xref: /openbmc/linux/arch/s390/net/bpf_jit_comp.c (revision b03afaa8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * BPF Jit compiler for s390.
4  *
5  * Minimum build requirements:
6  *
7  *  - HAVE_MARCH_Z196_FEATURES: laal, laalg
8  *  - HAVE_MARCH_Z10_FEATURES: msfi, cgrj, clgrj
9  *  - HAVE_MARCH_Z9_109_FEATURES: alfi, llilf, clfi, oilf, nilf
10  *  - PACK_STACK
11  *  - 64BIT
12  *
13  * Copyright IBM Corp. 2012,2015
14  *
15  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
16  *	      Michael Holzheu <holzheu@linux.vnet.ibm.com>
17  */
18 
19 #define KMSG_COMPONENT "bpf_jit"
20 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
21 
22 #include <linux/netdevice.h>
23 #include <linux/filter.h>
24 #include <linux/init.h>
25 #include <linux/bpf.h>
26 #include <linux/mm.h>
27 #include <linux/kernel.h>
28 #include <asm/cacheflush.h>
29 #include <asm/dis.h>
30 #include <asm/facility.h>
31 #include <asm/nospec-branch.h>
32 #include <asm/set_memory.h>
33 #include "bpf_jit.h"
34 
35 struct bpf_jit {
36 	u32 seen;		/* Flags to remember seen eBPF instructions */
37 	u32 seen_reg[16];	/* Array to remember which registers are used */
38 	u32 *addrs;		/* Array with relative instruction addresses */
39 	u8 *prg_buf;		/* Start of program */
40 	int size;		/* Size of program and literal pool */
41 	int size_prg;		/* Size of program */
42 	int prg;		/* Current position in program */
43 	int lit32_start;	/* Start of 32-bit literal pool */
44 	int lit32;		/* Current position in 32-bit literal pool */
45 	int lit64_start;	/* Start of 64-bit literal pool */
46 	int lit64;		/* Current position in 64-bit literal pool */
47 	int base_ip;		/* Base address for literal pool */
48 	int exit_ip;		/* Address of exit */
49 	int r1_thunk_ip;	/* Address of expoline thunk for 'br %r1' */
50 	int r14_thunk_ip;	/* Address of expoline thunk for 'br %r14' */
51 	int tail_call_start;	/* Tail call start offset */
52 	int labels[1];		/* Labels for local jumps */
53 };
54 
55 #define SEEN_MEM	BIT(0)		/* use mem[] for temporary storage */
56 #define SEEN_LITERAL	BIT(1)		/* code uses literals */
57 #define SEEN_FUNC	BIT(2)		/* calls C functions */
58 #define SEEN_TAIL_CALL	BIT(3)		/* code uses tail calls */
59 #define SEEN_STACK	(SEEN_FUNC | SEEN_MEM)
60 
61 /*
62  * s390 registers
63  */
64 #define REG_W0		(MAX_BPF_JIT_REG + 0)	/* Work register 1 (even) */
65 #define REG_W1		(MAX_BPF_JIT_REG + 1)	/* Work register 2 (odd) */
66 #define REG_L		(MAX_BPF_JIT_REG + 2)	/* Literal pool register */
67 #define REG_15		(MAX_BPF_JIT_REG + 3)	/* Register 15 */
68 #define REG_0		REG_W0			/* Register 0 */
69 #define REG_1		REG_W1			/* Register 1 */
70 #define REG_2		BPF_REG_1		/* Register 2 */
71 #define REG_14		BPF_REG_0		/* Register 14 */
72 
73 /*
74  * Mapping of BPF registers to s390 registers
75  */
76 static const int reg2hex[] = {
77 	/* Return code */
78 	[BPF_REG_0]	= 14,
79 	/* Function parameters */
80 	[BPF_REG_1]	= 2,
81 	[BPF_REG_2]	= 3,
82 	[BPF_REG_3]	= 4,
83 	[BPF_REG_4]	= 5,
84 	[BPF_REG_5]	= 6,
85 	/* Call saved registers */
86 	[BPF_REG_6]	= 7,
87 	[BPF_REG_7]	= 8,
88 	[BPF_REG_8]	= 9,
89 	[BPF_REG_9]	= 10,
90 	/* BPF stack pointer */
91 	[BPF_REG_FP]	= 13,
92 	/* Register for blinding */
93 	[BPF_REG_AX]	= 12,
94 	/* Work registers for s390x backend */
95 	[REG_W0]	= 0,
96 	[REG_W1]	= 1,
97 	[REG_L]		= 11,
98 	[REG_15]	= 15,
99 };
100 
101 static inline u32 reg(u32 dst_reg, u32 src_reg)
102 {
103 	return reg2hex[dst_reg] << 4 | reg2hex[src_reg];
104 }
105 
106 static inline u32 reg_high(u32 reg)
107 {
108 	return reg2hex[reg] << 4;
109 }
110 
111 static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
112 {
113 	u32 r1 = reg2hex[b1];
114 
115 	if (!jit->seen_reg[r1] && r1 >= 6 && r1 <= 15)
116 		jit->seen_reg[r1] = 1;
117 }
118 
119 #define REG_SET_SEEN(b1)					\
120 ({								\
121 	reg_set_seen(jit, b1);					\
122 })
123 
124 #define REG_SEEN(b1) jit->seen_reg[reg2hex[(b1)]]
125 
126 /*
127  * EMIT macros for code generation
128  */
129 
130 #define _EMIT2(op)						\
131 ({								\
132 	if (jit->prg_buf)					\
133 		*(u16 *) (jit->prg_buf + jit->prg) = (op);	\
134 	jit->prg += 2;						\
135 })
136 
137 #define EMIT2(op, b1, b2)					\
138 ({								\
139 	_EMIT2((op) | reg(b1, b2));				\
140 	REG_SET_SEEN(b1);					\
141 	REG_SET_SEEN(b2);					\
142 })
143 
144 #define _EMIT4(op)						\
145 ({								\
146 	if (jit->prg_buf)					\
147 		*(u32 *) (jit->prg_buf + jit->prg) = (op);	\
148 	jit->prg += 4;						\
149 })
150 
151 #define EMIT4(op, b1, b2)					\
152 ({								\
153 	_EMIT4((op) | reg(b1, b2));				\
154 	REG_SET_SEEN(b1);					\
155 	REG_SET_SEEN(b2);					\
156 })
157 
158 #define EMIT4_RRF(op, b1, b2, b3)				\
159 ({								\
160 	_EMIT4((op) | reg_high(b3) << 8 | reg(b1, b2));		\
161 	REG_SET_SEEN(b1);					\
162 	REG_SET_SEEN(b2);					\
163 	REG_SET_SEEN(b3);					\
164 })
165 
166 #define _EMIT4_DISP(op, disp)					\
167 ({								\
168 	unsigned int __disp = (disp) & 0xfff;			\
169 	_EMIT4((op) | __disp);					\
170 })
171 
172 #define EMIT4_DISP(op, b1, b2, disp)				\
173 ({								\
174 	_EMIT4_DISP((op) | reg_high(b1) << 16 |			\
175 		    reg_high(b2) << 8, (disp));			\
176 	REG_SET_SEEN(b1);					\
177 	REG_SET_SEEN(b2);					\
178 })
179 
180 #define EMIT4_IMM(op, b1, imm)					\
181 ({								\
182 	unsigned int __imm = (imm) & 0xffff;			\
183 	_EMIT4((op) | reg_high(b1) << 16 | __imm);		\
184 	REG_SET_SEEN(b1);					\
185 })
186 
187 #define EMIT4_PCREL(op, pcrel)					\
188 ({								\
189 	long __pcrel = ((pcrel) >> 1) & 0xffff;			\
190 	_EMIT4((op) | __pcrel);					\
191 })
192 
193 #define EMIT4_PCREL_RIC(op, mask, target)			\
194 ({								\
195 	int __rel = ((target) - jit->prg) / 2;			\
196 	_EMIT4((op) | (mask) << 20 | (__rel & 0xffff));		\
197 })
198 
199 #define _EMIT6(op1, op2)					\
200 ({								\
201 	if (jit->prg_buf) {					\
202 		*(u32 *) (jit->prg_buf + jit->prg) = (op1);	\
203 		*(u16 *) (jit->prg_buf + jit->prg + 4) = (op2);	\
204 	}							\
205 	jit->prg += 6;						\
206 })
207 
208 #define _EMIT6_DISP(op1, op2, disp)				\
209 ({								\
210 	unsigned int __disp = (disp) & 0xfff;			\
211 	_EMIT6((op1) | __disp, op2);				\
212 })
213 
214 #define _EMIT6_DISP_LH(op1, op2, disp)				\
215 ({								\
216 	u32 _disp = (u32) (disp);				\
217 	unsigned int __disp_h = _disp & 0xff000;		\
218 	unsigned int __disp_l = _disp & 0x00fff;		\
219 	_EMIT6((op1) | __disp_l, (op2) | __disp_h >> 4);	\
220 })
221 
222 #define EMIT6_DISP_LH(op1, op2, b1, b2, b3, disp)		\
223 ({								\
224 	_EMIT6_DISP_LH((op1) | reg(b1, b2) << 16 |		\
225 		       reg_high(b3) << 8, op2, disp);		\
226 	REG_SET_SEEN(b1);					\
227 	REG_SET_SEEN(b2);					\
228 	REG_SET_SEEN(b3);					\
229 })
230 
231 #define EMIT6_PCREL_LABEL(op1, op2, b1, b2, label, mask)	\
232 ({								\
233 	int rel = (jit->labels[label] - jit->prg) >> 1;		\
234 	_EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff),	\
235 	       (op2) | (mask) << 12);				\
236 	REG_SET_SEEN(b1);					\
237 	REG_SET_SEEN(b2);					\
238 })
239 
240 #define EMIT6_PCREL_IMM_LABEL(op1, op2, b1, imm, label, mask)	\
241 ({								\
242 	int rel = (jit->labels[label] - jit->prg) >> 1;		\
243 	_EMIT6((op1) | (reg_high(b1) | (mask)) << 16 |		\
244 		(rel & 0xffff), (op2) | ((imm) & 0xff) << 8);	\
245 	REG_SET_SEEN(b1);					\
246 	BUILD_BUG_ON(((unsigned long) (imm)) > 0xff);		\
247 })
248 
249 #define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask)		\
250 ({								\
251 	/* Branch instruction needs 6 bytes */			\
252 	int rel = (addrs[(i) + (off) + 1] - (addrs[(i) + 1] - 6)) / 2;\
253 	_EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), (op2) | (mask));\
254 	REG_SET_SEEN(b1);					\
255 	REG_SET_SEEN(b2);					\
256 })
257 
258 #define EMIT6_PCREL_RILB(op, b, target)				\
259 ({								\
260 	unsigned int rel = (int)((target) - jit->prg) / 2;	\
261 	_EMIT6((op) | reg_high(b) << 16 | rel >> 16, rel & 0xffff);\
262 	REG_SET_SEEN(b);					\
263 })
264 
265 #define EMIT6_PCREL_RIL(op, target)				\
266 ({								\
267 	unsigned int rel = (int)((target) - jit->prg) / 2;	\
268 	_EMIT6((op) | rel >> 16, rel & 0xffff);			\
269 })
270 
271 #define EMIT6_PCREL_RILC(op, mask, target)			\
272 ({								\
273 	EMIT6_PCREL_RIL((op) | (mask) << 20, (target));		\
274 })
275 
276 #define _EMIT6_IMM(op, imm)					\
277 ({								\
278 	unsigned int __imm = (imm);				\
279 	_EMIT6((op) | (__imm >> 16), __imm & 0xffff);		\
280 })
281 
282 #define EMIT6_IMM(op, b1, imm)					\
283 ({								\
284 	_EMIT6_IMM((op) | reg_high(b1) << 16, imm);		\
285 	REG_SET_SEEN(b1);					\
286 })
287 
288 #define _EMIT_CONST_U32(val)					\
289 ({								\
290 	unsigned int ret;					\
291 	ret = jit->lit32;					\
292 	if (jit->prg_buf)					\
293 		*(u32 *)(jit->prg_buf + jit->lit32) = (u32)(val);\
294 	jit->lit32 += 4;					\
295 	ret;							\
296 })
297 
298 #define EMIT_CONST_U32(val)					\
299 ({								\
300 	jit->seen |= SEEN_LITERAL;				\
301 	_EMIT_CONST_U32(val) - jit->base_ip;			\
302 })
303 
304 #define _EMIT_CONST_U64(val)					\
305 ({								\
306 	unsigned int ret;					\
307 	ret = jit->lit64;					\
308 	if (jit->prg_buf)					\
309 		*(u64 *)(jit->prg_buf + jit->lit64) = (u64)(val);\
310 	jit->lit64 += 8;					\
311 	ret;							\
312 })
313 
314 #define EMIT_CONST_U64(val)					\
315 ({								\
316 	jit->seen |= SEEN_LITERAL;				\
317 	_EMIT_CONST_U64(val) - jit->base_ip;			\
318 })
319 
320 #define EMIT_ZERO(b1)						\
321 ({								\
322 	if (!fp->aux->verifier_zext) {				\
323 		/* llgfr %dst,%dst (zero extend to 64 bit) */	\
324 		EMIT4(0xb9160000, b1, b1);			\
325 		REG_SET_SEEN(b1);				\
326 	}							\
327 })
328 
329 /*
330  * Return whether this is the first pass. The first pass is special, since we
331  * don't know any sizes yet, and thus must be conservative.
332  */
333 static bool is_first_pass(struct bpf_jit *jit)
334 {
335 	return jit->size == 0;
336 }
337 
338 /*
339  * Return whether this is the code generation pass. The code generation pass is
340  * special, since we should change as little as possible.
341  */
342 static bool is_codegen_pass(struct bpf_jit *jit)
343 {
344 	return jit->prg_buf;
345 }
346 
347 /*
348  * Return whether "rel" can be encoded as a short PC-relative offset
349  */
350 static bool is_valid_rel(int rel)
351 {
352 	return rel >= -65536 && rel <= 65534;
353 }
354 
355 /*
356  * Return whether "off" can be reached using a short PC-relative offset
357  */
358 static bool can_use_rel(struct bpf_jit *jit, int off)
359 {
360 	return is_valid_rel(off - jit->prg);
361 }
362 
363 /*
364  * Return whether given displacement can be encoded using
365  * Long-Displacement Facility
366  */
367 static bool is_valid_ldisp(int disp)
368 {
369 	return disp >= -524288 && disp <= 524287;
370 }
371 
372 /*
373  * Return whether the next 32-bit literal pool entry can be referenced using
374  * Long-Displacement Facility
375  */
376 static bool can_use_ldisp_for_lit32(struct bpf_jit *jit)
377 {
378 	return is_valid_ldisp(jit->lit32 - jit->base_ip);
379 }
380 
381 /*
382  * Return whether the next 64-bit literal pool entry can be referenced using
383  * Long-Displacement Facility
384  */
385 static bool can_use_ldisp_for_lit64(struct bpf_jit *jit)
386 {
387 	return is_valid_ldisp(jit->lit64 - jit->base_ip);
388 }
389 
390 /*
391  * Fill whole space with illegal instructions
392  */
393 static void jit_fill_hole(void *area, unsigned int size)
394 {
395 	memset(area, 0, size);
396 }
397 
398 /*
399  * Save registers from "rs" (register start) to "re" (register end) on stack
400  */
401 static void save_regs(struct bpf_jit *jit, u32 rs, u32 re)
402 {
403 	u32 off = STK_OFF_R6 + (rs - 6) * 8;
404 
405 	if (rs == re)
406 		/* stg %rs,off(%r15) */
407 		_EMIT6(0xe300f000 | rs << 20 | off, 0x0024);
408 	else
409 		/* stmg %rs,%re,off(%r15) */
410 		_EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0024, off);
411 }
412 
413 /*
414  * Restore registers from "rs" (register start) to "re" (register end) on stack
415  */
416 static void restore_regs(struct bpf_jit *jit, u32 rs, u32 re, u32 stack_depth)
417 {
418 	u32 off = STK_OFF_R6 + (rs - 6) * 8;
419 
420 	if (jit->seen & SEEN_STACK)
421 		off += STK_OFF + stack_depth;
422 
423 	if (rs == re)
424 		/* lg %rs,off(%r15) */
425 		_EMIT6(0xe300f000 | rs << 20 | off, 0x0004);
426 	else
427 		/* lmg %rs,%re,off(%r15) */
428 		_EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0004, off);
429 }
430 
431 /*
432  * Return first seen register (from start)
433  */
434 static int get_start(struct bpf_jit *jit, int start)
435 {
436 	int i;
437 
438 	for (i = start; i <= 15; i++) {
439 		if (jit->seen_reg[i])
440 			return i;
441 	}
442 	return 0;
443 }
444 
445 /*
446  * Return last seen register (from start) (gap >= 2)
447  */
448 static int get_end(struct bpf_jit *jit, int start)
449 {
450 	int i;
451 
452 	for (i = start; i < 15; i++) {
453 		if (!jit->seen_reg[i] && !jit->seen_reg[i + 1])
454 			return i - 1;
455 	}
456 	return jit->seen_reg[15] ? 15 : 14;
457 }
458 
459 #define REGS_SAVE	1
460 #define REGS_RESTORE	0
461 /*
462  * Save and restore clobbered registers (6-15) on stack.
463  * We save/restore registers in chunks with gap >= 2 registers.
464  */
465 static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth)
466 {
467 	const int last = 15, save_restore_size = 6;
468 	int re = 6, rs;
469 
470 	if (is_first_pass(jit)) {
471 		/*
472 		 * We don't know yet which registers are used. Reserve space
473 		 * conservatively.
474 		 */
475 		jit->prg += (last - re + 1) * save_restore_size;
476 		return;
477 	}
478 
479 	do {
480 		rs = get_start(jit, re);
481 		if (!rs)
482 			break;
483 		re = get_end(jit, rs + 1);
484 		if (op == REGS_SAVE)
485 			save_regs(jit, rs, re);
486 		else
487 			restore_regs(jit, rs, re, stack_depth);
488 		re++;
489 	} while (re <= last);
490 }
491 
492 static void bpf_skip(struct bpf_jit *jit, int size)
493 {
494 	if (size >= 6 && !is_valid_rel(size)) {
495 		/* brcl 0xf,size */
496 		EMIT6_PCREL_RIL(0xc0f4000000, size);
497 		size -= 6;
498 	} else if (size >= 4 && is_valid_rel(size)) {
499 		/* brc 0xf,size */
500 		EMIT4_PCREL(0xa7f40000, size);
501 		size -= 4;
502 	}
503 	while (size >= 2) {
504 		/* bcr 0,%0 */
505 		_EMIT2(0x0700);
506 		size -= 2;
507 	}
508 }
509 
510 /*
511  * Emit function prologue
512  *
513  * Save registers and create stack frame if necessary.
514  * See stack frame layout desription in "bpf_jit.h"!
515  */
516 static void bpf_jit_prologue(struct bpf_jit *jit, u32 stack_depth)
517 {
518 	if (jit->seen & SEEN_TAIL_CALL) {
519 		/* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */
520 		_EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT);
521 	} else {
522 		/*
523 		 * There are no tail calls. Insert nops in order to have
524 		 * tail_call_start at a predictable offset.
525 		 */
526 		bpf_skip(jit, 6);
527 	}
528 	/* Tail calls have to skip above initialization */
529 	jit->tail_call_start = jit->prg;
530 	/* Save registers */
531 	save_restore_regs(jit, REGS_SAVE, stack_depth);
532 	/* Setup literal pool */
533 	if (is_first_pass(jit) || (jit->seen & SEEN_LITERAL)) {
534 		if (!is_first_pass(jit) &&
535 		    is_valid_ldisp(jit->size - (jit->prg + 2))) {
536 			/* basr %l,0 */
537 			EMIT2(0x0d00, REG_L, REG_0);
538 			jit->base_ip = jit->prg;
539 		} else {
540 			/* larl %l,lit32_start */
541 			EMIT6_PCREL_RILB(0xc0000000, REG_L, jit->lit32_start);
542 			jit->base_ip = jit->lit32_start;
543 		}
544 	}
545 	/* Setup stack and backchain */
546 	if (is_first_pass(jit) || (jit->seen & SEEN_STACK)) {
547 		if (is_first_pass(jit) || (jit->seen & SEEN_FUNC))
548 			/* lgr %w1,%r15 (backchain) */
549 			EMIT4(0xb9040000, REG_W1, REG_15);
550 		/* la %bfp,STK_160_UNUSED(%r15) (BPF frame pointer) */
551 		EMIT4_DISP(0x41000000, BPF_REG_FP, REG_15, STK_160_UNUSED);
552 		/* aghi %r15,-STK_OFF */
553 		EMIT4_IMM(0xa70b0000, REG_15, -(STK_OFF + stack_depth));
554 		if (is_first_pass(jit) || (jit->seen & SEEN_FUNC))
555 			/* stg %w1,152(%r15) (backchain) */
556 			EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
557 				      REG_15, 152);
558 	}
559 }
560 
561 /*
562  * Function epilogue
563  */
564 static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
565 {
566 	jit->exit_ip = jit->prg;
567 	/* Load exit code: lgr %r2,%b0 */
568 	EMIT4(0xb9040000, REG_2, BPF_REG_0);
569 	/* Restore registers */
570 	save_restore_regs(jit, REGS_RESTORE, stack_depth);
571 	if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable) {
572 		jit->r14_thunk_ip = jit->prg;
573 		/* Generate __s390_indirect_jump_r14 thunk */
574 		if (test_facility(35)) {
575 			/* exrl %r0,.+10 */
576 			EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
577 		} else {
578 			/* larl %r1,.+14 */
579 			EMIT6_PCREL_RILB(0xc0000000, REG_1, jit->prg + 14);
580 			/* ex 0,0(%r1) */
581 			EMIT4_DISP(0x44000000, REG_0, REG_1, 0);
582 		}
583 		/* j . */
584 		EMIT4_PCREL(0xa7f40000, 0);
585 	}
586 	/* br %r14 */
587 	_EMIT2(0x07fe);
588 
589 	if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable &&
590 	    (is_first_pass(jit) || (jit->seen & SEEN_FUNC))) {
591 		jit->r1_thunk_ip = jit->prg;
592 		/* Generate __s390_indirect_jump_r1 thunk */
593 		if (test_facility(35)) {
594 			/* exrl %r0,.+10 */
595 			EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
596 			/* j . */
597 			EMIT4_PCREL(0xa7f40000, 0);
598 			/* br %r1 */
599 			_EMIT2(0x07f1);
600 		} else {
601 			/* ex 0,S390_lowcore.br_r1_tampoline */
602 			EMIT4_DISP(0x44000000, REG_0, REG_0,
603 				   offsetof(struct lowcore, br_r1_trampoline));
604 			/* j . */
605 			EMIT4_PCREL(0xa7f40000, 0);
606 		}
607 	}
608 }
609 
610 /*
611  * Compile one eBPF instruction into s390x code
612  *
613  * NOTE: Use noinline because for gcov (-fprofile-arcs) gcc allocates a lot of
614  * stack space for the large switch statement.
615  */
616 static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
617 				 int i, bool extra_pass, u32 stack_depth)
618 {
619 	struct bpf_insn *insn = &fp->insnsi[i];
620 	u32 dst_reg = insn->dst_reg;
621 	u32 src_reg = insn->src_reg;
622 	int last, insn_count = 1;
623 	u32 *addrs = jit->addrs;
624 	s32 imm = insn->imm;
625 	s16 off = insn->off;
626 	unsigned int mask;
627 
628 	switch (insn->code) {
629 	/*
630 	 * BPF_MOV
631 	 */
632 	case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */
633 		/* llgfr %dst,%src */
634 		EMIT4(0xb9160000, dst_reg, src_reg);
635 		if (insn_is_zext(&insn[1]))
636 			insn_count = 2;
637 		break;
638 	case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
639 		/* lgr %dst,%src */
640 		EMIT4(0xb9040000, dst_reg, src_reg);
641 		break;
642 	case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
643 		/* llilf %dst,imm */
644 		EMIT6_IMM(0xc00f0000, dst_reg, imm);
645 		if (insn_is_zext(&insn[1]))
646 			insn_count = 2;
647 		break;
648 	case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */
649 		/* lgfi %dst,imm */
650 		EMIT6_IMM(0xc0010000, dst_reg, imm);
651 		break;
652 	/*
653 	 * BPF_LD 64
654 	 */
655 	case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
656 	{
657 		/* 16 byte instruction that uses two 'struct bpf_insn' */
658 		u64 imm64;
659 
660 		imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32;
661 		/* lgrl %dst,imm */
662 		EMIT6_PCREL_RILB(0xc4080000, dst_reg, _EMIT_CONST_U64(imm64));
663 		insn_count = 2;
664 		break;
665 	}
666 	/*
667 	 * BPF_ADD
668 	 */
669 	case BPF_ALU | BPF_ADD | BPF_X: /* dst = (u32) dst + (u32) src */
670 		/* ar %dst,%src */
671 		EMIT2(0x1a00, dst_reg, src_reg);
672 		EMIT_ZERO(dst_reg);
673 		break;
674 	case BPF_ALU64 | BPF_ADD | BPF_X: /* dst = dst + src */
675 		/* agr %dst,%src */
676 		EMIT4(0xb9080000, dst_reg, src_reg);
677 		break;
678 	case BPF_ALU | BPF_ADD | BPF_K: /* dst = (u32) dst + (u32) imm */
679 		if (!imm)
680 			break;
681 		/* alfi %dst,imm */
682 		EMIT6_IMM(0xc20b0000, dst_reg, imm);
683 		EMIT_ZERO(dst_reg);
684 		break;
685 	case BPF_ALU64 | BPF_ADD | BPF_K: /* dst = dst + imm */
686 		if (!imm)
687 			break;
688 		/* agfi %dst,imm */
689 		EMIT6_IMM(0xc2080000, dst_reg, imm);
690 		break;
691 	/*
692 	 * BPF_SUB
693 	 */
694 	case BPF_ALU | BPF_SUB | BPF_X: /* dst = (u32) dst - (u32) src */
695 		/* sr %dst,%src */
696 		EMIT2(0x1b00, dst_reg, src_reg);
697 		EMIT_ZERO(dst_reg);
698 		break;
699 	case BPF_ALU64 | BPF_SUB | BPF_X: /* dst = dst - src */
700 		/* sgr %dst,%src */
701 		EMIT4(0xb9090000, dst_reg, src_reg);
702 		break;
703 	case BPF_ALU | BPF_SUB | BPF_K: /* dst = (u32) dst - (u32) imm */
704 		if (!imm)
705 			break;
706 		/* alfi %dst,-imm */
707 		EMIT6_IMM(0xc20b0000, dst_reg, -imm);
708 		EMIT_ZERO(dst_reg);
709 		break;
710 	case BPF_ALU64 | BPF_SUB | BPF_K: /* dst = dst - imm */
711 		if (!imm)
712 			break;
713 		/* agfi %dst,-imm */
714 		EMIT6_IMM(0xc2080000, dst_reg, -imm);
715 		break;
716 	/*
717 	 * BPF_MUL
718 	 */
719 	case BPF_ALU | BPF_MUL | BPF_X: /* dst = (u32) dst * (u32) src */
720 		/* msr %dst,%src */
721 		EMIT4(0xb2520000, dst_reg, src_reg);
722 		EMIT_ZERO(dst_reg);
723 		break;
724 	case BPF_ALU64 | BPF_MUL | BPF_X: /* dst = dst * src */
725 		/* msgr %dst,%src */
726 		EMIT4(0xb90c0000, dst_reg, src_reg);
727 		break;
728 	case BPF_ALU | BPF_MUL | BPF_K: /* dst = (u32) dst * (u32) imm */
729 		if (imm == 1)
730 			break;
731 		/* msfi %r5,imm */
732 		EMIT6_IMM(0xc2010000, dst_reg, imm);
733 		EMIT_ZERO(dst_reg);
734 		break;
735 	case BPF_ALU64 | BPF_MUL | BPF_K: /* dst = dst * imm */
736 		if (imm == 1)
737 			break;
738 		/* msgfi %dst,imm */
739 		EMIT6_IMM(0xc2000000, dst_reg, imm);
740 		break;
741 	/*
742 	 * BPF_DIV / BPF_MOD
743 	 */
744 	case BPF_ALU | BPF_DIV | BPF_X: /* dst = (u32) dst / (u32) src */
745 	case BPF_ALU | BPF_MOD | BPF_X: /* dst = (u32) dst % (u32) src */
746 	{
747 		int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
748 
749 		/* lhi %w0,0 */
750 		EMIT4_IMM(0xa7080000, REG_W0, 0);
751 		/* lr %w1,%dst */
752 		EMIT2(0x1800, REG_W1, dst_reg);
753 		/* dlr %w0,%src */
754 		EMIT4(0xb9970000, REG_W0, src_reg);
755 		/* llgfr %dst,%rc */
756 		EMIT4(0xb9160000, dst_reg, rc_reg);
757 		if (insn_is_zext(&insn[1]))
758 			insn_count = 2;
759 		break;
760 	}
761 	case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */
762 	case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % src */
763 	{
764 		int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
765 
766 		/* lghi %w0,0 */
767 		EMIT4_IMM(0xa7090000, REG_W0, 0);
768 		/* lgr %w1,%dst */
769 		EMIT4(0xb9040000, REG_W1, dst_reg);
770 		/* dlgr %w0,%dst */
771 		EMIT4(0xb9870000, REG_W0, src_reg);
772 		/* lgr %dst,%rc */
773 		EMIT4(0xb9040000, dst_reg, rc_reg);
774 		break;
775 	}
776 	case BPF_ALU | BPF_DIV | BPF_K: /* dst = (u32) dst / (u32) imm */
777 	case BPF_ALU | BPF_MOD | BPF_K: /* dst = (u32) dst % (u32) imm */
778 	{
779 		int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
780 
781 		if (imm == 1) {
782 			if (BPF_OP(insn->code) == BPF_MOD)
783 				/* lhgi %dst,0 */
784 				EMIT4_IMM(0xa7090000, dst_reg, 0);
785 			break;
786 		}
787 		/* lhi %w0,0 */
788 		EMIT4_IMM(0xa7080000, REG_W0, 0);
789 		/* lr %w1,%dst */
790 		EMIT2(0x1800, REG_W1, dst_reg);
791 		if (!is_first_pass(jit) && can_use_ldisp_for_lit32(jit)) {
792 			/* dl %w0,<d(imm)>(%l) */
793 			EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0, REG_L,
794 				      EMIT_CONST_U32(imm));
795 		} else {
796 			/* lgfrl %dst,imm */
797 			EMIT6_PCREL_RILB(0xc40c0000, dst_reg,
798 					 _EMIT_CONST_U32(imm));
799 			jit->seen |= SEEN_LITERAL;
800 			/* dlr %w0,%dst */
801 			EMIT4(0xb9970000, REG_W0, dst_reg);
802 		}
803 		/* llgfr %dst,%rc */
804 		EMIT4(0xb9160000, dst_reg, rc_reg);
805 		if (insn_is_zext(&insn[1]))
806 			insn_count = 2;
807 		break;
808 	}
809 	case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */
810 	case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % imm */
811 	{
812 		int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
813 
814 		if (imm == 1) {
815 			if (BPF_OP(insn->code) == BPF_MOD)
816 				/* lhgi %dst,0 */
817 				EMIT4_IMM(0xa7090000, dst_reg, 0);
818 			break;
819 		}
820 		/* lghi %w0,0 */
821 		EMIT4_IMM(0xa7090000, REG_W0, 0);
822 		/* lgr %w1,%dst */
823 		EMIT4(0xb9040000, REG_W1, dst_reg);
824 		if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
825 			/* dlg %w0,<d(imm)>(%l) */
826 			EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L,
827 				      EMIT_CONST_U64(imm));
828 		} else {
829 			/* lgrl %dst,imm */
830 			EMIT6_PCREL_RILB(0xc4080000, dst_reg,
831 					 _EMIT_CONST_U64(imm));
832 			jit->seen |= SEEN_LITERAL;
833 			/* dlgr %w0,%dst */
834 			EMIT4(0xb9870000, REG_W0, dst_reg);
835 		}
836 		/* lgr %dst,%rc */
837 		EMIT4(0xb9040000, dst_reg, rc_reg);
838 		break;
839 	}
840 	/*
841 	 * BPF_AND
842 	 */
843 	case BPF_ALU | BPF_AND | BPF_X: /* dst = (u32) dst & (u32) src */
844 		/* nr %dst,%src */
845 		EMIT2(0x1400, dst_reg, src_reg);
846 		EMIT_ZERO(dst_reg);
847 		break;
848 	case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
849 		/* ngr %dst,%src */
850 		EMIT4(0xb9800000, dst_reg, src_reg);
851 		break;
852 	case BPF_ALU | BPF_AND | BPF_K: /* dst = (u32) dst & (u32) imm */
853 		/* nilf %dst,imm */
854 		EMIT6_IMM(0xc00b0000, dst_reg, imm);
855 		EMIT_ZERO(dst_reg);
856 		break;
857 	case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
858 		if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
859 			/* ng %dst,<d(imm)>(%l) */
860 			EMIT6_DISP_LH(0xe3000000, 0x0080,
861 				      dst_reg, REG_0, REG_L,
862 				      EMIT_CONST_U64(imm));
863 		} else {
864 			/* lgrl %w0,imm */
865 			EMIT6_PCREL_RILB(0xc4080000, REG_W0,
866 					 _EMIT_CONST_U64(imm));
867 			jit->seen |= SEEN_LITERAL;
868 			/* ngr %dst,%w0 */
869 			EMIT4(0xb9800000, dst_reg, REG_W0);
870 		}
871 		break;
872 	/*
873 	 * BPF_OR
874 	 */
875 	case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
876 		/* or %dst,%src */
877 		EMIT2(0x1600, dst_reg, src_reg);
878 		EMIT_ZERO(dst_reg);
879 		break;
880 	case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
881 		/* ogr %dst,%src */
882 		EMIT4(0xb9810000, dst_reg, src_reg);
883 		break;
884 	case BPF_ALU | BPF_OR | BPF_K: /* dst = (u32) dst | (u32) imm */
885 		/* oilf %dst,imm */
886 		EMIT6_IMM(0xc00d0000, dst_reg, imm);
887 		EMIT_ZERO(dst_reg);
888 		break;
889 	case BPF_ALU64 | BPF_OR | BPF_K: /* dst = dst | imm */
890 		if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
891 			/* og %dst,<d(imm)>(%l) */
892 			EMIT6_DISP_LH(0xe3000000, 0x0081,
893 				      dst_reg, REG_0, REG_L,
894 				      EMIT_CONST_U64(imm));
895 		} else {
896 			/* lgrl %w0,imm */
897 			EMIT6_PCREL_RILB(0xc4080000, REG_W0,
898 					 _EMIT_CONST_U64(imm));
899 			jit->seen |= SEEN_LITERAL;
900 			/* ogr %dst,%w0 */
901 			EMIT4(0xb9810000, dst_reg, REG_W0);
902 		}
903 		break;
904 	/*
905 	 * BPF_XOR
906 	 */
907 	case BPF_ALU | BPF_XOR | BPF_X: /* dst = (u32) dst ^ (u32) src */
908 		/* xr %dst,%src */
909 		EMIT2(0x1700, dst_reg, src_reg);
910 		EMIT_ZERO(dst_reg);
911 		break;
912 	case BPF_ALU64 | BPF_XOR | BPF_X: /* dst = dst ^ src */
913 		/* xgr %dst,%src */
914 		EMIT4(0xb9820000, dst_reg, src_reg);
915 		break;
916 	case BPF_ALU | BPF_XOR | BPF_K: /* dst = (u32) dst ^ (u32) imm */
917 		if (!imm)
918 			break;
919 		/* xilf %dst,imm */
920 		EMIT6_IMM(0xc0070000, dst_reg, imm);
921 		EMIT_ZERO(dst_reg);
922 		break;
923 	case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ imm */
924 		if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
925 			/* xg %dst,<d(imm)>(%l) */
926 			EMIT6_DISP_LH(0xe3000000, 0x0082,
927 				      dst_reg, REG_0, REG_L,
928 				      EMIT_CONST_U64(imm));
929 		} else {
930 			/* lgrl %w0,imm */
931 			EMIT6_PCREL_RILB(0xc4080000, REG_W0,
932 					 _EMIT_CONST_U64(imm));
933 			jit->seen |= SEEN_LITERAL;
934 			/* xgr %dst,%w0 */
935 			EMIT4(0xb9820000, dst_reg, REG_W0);
936 		}
937 		break;
938 	/*
939 	 * BPF_LSH
940 	 */
941 	case BPF_ALU | BPF_LSH | BPF_X: /* dst = (u32) dst << (u32) src */
942 		/* sll %dst,0(%src) */
943 		EMIT4_DISP(0x89000000, dst_reg, src_reg, 0);
944 		EMIT_ZERO(dst_reg);
945 		break;
946 	case BPF_ALU64 | BPF_LSH | BPF_X: /* dst = dst << src */
947 		/* sllg %dst,%dst,0(%src) */
948 		EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, src_reg, 0);
949 		break;
950 	case BPF_ALU | BPF_LSH | BPF_K: /* dst = (u32) dst << (u32) imm */
951 		if (imm == 0)
952 			break;
953 		/* sll %dst,imm(%r0) */
954 		EMIT4_DISP(0x89000000, dst_reg, REG_0, imm);
955 		EMIT_ZERO(dst_reg);
956 		break;
957 	case BPF_ALU64 | BPF_LSH | BPF_K: /* dst = dst << imm */
958 		if (imm == 0)
959 			break;
960 		/* sllg %dst,%dst,imm(%r0) */
961 		EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, REG_0, imm);
962 		break;
963 	/*
964 	 * BPF_RSH
965 	 */
966 	case BPF_ALU | BPF_RSH | BPF_X: /* dst = (u32) dst >> (u32) src */
967 		/* srl %dst,0(%src) */
968 		EMIT4_DISP(0x88000000, dst_reg, src_reg, 0);
969 		EMIT_ZERO(dst_reg);
970 		break;
971 	case BPF_ALU64 | BPF_RSH | BPF_X: /* dst = dst >> src */
972 		/* srlg %dst,%dst,0(%src) */
973 		EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, src_reg, 0);
974 		break;
975 	case BPF_ALU | BPF_RSH | BPF_K: /* dst = (u32) dst >> (u32) imm */
976 		if (imm == 0)
977 			break;
978 		/* srl %dst,imm(%r0) */
979 		EMIT4_DISP(0x88000000, dst_reg, REG_0, imm);
980 		EMIT_ZERO(dst_reg);
981 		break;
982 	case BPF_ALU64 | BPF_RSH | BPF_K: /* dst = dst >> imm */
983 		if (imm == 0)
984 			break;
985 		/* srlg %dst,%dst,imm(%r0) */
986 		EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, REG_0, imm);
987 		break;
988 	/*
989 	 * BPF_ARSH
990 	 */
991 	case BPF_ALU | BPF_ARSH | BPF_X: /* ((s32) dst) >>= src */
992 		/* sra %dst,%dst,0(%src) */
993 		EMIT4_DISP(0x8a000000, dst_reg, src_reg, 0);
994 		EMIT_ZERO(dst_reg);
995 		break;
996 	case BPF_ALU64 | BPF_ARSH | BPF_X: /* ((s64) dst) >>= src */
997 		/* srag %dst,%dst,0(%src) */
998 		EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, src_reg, 0);
999 		break;
1000 	case BPF_ALU | BPF_ARSH | BPF_K: /* ((s32) dst >> imm */
1001 		if (imm == 0)
1002 			break;
1003 		/* sra %dst,imm(%r0) */
1004 		EMIT4_DISP(0x8a000000, dst_reg, REG_0, imm);
1005 		EMIT_ZERO(dst_reg);
1006 		break;
1007 	case BPF_ALU64 | BPF_ARSH | BPF_K: /* ((s64) dst) >>= imm */
1008 		if (imm == 0)
1009 			break;
1010 		/* srag %dst,%dst,imm(%r0) */
1011 		EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, REG_0, imm);
1012 		break;
1013 	/*
1014 	 * BPF_NEG
1015 	 */
1016 	case BPF_ALU | BPF_NEG: /* dst = (u32) -dst */
1017 		/* lcr %dst,%dst */
1018 		EMIT2(0x1300, dst_reg, dst_reg);
1019 		EMIT_ZERO(dst_reg);
1020 		break;
1021 	case BPF_ALU64 | BPF_NEG: /* dst = -dst */
1022 		/* lcgr %dst,%dst */
1023 		EMIT4(0xb9030000, dst_reg, dst_reg);
1024 		break;
1025 	/*
1026 	 * BPF_FROM_BE/LE
1027 	 */
1028 	case BPF_ALU | BPF_END | BPF_FROM_BE:
1029 		/* s390 is big endian, therefore only clear high order bytes */
1030 		switch (imm) {
1031 		case 16: /* dst = (u16) cpu_to_be16(dst) */
1032 			/* llghr %dst,%dst */
1033 			EMIT4(0xb9850000, dst_reg, dst_reg);
1034 			if (insn_is_zext(&insn[1]))
1035 				insn_count = 2;
1036 			break;
1037 		case 32: /* dst = (u32) cpu_to_be32(dst) */
1038 			if (!fp->aux->verifier_zext)
1039 				/* llgfr %dst,%dst */
1040 				EMIT4(0xb9160000, dst_reg, dst_reg);
1041 			break;
1042 		case 64: /* dst = (u64) cpu_to_be64(dst) */
1043 			break;
1044 		}
1045 		break;
1046 	case BPF_ALU | BPF_END | BPF_FROM_LE:
1047 		switch (imm) {
1048 		case 16: /* dst = (u16) cpu_to_le16(dst) */
1049 			/* lrvr %dst,%dst */
1050 			EMIT4(0xb91f0000, dst_reg, dst_reg);
1051 			/* srl %dst,16(%r0) */
1052 			EMIT4_DISP(0x88000000, dst_reg, REG_0, 16);
1053 			/* llghr %dst,%dst */
1054 			EMIT4(0xb9850000, dst_reg, dst_reg);
1055 			if (insn_is_zext(&insn[1]))
1056 				insn_count = 2;
1057 			break;
1058 		case 32: /* dst = (u32) cpu_to_le32(dst) */
1059 			/* lrvr %dst,%dst */
1060 			EMIT4(0xb91f0000, dst_reg, dst_reg);
1061 			if (!fp->aux->verifier_zext)
1062 				/* llgfr %dst,%dst */
1063 				EMIT4(0xb9160000, dst_reg, dst_reg);
1064 			break;
1065 		case 64: /* dst = (u64) cpu_to_le64(dst) */
1066 			/* lrvgr %dst,%dst */
1067 			EMIT4(0xb90f0000, dst_reg, dst_reg);
1068 			break;
1069 		}
1070 		break;
1071 	/*
1072 	 * BPF_ST(X)
1073 	 */
1074 	case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src_reg */
1075 		/* stcy %src,off(%dst) */
1076 		EMIT6_DISP_LH(0xe3000000, 0x0072, src_reg, dst_reg, REG_0, off);
1077 		jit->seen |= SEEN_MEM;
1078 		break;
1079 	case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
1080 		/* sthy %src,off(%dst) */
1081 		EMIT6_DISP_LH(0xe3000000, 0x0070, src_reg, dst_reg, REG_0, off);
1082 		jit->seen |= SEEN_MEM;
1083 		break;
1084 	case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
1085 		/* sty %src,off(%dst) */
1086 		EMIT6_DISP_LH(0xe3000000, 0x0050, src_reg, dst_reg, REG_0, off);
1087 		jit->seen |= SEEN_MEM;
1088 		break;
1089 	case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
1090 		/* stg %src,off(%dst) */
1091 		EMIT6_DISP_LH(0xe3000000, 0x0024, src_reg, dst_reg, REG_0, off);
1092 		jit->seen |= SEEN_MEM;
1093 		break;
1094 	case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
1095 		/* lhi %w0,imm */
1096 		EMIT4_IMM(0xa7080000, REG_W0, (u8) imm);
1097 		/* stcy %w0,off(dst) */
1098 		EMIT6_DISP_LH(0xe3000000, 0x0072, REG_W0, dst_reg, REG_0, off);
1099 		jit->seen |= SEEN_MEM;
1100 		break;
1101 	case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
1102 		/* lhi %w0,imm */
1103 		EMIT4_IMM(0xa7080000, REG_W0, (u16) imm);
1104 		/* sthy %w0,off(dst) */
1105 		EMIT6_DISP_LH(0xe3000000, 0x0070, REG_W0, dst_reg, REG_0, off);
1106 		jit->seen |= SEEN_MEM;
1107 		break;
1108 	case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
1109 		/* llilf %w0,imm  */
1110 		EMIT6_IMM(0xc00f0000, REG_W0, (u32) imm);
1111 		/* sty %w0,off(%dst) */
1112 		EMIT6_DISP_LH(0xe3000000, 0x0050, REG_W0, dst_reg, REG_0, off);
1113 		jit->seen |= SEEN_MEM;
1114 		break;
1115 	case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
1116 		/* lgfi %w0,imm */
1117 		EMIT6_IMM(0xc0010000, REG_W0, imm);
1118 		/* stg %w0,off(%dst) */
1119 		EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, dst_reg, REG_0, off);
1120 		jit->seen |= SEEN_MEM;
1121 		break;
1122 	/*
1123 	 * BPF_STX XADD (atomic_add)
1124 	 */
1125 	case BPF_STX | BPF_XADD | BPF_W: /* *(u32 *)(dst + off) += src */
1126 		/* laal %w0,%src,off(%dst) */
1127 		EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W0, src_reg,
1128 			      dst_reg, off);
1129 		jit->seen |= SEEN_MEM;
1130 		break;
1131 	case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */
1132 		/* laalg %w0,%src,off(%dst) */
1133 		EMIT6_DISP_LH(0xeb000000, 0x00ea, REG_W0, src_reg,
1134 			      dst_reg, off);
1135 		jit->seen |= SEEN_MEM;
1136 		break;
1137 	/*
1138 	 * BPF_LDX
1139 	 */
1140 	case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */
1141 		/* llgc %dst,0(off,%src) */
1142 		EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off);
1143 		jit->seen |= SEEN_MEM;
1144 		if (insn_is_zext(&insn[1]))
1145 			insn_count = 2;
1146 		break;
1147 	case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
1148 		/* llgh %dst,0(off,%src) */
1149 		EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off);
1150 		jit->seen |= SEEN_MEM;
1151 		if (insn_is_zext(&insn[1]))
1152 			insn_count = 2;
1153 		break;
1154 	case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */
1155 		/* llgf %dst,off(%src) */
1156 		jit->seen |= SEEN_MEM;
1157 		EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off);
1158 		if (insn_is_zext(&insn[1]))
1159 			insn_count = 2;
1160 		break;
1161 	case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
1162 		/* lg %dst,0(off,%src) */
1163 		jit->seen |= SEEN_MEM;
1164 		EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, src_reg, REG_0, off);
1165 		break;
1166 	/*
1167 	 * BPF_JMP / CALL
1168 	 */
1169 	case BPF_JMP | BPF_CALL:
1170 	{
1171 		u64 func;
1172 		bool func_addr_fixed;
1173 		int ret;
1174 
1175 		ret = bpf_jit_get_func_addr(fp, insn, extra_pass,
1176 					    &func, &func_addr_fixed);
1177 		if (ret < 0)
1178 			return -1;
1179 
1180 		REG_SET_SEEN(BPF_REG_5);
1181 		jit->seen |= SEEN_FUNC;
1182 		/* lgrl %w1,func */
1183 		EMIT6_PCREL_RILB(0xc4080000, REG_W1, _EMIT_CONST_U64(func));
1184 		if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable) {
1185 			/* brasl %r14,__s390_indirect_jump_r1 */
1186 			EMIT6_PCREL_RILB(0xc0050000, REG_14, jit->r1_thunk_ip);
1187 		} else {
1188 			/* basr %r14,%w1 */
1189 			EMIT2(0x0d00, REG_14, REG_W1);
1190 		}
1191 		/* lgr %b0,%r2: load return value into %b0 */
1192 		EMIT4(0xb9040000, BPF_REG_0, REG_2);
1193 		break;
1194 	}
1195 	case BPF_JMP | BPF_TAIL_CALL:
1196 		/*
1197 		 * Implicit input:
1198 		 *  B1: pointer to ctx
1199 		 *  B2: pointer to bpf_array
1200 		 *  B3: index in bpf_array
1201 		 */
1202 		jit->seen |= SEEN_TAIL_CALL;
1203 
1204 		/*
1205 		 * if (index >= array->map.max_entries)
1206 		 *         goto out;
1207 		 */
1208 
1209 		/* llgf %w1,map.max_entries(%b2) */
1210 		EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2,
1211 			      offsetof(struct bpf_array, map.max_entries));
1212 		/* if ((u32)%b3 >= (u32)%w1) goto out; */
1213 		if (!is_first_pass(jit) && can_use_rel(jit, jit->labels[0])) {
1214 			/* clrj %b3,%w1,0xa,label0 */
1215 			EMIT6_PCREL_LABEL(0xec000000, 0x0077, BPF_REG_3,
1216 					  REG_W1, 0, 0xa);
1217 		} else {
1218 			/* clr %b3,%w1 */
1219 			EMIT2(0x1500, BPF_REG_3, REG_W1);
1220 			/* brcl 0xa,label0 */
1221 			EMIT6_PCREL_RILC(0xc0040000, 0xa, jit->labels[0]);
1222 		}
1223 
1224 		/*
1225 		 * if (tail_call_cnt++ > MAX_TAIL_CALL_CNT)
1226 		 *         goto out;
1227 		 */
1228 
1229 		if (jit->seen & SEEN_STACK)
1230 			off = STK_OFF_TCCNT + STK_OFF + stack_depth;
1231 		else
1232 			off = STK_OFF_TCCNT;
1233 		/* lhi %w0,1 */
1234 		EMIT4_IMM(0xa7080000, REG_W0, 1);
1235 		/* laal %w1,%w0,off(%r15) */
1236 		EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, REG_15, off);
1237 		if (!is_first_pass(jit) && can_use_rel(jit, jit->labels[0])) {
1238 			/* clij %w1,MAX_TAIL_CALL_CNT,0x2,label0 */
1239 			EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007f, REG_W1,
1240 					      MAX_TAIL_CALL_CNT, 0, 0x2);
1241 		} else {
1242 			/* clfi %w1,MAX_TAIL_CALL_CNT */
1243 			EMIT6_IMM(0xc20f0000, REG_W1, MAX_TAIL_CALL_CNT);
1244 			/* brcl 0x2,label0 */
1245 			EMIT6_PCREL_RILC(0xc0040000, 0x2, jit->labels[0]);
1246 		}
1247 
1248 		/*
1249 		 * prog = array->ptrs[index];
1250 		 * if (prog == NULL)
1251 		 *         goto out;
1252 		 */
1253 
1254 		/* llgfr %r1,%b3: %r1 = (u32) index */
1255 		EMIT4(0xb9160000, REG_1, BPF_REG_3);
1256 		/* sllg %r1,%r1,3: %r1 *= 8 */
1257 		EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, REG_1, REG_0, 3);
1258 		/* ltg %r1,prog(%b2,%r1) */
1259 		EMIT6_DISP_LH(0xe3000000, 0x0002, REG_1, BPF_REG_2,
1260 			      REG_1, offsetof(struct bpf_array, ptrs));
1261 		if (!is_first_pass(jit) && can_use_rel(jit, jit->labels[0])) {
1262 			/* brc 0x8,label0 */
1263 			EMIT4_PCREL_RIC(0xa7040000, 0x8, jit->labels[0]);
1264 		} else {
1265 			/* brcl 0x8,label0 */
1266 			EMIT6_PCREL_RILC(0xc0040000, 0x8, jit->labels[0]);
1267 		}
1268 
1269 		/*
1270 		 * Restore registers before calling function
1271 		 */
1272 		save_restore_regs(jit, REGS_RESTORE, stack_depth);
1273 
1274 		/*
1275 		 * goto *(prog->bpf_func + tail_call_start);
1276 		 */
1277 
1278 		/* lg %r1,bpf_func(%r1) */
1279 		EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, REG_1, REG_0,
1280 			      offsetof(struct bpf_prog, bpf_func));
1281 		/* bc 0xf,tail_call_start(%r1) */
1282 		_EMIT4(0x47f01000 + jit->tail_call_start);
1283 		/* out: */
1284 		jit->labels[0] = jit->prg;
1285 		break;
1286 	case BPF_JMP | BPF_EXIT: /* return b0 */
1287 		last = (i == fp->len - 1) ? 1 : 0;
1288 		if (last)
1289 			break;
1290 		if (!is_first_pass(jit) && can_use_rel(jit, jit->exit_ip))
1291 			/* brc 0xf, <exit> */
1292 			EMIT4_PCREL_RIC(0xa7040000, 0xf, jit->exit_ip);
1293 		else
1294 			/* brcl 0xf, <exit> */
1295 			EMIT6_PCREL_RILC(0xc0040000, 0xf, jit->exit_ip);
1296 		break;
1297 	/*
1298 	 * Branch relative (number of skipped instructions) to offset on
1299 	 * condition.
1300 	 *
1301 	 * Condition code to mask mapping:
1302 	 *
1303 	 * CC | Description	   | Mask
1304 	 * ------------------------------
1305 	 * 0  | Operands equal	   |	8
1306 	 * 1  | First operand low  |	4
1307 	 * 2  | First operand high |	2
1308 	 * 3  | Unused		   |	1
1309 	 *
1310 	 * For s390x relative branches: ip = ip + off_bytes
1311 	 * For BPF relative branches:	insn = insn + off_insns + 1
1312 	 *
1313 	 * For example for s390x with offset 0 we jump to the branch
1314 	 * instruction itself (loop) and for BPF with offset 0 we
1315 	 * branch to the instruction behind the branch.
1316 	 */
1317 	case BPF_JMP | BPF_JA: /* if (true) */
1318 		mask = 0xf000; /* j */
1319 		goto branch_oc;
1320 	case BPF_JMP | BPF_JSGT | BPF_K: /* ((s64) dst > (s64) imm) */
1321 	case BPF_JMP32 | BPF_JSGT | BPF_K: /* ((s32) dst > (s32) imm) */
1322 		mask = 0x2000; /* jh */
1323 		goto branch_ks;
1324 	case BPF_JMP | BPF_JSLT | BPF_K: /* ((s64) dst < (s64) imm) */
1325 	case BPF_JMP32 | BPF_JSLT | BPF_K: /* ((s32) dst < (s32) imm) */
1326 		mask = 0x4000; /* jl */
1327 		goto branch_ks;
1328 	case BPF_JMP | BPF_JSGE | BPF_K: /* ((s64) dst >= (s64) imm) */
1329 	case BPF_JMP32 | BPF_JSGE | BPF_K: /* ((s32) dst >= (s32) imm) */
1330 		mask = 0xa000; /* jhe */
1331 		goto branch_ks;
1332 	case BPF_JMP | BPF_JSLE | BPF_K: /* ((s64) dst <= (s64) imm) */
1333 	case BPF_JMP32 | BPF_JSLE | BPF_K: /* ((s32) dst <= (s32) imm) */
1334 		mask = 0xc000; /* jle */
1335 		goto branch_ks;
1336 	case BPF_JMP | BPF_JGT | BPF_K: /* (dst_reg > imm) */
1337 	case BPF_JMP32 | BPF_JGT | BPF_K: /* ((u32) dst_reg > (u32) imm) */
1338 		mask = 0x2000; /* jh */
1339 		goto branch_ku;
1340 	case BPF_JMP | BPF_JLT | BPF_K: /* (dst_reg < imm) */
1341 	case BPF_JMP32 | BPF_JLT | BPF_K: /* ((u32) dst_reg < (u32) imm) */
1342 		mask = 0x4000; /* jl */
1343 		goto branch_ku;
1344 	case BPF_JMP | BPF_JGE | BPF_K: /* (dst_reg >= imm) */
1345 	case BPF_JMP32 | BPF_JGE | BPF_K: /* ((u32) dst_reg >= (u32) imm) */
1346 		mask = 0xa000; /* jhe */
1347 		goto branch_ku;
1348 	case BPF_JMP | BPF_JLE | BPF_K: /* (dst_reg <= imm) */
1349 	case BPF_JMP32 | BPF_JLE | BPF_K: /* ((u32) dst_reg <= (u32) imm) */
1350 		mask = 0xc000; /* jle */
1351 		goto branch_ku;
1352 	case BPF_JMP | BPF_JNE | BPF_K: /* (dst_reg != imm) */
1353 	case BPF_JMP32 | BPF_JNE | BPF_K: /* ((u32) dst_reg != (u32) imm) */
1354 		mask = 0x7000; /* jne */
1355 		goto branch_ku;
1356 	case BPF_JMP | BPF_JEQ | BPF_K: /* (dst_reg == imm) */
1357 	case BPF_JMP32 | BPF_JEQ | BPF_K: /* ((u32) dst_reg == (u32) imm) */
1358 		mask = 0x8000; /* je */
1359 		goto branch_ku;
1360 	case BPF_JMP | BPF_JSET | BPF_K: /* (dst_reg & imm) */
1361 	case BPF_JMP32 | BPF_JSET | BPF_K: /* ((u32) dst_reg & (u32) imm) */
1362 		mask = 0x7000; /* jnz */
1363 		if (BPF_CLASS(insn->code) == BPF_JMP32) {
1364 			/* llilf %w1,imm (load zero extend imm) */
1365 			EMIT6_IMM(0xc00f0000, REG_W1, imm);
1366 			/* nr %w1,%dst */
1367 			EMIT2(0x1400, REG_W1, dst_reg);
1368 		} else {
1369 			/* lgfi %w1,imm (load sign extend imm) */
1370 			EMIT6_IMM(0xc0010000, REG_W1, imm);
1371 			/* ngr %w1,%dst */
1372 			EMIT4(0xb9800000, REG_W1, dst_reg);
1373 		}
1374 		goto branch_oc;
1375 
1376 	case BPF_JMP | BPF_JSGT | BPF_X: /* ((s64) dst > (s64) src) */
1377 	case BPF_JMP32 | BPF_JSGT | BPF_X: /* ((s32) dst > (s32) src) */
1378 		mask = 0x2000; /* jh */
1379 		goto branch_xs;
1380 	case BPF_JMP | BPF_JSLT | BPF_X: /* ((s64) dst < (s64) src) */
1381 	case BPF_JMP32 | BPF_JSLT | BPF_X: /* ((s32) dst < (s32) src) */
1382 		mask = 0x4000; /* jl */
1383 		goto branch_xs;
1384 	case BPF_JMP | BPF_JSGE | BPF_X: /* ((s64) dst >= (s64) src) */
1385 	case BPF_JMP32 | BPF_JSGE | BPF_X: /* ((s32) dst >= (s32) src) */
1386 		mask = 0xa000; /* jhe */
1387 		goto branch_xs;
1388 	case BPF_JMP | BPF_JSLE | BPF_X: /* ((s64) dst <= (s64) src) */
1389 	case BPF_JMP32 | BPF_JSLE | BPF_X: /* ((s32) dst <= (s32) src) */
1390 		mask = 0xc000; /* jle */
1391 		goto branch_xs;
1392 	case BPF_JMP | BPF_JGT | BPF_X: /* (dst > src) */
1393 	case BPF_JMP32 | BPF_JGT | BPF_X: /* ((u32) dst > (u32) src) */
1394 		mask = 0x2000; /* jh */
1395 		goto branch_xu;
1396 	case BPF_JMP | BPF_JLT | BPF_X: /* (dst < src) */
1397 	case BPF_JMP32 | BPF_JLT | BPF_X: /* ((u32) dst < (u32) src) */
1398 		mask = 0x4000; /* jl */
1399 		goto branch_xu;
1400 	case BPF_JMP | BPF_JGE | BPF_X: /* (dst >= src) */
1401 	case BPF_JMP32 | BPF_JGE | BPF_X: /* ((u32) dst >= (u32) src) */
1402 		mask = 0xa000; /* jhe */
1403 		goto branch_xu;
1404 	case BPF_JMP | BPF_JLE | BPF_X: /* (dst <= src) */
1405 	case BPF_JMP32 | BPF_JLE | BPF_X: /* ((u32) dst <= (u32) src) */
1406 		mask = 0xc000; /* jle */
1407 		goto branch_xu;
1408 	case BPF_JMP | BPF_JNE | BPF_X: /* (dst != src) */
1409 	case BPF_JMP32 | BPF_JNE | BPF_X: /* ((u32) dst != (u32) src) */
1410 		mask = 0x7000; /* jne */
1411 		goto branch_xu;
1412 	case BPF_JMP | BPF_JEQ | BPF_X: /* (dst == src) */
1413 	case BPF_JMP32 | BPF_JEQ | BPF_X: /* ((u32) dst == (u32) src) */
1414 		mask = 0x8000; /* je */
1415 		goto branch_xu;
1416 	case BPF_JMP | BPF_JSET | BPF_X: /* (dst & src) */
1417 	case BPF_JMP32 | BPF_JSET | BPF_X: /* ((u32) dst & (u32) src) */
1418 	{
1419 		bool is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1420 
1421 		mask = 0x7000; /* jnz */
1422 		/* nrk or ngrk %w1,%dst,%src */
1423 		EMIT4_RRF((is_jmp32 ? 0xb9f40000 : 0xb9e40000),
1424 			  REG_W1, dst_reg, src_reg);
1425 		goto branch_oc;
1426 branch_ks:
1427 		is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1428 		/* cfi or cgfi %dst,imm */
1429 		EMIT6_IMM(is_jmp32 ? 0xc20d0000 : 0xc20c0000,
1430 			  dst_reg, imm);
1431 		if (!is_first_pass(jit) &&
1432 		    can_use_rel(jit, addrs[i + off + 1])) {
1433 			/* brc mask,off */
1434 			EMIT4_PCREL_RIC(0xa7040000,
1435 					mask >> 12, addrs[i + off + 1]);
1436 		} else {
1437 			/* brcl mask,off */
1438 			EMIT6_PCREL_RILC(0xc0040000,
1439 					 mask >> 12, addrs[i + off + 1]);
1440 		}
1441 		break;
1442 branch_ku:
1443 		/* lgfi %w1,imm (load sign extend imm) */
1444 		src_reg = REG_1;
1445 		EMIT6_IMM(0xc0010000, src_reg, imm);
1446 		goto branch_xu;
1447 branch_xs:
1448 		is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1449 		if (!is_first_pass(jit) &&
1450 		    can_use_rel(jit, addrs[i + off + 1])) {
1451 			/* crj or cgrj %dst,%src,mask,off */
1452 			EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0076 : 0x0064),
1453 				    dst_reg, src_reg, i, off, mask);
1454 		} else {
1455 			/* cr or cgr %dst,%src */
1456 			if (is_jmp32)
1457 				EMIT2(0x1900, dst_reg, src_reg);
1458 			else
1459 				EMIT4(0xb9200000, dst_reg, src_reg);
1460 			/* brcl mask,off */
1461 			EMIT6_PCREL_RILC(0xc0040000,
1462 					 mask >> 12, addrs[i + off + 1]);
1463 		}
1464 		break;
1465 branch_xu:
1466 		is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1467 		if (!is_first_pass(jit) &&
1468 		    can_use_rel(jit, addrs[i + off + 1])) {
1469 			/* clrj or clgrj %dst,%src,mask,off */
1470 			EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0077 : 0x0065),
1471 				    dst_reg, src_reg, i, off, mask);
1472 		} else {
1473 			/* clr or clgr %dst,%src */
1474 			if (is_jmp32)
1475 				EMIT2(0x1500, dst_reg, src_reg);
1476 			else
1477 				EMIT4(0xb9210000, dst_reg, src_reg);
1478 			/* brcl mask,off */
1479 			EMIT6_PCREL_RILC(0xc0040000,
1480 					 mask >> 12, addrs[i + off + 1]);
1481 		}
1482 		break;
1483 branch_oc:
1484 		if (!is_first_pass(jit) &&
1485 		    can_use_rel(jit, addrs[i + off + 1])) {
1486 			/* brc mask,off */
1487 			EMIT4_PCREL_RIC(0xa7040000,
1488 					mask >> 12, addrs[i + off + 1]);
1489 		} else {
1490 			/* brcl mask,off */
1491 			EMIT6_PCREL_RILC(0xc0040000,
1492 					 mask >> 12, addrs[i + off + 1]);
1493 		}
1494 		break;
1495 	}
1496 	default: /* too complex, give up */
1497 		pr_err("Unknown opcode %02x\n", insn->code);
1498 		return -1;
1499 	}
1500 	return insn_count;
1501 }
1502 
1503 /*
1504  * Return whether new i-th instruction address does not violate any invariant
1505  */
1506 static bool bpf_is_new_addr_sane(struct bpf_jit *jit, int i)
1507 {
1508 	/* On the first pass anything goes */
1509 	if (is_first_pass(jit))
1510 		return true;
1511 
1512 	/* The codegen pass must not change anything */
1513 	if (is_codegen_pass(jit))
1514 		return jit->addrs[i] == jit->prg;
1515 
1516 	/* Passes in between must not increase code size */
1517 	return jit->addrs[i] >= jit->prg;
1518 }
1519 
1520 /*
1521  * Update the address of i-th instruction
1522  */
1523 static int bpf_set_addr(struct bpf_jit *jit, int i)
1524 {
1525 	int delta;
1526 
1527 	if (is_codegen_pass(jit)) {
1528 		delta = jit->prg - jit->addrs[i];
1529 		if (delta < 0)
1530 			bpf_skip(jit, -delta);
1531 	}
1532 	if (WARN_ON_ONCE(!bpf_is_new_addr_sane(jit, i)))
1533 		return -1;
1534 	jit->addrs[i] = jit->prg;
1535 	return 0;
1536 }
1537 
1538 /*
1539  * Compile eBPF program into s390x code
1540  */
1541 static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp,
1542 			bool extra_pass, u32 stack_depth)
1543 {
1544 	int i, insn_count, lit32_size, lit64_size;
1545 
1546 	jit->lit32 = jit->lit32_start;
1547 	jit->lit64 = jit->lit64_start;
1548 	jit->prg = 0;
1549 
1550 	bpf_jit_prologue(jit, stack_depth);
1551 	if (bpf_set_addr(jit, 0) < 0)
1552 		return -1;
1553 	for (i = 0; i < fp->len; i += insn_count) {
1554 		insn_count = bpf_jit_insn(jit, fp, i, extra_pass, stack_depth);
1555 		if (insn_count < 0)
1556 			return -1;
1557 		/* Next instruction address */
1558 		if (bpf_set_addr(jit, i + insn_count) < 0)
1559 			return -1;
1560 	}
1561 	bpf_jit_epilogue(jit, stack_depth);
1562 
1563 	lit32_size = jit->lit32 - jit->lit32_start;
1564 	lit64_size = jit->lit64 - jit->lit64_start;
1565 	jit->lit32_start = jit->prg;
1566 	if (lit32_size)
1567 		jit->lit32_start = ALIGN(jit->lit32_start, 4);
1568 	jit->lit64_start = jit->lit32_start + lit32_size;
1569 	if (lit64_size)
1570 		jit->lit64_start = ALIGN(jit->lit64_start, 8);
1571 	jit->size = jit->lit64_start + lit64_size;
1572 	jit->size_prg = jit->prg;
1573 	return 0;
1574 }
1575 
1576 bool bpf_jit_needs_zext(void)
1577 {
1578 	return true;
1579 }
1580 
1581 struct s390_jit_data {
1582 	struct bpf_binary_header *header;
1583 	struct bpf_jit ctx;
1584 	int pass;
1585 };
1586 
1587 /*
1588  * Compile eBPF program "fp"
1589  */
1590 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
1591 {
1592 	u32 stack_depth = round_up(fp->aux->stack_depth, 8);
1593 	struct bpf_prog *tmp, *orig_fp = fp;
1594 	struct bpf_binary_header *header;
1595 	struct s390_jit_data *jit_data;
1596 	bool tmp_blinded = false;
1597 	bool extra_pass = false;
1598 	struct bpf_jit jit;
1599 	int pass;
1600 
1601 	if (!fp->jit_requested)
1602 		return orig_fp;
1603 
1604 	tmp = bpf_jit_blind_constants(fp);
1605 	/*
1606 	 * If blinding was requested and we failed during blinding,
1607 	 * we must fall back to the interpreter.
1608 	 */
1609 	if (IS_ERR(tmp))
1610 		return orig_fp;
1611 	if (tmp != fp) {
1612 		tmp_blinded = true;
1613 		fp = tmp;
1614 	}
1615 
1616 	jit_data = fp->aux->jit_data;
1617 	if (!jit_data) {
1618 		jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
1619 		if (!jit_data) {
1620 			fp = orig_fp;
1621 			goto out;
1622 		}
1623 		fp->aux->jit_data = jit_data;
1624 	}
1625 	if (jit_data->ctx.addrs) {
1626 		jit = jit_data->ctx;
1627 		header = jit_data->header;
1628 		extra_pass = true;
1629 		pass = jit_data->pass + 1;
1630 		goto skip_init_ctx;
1631 	}
1632 
1633 	memset(&jit, 0, sizeof(jit));
1634 	jit.addrs = kvcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
1635 	if (jit.addrs == NULL) {
1636 		fp = orig_fp;
1637 		goto out;
1638 	}
1639 	/*
1640 	 * Three initial passes:
1641 	 *   - 1/2: Determine clobbered registers
1642 	 *   - 3:   Calculate program size and addrs arrray
1643 	 */
1644 	for (pass = 1; pass <= 3; pass++) {
1645 		if (bpf_jit_prog(&jit, fp, extra_pass, stack_depth)) {
1646 			fp = orig_fp;
1647 			goto free_addrs;
1648 		}
1649 	}
1650 	/*
1651 	 * Final pass: Allocate and generate program
1652 	 */
1653 	header = bpf_jit_binary_alloc(jit.size, &jit.prg_buf, 8, jit_fill_hole);
1654 	if (!header) {
1655 		fp = orig_fp;
1656 		goto free_addrs;
1657 	}
1658 skip_init_ctx:
1659 	if (bpf_jit_prog(&jit, fp, extra_pass, stack_depth)) {
1660 		bpf_jit_binary_free(header);
1661 		fp = orig_fp;
1662 		goto free_addrs;
1663 	}
1664 	if (bpf_jit_enable > 1) {
1665 		bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf);
1666 		print_fn_code(jit.prg_buf, jit.size_prg);
1667 	}
1668 	if (!fp->is_func || extra_pass) {
1669 		bpf_jit_binary_lock_ro(header);
1670 	} else {
1671 		jit_data->header = header;
1672 		jit_data->ctx = jit;
1673 		jit_data->pass = pass;
1674 	}
1675 	fp->bpf_func = (void *) jit.prg_buf;
1676 	fp->jited = 1;
1677 	fp->jited_len = jit.size;
1678 
1679 	if (!fp->is_func || extra_pass) {
1680 		bpf_prog_fill_jited_linfo(fp, jit.addrs + 1);
1681 free_addrs:
1682 		kvfree(jit.addrs);
1683 		kfree(jit_data);
1684 		fp->aux->jit_data = NULL;
1685 	}
1686 out:
1687 	if (tmp_blinded)
1688 		bpf_jit_prog_release_other(fp, fp == orig_fp ?
1689 					   tmp : orig_fp);
1690 	return fp;
1691 }
1692