1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/moduleloader.h>
3 #include <linux/workqueue.h>
4 #include <linux/netdevice.h>
5 #include <linux/filter.h>
6 #include <linux/cache.h>
7 #include <linux/if_vlan.h>
8 
9 #include <asm/cacheflush.h>
10 #include <asm/ptrace.h>
11 
12 #include "bpf_jit_32.h"
13 
is_simm13(unsigned int value)14 static inline bool is_simm13(unsigned int value)
15 {
16 	return value + 0x1000 < 0x2000;
17 }
18 
19 #define SEEN_DATAREF 1 /* might call external helpers */
20 #define SEEN_XREG    2 /* ebx is used */
21 #define SEEN_MEM     4 /* use mem[] for temporary storage */
22 
23 #define S13(X)		((X) & 0x1fff)
24 #define IMMED		0x00002000
25 #define RD(X)		((X) << 25)
26 #define RS1(X)		((X) << 14)
27 #define RS2(X)		((X))
28 #define OP(X)		((X) << 30)
29 #define OP2(X)		((X) << 22)
30 #define OP3(X)		((X) << 19)
31 #define COND(X)		((X) << 25)
32 #define F1(X)		OP(X)
33 #define F2(X, Y)	(OP(X) | OP2(Y))
34 #define F3(X, Y)	(OP(X) | OP3(Y))
35 
36 #define CONDN		COND(0x0)
37 #define CONDE		COND(0x1)
38 #define CONDLE		COND(0x2)
39 #define CONDL		COND(0x3)
40 #define CONDLEU		COND(0x4)
41 #define CONDCS		COND(0x5)
42 #define CONDNEG		COND(0x6)
43 #define CONDVC		COND(0x7)
44 #define CONDA		COND(0x8)
45 #define CONDNE		COND(0x9)
46 #define CONDG		COND(0xa)
47 #define CONDGE		COND(0xb)
48 #define CONDGU		COND(0xc)
49 #define CONDCC		COND(0xd)
50 #define CONDPOS		COND(0xe)
51 #define CONDVS		COND(0xf)
52 
53 #define CONDGEU		CONDCC
54 #define CONDLU		CONDCS
55 
56 #define WDISP22(X)	(((X) >> 2) & 0x3fffff)
57 
58 #define BA		(F2(0, 2) | CONDA)
59 #define BGU		(F2(0, 2) | CONDGU)
60 #define BLEU		(F2(0, 2) | CONDLEU)
61 #define BGEU		(F2(0, 2) | CONDGEU)
62 #define BLU		(F2(0, 2) | CONDLU)
63 #define BE		(F2(0, 2) | CONDE)
64 #define BNE		(F2(0, 2) | CONDNE)
65 
66 #define BE_PTR		BE
67 
68 #define SETHI(K, REG)	\
69 	(F2(0, 0x4) | RD(REG) | (((K) >> 10) & 0x3fffff))
70 #define OR_LO(K, REG)	\
71 	(F3(2, 0x02) | IMMED | RS1(REG) | ((K) & 0x3ff) | RD(REG))
72 
73 #define ADD		F3(2, 0x00)
74 #define AND		F3(2, 0x01)
75 #define ANDCC		F3(2, 0x11)
76 #define OR		F3(2, 0x02)
77 #define XOR		F3(2, 0x03)
78 #define SUB		F3(2, 0x04)
79 #define SUBCC		F3(2, 0x14)
80 #define MUL		F3(2, 0x0a)	/* umul */
81 #define DIV		F3(2, 0x0e)	/* udiv */
82 #define SLL		F3(2, 0x25)
83 #define SRL		F3(2, 0x26)
84 #define JMPL		F3(2, 0x38)
85 #define CALL		F1(1)
86 #define BR		F2(0, 0x01)
87 #define RD_Y		F3(2, 0x28)
88 #define WR_Y		F3(2, 0x30)
89 
90 #define LD32		F3(3, 0x00)
91 #define LD8		F3(3, 0x01)
92 #define LD16		F3(3, 0x02)
93 #define LD64		F3(3, 0x0b)
94 #define ST32		F3(3, 0x04)
95 
96 #define LDPTR		LD32
97 #define BASE_STACKFRAME	96
98 
99 #define LD32I		(LD32 | IMMED)
100 #define LD8I		(LD8 | IMMED)
101 #define LD16I		(LD16 | IMMED)
102 #define LD64I		(LD64 | IMMED)
103 #define LDPTRI		(LDPTR | IMMED)
104 #define ST32I		(ST32 | IMMED)
105 
106 #define emit_nop()		\
107 do {				\
108 	*prog++ = SETHI(0, G0);	\
109 } while (0)
110 
111 #define emit_neg()					\
112 do {	/* sub %g0, r_A, r_A */				\
113 	*prog++ = SUB | RS1(G0) | RS2(r_A) | RD(r_A);	\
114 } while (0)
115 
116 #define emit_reg_move(FROM, TO)				\
117 do {	/* or %g0, FROM, TO */				\
118 	*prog++ = OR | RS1(G0) | RS2(FROM) | RD(TO);	\
119 } while (0)
120 
121 #define emit_clear(REG)					\
122 do {	/* or %g0, %g0, REG */				\
123 	*prog++ = OR | RS1(G0) | RS2(G0) | RD(REG);	\
124 } while (0)
125 
126 #define emit_set_const(K, REG)					\
127 do {	/* sethi %hi(K), REG */					\
128 	*prog++ = SETHI(K, REG);				\
129 	/* or REG, %lo(K), REG */				\
130 	*prog++ = OR_LO(K, REG);				\
131 } while (0)
132 
133 	/* Emit
134 	 *
135 	 *	OP	r_A, r_X, r_A
136 	 */
137 #define emit_alu_X(OPCODE)					\
138 do {								\
139 	seen |= SEEN_XREG;					\
140 	*prog++ = OPCODE | RS1(r_A) | RS2(r_X) | RD(r_A);	\
141 } while (0)
142 
143 	/* Emit either:
144 	 *
145 	 *	OP	r_A, K, r_A
146 	 *
147 	 * or
148 	 *
149 	 *	sethi	%hi(K), r_TMP
150 	 *	or	r_TMP, %lo(K), r_TMP
151 	 *	OP	r_A, r_TMP, r_A
152 	 *
153 	 * depending upon whether K fits in a signed 13-bit
154 	 * immediate instruction field.  Emit nothing if K
155 	 * is zero.
156 	 */
157 #define emit_alu_K(OPCODE, K)					\
158 do {								\
159 	if (K || OPCODE == AND || OPCODE == MUL) {		\
160 		unsigned int _insn = OPCODE;			\
161 		_insn |= RS1(r_A) | RD(r_A);			\
162 		if (is_simm13(K)) {				\
163 			*prog++ = _insn | IMMED | S13(K);	\
164 		} else {					\
165 			emit_set_const(K, r_TMP);		\
166 			*prog++ = _insn | RS2(r_TMP);		\
167 		}						\
168 	}							\
169 } while (0)
170 
171 #define emit_loadimm(K, DEST)						\
172 do {									\
173 	if (is_simm13(K)) {						\
174 		/* or %g0, K, DEST */					\
175 		*prog++ = OR | IMMED | RS1(G0) | S13(K) | RD(DEST);	\
176 	} else {							\
177 		emit_set_const(K, DEST);				\
178 	}								\
179 } while (0)
180 
181 #define emit_loadptr(BASE, STRUCT, FIELD, DEST)				\
182 do {	unsigned int _off = offsetof(STRUCT, FIELD);			\
183 	BUILD_BUG_ON(sizeof_field(STRUCT, FIELD) != sizeof(void *));	\
184 	*prog++ = LDPTRI | RS1(BASE) | S13(_off) | RD(DEST);		\
185 } while (0)
186 
187 #define emit_load32(BASE, STRUCT, FIELD, DEST)				\
188 do {	unsigned int _off = offsetof(STRUCT, FIELD);			\
189 	BUILD_BUG_ON(sizeof_field(STRUCT, FIELD) != sizeof(u32));	\
190 	*prog++ = LD32I | RS1(BASE) | S13(_off) | RD(DEST);		\
191 } while (0)
192 
193 #define emit_load16(BASE, STRUCT, FIELD, DEST)				\
194 do {	unsigned int _off = offsetof(STRUCT, FIELD);			\
195 	BUILD_BUG_ON(sizeof_field(STRUCT, FIELD) != sizeof(u16));	\
196 	*prog++ = LD16I | RS1(BASE) | S13(_off) | RD(DEST);		\
197 } while (0)
198 
199 #define __emit_load8(BASE, STRUCT, FIELD, DEST)				\
200 do {	unsigned int _off = offsetof(STRUCT, FIELD);			\
201 	*prog++ = LD8I | RS1(BASE) | S13(_off) | RD(DEST);		\
202 } while (0)
203 
204 #define emit_load8(BASE, STRUCT, FIELD, DEST)				\
205 do {	BUILD_BUG_ON(sizeof_field(STRUCT, FIELD) != sizeof(u8));	\
206 	__emit_load8(BASE, STRUCT, FIELD, DEST);			\
207 } while (0)
208 
209 #define BIAS (-4)
210 
211 #define emit_ldmem(OFF, DEST)						\
212 do {	*prog++ = LD32I | RS1(SP) | S13(BIAS - (OFF)) | RD(DEST);	\
213 } while (0)
214 
215 #define emit_stmem(OFF, SRC)						\
216 do {	*prog++ = ST32I | RS1(SP) | S13(BIAS - (OFF)) | RD(SRC);	\
217 } while (0)
218 
219 #ifdef CONFIG_SMP
220 #define emit_load_cpu(REG)						\
221 	emit_load32(G6, struct thread_info, cpu, REG)
222 #else
223 #define emit_load_cpu(REG)	emit_clear(REG)
224 #endif
225 
226 #define emit_skb_loadptr(FIELD, DEST) \
227 	emit_loadptr(r_SKB, struct sk_buff, FIELD, DEST)
228 #define emit_skb_load32(FIELD, DEST) \
229 	emit_load32(r_SKB, struct sk_buff, FIELD, DEST)
230 #define emit_skb_load16(FIELD, DEST) \
231 	emit_load16(r_SKB, struct sk_buff, FIELD, DEST)
232 #define __emit_skb_load8(FIELD, DEST) \
233 	__emit_load8(r_SKB, struct sk_buff, FIELD, DEST)
234 #define emit_skb_load8(FIELD, DEST) \
235 	emit_load8(r_SKB, struct sk_buff, FIELD, DEST)
236 
237 #define emit_jmpl(BASE, IMM_OFF, LREG) \
238 	*prog++ = (JMPL | IMMED | RS1(BASE) | S13(IMM_OFF) | RD(LREG))
239 
240 #define emit_call(FUNC)					\
241 do {	void *_here = image + addrs[i] - 8;		\
242 	unsigned int _off = (void *)(FUNC) - _here;	\
243 	*prog++ = CALL | (((_off) >> 2) & 0x3fffffff);	\
244 	emit_nop();					\
245 } while (0)
246 
247 #define emit_branch(BR_OPC, DEST)			\
248 do {	unsigned int _here = addrs[i] - 8;		\
249 	*prog++ = BR_OPC | WDISP22((DEST) - _here);	\
250 } while (0)
251 
252 #define emit_branch_off(BR_OPC, OFF)			\
253 do {	*prog++ = BR_OPC | WDISP22(OFF);		\
254 } while (0)
255 
256 #define emit_jump(DEST)		emit_branch(BA, DEST)
257 
258 #define emit_read_y(REG)	*prog++ = RD_Y | RD(REG)
259 #define emit_write_y(REG)	*prog++ = WR_Y | IMMED | RS1(REG) | S13(0)
260 
261 #define emit_cmp(R1, R2) \
262 	*prog++ = (SUBCC | RS1(R1) | RS2(R2) | RD(G0))
263 
264 #define emit_cmpi(R1, IMM) \
265 	*prog++ = (SUBCC | IMMED | RS1(R1) | S13(IMM) | RD(G0));
266 
267 #define emit_btst(R1, R2) \
268 	*prog++ = (ANDCC | RS1(R1) | RS2(R2) | RD(G0))
269 
270 #define emit_btsti(R1, IMM) \
271 	*prog++ = (ANDCC | IMMED | RS1(R1) | S13(IMM) | RD(G0));
272 
273 #define emit_sub(R1, R2, R3) \
274 	*prog++ = (SUB | RS1(R1) | RS2(R2) | RD(R3))
275 
276 #define emit_subi(R1, IMM, R3) \
277 	*prog++ = (SUB | IMMED | RS1(R1) | S13(IMM) | RD(R3))
278 
279 #define emit_add(R1, R2, R3) \
280 	*prog++ = (ADD | RS1(R1) | RS2(R2) | RD(R3))
281 
282 #define emit_addi(R1, IMM, R3) \
283 	*prog++ = (ADD | IMMED | RS1(R1) | S13(IMM) | RD(R3))
284 
285 #define emit_and(R1, R2, R3) \
286 	*prog++ = (AND | RS1(R1) | RS2(R2) | RD(R3))
287 
288 #define emit_andi(R1, IMM, R3) \
289 	*prog++ = (AND | IMMED | RS1(R1) | S13(IMM) | RD(R3))
290 
291 #define emit_alloc_stack(SZ) \
292 	*prog++ = (SUB | IMMED | RS1(SP) | S13(SZ) | RD(SP))
293 
294 #define emit_release_stack(SZ) \
295 	*prog++ = (ADD | IMMED | RS1(SP) | S13(SZ) | RD(SP))
296 
297 /* A note about branch offset calculations.  The addrs[] array,
298  * indexed by BPF instruction, records the address after all the
299  * sparc instructions emitted for that BPF instruction.
300  *
301  * The most common case is to emit a branch at the end of such
302  * a code sequence.  So this would be two instructions, the
303  * branch and it's delay slot.
304  *
305  * Therefore by default the branch emitters calculate the branch
306  * offset field as:
307  *
308  *	destination - (addrs[i] - 8)
309  *
310  * This "addrs[i] - 8" is the address of the branch itself or
311  * what "." would be in assembler notation.  The "8" part is
312  * how we take into consideration the branch and it's delay
313  * slot mentioned above.
314  *
315  * Sometimes we need to emit a branch earlier in the code
316  * sequence.  And in these situations we adjust "destination"
317  * to accommodate this difference.  For example, if we needed
318  * to emit a branch (and it's delay slot) right before the
319  * final instruction emitted for a BPF opcode, we'd use
320  * "destination + 4" instead of just plain "destination" above.
321  *
322  * This is why you see all of these funny emit_branch() and
323  * emit_jump() calls with adjusted offsets.
324  */
325 
bpf_jit_compile(struct bpf_prog * fp)326 void bpf_jit_compile(struct bpf_prog *fp)
327 {
328 	unsigned int cleanup_addr, proglen, oldproglen = 0;
329 	u32 temp[8], *prog, *func, seen = 0, pass;
330 	const struct sock_filter *filter = fp->insns;
331 	int i, flen = fp->len, pc_ret0 = -1;
332 	unsigned int *addrs;
333 	void *image;
334 
335 	if (!bpf_jit_enable)
336 		return;
337 
338 	addrs = kmalloc_array(flen, sizeof(*addrs), GFP_KERNEL);
339 	if (addrs == NULL)
340 		return;
341 
342 	/* Before first pass, make a rough estimation of addrs[]
343 	 * each bpf instruction is translated to less than 64 bytes
344 	 */
345 	for (proglen = 0, i = 0; i < flen; i++) {
346 		proglen += 64;
347 		addrs[i] = proglen;
348 	}
349 	cleanup_addr = proglen; /* epilogue address */
350 	image = NULL;
351 	for (pass = 0; pass < 10; pass++) {
352 		u8 seen_or_pass0 = (pass == 0) ? (SEEN_XREG | SEEN_DATAREF | SEEN_MEM) : seen;
353 
354 		/* no prologue/epilogue for trivial filters (RET something) */
355 		proglen = 0;
356 		prog = temp;
357 
358 		/* Prologue */
359 		if (seen_or_pass0) {
360 			if (seen_or_pass0 & SEEN_MEM) {
361 				unsigned int sz = BASE_STACKFRAME;
362 				sz += BPF_MEMWORDS * sizeof(u32);
363 				emit_alloc_stack(sz);
364 			}
365 
366 			/* Make sure we dont leek kernel memory. */
367 			if (seen_or_pass0 & SEEN_XREG)
368 				emit_clear(r_X);
369 
370 			/* If this filter needs to access skb data,
371 			 * load %o4 and %o5 with:
372 			 *  %o4 = skb->len - skb->data_len
373 			 *  %o5 = skb->data
374 			 * And also back up %o7 into r_saved_O7 so we can
375 			 * invoke the stubs using 'call'.
376 			 */
377 			if (seen_or_pass0 & SEEN_DATAREF) {
378 				emit_load32(r_SKB, struct sk_buff, len, r_HEADLEN);
379 				emit_load32(r_SKB, struct sk_buff, data_len, r_TMP);
380 				emit_sub(r_HEADLEN, r_TMP, r_HEADLEN);
381 				emit_loadptr(r_SKB, struct sk_buff, data, r_SKB_DATA);
382 			}
383 		}
384 		emit_reg_move(O7, r_saved_O7);
385 
386 		/* Make sure we dont leak kernel information to the user. */
387 		if (bpf_needs_clear_a(&filter[0]))
388 			emit_clear(r_A); /* A = 0 */
389 
390 		for (i = 0; i < flen; i++) {
391 			unsigned int K = filter[i].k;
392 			unsigned int t_offset;
393 			unsigned int f_offset;
394 			u32 t_op, f_op;
395 			u16 code = bpf_anc_helper(&filter[i]);
396 			int ilen;
397 
398 			switch (code) {
399 			case BPF_ALU | BPF_ADD | BPF_X:	/* A += X; */
400 				emit_alu_X(ADD);
401 				break;
402 			case BPF_ALU | BPF_ADD | BPF_K:	/* A += K; */
403 				emit_alu_K(ADD, K);
404 				break;
405 			case BPF_ALU | BPF_SUB | BPF_X:	/* A -= X; */
406 				emit_alu_X(SUB);
407 				break;
408 			case BPF_ALU | BPF_SUB | BPF_K:	/* A -= K */
409 				emit_alu_K(SUB, K);
410 				break;
411 			case BPF_ALU | BPF_AND | BPF_X:	/* A &= X */
412 				emit_alu_X(AND);
413 				break;
414 			case BPF_ALU | BPF_AND | BPF_K:	/* A &= K */
415 				emit_alu_K(AND, K);
416 				break;
417 			case BPF_ALU | BPF_OR | BPF_X:	/* A |= X */
418 				emit_alu_X(OR);
419 				break;
420 			case BPF_ALU | BPF_OR | BPF_K:	/* A |= K */
421 				emit_alu_K(OR, K);
422 				break;
423 			case BPF_ANC | SKF_AD_ALU_XOR_X: /* A ^= X; */
424 			case BPF_ALU | BPF_XOR | BPF_X:
425 				emit_alu_X(XOR);
426 				break;
427 			case BPF_ALU | BPF_XOR | BPF_K:	/* A ^= K */
428 				emit_alu_K(XOR, K);
429 				break;
430 			case BPF_ALU | BPF_LSH | BPF_X:	/* A <<= X */
431 				emit_alu_X(SLL);
432 				break;
433 			case BPF_ALU | BPF_LSH | BPF_K:	/* A <<= K */
434 				emit_alu_K(SLL, K);
435 				break;
436 			case BPF_ALU | BPF_RSH | BPF_X:	/* A >>= X */
437 				emit_alu_X(SRL);
438 				break;
439 			case BPF_ALU | BPF_RSH | BPF_K:	/* A >>= K */
440 				emit_alu_K(SRL, K);
441 				break;
442 			case BPF_ALU | BPF_MUL | BPF_X:	/* A *= X; */
443 				emit_alu_X(MUL);
444 				break;
445 			case BPF_ALU | BPF_MUL | BPF_K:	/* A *= K */
446 				emit_alu_K(MUL, K);
447 				break;
448 			case BPF_ALU | BPF_DIV | BPF_K:	/* A /= K with K != 0*/
449 				if (K == 1)
450 					break;
451 				emit_write_y(G0);
452 				/* The Sparc v8 architecture requires
453 				 * three instructions between a %y
454 				 * register write and the first use.
455 				 */
456 				emit_nop();
457 				emit_nop();
458 				emit_nop();
459 				emit_alu_K(DIV, K);
460 				break;
461 			case BPF_ALU | BPF_DIV | BPF_X:	/* A /= X; */
462 				emit_cmpi(r_X, 0);
463 				if (pc_ret0 > 0) {
464 					t_offset = addrs[pc_ret0 - 1];
465 					emit_branch(BE, t_offset + 20);
466 					emit_nop(); /* delay slot */
467 				} else {
468 					emit_branch_off(BNE, 16);
469 					emit_nop();
470 					emit_jump(cleanup_addr + 20);
471 					emit_clear(r_A);
472 				}
473 				emit_write_y(G0);
474 				/* The Sparc v8 architecture requires
475 				 * three instructions between a %y
476 				 * register write and the first use.
477 				 */
478 				emit_nop();
479 				emit_nop();
480 				emit_nop();
481 				emit_alu_X(DIV);
482 				break;
483 			case BPF_ALU | BPF_NEG:
484 				emit_neg();
485 				break;
486 			case BPF_RET | BPF_K:
487 				if (!K) {
488 					if (pc_ret0 == -1)
489 						pc_ret0 = i;
490 					emit_clear(r_A);
491 				} else {
492 					emit_loadimm(K, r_A);
493 				}
494 				fallthrough;
495 			case BPF_RET | BPF_A:
496 				if (seen_or_pass0) {
497 					if (i != flen - 1) {
498 						emit_jump(cleanup_addr);
499 						emit_nop();
500 						break;
501 					}
502 					if (seen_or_pass0 & SEEN_MEM) {
503 						unsigned int sz = BASE_STACKFRAME;
504 						sz += BPF_MEMWORDS * sizeof(u32);
505 						emit_release_stack(sz);
506 					}
507 				}
508 				/* jmpl %r_saved_O7 + 8, %g0 */
509 				emit_jmpl(r_saved_O7, 8, G0);
510 				emit_reg_move(r_A, O0); /* delay slot */
511 				break;
512 			case BPF_MISC | BPF_TAX:
513 				seen |= SEEN_XREG;
514 				emit_reg_move(r_A, r_X);
515 				break;
516 			case BPF_MISC | BPF_TXA:
517 				seen |= SEEN_XREG;
518 				emit_reg_move(r_X, r_A);
519 				break;
520 			case BPF_ANC | SKF_AD_CPU:
521 				emit_load_cpu(r_A);
522 				break;
523 			case BPF_ANC | SKF_AD_PROTOCOL:
524 				emit_skb_load16(protocol, r_A);
525 				break;
526 			case BPF_ANC | SKF_AD_PKTTYPE:
527 				__emit_skb_load8(__pkt_type_offset, r_A);
528 				emit_andi(r_A, PKT_TYPE_MAX, r_A);
529 				emit_alu_K(SRL, 5);
530 				break;
531 			case BPF_ANC | SKF_AD_IFINDEX:
532 				emit_skb_loadptr(dev, r_A);
533 				emit_cmpi(r_A, 0);
534 				emit_branch(BE_PTR, cleanup_addr + 4);
535 				emit_nop();
536 				emit_load32(r_A, struct net_device, ifindex, r_A);
537 				break;
538 			case BPF_ANC | SKF_AD_MARK:
539 				emit_skb_load32(mark, r_A);
540 				break;
541 			case BPF_ANC | SKF_AD_QUEUE:
542 				emit_skb_load16(queue_mapping, r_A);
543 				break;
544 			case BPF_ANC | SKF_AD_HATYPE:
545 				emit_skb_loadptr(dev, r_A);
546 				emit_cmpi(r_A, 0);
547 				emit_branch(BE_PTR, cleanup_addr + 4);
548 				emit_nop();
549 				emit_load16(r_A, struct net_device, type, r_A);
550 				break;
551 			case BPF_ANC | SKF_AD_RXHASH:
552 				emit_skb_load32(hash, r_A);
553 				break;
554 			case BPF_ANC | SKF_AD_VLAN_TAG:
555 				emit_skb_load16(vlan_tci, r_A);
556 				break;
557 			case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT:
558 				emit_skb_load32(vlan_all, r_A);
559 				emit_cmpi(r_A, 0);
560 				emit_branch_off(BE, 12);
561 				emit_nop();
562 				emit_loadimm(1, r_A);
563 				break;
564 			case BPF_LD | BPF_W | BPF_LEN:
565 				emit_skb_load32(len, r_A);
566 				break;
567 			case BPF_LDX | BPF_W | BPF_LEN:
568 				emit_skb_load32(len, r_X);
569 				break;
570 			case BPF_LD | BPF_IMM:
571 				emit_loadimm(K, r_A);
572 				break;
573 			case BPF_LDX | BPF_IMM:
574 				emit_loadimm(K, r_X);
575 				break;
576 			case BPF_LD | BPF_MEM:
577 				seen |= SEEN_MEM;
578 				emit_ldmem(K * 4, r_A);
579 				break;
580 			case BPF_LDX | BPF_MEM:
581 				seen |= SEEN_MEM | SEEN_XREG;
582 				emit_ldmem(K * 4, r_X);
583 				break;
584 			case BPF_ST:
585 				seen |= SEEN_MEM;
586 				emit_stmem(K * 4, r_A);
587 				break;
588 			case BPF_STX:
589 				seen |= SEEN_MEM | SEEN_XREG;
590 				emit_stmem(K * 4, r_X);
591 				break;
592 
593 #define CHOOSE_LOAD_FUNC(K, func) \
594 	((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
595 
596 			case BPF_LD | BPF_W | BPF_ABS:
597 				func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_word);
598 common_load:			seen |= SEEN_DATAREF;
599 				emit_loadimm(K, r_OFF);
600 				emit_call(func);
601 				break;
602 			case BPF_LD | BPF_H | BPF_ABS:
603 				func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_half);
604 				goto common_load;
605 			case BPF_LD | BPF_B | BPF_ABS:
606 				func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte);
607 				goto common_load;
608 			case BPF_LDX | BPF_B | BPF_MSH:
609 				func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte_msh);
610 				goto common_load;
611 			case BPF_LD | BPF_W | BPF_IND:
612 				func = bpf_jit_load_word;
613 common_load_ind:		seen |= SEEN_DATAREF | SEEN_XREG;
614 				if (K) {
615 					if (is_simm13(K)) {
616 						emit_addi(r_X, K, r_OFF);
617 					} else {
618 						emit_loadimm(K, r_TMP);
619 						emit_add(r_X, r_TMP, r_OFF);
620 					}
621 				} else {
622 					emit_reg_move(r_X, r_OFF);
623 				}
624 				emit_call(func);
625 				break;
626 			case BPF_LD | BPF_H | BPF_IND:
627 				func = bpf_jit_load_half;
628 				goto common_load_ind;
629 			case BPF_LD | BPF_B | BPF_IND:
630 				func = bpf_jit_load_byte;
631 				goto common_load_ind;
632 			case BPF_JMP | BPF_JA:
633 				emit_jump(addrs[i + K]);
634 				emit_nop();
635 				break;
636 
637 #define COND_SEL(CODE, TOP, FOP)	\
638 	case CODE:			\
639 		t_op = TOP;		\
640 		f_op = FOP;		\
641 		goto cond_branch
642 
643 			COND_SEL(BPF_JMP | BPF_JGT | BPF_K, BGU, BLEU);
644 			COND_SEL(BPF_JMP | BPF_JGE | BPF_K, BGEU, BLU);
645 			COND_SEL(BPF_JMP | BPF_JEQ | BPF_K, BE, BNE);
646 			COND_SEL(BPF_JMP | BPF_JSET | BPF_K, BNE, BE);
647 			COND_SEL(BPF_JMP | BPF_JGT | BPF_X, BGU, BLEU);
648 			COND_SEL(BPF_JMP | BPF_JGE | BPF_X, BGEU, BLU);
649 			COND_SEL(BPF_JMP | BPF_JEQ | BPF_X, BE, BNE);
650 			COND_SEL(BPF_JMP | BPF_JSET | BPF_X, BNE, BE);
651 
652 cond_branch:			f_offset = addrs[i + filter[i].jf];
653 				t_offset = addrs[i + filter[i].jt];
654 
655 				/* same targets, can avoid doing the test :) */
656 				if (filter[i].jt == filter[i].jf) {
657 					emit_jump(t_offset);
658 					emit_nop();
659 					break;
660 				}
661 
662 				switch (code) {
663 				case BPF_JMP | BPF_JGT | BPF_X:
664 				case BPF_JMP | BPF_JGE | BPF_X:
665 				case BPF_JMP | BPF_JEQ | BPF_X:
666 					seen |= SEEN_XREG;
667 					emit_cmp(r_A, r_X);
668 					break;
669 				case BPF_JMP | BPF_JSET | BPF_X:
670 					seen |= SEEN_XREG;
671 					emit_btst(r_A, r_X);
672 					break;
673 				case BPF_JMP | BPF_JEQ | BPF_K:
674 				case BPF_JMP | BPF_JGT | BPF_K:
675 				case BPF_JMP | BPF_JGE | BPF_K:
676 					if (is_simm13(K)) {
677 						emit_cmpi(r_A, K);
678 					} else {
679 						emit_loadimm(K, r_TMP);
680 						emit_cmp(r_A, r_TMP);
681 					}
682 					break;
683 				case BPF_JMP | BPF_JSET | BPF_K:
684 					if (is_simm13(K)) {
685 						emit_btsti(r_A, K);
686 					} else {
687 						emit_loadimm(K, r_TMP);
688 						emit_btst(r_A, r_TMP);
689 					}
690 					break;
691 				}
692 				if (filter[i].jt != 0) {
693 					if (filter[i].jf)
694 						t_offset += 8;
695 					emit_branch(t_op, t_offset);
696 					emit_nop(); /* delay slot */
697 					if (filter[i].jf) {
698 						emit_jump(f_offset);
699 						emit_nop();
700 					}
701 					break;
702 				}
703 				emit_branch(f_op, f_offset);
704 				emit_nop(); /* delay slot */
705 				break;
706 
707 			default:
708 				/* hmm, too complex filter, give up with jit compiler */
709 				goto out;
710 			}
711 			ilen = (void *) prog - (void *) temp;
712 			if (image) {
713 				if (unlikely(proglen + ilen > oldproglen)) {
714 					pr_err("bpb_jit_compile fatal error\n");
715 					kfree(addrs);
716 					module_memfree(image);
717 					return;
718 				}
719 				memcpy(image + proglen, temp, ilen);
720 			}
721 			proglen += ilen;
722 			addrs[i] = proglen;
723 			prog = temp;
724 		}
725 		/* last bpf instruction is always a RET :
726 		 * use it to give the cleanup instruction(s) addr
727 		 */
728 		cleanup_addr = proglen - 8; /* jmpl; mov r_A,%o0; */
729 		if (seen_or_pass0 & SEEN_MEM)
730 			cleanup_addr -= 4; /* add %sp, X, %sp; */
731 
732 		if (image) {
733 			if (proglen != oldproglen)
734 				pr_err("bpb_jit_compile proglen=%u != oldproglen=%u\n",
735 				       proglen, oldproglen);
736 			break;
737 		}
738 		if (proglen == oldproglen) {
739 			image = module_alloc(proglen);
740 			if (!image)
741 				goto out;
742 		}
743 		oldproglen = proglen;
744 	}
745 
746 	if (bpf_jit_enable > 1)
747 		bpf_jit_dump(flen, proglen, pass + 1, image);
748 
749 	if (image) {
750 		fp->bpf_func = (void *)image;
751 		fp->jited = 1;
752 	}
753 out:
754 	kfree(addrs);
755 	return;
756 }
757 
bpf_jit_free(struct bpf_prog * fp)758 void bpf_jit_free(struct bpf_prog *fp)
759 {
760 	if (fp->jited)
761 		module_memfree(fp->bpf_func);
762 
763 	bpf_prog_unlock_free(fp);
764 }
765