | BPF_X:
1000 		case BPF_JMP32 | BPF_JGT | BPF_K:
1001 		case BPF_JMP32 | BPF_JGT | BPF_X:
1002 		case BPF_JMP32 | BPF_JSGT | BPF_K:
1003 		case BPF_JMP32 | BPF_JSGT | BPF_X:
1004 			true_cond = COND_GT;
1005 			goto cond_branch;
1006 		case BPF_JMP | BPF_JLT | BPF_K:
1007 		case BPF_JMP | BPF_JLT | BPF_X:
1008 		case BPF_JMP | BPF_JSLT | BPF_K:
1009 		case BPF_JMP | BPF_JSLT | BPF_X:
1010 		case BPF_JMP32 | BPF_JLT | BPF_K:
1011 		case BPF_JMP32 | BPF_JLT | BPF_X:
1012 		case BPF_JMP32 | BPF_JSLT | BPF_K:
1013 		case BPF_JMP32 | BPF_JSLT | BPF_X:
1014 			true_cond = COND_LT;
1015 			goto cond_branch;
1016 		case BPF_JMP | BPF_JGE | BPF_K:
1017 		case BPF_JMP | BPF_JGE | BPF_X:
1018 		case BPF_JMP | BPF_JSGE | BPF_K:
1019 		case BPF_JMP | BPF_JSGE | BPF_X:
1020 		case BPF_JMP32 | BPF_JGE | BPF_K:
1021 		case BPF_JMP32 | BPF_JGE | BPF_X:
1022 		case BPF_JMP32 | BPF_JSGE | BPF_K:
1023 		case BPF_JMP32 | BPF_JSGE | BPF_X:
1024 			true_cond = COND_GE;
1025 			goto cond_branch;
1026 		case BPF_JMP | BPF_JLE | BPF_K:
1027 		case BPF_JMP | BPF_JLE | BPF_X:
1028 		case BPF_JMP | BPF_JSLE | BPF_K:
1029 		case BPF_JMP | BPF_JSLE | BPF_X:
1030 		case BPF_JMP32 | BPF_JLE | BPF_K:
1031 		case BPF_JMP32 | BPF_JLE | BPF_X:
1032 		case BPF_JMP32 | BPF_JSLE | BPF_K:
1033 		case BPF_JMP32 | BPF_JSLE | BPF_X:
1034 			true_cond = COND_LE;
1035 			goto cond_branch;
1036 		case BPF_JMP | BPF_JEQ | BPF_K:
1037 		case BPF_JMP | BPF_JEQ | BPF_X:
1038 		case BPF_JMP32 | BPF_JEQ | BPF_K:
1039 		case BPF_JMP32 | BPF_JEQ | BPF_X:
1040 			true_cond = COND_EQ;
1041 			goto cond_branch;
1042 		case BPF_JMP | BPF_JNE | BPF_K:
1043 		case BPF_JMP | BPF_JNE | BPF_X:
1044 		case BPF_JMP32 | BPF_JNE | BPF_K:
1045 		case BPF_JMP32 | BPF_JNE | BPF_X:
1046 			true_cond = COND_NE;
1047 			goto cond_branch;
1048 		case BPF_JMP | BPF_JSET | BPF_K:
1049 		case BPF_JMP | BPF_JSET | BPF_X:
1050 		case BPF_JMP32 | BPF_JSET | BPF_K:
1051 		case BPF_JMP32 | BPF_JSET | BPF_X:
1052 			true_cond = COND_NE;
1053 			/* Fall through */
1054 
1055 cond_branch:
1056 			switch (code) {
1057 			case BPF_JMP | BPF_JGT | BPF_X:
1058 			case BPF_JMP | BPF_JLT | BPF_X:
1059 			case BPF_JMP | BPF_JGE | BPF_X:
1060 			case BPF_JMP | BPF_JLE | BPF_X:
1061 			case BPF_JMP | BPF_JEQ | BPF_X:
1062 			case BPF_JMP | BPF_JNE | BPF_X:
1063 			case BPF_JMP32 | BPF_JGT | BPF_X:
1064 			case BPF_JMP32 | BPF_JLT | BPF_X:
1065 			case BPF_JMP32 | BPF_JGE | BPF_X:
1066 			case BPF_JMP32 | BPF_JLE | BPF_X:
1067 			case BPF_JMP32 | BPF_JEQ | BPF_X:
1068 			case BPF_JMP32 | BPF_JNE | BPF_X:
1069 				/* unsigned comparison */
1070 				if (BPF_CLASS(code) == BPF_JMP32)
1071 					EMIT(PPC_RAW_CMPLW(dst_reg, src_reg));
1072 				else
1073 					EMIT(PPC_RAW_CMPLD(dst_reg, src_reg));
1074 				break;
1075 			case BPF_JMP | BPF_JSGT | BPF_X:
1076 			case BPF_JMP | BPF_JSLT | BPF_X:
1077 			case BPF_JMP | BPF_JSGE | BPF_X:
1078 			case BPF_JMP | BPF_JSLE | BPF_X:
1079 			case BPF_JMP32 | BPF_JSGT | BPF_X:
1080 			case BPF_JMP32 | BPF_JSLT | BPF_X:
1081 			case BPF_JMP32 | BPF_JSGE | BPF_X:
1082 			case BPF_JMP32 | BPF_JSLE | BPF_X:
1083 				/* signed comparison */
1084 				if (BPF_CLASS(code) == BPF_JMP32)
1085 					EMIT(PPC_RAW_CMPW(dst_reg, src_reg));
1086 				else
1087 					EMIT(PPC_RAW_CMPD(dst_reg, src_reg));
1088 				break;
1089 			case BPF_JMP | BPF_JSET | BPF_X:
1090 			case BPF_JMP32 | BPF_JSET | BPF_X:
1091 				if (BPF_CLASS(code) == BPF_JMP) {
1092 					EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg, src_reg));
1093 				} else {
1094 					EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, src_reg));
1095 					EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg, 0, 0, 31));
1096 				}
1097 				break;
1098 			case BPF_JMP | BPF_JNE | BPF_K:
1099 			case BPF_JMP | BPF_JEQ | BPF_K:
1100 			case BPF_JMP | BPF_JGT | BPF_K:
1101 			case BPF_JMP | BPF_JLT | BPF_K:
1102 			case BPF_JMP | BPF_JGE | BPF_K:
1103 			case BPF_JMP | BPF_JLE | BPF_K:
1104 			case BPF_JMP32 | BPF_JNE | BPF_K:
1105 			case BPF_JMP32 | BPF_JEQ | BPF_K:
1106 			case BPF_JMP32 | BPF_JGT | BPF_K:
1107 			case BPF_JMP32 | BPF_JLT | BPF_K:
1108 			case BPF_JMP32 | BPF_JGE | BPF_K:
1109 			case BPF_JMP32 | BPF_JLE | BPF_K:
1110 			{
1111 				bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32;
1112 
1113 				/*
1114 				 * Need sign-extended load, so only positive
1115 				 * values can be used as imm in cmpldi
1116 				 */
1117 				if (imm >= 0 && imm < 32768) {
1118 					if (is_jmp32)
1119 						EMIT(PPC_RAW_CMPLWI(dst_reg, imm));
1120 					else
1121 						EMIT(PPC_RAW_CMPLDI(dst_reg, imm));
1122 				} else {
1123 					/* sign-extending load */
1124 					PPC_LI32(tmp1_reg, imm);
1125 					/* ... but unsigned comparison */
1126 					if (is_jmp32)
1127 						EMIT(PPC_RAW_CMPLW(dst_reg, tmp1_reg));
1128 					else
1129 						EMIT(PPC_RAW_CMPLD(dst_reg, tmp1_reg));
1130 				}
1131 				break;
1132 			}
1133 			case BPF_JMP | BPF_JSGT | BPF_K:
1134 			case BPF_JMP | BPF_JSLT | BPF_K:
1135 			case BPF_JMP | BPF_JSGE | BPF_K:
1136 			case BPF_JMP | BPF_JSLE | BPF_K:
1137 			case BPF_JMP32 | BPF_JSGT | BPF_K:
1138 			case BPF_JMP32 | BPF_JSLT | BPF_K:
1139 			case BPF_JMP32 | BPF_JSGE | BPF_K:
1140 			case BPF_JMP32 | BPF_JSLE | BPF_K:
1141 			{
1142 				bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32;
1143 
1144 				/*
1145 				 * signed comparison, so any 16-bit value
1146 				 * can be used in cmpdi
1147 				 */
1148 				if (imm >= -32768 && imm < 32768) {
1149 					if (is_jmp32)
1150 						EMIT(PPC_RAW_CMPWI(dst_reg, imm));
1151 					else
1152 						EMIT(PPC_RAW_CMPDI(dst_reg, imm));
1153 				} else {
1154 					PPC_LI32(tmp1_reg, imm);
1155 					if (is_jmp32)
1156 						EMIT(PPC_RAW_CMPW(dst_reg, tmp1_reg));
1157 					else
1158 						EMIT(PPC_RAW_CMPD(dst_reg, tmp1_reg));
1159 				}
1160 				break;
1161 			}
1162 			case BPF_JMP | BPF_JSET | BPF_K:
1163 			case BPF_JMP32 | BPF_JSET | BPF_K:
1164 				/* andi does not sign-extend the immediate */
1165 				if (imm >= 0 && imm < 32768)
1166 					/* PPC_ANDI is _only/always_ dot-form */
1167 					EMIT(PPC_RAW_ANDI(tmp1_reg, dst_reg, imm));
1168 				else {
1169 					PPC_LI32(tmp1_reg, imm);
1170 					if (BPF_CLASS(code) == BPF_JMP) {
1171 						EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg,
1172 								     tmp1_reg));
1173 					} else {
1174 						EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, tmp1_reg));
1175 						EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg,
1176 									0, 0, 31));
1177 					}
1178 				}
1179 				break;
1180 			}
1181 			PPC_BCC(true_cond, addrs[i + 1 + off]);
1182 			break;
1183 
1184 		/*
1185 		 * Tail call
1186 		 */
1187 		case BPF_JMP | BPF_TAIL_CALL:
1188 			ctx->seen |= SEEN_TAILCALL;
1189 			ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]);
1190 			if (ret < 0)
1191 				return ret;
1192 			break;
1193 
1194 		default:
1195 			/*
1196 			 * The filter contains something cruel & unusual.
1197 			 * We don't handle it, but also there shouldn't be
1198 			 * anything missing from our list.
1199 			 */
1200 			pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n",
1201 					code, i);
1202 			return -ENOTSUPP;
1203 		}
1204 	}
1205 
1206 	/* Set end-of-body-code address for exit. */
1207 	addrs[i] = ctx->idx * 4;
1208 
1209 	return 0;
1210 }
1211