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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 * - 64BIT
11 *
12 * Copyright IBM Corp. 2012,2015
13 *
14 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
15 * Michael Holzheu <holzheu@linux.vnet.ibm.com>
16 */
17
18#define KMSG_COMPONENT "bpf_jit"
19#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
20
21#include <linux/netdevice.h>
22#include <linux/filter.h>
23#include <linux/init.h>
24#include <linux/bpf.h>
25#include <linux/mm.h>
26#include <linux/kernel.h>
27#include <asm/cacheflush.h>
28#include <asm/extable.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 <asm/text-patching.h>
34#include "bpf_jit.h"
35
36struct bpf_jit {
37 u32 seen; /* Flags to remember seen eBPF instructions */
38 u32 seen_reg[16]; /* Array to remember which registers are used */
39 u32 *addrs; /* Array with relative instruction addresses */
40 u8 *prg_buf; /* Start of program */
41 int size; /* Size of program and literal pool */
42 int size_prg; /* Size of program */
43 int prg; /* Current position in program */
44 int lit32_start; /* Start of 32-bit literal pool */
45 int lit32; /* Current position in 32-bit literal pool */
46 int lit64_start; /* Start of 64-bit literal pool */
47 int lit64; /* Current position in 64-bit literal pool */
48 int base_ip; /* Base address for literal pool */
49 int exit_ip; /* Address of exit */
50 int r1_thunk_ip; /* Address of expoline thunk for 'br %r1' */
51 int r14_thunk_ip; /* Address of expoline thunk for 'br %r14' */
52 int tail_call_start; /* Tail call start offset */
53 int excnt; /* Number of exception table entries */
54 int prologue_plt_ret; /* Return address for prologue hotpatch PLT */
55 int prologue_plt; /* Start of prologue hotpatch PLT */
56};
57
58#define SEEN_MEM BIT(0) /* use mem[] for temporary storage */
59#define SEEN_LITERAL BIT(1) /* code uses literals */
60#define SEEN_FUNC BIT(2) /* calls C functions */
61#define SEEN_STACK (SEEN_FUNC | SEEN_MEM)
62
63/*
64 * s390 registers
65 */
66#define REG_W0 (MAX_BPF_JIT_REG + 0) /* Work register 1 (even) */
67#define REG_W1 (MAX_BPF_JIT_REG + 1) /* Work register 2 (odd) */
68#define REG_L (MAX_BPF_JIT_REG + 2) /* Literal pool register */
69#define REG_15 (MAX_BPF_JIT_REG + 3) /* Register 15 */
70#define REG_0 REG_W0 /* Register 0 */
71#define REG_1 REG_W1 /* Register 1 */
72#define REG_2 BPF_REG_1 /* Register 2 */
73#define REG_3 BPF_REG_2 /* Register 3 */
74#define REG_4 BPF_REG_3 /* Register 4 */
75#define REG_7 BPF_REG_6 /* Register 7 */
76#define REG_8 BPF_REG_7 /* Register 8 */
77#define REG_14 BPF_REG_0 /* Register 14 */
78
79/*
80 * Mapping of BPF registers to s390 registers
81 */
82static const int reg2hex[] = {
83 /* Return code */
84 [BPF_REG_0] = 14,
85 /* Function parameters */
86 [BPF_REG_1] = 2,
87 [BPF_REG_2] = 3,
88 [BPF_REG_3] = 4,
89 [BPF_REG_4] = 5,
90 [BPF_REG_5] = 6,
91 /* Call saved registers */
92 [BPF_REG_6] = 7,
93 [BPF_REG_7] = 8,
94 [BPF_REG_8] = 9,
95 [BPF_REG_9] = 10,
96 /* BPF stack pointer */
97 [BPF_REG_FP] = 13,
98 /* Register for blinding */
99 [BPF_REG_AX] = 12,
100 /* Work registers for s390x backend */
101 [REG_W0] = 0,
102 [REG_W1] = 1,
103 [REG_L] = 11,
104 [REG_15] = 15,
105};
106
107static inline u32 reg(u32 dst_reg, u32 src_reg)
108{
109 return reg2hex[dst_reg] << 4 | reg2hex[src_reg];
110}
111
112static inline u32 reg_high(u32 reg)
113{
114 return reg2hex[reg] << 4;
115}
116
117static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
118{
119 u32 r1 = reg2hex[b1];
120
121 if (r1 >= 6 && r1 <= 15 && !jit->seen_reg[r1])
122 jit->seen_reg[r1] = 1;
123}
124
125#define REG_SET_SEEN(b1) \
126({ \
127 reg_set_seen(jit, b1); \
128})
129
130#define REG_SEEN(b1) jit->seen_reg[reg2hex[(b1)]]
131
132/*
133 * EMIT macros for code generation
134 */
135
136#define _EMIT2(op) \
137({ \
138 if (jit->prg_buf) \
139 *(u16 *) (jit->prg_buf + jit->prg) = (op); \
140 jit->prg += 2; \
141})
142
143#define EMIT2(op, b1, b2) \
144({ \
145 _EMIT2((op) | reg(b1, b2)); \
146 REG_SET_SEEN(b1); \
147 REG_SET_SEEN(b2); \
148})
149
150#define _EMIT4(op) \
151({ \
152 if (jit->prg_buf) \
153 *(u32 *) (jit->prg_buf + jit->prg) = (op); \
154 jit->prg += 4; \
155})
156
157#define EMIT4(op, b1, b2) \
158({ \
159 _EMIT4((op) | reg(b1, b2)); \
160 REG_SET_SEEN(b1); \
161 REG_SET_SEEN(b2); \
162})
163
164#define EMIT4_RRF(op, b1, b2, b3) \
165({ \
166 _EMIT4((op) | reg_high(b3) << 8 | reg(b1, b2)); \
167 REG_SET_SEEN(b1); \
168 REG_SET_SEEN(b2); \
169 REG_SET_SEEN(b3); \
170})
171
172#define _EMIT4_DISP(op, disp) \
173({ \
174 unsigned int __disp = (disp) & 0xfff; \
175 _EMIT4((op) | __disp); \
176})
177
178#define EMIT4_DISP(op, b1, b2, disp) \
179({ \
180 _EMIT4_DISP((op) | reg_high(b1) << 16 | \
181 reg_high(b2) << 8, (disp)); \
182 REG_SET_SEEN(b1); \
183 REG_SET_SEEN(b2); \
184})
185
186#define EMIT4_IMM(op, b1, imm) \
187({ \
188 unsigned int __imm = (imm) & 0xffff; \
189 _EMIT4((op) | reg_high(b1) << 16 | __imm); \
190 REG_SET_SEEN(b1); \
191})
192
193#define EMIT4_PCREL(op, pcrel) \
194({ \
195 long __pcrel = ((pcrel) >> 1) & 0xffff; \
196 _EMIT4((op) | __pcrel); \
197})
198
199#define EMIT4_PCREL_RIC(op, mask, target) \
200({ \
201 int __rel = ((target) - jit->prg) / 2; \
202 _EMIT4((op) | (mask) << 20 | (__rel & 0xffff)); \
203})
204
205#define _EMIT6(op1, op2) \
206({ \
207 if (jit->prg_buf) { \
208 *(u32 *) (jit->prg_buf + jit->prg) = (op1); \
209 *(u16 *) (jit->prg_buf + jit->prg + 4) = (op2); \
210 } \
211 jit->prg += 6; \
212})
213
214#define _EMIT6_DISP(op1, op2, disp) \
215({ \
216 unsigned int __disp = (disp) & 0xfff; \
217 _EMIT6((op1) | __disp, op2); \
218})
219
220#define _EMIT6_DISP_LH(op1, op2, disp) \
221({ \
222 u32 _disp = (u32) (disp); \
223 unsigned int __disp_h = _disp & 0xff000; \
224 unsigned int __disp_l = _disp & 0x00fff; \
225 _EMIT6((op1) | __disp_l, (op2) | __disp_h >> 4); \
226})
227
228#define EMIT6_DISP_LH(op1, op2, b1, b2, b3, disp) \
229({ \
230 _EMIT6_DISP_LH((op1) | reg(b1, b2) << 16 | \
231 reg_high(b3) << 8, op2, disp); \
232 REG_SET_SEEN(b1); \
233 REG_SET_SEEN(b2); \
234 REG_SET_SEEN(b3); \
235})
236
237#define EMIT6_PCREL_RIEB(op1, op2, b1, b2, mask, target) \
238({ \
239 unsigned int rel = (int)((target) - jit->prg) / 2; \
240 _EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), \
241 (op2) | (mask) << 12); \
242 REG_SET_SEEN(b1); \
243 REG_SET_SEEN(b2); \
244})
245
246#define EMIT6_PCREL_RIEC(op1, op2, b1, imm, mask, target) \
247({ \
248 unsigned int rel = (int)((target) - jit->prg) / 2; \
249 _EMIT6((op1) | (reg_high(b1) | (mask)) << 16 | \
250 (rel & 0xffff), (op2) | ((imm) & 0xff) << 8); \
251 REG_SET_SEEN(b1); \
252 BUILD_BUG_ON(((unsigned long) (imm)) > 0xff); \
253})
254
255#define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask) \
256({ \
257 int rel = (addrs[(i) + (off) + 1] - jit->prg) / 2; \
258 _EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), (op2) | (mask));\
259 REG_SET_SEEN(b1); \
260 REG_SET_SEEN(b2); \
261})
262
263#define EMIT6_PCREL_RILB(op, b, target) \
264({ \
265 unsigned int rel = (int)((target) - jit->prg) / 2; \
266 _EMIT6((op) | reg_high(b) << 16 | rel >> 16, rel & 0xffff);\
267 REG_SET_SEEN(b); \
268})
269
270#define EMIT6_PCREL_RIL(op, target) \
271({ \
272 unsigned int rel = (int)((target) - jit->prg) / 2; \
273 _EMIT6((op) | rel >> 16, rel & 0xffff); \
274})
275
276#define EMIT6_PCREL_RILC(op, mask, target) \
277({ \
278 EMIT6_PCREL_RIL((op) | (mask) << 20, (target)); \
279})
280
281#define _EMIT6_IMM(op, imm) \
282({ \
283 unsigned int __imm = (imm); \
284 _EMIT6((op) | (__imm >> 16), __imm & 0xffff); \
285})
286
287#define EMIT6_IMM(op, b1, imm) \
288({ \
289 _EMIT6_IMM((op) | reg_high(b1) << 16, imm); \
290 REG_SET_SEEN(b1); \
291})
292
293#define _EMIT_CONST_U32(val) \
294({ \
295 unsigned int ret; \
296 ret = jit->lit32; \
297 if (jit->prg_buf) \
298 *(u32 *)(jit->prg_buf + jit->lit32) = (u32)(val);\
299 jit->lit32 += 4; \
300 ret; \
301})
302
303#define EMIT_CONST_U32(val) \
304({ \
305 jit->seen |= SEEN_LITERAL; \
306 _EMIT_CONST_U32(val) - jit->base_ip; \
307})
308
309#define _EMIT_CONST_U64(val) \
310({ \
311 unsigned int ret; \
312 ret = jit->lit64; \
313 if (jit->prg_buf) \
314 *(u64 *)(jit->prg_buf + jit->lit64) = (u64)(val);\
315 jit->lit64 += 8; \
316 ret; \
317})
318
319#define EMIT_CONST_U64(val) \
320({ \
321 jit->seen |= SEEN_LITERAL; \
322 _EMIT_CONST_U64(val) - jit->base_ip; \
323})
324
325#define EMIT_ZERO(b1) \
326({ \
327 if (!fp->aux->verifier_zext) { \
328 /* llgfr %dst,%dst (zero extend to 64 bit) */ \
329 EMIT4(0xb9160000, b1, b1); \
330 REG_SET_SEEN(b1); \
331 } \
332})
333
334/*
335 * Return whether this is the first pass. The first pass is special, since we
336 * don't know any sizes yet, and thus must be conservative.
337 */
338static bool is_first_pass(struct bpf_jit *jit)
339{
340 return jit->size == 0;
341}
342
343/*
344 * Return whether this is the code generation pass. The code generation pass is
345 * special, since we should change as little as possible.
346 */
347static bool is_codegen_pass(struct bpf_jit *jit)
348{
349 return jit->prg_buf;
350}
351
352/*
353 * Return whether "rel" can be encoded as a short PC-relative offset
354 */
355static bool is_valid_rel(int rel)
356{
357 return rel >= -65536 && rel <= 65534;
358}
359
360/*
361 * Return whether "off" can be reached using a short PC-relative offset
362 */
363static bool can_use_rel(struct bpf_jit *jit, int off)
364{
365 return is_valid_rel(off - jit->prg);
366}
367
368/*
369 * Return whether given displacement can be encoded using
370 * Long-Displacement Facility
371 */
372static bool is_valid_ldisp(int disp)
373{
374 return disp >= -524288 && disp <= 524287;
375}
376
377/*
378 * Return whether the next 32-bit literal pool entry can be referenced using
379 * Long-Displacement Facility
380 */
381static bool can_use_ldisp_for_lit32(struct bpf_jit *jit)
382{
383 return is_valid_ldisp(jit->lit32 - jit->base_ip);
384}
385
386/*
387 * Return whether the next 64-bit literal pool entry can be referenced using
388 * Long-Displacement Facility
389 */
390static bool can_use_ldisp_for_lit64(struct bpf_jit *jit)
391{
392 return is_valid_ldisp(jit->lit64 - jit->base_ip);
393}
394
395/*
396 * Fill whole space with illegal instructions
397 */
398static void jit_fill_hole(void *area, unsigned int size)
399{
400 memset(area, 0, size);
401}
402
403/*
404 * Save registers from "rs" (register start) to "re" (register end) on stack
405 */
406static void save_regs(struct bpf_jit *jit, u32 rs, u32 re)
407{
408 u32 off = STK_OFF_R6 + (rs - 6) * 8;
409
410 if (rs == re)
411 /* stg %rs,off(%r15) */
412 _EMIT6(0xe300f000 | rs << 20 | off, 0x0024);
413 else
414 /* stmg %rs,%re,off(%r15) */
415 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0024, off);
416}
417
418/*
419 * Restore registers from "rs" (register start) to "re" (register end) on stack
420 */
421static void restore_regs(struct bpf_jit *jit, u32 rs, u32 re, u32 stack_depth)
422{
423 u32 off = STK_OFF_R6 + (rs - 6) * 8;
424
425 if (jit->seen & SEEN_STACK)
426 off += STK_OFF + stack_depth;
427
428 if (rs == re)
429 /* lg %rs,off(%r15) */
430 _EMIT6(0xe300f000 | rs << 20 | off, 0x0004);
431 else
432 /* lmg %rs,%re,off(%r15) */
433 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0004, off);
434}
435
436/*
437 * Return first seen register (from start)
438 */
439static int get_start(struct bpf_jit *jit, int start)
440{
441 int i;
442
443 for (i = start; i <= 15; i++) {
444 if (jit->seen_reg[i])
445 return i;
446 }
447 return 0;
448}
449
450/*
451 * Return last seen register (from start) (gap >= 2)
452 */
453static int get_end(struct bpf_jit *jit, int start)
454{
455 int i;
456
457 for (i = start; i < 15; i++) {
458 if (!jit->seen_reg[i] && !jit->seen_reg[i + 1])
459 return i - 1;
460 }
461 return jit->seen_reg[15] ? 15 : 14;
462}
463
464#define REGS_SAVE 1
465#define REGS_RESTORE 0
466/*
467 * Save and restore clobbered registers (6-15) on stack.
468 * We save/restore registers in chunks with gap >= 2 registers.
469 */
470static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth)
471{
472 const int last = 15, save_restore_size = 6;
473 int re = 6, rs;
474
475 if (is_first_pass(jit)) {
476 /*
477 * We don't know yet which registers are used. Reserve space
478 * conservatively.
479 */
480 jit->prg += (last - re + 1) * save_restore_size;
481 return;
482 }
483
484 do {
485 rs = get_start(jit, re);
486 if (!rs)
487 break;
488 re = get_end(jit, rs + 1);
489 if (op == REGS_SAVE)
490 save_regs(jit, rs, re);
491 else
492 restore_regs(jit, rs, re, stack_depth);
493 re++;
494 } while (re <= last);
495}
496
497static void bpf_skip(struct bpf_jit *jit, int size)
498{
499 if (size >= 6 && !is_valid_rel(size)) {
500 /* brcl 0xf,size */
501 EMIT6_PCREL_RIL(0xc0f4000000, size);
502 size -= 6;
503 } else if (size >= 4 && is_valid_rel(size)) {
504 /* brc 0xf,size */
505 EMIT4_PCREL(0xa7f40000, size);
506 size -= 4;
507 }
508 while (size >= 2) {
509 /* bcr 0,%0 */
510 _EMIT2(0x0700);
511 size -= 2;
512 }
513}
514
515/*
516 * PLT for hotpatchable calls. The calling convention is the same as for the
517 * ftrace hotpatch trampolines: %r0 is return address, %r1 is clobbered.
518 */
519extern const char bpf_plt[];
520extern const char bpf_plt_ret[];
521extern const char bpf_plt_target[];
522extern const char bpf_plt_end[];
523#define BPF_PLT_SIZE 32
524asm(
525 ".pushsection .rodata\n"
526 " .balign 8\n"
527 "bpf_plt:\n"
528 " lgrl %r0,bpf_plt_ret\n"
529 " lgrl %r1,bpf_plt_target\n"
530 " br %r1\n"
531 " .balign 8\n"
532 "bpf_plt_ret: .quad 0\n"
533 "bpf_plt_target: .quad 0\n"
534 "bpf_plt_end:\n"
535 " .popsection\n"
536);
537
538static void bpf_jit_plt(void *plt, void *ret, void *target)
539{
540 memcpy(plt, bpf_plt, BPF_PLT_SIZE);
541 *(void **)((char *)plt + (bpf_plt_ret - bpf_plt)) = ret;
542 *(void **)((char *)plt + (bpf_plt_target - bpf_plt)) = target ?: ret;
543}
544
545/*
546 * Emit function prologue
547 *
548 * Save registers and create stack frame if necessary.
549 * See stack frame layout description in "bpf_jit.h"!
550 */
551static void bpf_jit_prologue(struct bpf_jit *jit, struct bpf_prog *fp,
552 u32 stack_depth)
553{
554 /* No-op for hotpatching */
555 /* brcl 0,prologue_plt */
556 EMIT6_PCREL_RILC(0xc0040000, 0, jit->prologue_plt);
557 jit->prologue_plt_ret = jit->prg;
558
559 if (!bpf_is_subprog(fp)) {
560 /* Initialize the tail call counter in the main program. */
561 /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */
562 _EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT);
563 } else {
564 /*
565 * Skip the tail call counter initialization in subprograms.
566 * Insert nops in order to have tail_call_start at a
567 * predictable offset.
568 */
569 bpf_skip(jit, 6);
570 }
571 /* Tail calls have to skip above initialization */
572 jit->tail_call_start = jit->prg;
573 /* Save registers */
574 save_restore_regs(jit, REGS_SAVE, stack_depth);
575 /* Setup literal pool */
576 if (is_first_pass(jit) || (jit->seen & SEEN_LITERAL)) {
577 if (!is_first_pass(jit) &&
578 is_valid_ldisp(jit->size - (jit->prg + 2))) {
579 /* basr %l,0 */
580 EMIT2(0x0d00, REG_L, REG_0);
581 jit->base_ip = jit->prg;
582 } else {
583 /* larl %l,lit32_start */
584 EMIT6_PCREL_RILB(0xc0000000, REG_L, jit->lit32_start);
585 jit->base_ip = jit->lit32_start;
586 }
587 }
588 /* Setup stack and backchain */
589 if (is_first_pass(jit) || (jit->seen & SEEN_STACK)) {
590 if (is_first_pass(jit) || (jit->seen & SEEN_FUNC))
591 /* lgr %w1,%r15 (backchain) */
592 EMIT4(0xb9040000, REG_W1, REG_15);
593 /* la %bfp,STK_160_UNUSED(%r15) (BPF frame pointer) */
594 EMIT4_DISP(0x41000000, BPF_REG_FP, REG_15, STK_160_UNUSED);
595 /* aghi %r15,-STK_OFF */
596 EMIT4_IMM(0xa70b0000, REG_15, -(STK_OFF + stack_depth));
597 if (is_first_pass(jit) || (jit->seen & SEEN_FUNC))
598 /* stg %w1,152(%r15) (backchain) */
599 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
600 REG_15, 152);
601 }
602}
603
604/*
605 * Emit an expoline for a jump that follows
606 */
607static void emit_expoline(struct bpf_jit *jit)
608{
609 /* exrl %r0,.+10 */
610 EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
611 /* j . */
612 EMIT4_PCREL(0xa7f40000, 0);
613}
614
615/*
616 * Emit __s390_indirect_jump_r1 thunk if necessary
617 */
618static void emit_r1_thunk(struct bpf_jit *jit)
619{
620 if (nospec_uses_trampoline()) {
621 jit->r1_thunk_ip = jit->prg;
622 emit_expoline(jit);
623 /* br %r1 */
624 _EMIT2(0x07f1);
625 }
626}
627
628/*
629 * Call r1 either directly or via __s390_indirect_jump_r1 thunk
630 */
631static void call_r1(struct bpf_jit *jit)
632{
633 if (nospec_uses_trampoline())
634 /* brasl %r14,__s390_indirect_jump_r1 */
635 EMIT6_PCREL_RILB(0xc0050000, REG_14, jit->r1_thunk_ip);
636 else
637 /* basr %r14,%r1 */
638 EMIT2(0x0d00, REG_14, REG_1);
639}
640
641/*
642 * Function epilogue
643 */
644static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
645{
646 jit->exit_ip = jit->prg;
647 /* Load exit code: lgr %r2,%b0 */
648 EMIT4(0xb9040000, REG_2, BPF_REG_0);
649 /* Restore registers */
650 save_restore_regs(jit, REGS_RESTORE, stack_depth);
651 if (nospec_uses_trampoline()) {
652 jit->r14_thunk_ip = jit->prg;
653 /* Generate __s390_indirect_jump_r14 thunk */
654 emit_expoline(jit);
655 }
656 /* br %r14 */
657 _EMIT2(0x07fe);
658
659 if (is_first_pass(jit) || (jit->seen & SEEN_FUNC))
660 emit_r1_thunk(jit);
661
662 jit->prg = ALIGN(jit->prg, 8);
663 jit->prologue_plt = jit->prg;
664 if (jit->prg_buf)
665 bpf_jit_plt(jit->prg_buf + jit->prg,
666 jit->prg_buf + jit->prologue_plt_ret, NULL);
667 jit->prg += BPF_PLT_SIZE;
668}
669
670static int get_probe_mem_regno(const u8 *insn)
671{
672 /*
673 * insn must point to llgc, llgh, llgf, lg, lgb, lgh or lgf, which have
674 * destination register at the same position.
675 */
676 if (insn[0] != 0xe3) /* common prefix */
677 return -1;
678 if (insn[5] != 0x90 && /* llgc */
679 insn[5] != 0x91 && /* llgh */
680 insn[5] != 0x16 && /* llgf */
681 insn[5] != 0x04 && /* lg */
682 insn[5] != 0x77 && /* lgb */
683 insn[5] != 0x15 && /* lgh */
684 insn[5] != 0x14) /* lgf */
685 return -1;
686 return insn[1] >> 4;
687}
688
689bool ex_handler_bpf(const struct exception_table_entry *x, struct pt_regs *regs)
690{
691 regs->psw.addr = extable_fixup(x);
692 regs->gprs[x->data] = 0;
693 return true;
694}
695
696static int bpf_jit_probe_mem(struct bpf_jit *jit, struct bpf_prog *fp,
697 int probe_prg, int nop_prg)
698{
699 struct exception_table_entry *ex;
700 int reg, prg;
701 s64 delta;
702 u8 *insn;
703 int i;
704
705 if (!fp->aux->extable)
706 /* Do nothing during early JIT passes. */
707 return 0;
708 insn = jit->prg_buf + probe_prg;
709 reg = get_probe_mem_regno(insn);
710 if (WARN_ON_ONCE(reg < 0))
711 /* JIT bug - unexpected probe instruction. */
712 return -1;
713 if (WARN_ON_ONCE(probe_prg + insn_length(*insn) != nop_prg))
714 /* JIT bug - gap between probe and nop instructions. */
715 return -1;
716 for (i = 0; i < 2; i++) {
717 if (WARN_ON_ONCE(jit->excnt >= fp->aux->num_exentries))
718 /* Verifier bug - not enough entries. */
719 return -1;
720 ex = &fp->aux->extable[jit->excnt];
721 /* Add extable entries for probe and nop instructions. */
722 prg = i == 0 ? probe_prg : nop_prg;
723 delta = jit->prg_buf + prg - (u8 *)&ex->insn;
724 if (WARN_ON_ONCE(delta < INT_MIN || delta > INT_MAX))
725 /* JIT bug - code and extable must be close. */
726 return -1;
727 ex->insn = delta;
728 /*
729 * Always land on the nop. Note that extable infrastructure
730 * ignores fixup field, it is handled by ex_handler_bpf().
731 */
732 delta = jit->prg_buf + nop_prg - (u8 *)&ex->fixup;
733 if (WARN_ON_ONCE(delta < INT_MIN || delta > INT_MAX))
734 /* JIT bug - landing pad and extable must be close. */
735 return -1;
736 ex->fixup = delta;
737 ex->type = EX_TYPE_BPF;
738 ex->data = reg;
739 jit->excnt++;
740 }
741 return 0;
742}
743
744/*
745 * Sign-extend the register if necessary
746 */
747static int sign_extend(struct bpf_jit *jit, int r, u8 size, u8 flags)
748{
749 if (!(flags & BTF_FMODEL_SIGNED_ARG))
750 return 0;
751
752 switch (size) {
753 case 1:
754 /* lgbr %r,%r */
755 EMIT4(0xb9060000, r, r);
756 return 0;
757 case 2:
758 /* lghr %r,%r */
759 EMIT4(0xb9070000, r, r);
760 return 0;
761 case 4:
762 /* lgfr %r,%r */
763 EMIT4(0xb9140000, r, r);
764 return 0;
765 case 8:
766 return 0;
767 default:
768 return -1;
769 }
770}
771
772/*
773 * Compile one eBPF instruction into s390x code
774 *
775 * NOTE: Use noinline because for gcov (-fprofile-arcs) gcc allocates a lot of
776 * stack space for the large switch statement.
777 */
778static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
779 int i, bool extra_pass, u32 stack_depth)
780{
781 struct bpf_insn *insn = &fp->insnsi[i];
782 s32 branch_oc_off = insn->off;
783 u32 dst_reg = insn->dst_reg;
784 u32 src_reg = insn->src_reg;
785 int last, insn_count = 1;
786 u32 *addrs = jit->addrs;
787 s32 imm = insn->imm;
788 s16 off = insn->off;
789 int probe_prg = -1;
790 unsigned int mask;
791 int nop_prg;
792 int err;
793
794 if (BPF_CLASS(insn->code) == BPF_LDX &&
795 (BPF_MODE(insn->code) == BPF_PROBE_MEM ||
796 BPF_MODE(insn->code) == BPF_PROBE_MEMSX))
797 probe_prg = jit->prg;
798
799 switch (insn->code) {
800 /*
801 * BPF_MOV
802 */
803 case BPF_ALU | BPF_MOV | BPF_X:
804 switch (insn->off) {
805 case 0: /* DST = (u32) SRC */
806 /* llgfr %dst,%src */
807 EMIT4(0xb9160000, dst_reg, src_reg);
808 if (insn_is_zext(&insn[1]))
809 insn_count = 2;
810 break;
811 case 8: /* DST = (u32)(s8) SRC */
812 /* lbr %dst,%src */
813 EMIT4(0xb9260000, dst_reg, src_reg);
814 /* llgfr %dst,%dst */
815 EMIT4(0xb9160000, dst_reg, dst_reg);
816 break;
817 case 16: /* DST = (u32)(s16) SRC */
818 /* lhr %dst,%src */
819 EMIT4(0xb9270000, dst_reg, src_reg);
820 /* llgfr %dst,%dst */
821 EMIT4(0xb9160000, dst_reg, dst_reg);
822 break;
823 }
824 break;
825 case BPF_ALU64 | BPF_MOV | BPF_X:
826 switch (insn->off) {
827 case 0: /* DST = SRC */
828 /* lgr %dst,%src */
829 EMIT4(0xb9040000, dst_reg, src_reg);
830 break;
831 case 8: /* DST = (s8) SRC */
832 /* lgbr %dst,%src */
833 EMIT4(0xb9060000, dst_reg, src_reg);
834 break;
835 case 16: /* DST = (s16) SRC */
836 /* lghr %dst,%src */
837 EMIT4(0xb9070000, dst_reg, src_reg);
838 break;
839 case 32: /* DST = (s32) SRC */
840 /* lgfr %dst,%src */
841 EMIT4(0xb9140000, dst_reg, src_reg);
842 break;
843 }
844 break;
845 case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
846 /* llilf %dst,imm */
847 EMIT6_IMM(0xc00f0000, dst_reg, imm);
848 if (insn_is_zext(&insn[1]))
849 insn_count = 2;
850 break;
851 case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */
852 /* lgfi %dst,imm */
853 EMIT6_IMM(0xc0010000, dst_reg, imm);
854 break;
855 /*
856 * BPF_LD 64
857 */
858 case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
859 {
860 /* 16 byte instruction that uses two 'struct bpf_insn' */
861 u64 imm64;
862
863 imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32;
864 /* lgrl %dst,imm */
865 EMIT6_PCREL_RILB(0xc4080000, dst_reg, _EMIT_CONST_U64(imm64));
866 insn_count = 2;
867 break;
868 }
869 /*
870 * BPF_ADD
871 */
872 case BPF_ALU | BPF_ADD | BPF_X: /* dst = (u32) dst + (u32) src */
873 /* ar %dst,%src */
874 EMIT2(0x1a00, dst_reg, src_reg);
875 EMIT_ZERO(dst_reg);
876 break;
877 case BPF_ALU64 | BPF_ADD | BPF_X: /* dst = dst + src */
878 /* agr %dst,%src */
879 EMIT4(0xb9080000, dst_reg, src_reg);
880 break;
881 case BPF_ALU | BPF_ADD | BPF_K: /* dst = (u32) dst + (u32) imm */
882 if (imm != 0) {
883 /* alfi %dst,imm */
884 EMIT6_IMM(0xc20b0000, dst_reg, imm);
885 }
886 EMIT_ZERO(dst_reg);
887 break;
888 case BPF_ALU64 | BPF_ADD | BPF_K: /* dst = dst + imm */
889 if (!imm)
890 break;
891 /* agfi %dst,imm */
892 EMIT6_IMM(0xc2080000, dst_reg, imm);
893 break;
894 /*
895 * BPF_SUB
896 */
897 case BPF_ALU | BPF_SUB | BPF_X: /* dst = (u32) dst - (u32) src */
898 /* sr %dst,%src */
899 EMIT2(0x1b00, dst_reg, src_reg);
900 EMIT_ZERO(dst_reg);
901 break;
902 case BPF_ALU64 | BPF_SUB | BPF_X: /* dst = dst - src */
903 /* sgr %dst,%src */
904 EMIT4(0xb9090000, dst_reg, src_reg);
905 break;
906 case BPF_ALU | BPF_SUB | BPF_K: /* dst = (u32) dst - (u32) imm */
907 if (imm != 0) {
908 /* alfi %dst,-imm */
909 EMIT6_IMM(0xc20b0000, dst_reg, -imm);
910 }
911 EMIT_ZERO(dst_reg);
912 break;
913 case BPF_ALU64 | BPF_SUB | BPF_K: /* dst = dst - imm */
914 if (!imm)
915 break;
916 if (imm == -0x80000000) {
917 /* algfi %dst,0x80000000 */
918 EMIT6_IMM(0xc20a0000, dst_reg, 0x80000000);
919 } else {
920 /* agfi %dst,-imm */
921 EMIT6_IMM(0xc2080000, dst_reg, -imm);
922 }
923 break;
924 /*
925 * BPF_MUL
926 */
927 case BPF_ALU | BPF_MUL | BPF_X: /* dst = (u32) dst * (u32) src */
928 /* msr %dst,%src */
929 EMIT4(0xb2520000, dst_reg, src_reg);
930 EMIT_ZERO(dst_reg);
931 break;
932 case BPF_ALU64 | BPF_MUL | BPF_X: /* dst = dst * src */
933 /* msgr %dst,%src */
934 EMIT4(0xb90c0000, dst_reg, src_reg);
935 break;
936 case BPF_ALU | BPF_MUL | BPF_K: /* dst = (u32) dst * (u32) imm */
937 if (imm != 1) {
938 /* msfi %r5,imm */
939 EMIT6_IMM(0xc2010000, dst_reg, imm);
940 }
941 EMIT_ZERO(dst_reg);
942 break;
943 case BPF_ALU64 | BPF_MUL | BPF_K: /* dst = dst * imm */
944 if (imm == 1)
945 break;
946 /* msgfi %dst,imm */
947 EMIT6_IMM(0xc2000000, dst_reg, imm);
948 break;
949 /*
950 * BPF_DIV / BPF_MOD
951 */
952 case BPF_ALU | BPF_DIV | BPF_X:
953 case BPF_ALU | BPF_MOD | BPF_X:
954 {
955 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
956
957 switch (off) {
958 case 0: /* dst = (u32) dst {/,%} (u32) src */
959 /* xr %w0,%w0 */
960 EMIT2(0x1700, REG_W0, REG_W0);
961 /* lr %w1,%dst */
962 EMIT2(0x1800, REG_W1, dst_reg);
963 /* dlr %w0,%src */
964 EMIT4(0xb9970000, REG_W0, src_reg);
965 break;
966 case 1: /* dst = (u32) ((s32) dst {/,%} (s32) src) */
967 /* lgfr %r1,%dst */
968 EMIT4(0xb9140000, REG_W1, dst_reg);
969 /* dsgfr %r0,%src */
970 EMIT4(0xb91d0000, REG_W0, src_reg);
971 break;
972 }
973 /* llgfr %dst,%rc */
974 EMIT4(0xb9160000, dst_reg, rc_reg);
975 if (insn_is_zext(&insn[1]))
976 insn_count = 2;
977 break;
978 }
979 case BPF_ALU64 | BPF_DIV | BPF_X:
980 case BPF_ALU64 | BPF_MOD | BPF_X:
981 {
982 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
983
984 switch (off) {
985 case 0: /* dst = dst {/,%} src */
986 /* lghi %w0,0 */
987 EMIT4_IMM(0xa7090000, REG_W0, 0);
988 /* lgr %w1,%dst */
989 EMIT4(0xb9040000, REG_W1, dst_reg);
990 /* dlgr %w0,%src */
991 EMIT4(0xb9870000, REG_W0, src_reg);
992 break;
993 case 1: /* dst = (s64) dst {/,%} (s64) src */
994 /* lgr %w1,%dst */
995 EMIT4(0xb9040000, REG_W1, dst_reg);
996 /* dsgr %w0,%src */
997 EMIT4(0xb90d0000, REG_W0, src_reg);
998 break;
999 }
1000 /* lgr %dst,%rc */
1001 EMIT4(0xb9040000, dst_reg, rc_reg);
1002 break;
1003 }
1004 case BPF_ALU | BPF_DIV | BPF_K:
1005 case BPF_ALU | BPF_MOD | BPF_K:
1006 {
1007 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
1008
1009 if (imm == 1) {
1010 if (BPF_OP(insn->code) == BPF_MOD)
1011 /* lghi %dst,0 */
1012 EMIT4_IMM(0xa7090000, dst_reg, 0);
1013 else
1014 EMIT_ZERO(dst_reg);
1015 break;
1016 }
1017 if (!is_first_pass(jit) && can_use_ldisp_for_lit32(jit)) {
1018 switch (off) {
1019 case 0: /* dst = (u32) dst {/,%} (u32) imm */
1020 /* xr %w0,%w0 */
1021 EMIT2(0x1700, REG_W0, REG_W0);
1022 /* lr %w1,%dst */
1023 EMIT2(0x1800, REG_W1, dst_reg);
1024 /* dl %w0,<d(imm)>(%l) */
1025 EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0,
1026 REG_L, EMIT_CONST_U32(imm));
1027 break;
1028 case 1: /* dst = (s32) dst {/,%} (s32) imm */
1029 /* lgfr %r1,%dst */
1030 EMIT4(0xb9140000, REG_W1, dst_reg);
1031 /* dsgf %r0,<d(imm)>(%l) */
1032 EMIT6_DISP_LH(0xe3000000, 0x001d, REG_W0, REG_0,
1033 REG_L, EMIT_CONST_U32(imm));
1034 break;
1035 }
1036 } else {
1037 switch (off) {
1038 case 0: /* dst = (u32) dst {/,%} (u32) imm */
1039 /* xr %w0,%w0 */
1040 EMIT2(0x1700, REG_W0, REG_W0);
1041 /* lr %w1,%dst */
1042 EMIT2(0x1800, REG_W1, dst_reg);
1043 /* lrl %dst,imm */
1044 EMIT6_PCREL_RILB(0xc40d0000, dst_reg,
1045 _EMIT_CONST_U32(imm));
1046 jit->seen |= SEEN_LITERAL;
1047 /* dlr %w0,%dst */
1048 EMIT4(0xb9970000, REG_W0, dst_reg);
1049 break;
1050 case 1: /* dst = (s32) dst {/,%} (s32) imm */
1051 /* lgfr %w1,%dst */
1052 EMIT4(0xb9140000, REG_W1, dst_reg);
1053 /* lgfrl %dst,imm */
1054 EMIT6_PCREL_RILB(0xc40c0000, dst_reg,
1055 _EMIT_CONST_U32(imm));
1056 jit->seen |= SEEN_LITERAL;
1057 /* dsgr %w0,%dst */
1058 EMIT4(0xb90d0000, REG_W0, dst_reg);
1059 break;
1060 }
1061 }
1062 /* llgfr %dst,%rc */
1063 EMIT4(0xb9160000, dst_reg, rc_reg);
1064 if (insn_is_zext(&insn[1]))
1065 insn_count = 2;
1066 break;
1067 }
1068 case BPF_ALU64 | BPF_DIV | BPF_K:
1069 case BPF_ALU64 | BPF_MOD | BPF_K:
1070 {
1071 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
1072
1073 if (imm == 1) {
1074 if (BPF_OP(insn->code) == BPF_MOD)
1075 /* lhgi %dst,0 */
1076 EMIT4_IMM(0xa7090000, dst_reg, 0);
1077 break;
1078 }
1079 if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
1080 switch (off) {
1081 case 0: /* dst = dst {/,%} imm */
1082 /* lghi %w0,0 */
1083 EMIT4_IMM(0xa7090000, REG_W0, 0);
1084 /* lgr %w1,%dst */
1085 EMIT4(0xb9040000, REG_W1, dst_reg);
1086 /* dlg %w0,<d(imm)>(%l) */
1087 EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0,
1088 REG_L, EMIT_CONST_U64(imm));
1089 break;
1090 case 1: /* dst = (s64) dst {/,%} (s64) imm */
1091 /* lgr %w1,%dst */
1092 EMIT4(0xb9040000, REG_W1, dst_reg);
1093 /* dsg %w0,<d(imm)>(%l) */
1094 EMIT6_DISP_LH(0xe3000000, 0x000d, REG_W0, REG_0,
1095 REG_L, EMIT_CONST_U64(imm));
1096 break;
1097 }
1098 } else {
1099 switch (off) {
1100 case 0: /* dst = dst {/,%} imm */
1101 /* lghi %w0,0 */
1102 EMIT4_IMM(0xa7090000, REG_W0, 0);
1103 /* lgr %w1,%dst */
1104 EMIT4(0xb9040000, REG_W1, dst_reg);
1105 /* lgrl %dst,imm */
1106 EMIT6_PCREL_RILB(0xc4080000, dst_reg,
1107 _EMIT_CONST_U64(imm));
1108 jit->seen |= SEEN_LITERAL;
1109 /* dlgr %w0,%dst */
1110 EMIT4(0xb9870000, REG_W0, dst_reg);
1111 break;
1112 case 1: /* dst = (s64) dst {/,%} (s64) imm */
1113 /* lgr %w1,%dst */
1114 EMIT4(0xb9040000, REG_W1, dst_reg);
1115 /* lgrl %dst,imm */
1116 EMIT6_PCREL_RILB(0xc4080000, dst_reg,
1117 _EMIT_CONST_U64(imm));
1118 jit->seen |= SEEN_LITERAL;
1119 /* dsgr %w0,%dst */
1120 EMIT4(0xb90d0000, REG_W0, dst_reg);
1121 break;
1122 }
1123 }
1124 /* lgr %dst,%rc */
1125 EMIT4(0xb9040000, dst_reg, rc_reg);
1126 break;
1127 }
1128 /*
1129 * BPF_AND
1130 */
1131 case BPF_ALU | BPF_AND | BPF_X: /* dst = (u32) dst & (u32) src */
1132 /* nr %dst,%src */
1133 EMIT2(0x1400, dst_reg, src_reg);
1134 EMIT_ZERO(dst_reg);
1135 break;
1136 case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
1137 /* ngr %dst,%src */
1138 EMIT4(0xb9800000, dst_reg, src_reg);
1139 break;
1140 case BPF_ALU | BPF_AND | BPF_K: /* dst = (u32) dst & (u32) imm */
1141 /* nilf %dst,imm */
1142 EMIT6_IMM(0xc00b0000, dst_reg, imm);
1143 EMIT_ZERO(dst_reg);
1144 break;
1145 case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
1146 if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
1147 /* ng %dst,<d(imm)>(%l) */
1148 EMIT6_DISP_LH(0xe3000000, 0x0080,
1149 dst_reg, REG_0, REG_L,
1150 EMIT_CONST_U64(imm));
1151 } else {
1152 /* lgrl %w0,imm */
1153 EMIT6_PCREL_RILB(0xc4080000, REG_W0,
1154 _EMIT_CONST_U64(imm));
1155 jit->seen |= SEEN_LITERAL;
1156 /* ngr %dst,%w0 */
1157 EMIT4(0xb9800000, dst_reg, REG_W0);
1158 }
1159 break;
1160 /*
1161 * BPF_OR
1162 */
1163 case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
1164 /* or %dst,%src */
1165 EMIT2(0x1600, dst_reg, src_reg);
1166 EMIT_ZERO(dst_reg);
1167 break;
1168 case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
1169 /* ogr %dst,%src */
1170 EMIT4(0xb9810000, dst_reg, src_reg);
1171 break;
1172 case BPF_ALU | BPF_OR | BPF_K: /* dst = (u32) dst | (u32) imm */
1173 /* oilf %dst,imm */
1174 EMIT6_IMM(0xc00d0000, dst_reg, imm);
1175 EMIT_ZERO(dst_reg);
1176 break;
1177 case BPF_ALU64 | BPF_OR | BPF_K: /* dst = dst | imm */
1178 if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
1179 /* og %dst,<d(imm)>(%l) */
1180 EMIT6_DISP_LH(0xe3000000, 0x0081,
1181 dst_reg, REG_0, REG_L,
1182 EMIT_CONST_U64(imm));
1183 } else {
1184 /* lgrl %w0,imm */
1185 EMIT6_PCREL_RILB(0xc4080000, REG_W0,
1186 _EMIT_CONST_U64(imm));
1187 jit->seen |= SEEN_LITERAL;
1188 /* ogr %dst,%w0 */
1189 EMIT4(0xb9810000, dst_reg, REG_W0);
1190 }
1191 break;
1192 /*
1193 * BPF_XOR
1194 */
1195 case BPF_ALU | BPF_XOR | BPF_X: /* dst = (u32) dst ^ (u32) src */
1196 /* xr %dst,%src */
1197 EMIT2(0x1700, dst_reg, src_reg);
1198 EMIT_ZERO(dst_reg);
1199 break;
1200 case BPF_ALU64 | BPF_XOR | BPF_X: /* dst = dst ^ src */
1201 /* xgr %dst,%src */
1202 EMIT4(0xb9820000, dst_reg, src_reg);
1203 break;
1204 case BPF_ALU | BPF_XOR | BPF_K: /* dst = (u32) dst ^ (u32) imm */
1205 if (imm != 0) {
1206 /* xilf %dst,imm */
1207 EMIT6_IMM(0xc0070000, dst_reg, imm);
1208 }
1209 EMIT_ZERO(dst_reg);
1210 break;
1211 case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ imm */
1212 if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
1213 /* xg %dst,<d(imm)>(%l) */
1214 EMIT6_DISP_LH(0xe3000000, 0x0082,
1215 dst_reg, REG_0, REG_L,
1216 EMIT_CONST_U64(imm));
1217 } else {
1218 /* lgrl %w0,imm */
1219 EMIT6_PCREL_RILB(0xc4080000, REG_W0,
1220 _EMIT_CONST_U64(imm));
1221 jit->seen |= SEEN_LITERAL;
1222 /* xgr %dst,%w0 */
1223 EMIT4(0xb9820000, dst_reg, REG_W0);
1224 }
1225 break;
1226 /*
1227 * BPF_LSH
1228 */
1229 case BPF_ALU | BPF_LSH | BPF_X: /* dst = (u32) dst << (u32) src */
1230 /* sll %dst,0(%src) */
1231 EMIT4_DISP(0x89000000, dst_reg, src_reg, 0);
1232 EMIT_ZERO(dst_reg);
1233 break;
1234 case BPF_ALU64 | BPF_LSH | BPF_X: /* dst = dst << src */
1235 /* sllg %dst,%dst,0(%src) */
1236 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, src_reg, 0);
1237 break;
1238 case BPF_ALU | BPF_LSH | BPF_K: /* dst = (u32) dst << (u32) imm */
1239 if (imm != 0) {
1240 /* sll %dst,imm(%r0) */
1241 EMIT4_DISP(0x89000000, dst_reg, REG_0, imm);
1242 }
1243 EMIT_ZERO(dst_reg);
1244 break;
1245 case BPF_ALU64 | BPF_LSH | BPF_K: /* dst = dst << imm */
1246 if (imm == 0)
1247 break;
1248 /* sllg %dst,%dst,imm(%r0) */
1249 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, REG_0, imm);
1250 break;
1251 /*
1252 * BPF_RSH
1253 */
1254 case BPF_ALU | BPF_RSH | BPF_X: /* dst = (u32) dst >> (u32) src */
1255 /* srl %dst,0(%src) */
1256 EMIT4_DISP(0x88000000, dst_reg, src_reg, 0);
1257 EMIT_ZERO(dst_reg);
1258 break;
1259 case BPF_ALU64 | BPF_RSH | BPF_X: /* dst = dst >> src */
1260 /* srlg %dst,%dst,0(%src) */
1261 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, src_reg, 0);
1262 break;
1263 case BPF_ALU | BPF_RSH | BPF_K: /* dst = (u32) dst >> (u32) imm */
1264 if (imm != 0) {
1265 /* srl %dst,imm(%r0) */
1266 EMIT4_DISP(0x88000000, dst_reg, REG_0, imm);
1267 }
1268 EMIT_ZERO(dst_reg);
1269 break;
1270 case BPF_ALU64 | BPF_RSH | BPF_K: /* dst = dst >> imm */
1271 if (imm == 0)
1272 break;
1273 /* srlg %dst,%dst,imm(%r0) */
1274 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, REG_0, imm);
1275 break;
1276 /*
1277 * BPF_ARSH
1278 */
1279 case BPF_ALU | BPF_ARSH | BPF_X: /* ((s32) dst) >>= src */
1280 /* sra %dst,%dst,0(%src) */
1281 EMIT4_DISP(0x8a000000, dst_reg, src_reg, 0);
1282 EMIT_ZERO(dst_reg);
1283 break;
1284 case BPF_ALU64 | BPF_ARSH | BPF_X: /* ((s64) dst) >>= src */
1285 /* srag %dst,%dst,0(%src) */
1286 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, src_reg, 0);
1287 break;
1288 case BPF_ALU | BPF_ARSH | BPF_K: /* ((s32) dst >> imm */
1289 if (imm != 0) {
1290 /* sra %dst,imm(%r0) */
1291 EMIT4_DISP(0x8a000000, dst_reg, REG_0, imm);
1292 }
1293 EMIT_ZERO(dst_reg);
1294 break;
1295 case BPF_ALU64 | BPF_ARSH | BPF_K: /* ((s64) dst) >>= imm */
1296 if (imm == 0)
1297 break;
1298 /* srag %dst,%dst,imm(%r0) */
1299 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, REG_0, imm);
1300 break;
1301 /*
1302 * BPF_NEG
1303 */
1304 case BPF_ALU | BPF_NEG: /* dst = (u32) -dst */
1305 /* lcr %dst,%dst */
1306 EMIT2(0x1300, dst_reg, dst_reg);
1307 EMIT_ZERO(dst_reg);
1308 break;
1309 case BPF_ALU64 | BPF_NEG: /* dst = -dst */
1310 /* lcgr %dst,%dst */
1311 EMIT4(0xb9030000, dst_reg, dst_reg);
1312 break;
1313 /*
1314 * BPF_FROM_BE/LE
1315 */
1316 case BPF_ALU | BPF_END | BPF_FROM_BE:
1317 /* s390 is big endian, therefore only clear high order bytes */
1318 switch (imm) {
1319 case 16: /* dst = (u16) cpu_to_be16(dst) */
1320 /* llghr %dst,%dst */
1321 EMIT4(0xb9850000, dst_reg, dst_reg);
1322 if (insn_is_zext(&insn[1]))
1323 insn_count = 2;
1324 break;
1325 case 32: /* dst = (u32) cpu_to_be32(dst) */
1326 if (!fp->aux->verifier_zext)
1327 /* llgfr %dst,%dst */
1328 EMIT4(0xb9160000, dst_reg, dst_reg);
1329 break;
1330 case 64: /* dst = (u64) cpu_to_be64(dst) */
1331 break;
1332 }
1333 break;
1334 case BPF_ALU | BPF_END | BPF_FROM_LE:
1335 case BPF_ALU64 | BPF_END | BPF_FROM_LE:
1336 switch (imm) {
1337 case 16: /* dst = (u16) cpu_to_le16(dst) */
1338 /* lrvr %dst,%dst */
1339 EMIT4(0xb91f0000, dst_reg, dst_reg);
1340 /* srl %dst,16(%r0) */
1341 EMIT4_DISP(0x88000000, dst_reg, REG_0, 16);
1342 /* llghr %dst,%dst */
1343 EMIT4(0xb9850000, dst_reg, dst_reg);
1344 if (insn_is_zext(&insn[1]))
1345 insn_count = 2;
1346 break;
1347 case 32: /* dst = (u32) cpu_to_le32(dst) */
1348 /* lrvr %dst,%dst */
1349 EMIT4(0xb91f0000, dst_reg, dst_reg);
1350 if (!fp->aux->verifier_zext)
1351 /* llgfr %dst,%dst */
1352 EMIT4(0xb9160000, dst_reg, dst_reg);
1353 break;
1354 case 64: /* dst = (u64) cpu_to_le64(dst) */
1355 /* lrvgr %dst,%dst */
1356 EMIT4(0xb90f0000, dst_reg, dst_reg);
1357 break;
1358 }
1359 break;
1360 /*
1361 * BPF_NOSPEC (speculation barrier)
1362 */
1363 case BPF_ST | BPF_NOSPEC:
1364 break;
1365 /*
1366 * BPF_ST(X)
1367 */
1368 case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src_reg */
1369 /* stcy %src,off(%dst) */
1370 EMIT6_DISP_LH(0xe3000000, 0x0072, src_reg, dst_reg, REG_0, off);
1371 jit->seen |= SEEN_MEM;
1372 break;
1373 case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
1374 /* sthy %src,off(%dst) */
1375 EMIT6_DISP_LH(0xe3000000, 0x0070, src_reg, dst_reg, REG_0, off);
1376 jit->seen |= SEEN_MEM;
1377 break;
1378 case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
1379 /* sty %src,off(%dst) */
1380 EMIT6_DISP_LH(0xe3000000, 0x0050, src_reg, dst_reg, REG_0, off);
1381 jit->seen |= SEEN_MEM;
1382 break;
1383 case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
1384 /* stg %src,off(%dst) */
1385 EMIT6_DISP_LH(0xe3000000, 0x0024, src_reg, dst_reg, REG_0, off);
1386 jit->seen |= SEEN_MEM;
1387 break;
1388 case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
1389 /* lhi %w0,imm */
1390 EMIT4_IMM(0xa7080000, REG_W0, (u8) imm);
1391 /* stcy %w0,off(dst) */
1392 EMIT6_DISP_LH(0xe3000000, 0x0072, REG_W0, dst_reg, REG_0, off);
1393 jit->seen |= SEEN_MEM;
1394 break;
1395 case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
1396 /* lhi %w0,imm */
1397 EMIT4_IMM(0xa7080000, REG_W0, (u16) imm);
1398 /* sthy %w0,off(dst) */
1399 EMIT6_DISP_LH(0xe3000000, 0x0070, REG_W0, dst_reg, REG_0, off);
1400 jit->seen |= SEEN_MEM;
1401 break;
1402 case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
1403 /* llilf %w0,imm */
1404 EMIT6_IMM(0xc00f0000, REG_W0, (u32) imm);
1405 /* sty %w0,off(%dst) */
1406 EMIT6_DISP_LH(0xe3000000, 0x0050, REG_W0, dst_reg, REG_0, off);
1407 jit->seen |= SEEN_MEM;
1408 break;
1409 case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
1410 /* lgfi %w0,imm */
1411 EMIT6_IMM(0xc0010000, REG_W0, imm);
1412 /* stg %w0,off(%dst) */
1413 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, dst_reg, REG_0, off);
1414 jit->seen |= SEEN_MEM;
1415 break;
1416 /*
1417 * BPF_ATOMIC
1418 */
1419 case BPF_STX | BPF_ATOMIC | BPF_DW:
1420 case BPF_STX | BPF_ATOMIC | BPF_W:
1421 {
1422 bool is32 = BPF_SIZE(insn->code) == BPF_W;
1423
1424 switch (insn->imm) {
1425/* {op32|op64} {%w0|%src},%src,off(%dst) */
1426#define EMIT_ATOMIC(op32, op64) do { \
1427 EMIT6_DISP_LH(0xeb000000, is32 ? (op32) : (op64), \
1428 (insn->imm & BPF_FETCH) ? src_reg : REG_W0, \
1429 src_reg, dst_reg, off); \
1430 if (is32 && (insn->imm & BPF_FETCH)) \
1431 EMIT_ZERO(src_reg); \
1432} while (0)
1433 case BPF_ADD:
1434 case BPF_ADD | BPF_FETCH:
1435 /* {laal|laalg} */
1436 EMIT_ATOMIC(0x00fa, 0x00ea);
1437 break;
1438 case BPF_AND:
1439 case BPF_AND | BPF_FETCH:
1440 /* {lan|lang} */
1441 EMIT_ATOMIC(0x00f4, 0x00e4);
1442 break;
1443 case BPF_OR:
1444 case BPF_OR | BPF_FETCH:
1445 /* {lao|laog} */
1446 EMIT_ATOMIC(0x00f6, 0x00e6);
1447 break;
1448 case BPF_XOR:
1449 case BPF_XOR | BPF_FETCH:
1450 /* {lax|laxg} */
1451 EMIT_ATOMIC(0x00f7, 0x00e7);
1452 break;
1453#undef EMIT_ATOMIC
1454 case BPF_XCHG:
1455 /* {ly|lg} %w0,off(%dst) */
1456 EMIT6_DISP_LH(0xe3000000,
1457 is32 ? 0x0058 : 0x0004, REG_W0, REG_0,
1458 dst_reg, off);
1459 /* 0: {csy|csg} %w0,%src,off(%dst) */
1460 EMIT6_DISP_LH(0xeb000000, is32 ? 0x0014 : 0x0030,
1461 REG_W0, src_reg, dst_reg, off);
1462 /* brc 4,0b */
1463 EMIT4_PCREL_RIC(0xa7040000, 4, jit->prg - 6);
1464 /* {llgfr|lgr} %src,%w0 */
1465 EMIT4(is32 ? 0xb9160000 : 0xb9040000, src_reg, REG_W0);
1466 if (is32 && insn_is_zext(&insn[1]))
1467 insn_count = 2;
1468 break;
1469 case BPF_CMPXCHG:
1470 /* 0: {csy|csg} %b0,%src,off(%dst) */
1471 EMIT6_DISP_LH(0xeb000000, is32 ? 0x0014 : 0x0030,
1472 BPF_REG_0, src_reg, dst_reg, off);
1473 break;
1474 default:
1475 pr_err("Unknown atomic operation %02x\n", insn->imm);
1476 return -1;
1477 }
1478
1479 jit->seen |= SEEN_MEM;
1480 break;
1481 }
1482 /*
1483 * BPF_LDX
1484 */
1485 case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */
1486 case BPF_LDX | BPF_PROBE_MEM | BPF_B:
1487 /* llgc %dst,0(off,%src) */
1488 EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off);
1489 jit->seen |= SEEN_MEM;
1490 if (insn_is_zext(&insn[1]))
1491 insn_count = 2;
1492 break;
1493 case BPF_LDX | BPF_MEMSX | BPF_B: /* dst = *(s8 *)(ul) (src + off) */
1494 case BPF_LDX | BPF_PROBE_MEMSX | BPF_B:
1495 /* lgb %dst,0(off,%src) */
1496 EMIT6_DISP_LH(0xe3000000, 0x0077, dst_reg, src_reg, REG_0, off);
1497 jit->seen |= SEEN_MEM;
1498 break;
1499 case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
1500 case BPF_LDX | BPF_PROBE_MEM | BPF_H:
1501 /* llgh %dst,0(off,%src) */
1502 EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off);
1503 jit->seen |= SEEN_MEM;
1504 if (insn_is_zext(&insn[1]))
1505 insn_count = 2;
1506 break;
1507 case BPF_LDX | BPF_MEMSX | BPF_H: /* dst = *(s16 *)(ul) (src + off) */
1508 case BPF_LDX | BPF_PROBE_MEMSX | BPF_H:
1509 /* lgh %dst,0(off,%src) */
1510 EMIT6_DISP_LH(0xe3000000, 0x0015, dst_reg, src_reg, REG_0, off);
1511 jit->seen |= SEEN_MEM;
1512 break;
1513 case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */
1514 case BPF_LDX | BPF_PROBE_MEM | BPF_W:
1515 /* llgf %dst,off(%src) */
1516 jit->seen |= SEEN_MEM;
1517 EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off);
1518 if (insn_is_zext(&insn[1]))
1519 insn_count = 2;
1520 break;
1521 case BPF_LDX | BPF_MEMSX | BPF_W: /* dst = *(s32 *)(ul) (src + off) */
1522 case BPF_LDX | BPF_PROBE_MEMSX | BPF_W:
1523 /* lgf %dst,off(%src) */
1524 jit->seen |= SEEN_MEM;
1525 EMIT6_DISP_LH(0xe3000000, 0x0014, dst_reg, src_reg, REG_0, off);
1526 break;
1527 case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
1528 case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
1529 /* lg %dst,0(off,%src) */
1530 jit->seen |= SEEN_MEM;
1531 EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, src_reg, REG_0, off);
1532 break;
1533 /*
1534 * BPF_JMP / CALL
1535 */
1536 case BPF_JMP | BPF_CALL:
1537 {
1538 const struct btf_func_model *m;
1539 bool func_addr_fixed;
1540 int j, ret;
1541 u64 func;
1542
1543 ret = bpf_jit_get_func_addr(fp, insn, extra_pass,
1544 &func, &func_addr_fixed);
1545 if (ret < 0)
1546 return -1;
1547
1548 REG_SET_SEEN(BPF_REG_5);
1549 jit->seen |= SEEN_FUNC;
1550 /*
1551 * Copy the tail call counter to where the callee expects it.
1552 *
1553 * Note 1: The callee can increment the tail call counter, but
1554 * we do not load it back, since the x86 JIT does not do this
1555 * either.
1556 *
1557 * Note 2: We assume that the verifier does not let us call the
1558 * main program, which clears the tail call counter on entry.
1559 */
1560 /* mvc STK_OFF_TCCNT(4,%r15),N(%r15) */
1561 _EMIT6(0xd203f000 | STK_OFF_TCCNT,
1562 0xf000 | (STK_OFF_TCCNT + STK_OFF + stack_depth));
1563
1564 /* Sign-extend the kfunc arguments. */
1565 if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) {
1566 m = bpf_jit_find_kfunc_model(fp, insn);
1567 if (!m)
1568 return -1;
1569
1570 for (j = 0; j < m->nr_args; j++) {
1571 if (sign_extend(jit, BPF_REG_1 + j,
1572 m->arg_size[j],
1573 m->arg_flags[j]))
1574 return -1;
1575 }
1576 }
1577
1578 /* lgrl %w1,func */
1579 EMIT6_PCREL_RILB(0xc4080000, REG_W1, _EMIT_CONST_U64(func));
1580 /* %r1() */
1581 call_r1(jit);
1582 /* lgr %b0,%r2: load return value into %b0 */
1583 EMIT4(0xb9040000, BPF_REG_0, REG_2);
1584 break;
1585 }
1586 case BPF_JMP | BPF_TAIL_CALL: {
1587 int patch_1_clrj, patch_2_clij, patch_3_brc;
1588
1589 /*
1590 * Implicit input:
1591 * B1: pointer to ctx
1592 * B2: pointer to bpf_array
1593 * B3: index in bpf_array
1594 *
1595 * if (index >= array->map.max_entries)
1596 * goto out;
1597 */
1598
1599 /* llgf %w1,map.max_entries(%b2) */
1600 EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2,
1601 offsetof(struct bpf_array, map.max_entries));
1602 /* if ((u32)%b3 >= (u32)%w1) goto out; */
1603 /* clrj %b3,%w1,0xa,out */
1604 patch_1_clrj = jit->prg;
1605 EMIT6_PCREL_RIEB(0xec000000, 0x0077, BPF_REG_3, REG_W1, 0xa,
1606 jit->prg);
1607
1608 /*
1609 * if (tail_call_cnt++ >= MAX_TAIL_CALL_CNT)
1610 * goto out;
1611 */
1612
1613 if (jit->seen & SEEN_STACK)
1614 off = STK_OFF_TCCNT + STK_OFF + stack_depth;
1615 else
1616 off = STK_OFF_TCCNT;
1617 /* lhi %w0,1 */
1618 EMIT4_IMM(0xa7080000, REG_W0, 1);
1619 /* laal %w1,%w0,off(%r15) */
1620 EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, REG_15, off);
1621 /* clij %w1,MAX_TAIL_CALL_CNT-1,0x2,out */
1622 patch_2_clij = jit->prg;
1623 EMIT6_PCREL_RIEC(0xec000000, 0x007f, REG_W1, MAX_TAIL_CALL_CNT - 1,
1624 2, jit->prg);
1625
1626 /*
1627 * prog = array->ptrs[index];
1628 * if (prog == NULL)
1629 * goto out;
1630 */
1631
1632 /* llgfr %r1,%b3: %r1 = (u32) index */
1633 EMIT4(0xb9160000, REG_1, BPF_REG_3);
1634 /* sllg %r1,%r1,3: %r1 *= 8 */
1635 EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, REG_1, REG_0, 3);
1636 /* ltg %r1,prog(%b2,%r1) */
1637 EMIT6_DISP_LH(0xe3000000, 0x0002, REG_1, BPF_REG_2,
1638 REG_1, offsetof(struct bpf_array, ptrs));
1639 /* brc 0x8,out */
1640 patch_3_brc = jit->prg;
1641 EMIT4_PCREL_RIC(0xa7040000, 8, jit->prg);
1642
1643 /*
1644 * Restore registers before calling function
1645 */
1646 save_restore_regs(jit, REGS_RESTORE, stack_depth);
1647
1648 /*
1649 * goto *(prog->bpf_func + tail_call_start);
1650 */
1651
1652 /* lg %r1,bpf_func(%r1) */
1653 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, REG_1, REG_0,
1654 offsetof(struct bpf_prog, bpf_func));
1655 if (nospec_uses_trampoline()) {
1656 jit->seen |= SEEN_FUNC;
1657 /* aghi %r1,tail_call_start */
1658 EMIT4_IMM(0xa70b0000, REG_1, jit->tail_call_start);
1659 /* brcl 0xf,__s390_indirect_jump_r1 */
1660 EMIT6_PCREL_RILC(0xc0040000, 0xf, jit->r1_thunk_ip);
1661 } else {
1662 /* bc 0xf,tail_call_start(%r1) */
1663 _EMIT4(0x47f01000 + jit->tail_call_start);
1664 }
1665 /* out: */
1666 if (jit->prg_buf) {
1667 *(u16 *)(jit->prg_buf + patch_1_clrj + 2) =
1668 (jit->prg - patch_1_clrj) >> 1;
1669 *(u16 *)(jit->prg_buf + patch_2_clij + 2) =
1670 (jit->prg - patch_2_clij) >> 1;
1671 *(u16 *)(jit->prg_buf + patch_3_brc + 2) =
1672 (jit->prg - patch_3_brc) >> 1;
1673 }
1674 break;
1675 }
1676 case BPF_JMP | BPF_EXIT: /* return b0 */
1677 last = (i == fp->len - 1) ? 1 : 0;
1678 if (last)
1679 break;
1680 if (!is_first_pass(jit) && can_use_rel(jit, jit->exit_ip))
1681 /* brc 0xf, <exit> */
1682 EMIT4_PCREL_RIC(0xa7040000, 0xf, jit->exit_ip);
1683 else
1684 /* brcl 0xf, <exit> */
1685 EMIT6_PCREL_RILC(0xc0040000, 0xf, jit->exit_ip);
1686 break;
1687 /*
1688 * Branch relative (number of skipped instructions) to offset on
1689 * condition.
1690 *
1691 * Condition code to mask mapping:
1692 *
1693 * CC | Description | Mask
1694 * ------------------------------
1695 * 0 | Operands equal | 8
1696 * 1 | First operand low | 4
1697 * 2 | First operand high | 2
1698 * 3 | Unused | 1
1699 *
1700 * For s390x relative branches: ip = ip + off_bytes
1701 * For BPF relative branches: insn = insn + off_insns + 1
1702 *
1703 * For example for s390x with offset 0 we jump to the branch
1704 * instruction itself (loop) and for BPF with offset 0 we
1705 * branch to the instruction behind the branch.
1706 */
1707 case BPF_JMP32 | BPF_JA: /* if (true) */
1708 branch_oc_off = imm;
1709 fallthrough;
1710 case BPF_JMP | BPF_JA: /* if (true) */
1711 mask = 0xf000; /* j */
1712 goto branch_oc;
1713 case BPF_JMP | BPF_JSGT | BPF_K: /* ((s64) dst > (s64) imm) */
1714 case BPF_JMP32 | BPF_JSGT | BPF_K: /* ((s32) dst > (s32) imm) */
1715 mask = 0x2000; /* jh */
1716 goto branch_ks;
1717 case BPF_JMP | BPF_JSLT | BPF_K: /* ((s64) dst < (s64) imm) */
1718 case BPF_JMP32 | BPF_JSLT | BPF_K: /* ((s32) dst < (s32) imm) */
1719 mask = 0x4000; /* jl */
1720 goto branch_ks;
1721 case BPF_JMP | BPF_JSGE | BPF_K: /* ((s64) dst >= (s64) imm) */
1722 case BPF_JMP32 | BPF_JSGE | BPF_K: /* ((s32) dst >= (s32) imm) */
1723 mask = 0xa000; /* jhe */
1724 goto branch_ks;
1725 case BPF_JMP | BPF_JSLE | BPF_K: /* ((s64) dst <= (s64) imm) */
1726 case BPF_JMP32 | BPF_JSLE | BPF_K: /* ((s32) dst <= (s32) imm) */
1727 mask = 0xc000; /* jle */
1728 goto branch_ks;
1729 case BPF_JMP | BPF_JGT | BPF_K: /* (dst_reg > imm) */
1730 case BPF_JMP32 | BPF_JGT | BPF_K: /* ((u32) dst_reg > (u32) imm) */
1731 mask = 0x2000; /* jh */
1732 goto branch_ku;
1733 case BPF_JMP | BPF_JLT | BPF_K: /* (dst_reg < imm) */
1734 case BPF_JMP32 | BPF_JLT | BPF_K: /* ((u32) dst_reg < (u32) imm) */
1735 mask = 0x4000; /* jl */
1736 goto branch_ku;
1737 case BPF_JMP | BPF_JGE | BPF_K: /* (dst_reg >= imm) */
1738 case BPF_JMP32 | BPF_JGE | BPF_K: /* ((u32) dst_reg >= (u32) imm) */
1739 mask = 0xa000; /* jhe */
1740 goto branch_ku;
1741 case BPF_JMP | BPF_JLE | BPF_K: /* (dst_reg <= imm) */
1742 case BPF_JMP32 | BPF_JLE | BPF_K: /* ((u32) dst_reg <= (u32) imm) */
1743 mask = 0xc000; /* jle */
1744 goto branch_ku;
1745 case BPF_JMP | BPF_JNE | BPF_K: /* (dst_reg != imm) */
1746 case BPF_JMP32 | BPF_JNE | BPF_K: /* ((u32) dst_reg != (u32) imm) */
1747 mask = 0x7000; /* jne */
1748 goto branch_ku;
1749 case BPF_JMP | BPF_JEQ | BPF_K: /* (dst_reg == imm) */
1750 case BPF_JMP32 | BPF_JEQ | BPF_K: /* ((u32) dst_reg == (u32) imm) */
1751 mask = 0x8000; /* je */
1752 goto branch_ku;
1753 case BPF_JMP | BPF_JSET | BPF_K: /* (dst_reg & imm) */
1754 case BPF_JMP32 | BPF_JSET | BPF_K: /* ((u32) dst_reg & (u32) imm) */
1755 mask = 0x7000; /* jnz */
1756 if (BPF_CLASS(insn->code) == BPF_JMP32) {
1757 /* llilf %w1,imm (load zero extend imm) */
1758 EMIT6_IMM(0xc00f0000, REG_W1, imm);
1759 /* nr %w1,%dst */
1760 EMIT2(0x1400, REG_W1, dst_reg);
1761 } else {
1762 /* lgfi %w1,imm (load sign extend imm) */
1763 EMIT6_IMM(0xc0010000, REG_W1, imm);
1764 /* ngr %w1,%dst */
1765 EMIT4(0xb9800000, REG_W1, dst_reg);
1766 }
1767 goto branch_oc;
1768
1769 case BPF_JMP | BPF_JSGT | BPF_X: /* ((s64) dst > (s64) src) */
1770 case BPF_JMP32 | BPF_JSGT | BPF_X: /* ((s32) dst > (s32) src) */
1771 mask = 0x2000; /* jh */
1772 goto branch_xs;
1773 case BPF_JMP | BPF_JSLT | BPF_X: /* ((s64) dst < (s64) src) */
1774 case BPF_JMP32 | BPF_JSLT | BPF_X: /* ((s32) dst < (s32) src) */
1775 mask = 0x4000; /* jl */
1776 goto branch_xs;
1777 case BPF_JMP | BPF_JSGE | BPF_X: /* ((s64) dst >= (s64) src) */
1778 case BPF_JMP32 | BPF_JSGE | BPF_X: /* ((s32) dst >= (s32) src) */
1779 mask = 0xa000; /* jhe */
1780 goto branch_xs;
1781 case BPF_JMP | BPF_JSLE | BPF_X: /* ((s64) dst <= (s64) src) */
1782 case BPF_JMP32 | BPF_JSLE | BPF_X: /* ((s32) dst <= (s32) src) */
1783 mask = 0xc000; /* jle */
1784 goto branch_xs;
1785 case BPF_JMP | BPF_JGT | BPF_X: /* (dst > src) */
1786 case BPF_JMP32 | BPF_JGT | BPF_X: /* ((u32) dst > (u32) src) */
1787 mask = 0x2000; /* jh */
1788 goto branch_xu;
1789 case BPF_JMP | BPF_JLT | BPF_X: /* (dst < src) */
1790 case BPF_JMP32 | BPF_JLT | BPF_X: /* ((u32) dst < (u32) src) */
1791 mask = 0x4000; /* jl */
1792 goto branch_xu;
1793 case BPF_JMP | BPF_JGE | BPF_X: /* (dst >= src) */
1794 case BPF_JMP32 | BPF_JGE | BPF_X: /* ((u32) dst >= (u32) src) */
1795 mask = 0xa000; /* jhe */
1796 goto branch_xu;
1797 case BPF_JMP | BPF_JLE | BPF_X: /* (dst <= src) */
1798 case BPF_JMP32 | BPF_JLE | BPF_X: /* ((u32) dst <= (u32) src) */
1799 mask = 0xc000; /* jle */
1800 goto branch_xu;
1801 case BPF_JMP | BPF_JNE | BPF_X: /* (dst != src) */
1802 case BPF_JMP32 | BPF_JNE | BPF_X: /* ((u32) dst != (u32) src) */
1803 mask = 0x7000; /* jne */
1804 goto branch_xu;
1805 case BPF_JMP | BPF_JEQ | BPF_X: /* (dst == src) */
1806 case BPF_JMP32 | BPF_JEQ | BPF_X: /* ((u32) dst == (u32) src) */
1807 mask = 0x8000; /* je */
1808 goto branch_xu;
1809 case BPF_JMP | BPF_JSET | BPF_X: /* (dst & src) */
1810 case BPF_JMP32 | BPF_JSET | BPF_X: /* ((u32) dst & (u32) src) */
1811 {
1812 bool is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1813
1814 mask = 0x7000; /* jnz */
1815 /* nrk or ngrk %w1,%dst,%src */
1816 EMIT4_RRF((is_jmp32 ? 0xb9f40000 : 0xb9e40000),
1817 REG_W1, dst_reg, src_reg);
1818 goto branch_oc;
1819branch_ks:
1820 is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1821 /* cfi or cgfi %dst,imm */
1822 EMIT6_IMM(is_jmp32 ? 0xc20d0000 : 0xc20c0000,
1823 dst_reg, imm);
1824 if (!is_first_pass(jit) &&
1825 can_use_rel(jit, addrs[i + off + 1])) {
1826 /* brc mask,off */
1827 EMIT4_PCREL_RIC(0xa7040000,
1828 mask >> 12, addrs[i + off + 1]);
1829 } else {
1830 /* brcl mask,off */
1831 EMIT6_PCREL_RILC(0xc0040000,
1832 mask >> 12, addrs[i + off + 1]);
1833 }
1834 break;
1835branch_ku:
1836 /* lgfi %w1,imm (load sign extend imm) */
1837 src_reg = REG_1;
1838 EMIT6_IMM(0xc0010000, src_reg, imm);
1839 goto branch_xu;
1840branch_xs:
1841 is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1842 if (!is_first_pass(jit) &&
1843 can_use_rel(jit, addrs[i + off + 1])) {
1844 /* crj or cgrj %dst,%src,mask,off */
1845 EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0076 : 0x0064),
1846 dst_reg, src_reg, i, off, mask);
1847 } else {
1848 /* cr or cgr %dst,%src */
1849 if (is_jmp32)
1850 EMIT2(0x1900, dst_reg, src_reg);
1851 else
1852 EMIT4(0xb9200000, dst_reg, src_reg);
1853 /* brcl mask,off */
1854 EMIT6_PCREL_RILC(0xc0040000,
1855 mask >> 12, addrs[i + off + 1]);
1856 }
1857 break;
1858branch_xu:
1859 is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1860 if (!is_first_pass(jit) &&
1861 can_use_rel(jit, addrs[i + off + 1])) {
1862 /* clrj or clgrj %dst,%src,mask,off */
1863 EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0077 : 0x0065),
1864 dst_reg, src_reg, i, off, mask);
1865 } else {
1866 /* clr or clgr %dst,%src */
1867 if (is_jmp32)
1868 EMIT2(0x1500, dst_reg, src_reg);
1869 else
1870 EMIT4(0xb9210000, dst_reg, src_reg);
1871 /* brcl mask,off */
1872 EMIT6_PCREL_RILC(0xc0040000,
1873 mask >> 12, addrs[i + off + 1]);
1874 }
1875 break;
1876branch_oc:
1877 if (!is_first_pass(jit) &&
1878 can_use_rel(jit, addrs[i + branch_oc_off + 1])) {
1879 /* brc mask,off */
1880 EMIT4_PCREL_RIC(0xa7040000,
1881 mask >> 12,
1882 addrs[i + branch_oc_off + 1]);
1883 } else {
1884 /* brcl mask,off */
1885 EMIT6_PCREL_RILC(0xc0040000,
1886 mask >> 12,
1887 addrs[i + branch_oc_off + 1]);
1888 }
1889 break;
1890 }
1891 default: /* too complex, give up */
1892 pr_err("Unknown opcode %02x\n", insn->code);
1893 return -1;
1894 }
1895
1896 if (probe_prg != -1) {
1897 /*
1898 * Handlers of certain exceptions leave psw.addr pointing to
1899 * the instruction directly after the failing one. Therefore,
1900 * create two exception table entries and also add a nop in
1901 * case two probing instructions come directly after each
1902 * other.
1903 */
1904 nop_prg = jit->prg;
1905 /* bcr 0,%0 */
1906 _EMIT2(0x0700);
1907 err = bpf_jit_probe_mem(jit, fp, probe_prg, nop_prg);
1908 if (err < 0)
1909 return err;
1910 }
1911
1912 return insn_count;
1913}
1914
1915/*
1916 * Return whether new i-th instruction address does not violate any invariant
1917 */
1918static bool bpf_is_new_addr_sane(struct bpf_jit *jit, int i)
1919{
1920 /* On the first pass anything goes */
1921 if (is_first_pass(jit))
1922 return true;
1923
1924 /* The codegen pass must not change anything */
1925 if (is_codegen_pass(jit))
1926 return jit->addrs[i] == jit->prg;
1927
1928 /* Passes in between must not increase code size */
1929 return jit->addrs[i] >= jit->prg;
1930}
1931
1932/*
1933 * Update the address of i-th instruction
1934 */
1935static int bpf_set_addr(struct bpf_jit *jit, int i)
1936{
1937 int delta;
1938
1939 if (is_codegen_pass(jit)) {
1940 delta = jit->prg - jit->addrs[i];
1941 if (delta < 0)
1942 bpf_skip(jit, -delta);
1943 }
1944 if (WARN_ON_ONCE(!bpf_is_new_addr_sane(jit, i)))
1945 return -1;
1946 jit->addrs[i] = jit->prg;
1947 return 0;
1948}
1949
1950/*
1951 * Compile eBPF program into s390x code
1952 */
1953static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp,
1954 bool extra_pass, u32 stack_depth)
1955{
1956 int i, insn_count, lit32_size, lit64_size;
1957
1958 jit->lit32 = jit->lit32_start;
1959 jit->lit64 = jit->lit64_start;
1960 jit->prg = 0;
1961 jit->excnt = 0;
1962
1963 bpf_jit_prologue(jit, fp, stack_depth);
1964 if (bpf_set_addr(jit, 0) < 0)
1965 return -1;
1966 for (i = 0; i < fp->len; i += insn_count) {
1967 insn_count = bpf_jit_insn(jit, fp, i, extra_pass, stack_depth);
1968 if (insn_count < 0)
1969 return -1;
1970 /* Next instruction address */
1971 if (bpf_set_addr(jit, i + insn_count) < 0)
1972 return -1;
1973 }
1974 bpf_jit_epilogue(jit, stack_depth);
1975
1976 lit32_size = jit->lit32 - jit->lit32_start;
1977 lit64_size = jit->lit64 - jit->lit64_start;
1978 jit->lit32_start = jit->prg;
1979 if (lit32_size)
1980 jit->lit32_start = ALIGN(jit->lit32_start, 4);
1981 jit->lit64_start = jit->lit32_start + lit32_size;
1982 if (lit64_size)
1983 jit->lit64_start = ALIGN(jit->lit64_start, 8);
1984 jit->size = jit->lit64_start + lit64_size;
1985 jit->size_prg = jit->prg;
1986
1987 if (WARN_ON_ONCE(fp->aux->extable &&
1988 jit->excnt != fp->aux->num_exentries))
1989 /* Verifier bug - too many entries. */
1990 return -1;
1991
1992 return 0;
1993}
1994
1995bool bpf_jit_needs_zext(void)
1996{
1997 return true;
1998}
1999
2000struct s390_jit_data {
2001 struct bpf_binary_header *header;
2002 struct bpf_jit ctx;
2003 int pass;
2004};
2005
2006static struct bpf_binary_header *bpf_jit_alloc(struct bpf_jit *jit,
2007 struct bpf_prog *fp)
2008{
2009 struct bpf_binary_header *header;
2010 u32 extable_size;
2011 u32 code_size;
2012
2013 /* We need two entries per insn. */
2014 fp->aux->num_exentries *= 2;
2015
2016 code_size = roundup(jit->size,
2017 __alignof__(struct exception_table_entry));
2018 extable_size = fp->aux->num_exentries *
2019 sizeof(struct exception_table_entry);
2020 header = bpf_jit_binary_alloc(code_size + extable_size, &jit->prg_buf,
2021 8, jit_fill_hole);
2022 if (!header)
2023 return NULL;
2024 fp->aux->extable = (struct exception_table_entry *)
2025 (jit->prg_buf + code_size);
2026 return header;
2027}
2028
2029/*
2030 * Compile eBPF program "fp"
2031 */
2032struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
2033{
2034 u32 stack_depth = round_up(fp->aux->stack_depth, 8);
2035 struct bpf_prog *tmp, *orig_fp = fp;
2036 struct bpf_binary_header *header;
2037 struct s390_jit_data *jit_data;
2038 bool tmp_blinded = false;
2039 bool extra_pass = false;
2040 struct bpf_jit jit;
2041 int pass;
2042
2043 if (WARN_ON_ONCE(bpf_plt_end - bpf_plt != BPF_PLT_SIZE))
2044 return orig_fp;
2045
2046 if (!fp->jit_requested)
2047 return orig_fp;
2048
2049 tmp = bpf_jit_blind_constants(fp);
2050 /*
2051 * If blinding was requested and we failed during blinding,
2052 * we must fall back to the interpreter.
2053 */
2054 if (IS_ERR(tmp))
2055 return orig_fp;
2056 if (tmp != fp) {
2057 tmp_blinded = true;
2058 fp = tmp;
2059 }
2060
2061 jit_data = fp->aux->jit_data;
2062 if (!jit_data) {
2063 jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
2064 if (!jit_data) {
2065 fp = orig_fp;
2066 goto out;
2067 }
2068 fp->aux->jit_data = jit_data;
2069 }
2070 if (jit_data->ctx.addrs) {
2071 jit = jit_data->ctx;
2072 header = jit_data->header;
2073 extra_pass = true;
2074 pass = jit_data->pass + 1;
2075 goto skip_init_ctx;
2076 }
2077
2078 memset(&jit, 0, sizeof(jit));
2079 jit.addrs = kvcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
2080 if (jit.addrs == NULL) {
2081 fp = orig_fp;
2082 goto free_addrs;
2083 }
2084 /*
2085 * Three initial passes:
2086 * - 1/2: Determine clobbered registers
2087 * - 3: Calculate program size and addrs array
2088 */
2089 for (pass = 1; pass <= 3; pass++) {
2090 if (bpf_jit_prog(&jit, fp, extra_pass, stack_depth)) {
2091 fp = orig_fp;
2092 goto free_addrs;
2093 }
2094 }
2095 /*
2096 * Final pass: Allocate and generate program
2097 */
2098 header = bpf_jit_alloc(&jit, fp);
2099 if (!header) {
2100 fp = orig_fp;
2101 goto free_addrs;
2102 }
2103skip_init_ctx:
2104 if (bpf_jit_prog(&jit, fp, extra_pass, stack_depth)) {
2105 bpf_jit_binary_free(header);
2106 fp = orig_fp;
2107 goto free_addrs;
2108 }
2109 if (bpf_jit_enable > 1) {
2110 bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf);
2111 print_fn_code(jit.prg_buf, jit.size_prg);
2112 }
2113 if (!fp->is_func || extra_pass) {
2114 bpf_jit_binary_lock_ro(header);
2115 } else {
2116 jit_data->header = header;
2117 jit_data->ctx = jit;
2118 jit_data->pass = pass;
2119 }
2120 fp->bpf_func = (void *) jit.prg_buf;
2121 fp->jited = 1;
2122 fp->jited_len = jit.size;
2123
2124 if (!fp->is_func || extra_pass) {
2125 bpf_prog_fill_jited_linfo(fp, jit.addrs + 1);
2126free_addrs:
2127 kvfree(jit.addrs);
2128 kfree(jit_data);
2129 fp->aux->jit_data = NULL;
2130 }
2131out:
2132 if (tmp_blinded)
2133 bpf_jit_prog_release_other(fp, fp == orig_fp ?
2134 tmp : orig_fp);
2135 return fp;
2136}
2137
2138bool bpf_jit_supports_kfunc_call(void)
2139{
2140 return true;
2141}
2142
2143bool bpf_jit_supports_far_kfunc_call(void)
2144{
2145 return true;
2146}
2147
2148int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
2149 void *old_addr, void *new_addr)
2150{
2151 struct {
2152 u16 opc;
2153 s32 disp;
2154 } __packed insn;
2155 char expected_plt[BPF_PLT_SIZE];
2156 char current_plt[BPF_PLT_SIZE];
2157 char new_plt[BPF_PLT_SIZE];
2158 char *plt;
2159 char *ret;
2160 int err;
2161
2162 /* Verify the branch to be patched. */
2163 err = copy_from_kernel_nofault(&insn, ip, sizeof(insn));
2164 if (err < 0)
2165 return err;
2166 if (insn.opc != (0xc004 | (old_addr ? 0xf0 : 0)))
2167 return -EINVAL;
2168
2169 if (t == BPF_MOD_JUMP &&
2170 insn.disp == ((char *)new_addr - (char *)ip) >> 1) {
2171 /*
2172 * The branch already points to the destination,
2173 * there is no PLT.
2174 */
2175 } else {
2176 /* Verify the PLT. */
2177 plt = (char *)ip + (insn.disp << 1);
2178 err = copy_from_kernel_nofault(current_plt, plt, BPF_PLT_SIZE);
2179 if (err < 0)
2180 return err;
2181 ret = (char *)ip + 6;
2182 bpf_jit_plt(expected_plt, ret, old_addr);
2183 if (memcmp(current_plt, expected_plt, BPF_PLT_SIZE))
2184 return -EINVAL;
2185 /* Adjust the call address. */
2186 bpf_jit_plt(new_plt, ret, new_addr);
2187 s390_kernel_write(plt + (bpf_plt_target - bpf_plt),
2188 new_plt + (bpf_plt_target - bpf_plt),
2189 sizeof(void *));
2190 }
2191
2192 /* Adjust the mask of the branch. */
2193 insn.opc = 0xc004 | (new_addr ? 0xf0 : 0);
2194 s390_kernel_write((char *)ip + 1, (char *)&insn.opc + 1, 1);
2195
2196 /* Make the new code visible to the other CPUs. */
2197 text_poke_sync_lock();
2198
2199 return 0;
2200}
2201
2202struct bpf_tramp_jit {
2203 struct bpf_jit common;
2204 int orig_stack_args_off;/* Offset of arguments placed on stack by the
2205 * func_addr's original caller
2206 */
2207 int stack_size; /* Trampoline stack size */
2208 int backchain_off; /* Offset of backchain */
2209 int stack_args_off; /* Offset of stack arguments for calling
2210 * func_addr, has to be at the top
2211 */
2212 int reg_args_off; /* Offset of register arguments for calling
2213 * func_addr
2214 */
2215 int ip_off; /* For bpf_get_func_ip(), has to be at
2216 * (ctx - 16)
2217 */
2218 int arg_cnt_off; /* For bpf_get_func_arg_cnt(), has to be at
2219 * (ctx - 8)
2220 */
2221 int bpf_args_off; /* Offset of BPF_PROG context, which consists
2222 * of BPF arguments followed by return value
2223 */
2224 int retval_off; /* Offset of return value (see above) */
2225 int r7_r8_off; /* Offset of saved %r7 and %r8, which are used
2226 * for __bpf_prog_enter() return value and
2227 * func_addr respectively
2228 */
2229 int run_ctx_off; /* Offset of struct bpf_tramp_run_ctx */
2230 int tccnt_off; /* Offset of saved tailcall counter */
2231 int r14_off; /* Offset of saved %r14, has to be at the
2232 * bottom */
2233 int do_fexit; /* do_fexit: label */
2234};
2235
2236static void load_imm64(struct bpf_jit *jit, int dst_reg, u64 val)
2237{
2238 /* llihf %dst_reg,val_hi */
2239 EMIT6_IMM(0xc00e0000, dst_reg, (val >> 32));
2240 /* oilf %rdst_reg,val_lo */
2241 EMIT6_IMM(0xc00d0000, dst_reg, val);
2242}
2243
2244static int invoke_bpf_prog(struct bpf_tramp_jit *tjit,
2245 const struct btf_func_model *m,
2246 struct bpf_tramp_link *tlink, bool save_ret)
2247{
2248 struct bpf_jit *jit = &tjit->common;
2249 int cookie_off = tjit->run_ctx_off +
2250 offsetof(struct bpf_tramp_run_ctx, bpf_cookie);
2251 struct bpf_prog *p = tlink->link.prog;
2252 int patch;
2253
2254 /*
2255 * run_ctx.cookie = tlink->cookie;
2256 */
2257
2258 /* %r0 = tlink->cookie */
2259 load_imm64(jit, REG_W0, tlink->cookie);
2260 /* stg %r0,cookie_off(%r15) */
2261 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, REG_0, REG_15, cookie_off);
2262
2263 /*
2264 * if ((start = __bpf_prog_enter(p, &run_ctx)) == 0)
2265 * goto skip;
2266 */
2267
2268 /* %r1 = __bpf_prog_enter */
2269 load_imm64(jit, REG_1, (u64)bpf_trampoline_enter(p));
2270 /* %r2 = p */
2271 load_imm64(jit, REG_2, (u64)p);
2272 /* la %r3,run_ctx_off(%r15) */
2273 EMIT4_DISP(0x41000000, REG_3, REG_15, tjit->run_ctx_off);
2274 /* %r1() */
2275 call_r1(jit);
2276 /* ltgr %r7,%r2 */
2277 EMIT4(0xb9020000, REG_7, REG_2);
2278 /* brcl 8,skip */
2279 patch = jit->prg;
2280 EMIT6_PCREL_RILC(0xc0040000, 8, 0);
2281
2282 /*
2283 * retval = bpf_func(args, p->insnsi);
2284 */
2285
2286 /* %r1 = p->bpf_func */
2287 load_imm64(jit, REG_1, (u64)p->bpf_func);
2288 /* la %r2,bpf_args_off(%r15) */
2289 EMIT4_DISP(0x41000000, REG_2, REG_15, tjit->bpf_args_off);
2290 /* %r3 = p->insnsi */
2291 if (!p->jited)
2292 load_imm64(jit, REG_3, (u64)p->insnsi);
2293 /* %r1() */
2294 call_r1(jit);
2295 /* stg %r2,retval_off(%r15) */
2296 if (save_ret) {
2297 if (sign_extend(jit, REG_2, m->ret_size, m->ret_flags))
2298 return -1;
2299 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_2, REG_0, REG_15,
2300 tjit->retval_off);
2301 }
2302
2303 /* skip: */
2304 if (jit->prg_buf)
2305 *(u32 *)&jit->prg_buf[patch + 2] = (jit->prg - patch) >> 1;
2306
2307 /*
2308 * __bpf_prog_exit(p, start, &run_ctx);
2309 */
2310
2311 /* %r1 = __bpf_prog_exit */
2312 load_imm64(jit, REG_1, (u64)bpf_trampoline_exit(p));
2313 /* %r2 = p */
2314 load_imm64(jit, REG_2, (u64)p);
2315 /* lgr %r3,%r7 */
2316 EMIT4(0xb9040000, REG_3, REG_7);
2317 /* la %r4,run_ctx_off(%r15) */
2318 EMIT4_DISP(0x41000000, REG_4, REG_15, tjit->run_ctx_off);
2319 /* %r1() */
2320 call_r1(jit);
2321
2322 return 0;
2323}
2324
2325static int alloc_stack(struct bpf_tramp_jit *tjit, size_t size)
2326{
2327 int stack_offset = tjit->stack_size;
2328
2329 tjit->stack_size += size;
2330 return stack_offset;
2331}
2332
2333/* ABI uses %r2 - %r6 for parameter passing. */
2334#define MAX_NR_REG_ARGS 5
2335
2336/* The "L" field of the "mvc" instruction is 8 bits. */
2337#define MAX_MVC_SIZE 256
2338#define MAX_NR_STACK_ARGS (MAX_MVC_SIZE / sizeof(u64))
2339
2340/* -mfentry generates a 6-byte nop on s390x. */
2341#define S390X_PATCH_SIZE 6
2342
2343static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im,
2344 struct bpf_tramp_jit *tjit,
2345 const struct btf_func_model *m,
2346 u32 flags,
2347 struct bpf_tramp_links *tlinks,
2348 void *func_addr)
2349{
2350 struct bpf_tramp_links *fmod_ret = &tlinks[BPF_TRAMP_MODIFY_RETURN];
2351 struct bpf_tramp_links *fentry = &tlinks[BPF_TRAMP_FENTRY];
2352 struct bpf_tramp_links *fexit = &tlinks[BPF_TRAMP_FEXIT];
2353 int nr_bpf_args, nr_reg_args, nr_stack_args;
2354 struct bpf_jit *jit = &tjit->common;
2355 int arg, bpf_arg_off;
2356 int i, j;
2357
2358 /* Support as many stack arguments as "mvc" instruction can handle. */
2359 nr_reg_args = min_t(int, m->nr_args, MAX_NR_REG_ARGS);
2360 nr_stack_args = m->nr_args - nr_reg_args;
2361 if (nr_stack_args > MAX_NR_STACK_ARGS)
2362 return -ENOTSUPP;
2363
2364 /* Return to %r14, since func_addr and %r0 are not available. */
2365 if ((!func_addr && !(flags & BPF_TRAMP_F_ORIG_STACK)) ||
2366 (flags & BPF_TRAMP_F_INDIRECT))
2367 flags |= BPF_TRAMP_F_SKIP_FRAME;
2368
2369 /*
2370 * Compute how many arguments we need to pass to BPF programs.
2371 * BPF ABI mirrors that of x86_64: arguments that are 16 bytes or
2372 * smaller are packed into 1 or 2 registers; larger arguments are
2373 * passed via pointers.
2374 * In s390x ABI, arguments that are 8 bytes or smaller are packed into
2375 * a register; larger arguments are passed via pointers.
2376 * We need to deal with this difference.
2377 */
2378 nr_bpf_args = 0;
2379 for (i = 0; i < m->nr_args; i++) {
2380 if (m->arg_size[i] <= 8)
2381 nr_bpf_args += 1;
2382 else if (m->arg_size[i] <= 16)
2383 nr_bpf_args += 2;
2384 else
2385 return -ENOTSUPP;
2386 }
2387
2388 /*
2389 * Calculate the stack layout.
2390 */
2391
2392 /*
2393 * Allocate STACK_FRAME_OVERHEAD bytes for the callees. As the s390x
2394 * ABI requires, put our backchain at the end of the allocated memory.
2395 */
2396 tjit->stack_size = STACK_FRAME_OVERHEAD;
2397 tjit->backchain_off = tjit->stack_size - sizeof(u64);
2398 tjit->stack_args_off = alloc_stack(tjit, nr_stack_args * sizeof(u64));
2399 tjit->reg_args_off = alloc_stack(tjit, nr_reg_args * sizeof(u64));
2400 tjit->ip_off = alloc_stack(tjit, sizeof(u64));
2401 tjit->arg_cnt_off = alloc_stack(tjit, sizeof(u64));
2402 tjit->bpf_args_off = alloc_stack(tjit, nr_bpf_args * sizeof(u64));
2403 tjit->retval_off = alloc_stack(tjit, sizeof(u64));
2404 tjit->r7_r8_off = alloc_stack(tjit, 2 * sizeof(u64));
2405 tjit->run_ctx_off = alloc_stack(tjit,
2406 sizeof(struct bpf_tramp_run_ctx));
2407 tjit->tccnt_off = alloc_stack(tjit, sizeof(u64));
2408 tjit->r14_off = alloc_stack(tjit, sizeof(u64) * 2);
2409 /*
2410 * In accordance with the s390x ABI, the caller has allocated
2411 * STACK_FRAME_OVERHEAD bytes for us. 8 of them contain the caller's
2412 * backchain, and the rest we can use.
2413 */
2414 tjit->stack_size -= STACK_FRAME_OVERHEAD - sizeof(u64);
2415 tjit->orig_stack_args_off = tjit->stack_size + STACK_FRAME_OVERHEAD;
2416
2417 /* lgr %r1,%r15 */
2418 EMIT4(0xb9040000, REG_1, REG_15);
2419 /* aghi %r15,-stack_size */
2420 EMIT4_IMM(0xa70b0000, REG_15, -tjit->stack_size);
2421 /* stg %r1,backchain_off(%r15) */
2422 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_1, REG_0, REG_15,
2423 tjit->backchain_off);
2424 /* mvc tccnt_off(4,%r15),stack_size+STK_OFF_TCCNT(%r15) */
2425 _EMIT6(0xd203f000 | tjit->tccnt_off,
2426 0xf000 | (tjit->stack_size + STK_OFF_TCCNT));
2427 /* stmg %r2,%rN,fwd_reg_args_off(%r15) */
2428 if (nr_reg_args)
2429 EMIT6_DISP_LH(0xeb000000, 0x0024, REG_2,
2430 REG_2 + (nr_reg_args - 1), REG_15,
2431 tjit->reg_args_off);
2432 for (i = 0, j = 0; i < m->nr_args; i++) {
2433 if (i < MAX_NR_REG_ARGS)
2434 arg = REG_2 + i;
2435 else
2436 arg = tjit->orig_stack_args_off +
2437 (i - MAX_NR_REG_ARGS) * sizeof(u64);
2438 bpf_arg_off = tjit->bpf_args_off + j * sizeof(u64);
2439 if (m->arg_size[i] <= 8) {
2440 if (i < MAX_NR_REG_ARGS)
2441 /* stg %arg,bpf_arg_off(%r15) */
2442 EMIT6_DISP_LH(0xe3000000, 0x0024, arg,
2443 REG_0, REG_15, bpf_arg_off);
2444 else
2445 /* mvc bpf_arg_off(8,%r15),arg(%r15) */
2446 _EMIT6(0xd207f000 | bpf_arg_off,
2447 0xf000 | arg);
2448 j += 1;
2449 } else {
2450 if (i < MAX_NR_REG_ARGS) {
2451 /* mvc bpf_arg_off(16,%r15),0(%arg) */
2452 _EMIT6(0xd20ff000 | bpf_arg_off,
2453 reg2hex[arg] << 12);
2454 } else {
2455 /* lg %r1,arg(%r15) */
2456 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, REG_0,
2457 REG_15, arg);
2458 /* mvc bpf_arg_off(16,%r15),0(%r1) */
2459 _EMIT6(0xd20ff000 | bpf_arg_off, 0x1000);
2460 }
2461 j += 2;
2462 }
2463 }
2464 /* stmg %r7,%r8,r7_r8_off(%r15) */
2465 EMIT6_DISP_LH(0xeb000000, 0x0024, REG_7, REG_8, REG_15,
2466 tjit->r7_r8_off);
2467 /* stg %r14,r14_off(%r15) */
2468 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_14, REG_0, REG_15, tjit->r14_off);
2469
2470 if (flags & BPF_TRAMP_F_ORIG_STACK) {
2471 /*
2472 * The ftrace trampoline puts the return address (which is the
2473 * address of the original function + S390X_PATCH_SIZE) into
2474 * %r0; see ftrace_shared_hotpatch_trampoline_br and
2475 * ftrace_init_nop() for details.
2476 */
2477
2478 /* lgr %r8,%r0 */
2479 EMIT4(0xb9040000, REG_8, REG_0);
2480 } else {
2481 /* %r8 = func_addr + S390X_PATCH_SIZE */
2482 load_imm64(jit, REG_8, (u64)func_addr + S390X_PATCH_SIZE);
2483 }
2484
2485 /*
2486 * ip = func_addr;
2487 * arg_cnt = m->nr_args;
2488 */
2489
2490 if (flags & BPF_TRAMP_F_IP_ARG) {
2491 /* %r0 = func_addr */
2492 load_imm64(jit, REG_0, (u64)func_addr);
2493 /* stg %r0,ip_off(%r15) */
2494 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_0, REG_0, REG_15,
2495 tjit->ip_off);
2496 }
2497 /* lghi %r0,nr_bpf_args */
2498 EMIT4_IMM(0xa7090000, REG_0, nr_bpf_args);
2499 /* stg %r0,arg_cnt_off(%r15) */
2500 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_0, REG_0, REG_15,
2501 tjit->arg_cnt_off);
2502
2503 if (flags & BPF_TRAMP_F_CALL_ORIG) {
2504 /*
2505 * __bpf_tramp_enter(im);
2506 */
2507
2508 /* %r1 = __bpf_tramp_enter */
2509 load_imm64(jit, REG_1, (u64)__bpf_tramp_enter);
2510 /* %r2 = im */
2511 load_imm64(jit, REG_2, (u64)im);
2512 /* %r1() */
2513 call_r1(jit);
2514 }
2515
2516 for (i = 0; i < fentry->nr_links; i++)
2517 if (invoke_bpf_prog(tjit, m, fentry->links[i],
2518 flags & BPF_TRAMP_F_RET_FENTRY_RET))
2519 return -EINVAL;
2520
2521 if (fmod_ret->nr_links) {
2522 /*
2523 * retval = 0;
2524 */
2525
2526 /* xc retval_off(8,%r15),retval_off(%r15) */
2527 _EMIT6(0xd707f000 | tjit->retval_off,
2528 0xf000 | tjit->retval_off);
2529
2530 for (i = 0; i < fmod_ret->nr_links; i++) {
2531 if (invoke_bpf_prog(tjit, m, fmod_ret->links[i], true))
2532 return -EINVAL;
2533
2534 /*
2535 * if (retval)
2536 * goto do_fexit;
2537 */
2538
2539 /* ltg %r0,retval_off(%r15) */
2540 EMIT6_DISP_LH(0xe3000000, 0x0002, REG_0, REG_0, REG_15,
2541 tjit->retval_off);
2542 /* brcl 7,do_fexit */
2543 EMIT6_PCREL_RILC(0xc0040000, 7, tjit->do_fexit);
2544 }
2545 }
2546
2547 if (flags & BPF_TRAMP_F_CALL_ORIG) {
2548 /*
2549 * retval = func_addr(args);
2550 */
2551
2552 /* lmg %r2,%rN,reg_args_off(%r15) */
2553 if (nr_reg_args)
2554 EMIT6_DISP_LH(0xeb000000, 0x0004, REG_2,
2555 REG_2 + (nr_reg_args - 1), REG_15,
2556 tjit->reg_args_off);
2557 /* mvc stack_args_off(N,%r15),orig_stack_args_off(%r15) */
2558 if (nr_stack_args)
2559 _EMIT6(0xd200f000 |
2560 (nr_stack_args * sizeof(u64) - 1) << 16 |
2561 tjit->stack_args_off,
2562 0xf000 | tjit->orig_stack_args_off);
2563 /* mvc STK_OFF_TCCNT(4,%r15),tccnt_off(%r15) */
2564 _EMIT6(0xd203f000 | STK_OFF_TCCNT, 0xf000 | tjit->tccnt_off);
2565 /* lgr %r1,%r8 */
2566 EMIT4(0xb9040000, REG_1, REG_8);
2567 /* %r1() */
2568 call_r1(jit);
2569 /* stg %r2,retval_off(%r15) */
2570 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_2, REG_0, REG_15,
2571 tjit->retval_off);
2572
2573 im->ip_after_call = jit->prg_buf + jit->prg;
2574
2575 /*
2576 * The following nop will be patched by bpf_tramp_image_put().
2577 */
2578
2579 /* brcl 0,im->ip_epilogue */
2580 EMIT6_PCREL_RILC(0xc0040000, 0, (u64)im->ip_epilogue);
2581 }
2582
2583 /* do_fexit: */
2584 tjit->do_fexit = jit->prg;
2585 for (i = 0; i < fexit->nr_links; i++)
2586 if (invoke_bpf_prog(tjit, m, fexit->links[i], false))
2587 return -EINVAL;
2588
2589 if (flags & BPF_TRAMP_F_CALL_ORIG) {
2590 im->ip_epilogue = jit->prg_buf + jit->prg;
2591
2592 /*
2593 * __bpf_tramp_exit(im);
2594 */
2595
2596 /* %r1 = __bpf_tramp_exit */
2597 load_imm64(jit, REG_1, (u64)__bpf_tramp_exit);
2598 /* %r2 = im */
2599 load_imm64(jit, REG_2, (u64)im);
2600 /* %r1() */
2601 call_r1(jit);
2602 }
2603
2604 /* lmg %r2,%rN,reg_args_off(%r15) */
2605 if ((flags & BPF_TRAMP_F_RESTORE_REGS) && nr_reg_args)
2606 EMIT6_DISP_LH(0xeb000000, 0x0004, REG_2,
2607 REG_2 + (nr_reg_args - 1), REG_15,
2608 tjit->reg_args_off);
2609 /* lgr %r1,%r8 */
2610 if (!(flags & BPF_TRAMP_F_SKIP_FRAME))
2611 EMIT4(0xb9040000, REG_1, REG_8);
2612 /* lmg %r7,%r8,r7_r8_off(%r15) */
2613 EMIT6_DISP_LH(0xeb000000, 0x0004, REG_7, REG_8, REG_15,
2614 tjit->r7_r8_off);
2615 /* lg %r14,r14_off(%r15) */
2616 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_14, REG_0, REG_15, tjit->r14_off);
2617 /* lg %r2,retval_off(%r15) */
2618 if (flags & (BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_RET_FENTRY_RET))
2619 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_2, REG_0, REG_15,
2620 tjit->retval_off);
2621 /* mvc stack_size+STK_OFF_TCCNT(4,%r15),tccnt_off(%r15) */
2622 _EMIT6(0xd203f000 | (tjit->stack_size + STK_OFF_TCCNT),
2623 0xf000 | tjit->tccnt_off);
2624 /* aghi %r15,stack_size */
2625 EMIT4_IMM(0xa70b0000, REG_15, tjit->stack_size);
2626 /* Emit an expoline for the following indirect jump. */
2627 if (nospec_uses_trampoline())
2628 emit_expoline(jit);
2629 if (flags & BPF_TRAMP_F_SKIP_FRAME)
2630 /* br %r14 */
2631 _EMIT2(0x07fe);
2632 else
2633 /* br %r1 */
2634 _EMIT2(0x07f1);
2635
2636 emit_r1_thunk(jit);
2637
2638 return 0;
2639}
2640
2641int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
2642 struct bpf_tramp_links *tlinks, void *orig_call)
2643{
2644 struct bpf_tramp_image im;
2645 struct bpf_tramp_jit tjit;
2646 int ret;
2647
2648 memset(&tjit, 0, sizeof(tjit));
2649
2650 ret = __arch_prepare_bpf_trampoline(&im, &tjit, m, flags,
2651 tlinks, orig_call);
2652
2653 return ret < 0 ? ret : tjit.common.prg;
2654}
2655
2656int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image,
2657 void *image_end, const struct btf_func_model *m,
2658 u32 flags, struct bpf_tramp_links *tlinks,
2659 void *func_addr)
2660{
2661 struct bpf_tramp_jit tjit;
2662 int ret;
2663
2664 /* Compute offsets, check whether the code fits. */
2665 memset(&tjit, 0, sizeof(tjit));
2666 ret = __arch_prepare_bpf_trampoline(im, &tjit, m, flags,
2667 tlinks, func_addr);
2668
2669 if (ret < 0)
2670 return ret;
2671 if (tjit.common.prg > (char *)image_end - (char *)image)
2672 /*
2673 * Use the same error code as for exceeding
2674 * BPF_MAX_TRAMP_LINKS.
2675 */
2676 return -E2BIG;
2677
2678 tjit.common.prg = 0;
2679 tjit.common.prg_buf = image;
2680 ret = __arch_prepare_bpf_trampoline(im, &tjit, m, flags,
2681 tlinks, func_addr);
2682
2683 return ret < 0 ? ret : tjit.common.prg;
2684}
2685
2686bool bpf_jit_supports_subprog_tailcalls(void)
2687{
2688 return true;
2689}
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 <asm/cacheflush.h>
27#include <asm/dis.h>
28#include <asm/facility.h>
29#include <asm/nospec-branch.h>
30#include <asm/set_memory.h>
31#include "bpf_jit.h"
32
33struct bpf_jit {
34 u32 seen; /* Flags to remember seen eBPF instructions */
35 u32 seen_reg[16]; /* Array to remember which registers are used */
36 u32 *addrs; /* Array with relative instruction addresses */
37 u8 *prg_buf; /* Start of program */
38 int size; /* Size of program and literal pool */
39 int size_prg; /* Size of program */
40 int prg; /* Current position in program */
41 int lit_start; /* Start of literal pool */
42 int lit; /* Current position in literal pool */
43 int base_ip; /* Base address for literal pool */
44 int ret0_ip; /* Address of return 0 */
45 int exit_ip; /* Address of exit */
46 int r1_thunk_ip; /* Address of expoline thunk for 'br %r1' */
47 int r14_thunk_ip; /* Address of expoline thunk for 'br %r14' */
48 int tail_call_start; /* Tail call start offset */
49 int labels[1]; /* Labels for local jumps */
50};
51
52#define BPF_SIZE_MAX 0xffff /* Max size for program (16 bit branches) */
53
54#define SEEN_SKB 1 /* skb access */
55#define SEEN_MEM 2 /* use mem[] for temporary storage */
56#define SEEN_RET0 4 /* ret0_ip points to a valid return 0 */
57#define SEEN_LITERAL 8 /* code uses literals */
58#define SEEN_FUNC 16 /* calls C functions */
59#define SEEN_TAIL_CALL 32 /* code uses tail calls */
60#define SEEN_REG_AX 64 /* code uses constant blinding */
61#define SEEN_STACK (SEEN_FUNC | SEEN_MEM | SEEN_SKB)
62
63/*
64 * s390 registers
65 */
66#define REG_W0 (MAX_BPF_JIT_REG + 0) /* Work register 1 (even) */
67#define REG_W1 (MAX_BPF_JIT_REG + 1) /* Work register 2 (odd) */
68#define REG_SKB_DATA (MAX_BPF_JIT_REG + 2) /* SKB data register */
69#define REG_L (MAX_BPF_JIT_REG + 3) /* Literal pool register */
70#define REG_15 (MAX_BPF_JIT_REG + 4) /* Register 15 */
71#define REG_0 REG_W0 /* Register 0 */
72#define REG_1 REG_W1 /* Register 1 */
73#define REG_2 BPF_REG_1 /* Register 2 */
74#define REG_14 BPF_REG_0 /* Register 14 */
75
76/*
77 * Mapping of BPF registers to s390 registers
78 */
79static const int reg2hex[] = {
80 /* Return code */
81 [BPF_REG_0] = 14,
82 /* Function parameters */
83 [BPF_REG_1] = 2,
84 [BPF_REG_2] = 3,
85 [BPF_REG_3] = 4,
86 [BPF_REG_4] = 5,
87 [BPF_REG_5] = 6,
88 /* Call saved registers */
89 [BPF_REG_6] = 7,
90 [BPF_REG_7] = 8,
91 [BPF_REG_8] = 9,
92 [BPF_REG_9] = 10,
93 /* BPF stack pointer */
94 [BPF_REG_FP] = 13,
95 /* Register for blinding (shared with REG_SKB_DATA) */
96 [BPF_REG_AX] = 12,
97 /* SKB data pointer */
98 [REG_SKB_DATA] = 12,
99 /* Work registers for s390x backend */
100 [REG_W0] = 0,
101 [REG_W1] = 1,
102 [REG_L] = 11,
103 [REG_15] = 15,
104};
105
106static inline u32 reg(u32 dst_reg, u32 src_reg)
107{
108 return reg2hex[dst_reg] << 4 | reg2hex[src_reg];
109}
110
111static inline u32 reg_high(u32 reg)
112{
113 return reg2hex[reg] << 4;
114}
115
116static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
117{
118 u32 r1 = reg2hex[b1];
119
120 if (!jit->seen_reg[r1] && r1 >= 6 && r1 <= 15)
121 jit->seen_reg[r1] = 1;
122}
123
124#define REG_SET_SEEN(b1) \
125({ \
126 reg_set_seen(jit, b1); \
127})
128
129#define REG_SEEN(b1) jit->seen_reg[reg2hex[(b1)]]
130
131/*
132 * EMIT macros for code generation
133 */
134
135#define _EMIT2(op) \
136({ \
137 if (jit->prg_buf) \
138 *(u16 *) (jit->prg_buf + jit->prg) = op; \
139 jit->prg += 2; \
140})
141
142#define EMIT2(op, b1, b2) \
143({ \
144 _EMIT2(op | reg(b1, b2)); \
145 REG_SET_SEEN(b1); \
146 REG_SET_SEEN(b2); \
147})
148
149#define _EMIT4(op) \
150({ \
151 if (jit->prg_buf) \
152 *(u32 *) (jit->prg_buf + jit->prg) = op; \
153 jit->prg += 4; \
154})
155
156#define EMIT4(op, b1, b2) \
157({ \
158 _EMIT4(op | reg(b1, b2)); \
159 REG_SET_SEEN(b1); \
160 REG_SET_SEEN(b2); \
161})
162
163#define EMIT4_RRF(op, b1, b2, b3) \
164({ \
165 _EMIT4(op | reg_high(b3) << 8 | reg(b1, b2)); \
166 REG_SET_SEEN(b1); \
167 REG_SET_SEEN(b2); \
168 REG_SET_SEEN(b3); \
169})
170
171#define _EMIT4_DISP(op, disp) \
172({ \
173 unsigned int __disp = (disp) & 0xfff; \
174 _EMIT4(op | __disp); \
175})
176
177#define EMIT4_DISP(op, b1, b2, disp) \
178({ \
179 _EMIT4_DISP(op | reg_high(b1) << 16 | \
180 reg_high(b2) << 8, disp); \
181 REG_SET_SEEN(b1); \
182 REG_SET_SEEN(b2); \
183})
184
185#define EMIT4_IMM(op, b1, imm) \
186({ \
187 unsigned int __imm = (imm) & 0xffff; \
188 _EMIT4(op | reg_high(b1) << 16 | __imm); \
189 REG_SET_SEEN(b1); \
190})
191
192#define EMIT4_PCREL(op, pcrel) \
193({ \
194 long __pcrel = ((pcrel) >> 1) & 0xffff; \
195 _EMIT4(op | __pcrel); \
196})
197
198#define _EMIT6(op1, op2) \
199({ \
200 if (jit->prg_buf) { \
201 *(u32 *) (jit->prg_buf + jit->prg) = op1; \
202 *(u16 *) (jit->prg_buf + jit->prg + 4) = op2; \
203 } \
204 jit->prg += 6; \
205})
206
207#define _EMIT6_DISP(op1, op2, disp) \
208({ \
209 unsigned int __disp = (disp) & 0xfff; \
210 _EMIT6(op1 | __disp, op2); \
211})
212
213#define _EMIT6_DISP_LH(op1, op2, disp) \
214({ \
215 u32 _disp = (u32) disp; \
216 unsigned int __disp_h = _disp & 0xff000; \
217 unsigned int __disp_l = _disp & 0x00fff; \
218 _EMIT6(op1 | __disp_l, op2 | __disp_h >> 4); \
219})
220
221#define EMIT6_DISP_LH(op1, op2, b1, b2, b3, disp) \
222({ \
223 _EMIT6_DISP_LH(op1 | reg(b1, b2) << 16 | \
224 reg_high(b3) << 8, op2, disp); \
225 REG_SET_SEEN(b1); \
226 REG_SET_SEEN(b2); \
227 REG_SET_SEEN(b3); \
228})
229
230#define EMIT6_PCREL_LABEL(op1, op2, b1, b2, label, mask) \
231({ \
232 int rel = (jit->labels[label] - jit->prg) >> 1; \
233 _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), \
234 op2 | mask << 12); \
235 REG_SET_SEEN(b1); \
236 REG_SET_SEEN(b2); \
237})
238
239#define EMIT6_PCREL_IMM_LABEL(op1, op2, b1, imm, label, mask) \
240({ \
241 int rel = (jit->labels[label] - jit->prg) >> 1; \
242 _EMIT6(op1 | (reg_high(b1) | mask) << 16 | \
243 (rel & 0xffff), op2 | (imm & 0xff) << 8); \
244 REG_SET_SEEN(b1); \
245 BUILD_BUG_ON(((unsigned long) imm) > 0xff); \
246})
247
248#define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask) \
249({ \
250 /* Branch instruction needs 6 bytes */ \
251 int rel = (addrs[i + off + 1] - (addrs[i + 1] - 6)) / 2;\
252 _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), op2 | mask); \
253 REG_SET_SEEN(b1); \
254 REG_SET_SEEN(b2); \
255})
256
257#define EMIT6_PCREL_RILB(op, b, target) \
258({ \
259 int rel = (target - jit->prg) / 2; \
260 _EMIT6(op | reg_high(b) << 16 | rel >> 16, rel & 0xffff); \
261 REG_SET_SEEN(b); \
262})
263
264#define EMIT6_PCREL_RIL(op, target) \
265({ \
266 int rel = (target - jit->prg) / 2; \
267 _EMIT6(op | rel >> 16, rel & 0xffff); \
268})
269
270#define _EMIT6_IMM(op, imm) \
271({ \
272 unsigned int __imm = (imm); \
273 _EMIT6(op | (__imm >> 16), __imm & 0xffff); \
274})
275
276#define EMIT6_IMM(op, b1, imm) \
277({ \
278 _EMIT6_IMM(op | reg_high(b1) << 16, imm); \
279 REG_SET_SEEN(b1); \
280})
281
282#define EMIT_CONST_U32(val) \
283({ \
284 unsigned int ret; \
285 ret = jit->lit - jit->base_ip; \
286 jit->seen |= SEEN_LITERAL; \
287 if (jit->prg_buf) \
288 *(u32 *) (jit->prg_buf + jit->lit) = (u32) val; \
289 jit->lit += 4; \
290 ret; \
291})
292
293#define EMIT_CONST_U64(val) \
294({ \
295 unsigned int ret; \
296 ret = jit->lit - jit->base_ip; \
297 jit->seen |= SEEN_LITERAL; \
298 if (jit->prg_buf) \
299 *(u64 *) (jit->prg_buf + jit->lit) = (u64) val; \
300 jit->lit += 8; \
301 ret; \
302})
303
304#define EMIT_ZERO(b1) \
305({ \
306 /* llgfr %dst,%dst (zero extend to 64 bit) */ \
307 EMIT4(0xb9160000, b1, b1); \
308 REG_SET_SEEN(b1); \
309})
310
311/*
312 * Fill whole space with illegal instructions
313 */
314static void jit_fill_hole(void *area, unsigned int size)
315{
316 memset(area, 0, size);
317}
318
319/*
320 * Save registers from "rs" (register start) to "re" (register end) on stack
321 */
322static void save_regs(struct bpf_jit *jit, u32 rs, u32 re)
323{
324 u32 off = STK_OFF_R6 + (rs - 6) * 8;
325
326 if (rs == re)
327 /* stg %rs,off(%r15) */
328 _EMIT6(0xe300f000 | rs << 20 | off, 0x0024);
329 else
330 /* stmg %rs,%re,off(%r15) */
331 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0024, off);
332}
333
334/*
335 * Restore registers from "rs" (register start) to "re" (register end) on stack
336 */
337static void restore_regs(struct bpf_jit *jit, u32 rs, u32 re, u32 stack_depth)
338{
339 u32 off = STK_OFF_R6 + (rs - 6) * 8;
340
341 if (jit->seen & SEEN_STACK)
342 off += STK_OFF + stack_depth;
343
344 if (rs == re)
345 /* lg %rs,off(%r15) */
346 _EMIT6(0xe300f000 | rs << 20 | off, 0x0004);
347 else
348 /* lmg %rs,%re,off(%r15) */
349 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0004, off);
350}
351
352/*
353 * Return first seen register (from start)
354 */
355static int get_start(struct bpf_jit *jit, int start)
356{
357 int i;
358
359 for (i = start; i <= 15; i++) {
360 if (jit->seen_reg[i])
361 return i;
362 }
363 return 0;
364}
365
366/*
367 * Return last seen register (from start) (gap >= 2)
368 */
369static int get_end(struct bpf_jit *jit, int start)
370{
371 int i;
372
373 for (i = start; i < 15; i++) {
374 if (!jit->seen_reg[i] && !jit->seen_reg[i + 1])
375 return i - 1;
376 }
377 return jit->seen_reg[15] ? 15 : 14;
378}
379
380#define REGS_SAVE 1
381#define REGS_RESTORE 0
382/*
383 * Save and restore clobbered registers (6-15) on stack.
384 * We save/restore registers in chunks with gap >= 2 registers.
385 */
386static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth)
387{
388
389 int re = 6, rs;
390
391 do {
392 rs = get_start(jit, re);
393 if (!rs)
394 break;
395 re = get_end(jit, rs + 1);
396 if (op == REGS_SAVE)
397 save_regs(jit, rs, re);
398 else
399 restore_regs(jit, rs, re, stack_depth);
400 re++;
401 } while (re <= 15);
402}
403
404/*
405 * For SKB access %b1 contains the SKB pointer. For "bpf_jit.S"
406 * we store the SKB header length on the stack and the SKB data
407 * pointer in REG_SKB_DATA if BPF_REG_AX is not used.
408 */
409static void emit_load_skb_data_hlen(struct bpf_jit *jit)
410{
411 /* Header length: llgf %w1,<len>(%b1) */
412 EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_1,
413 offsetof(struct sk_buff, len));
414 /* s %w1,<data_len>(%b1) */
415 EMIT4_DISP(0x5b000000, REG_W1, BPF_REG_1,
416 offsetof(struct sk_buff, data_len));
417 /* stg %w1,ST_OFF_HLEN(%r0,%r15) */
418 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15, STK_OFF_HLEN);
419 if (!(jit->seen & SEEN_REG_AX))
420 /* lg %skb_data,data_off(%b1) */
421 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0,
422 BPF_REG_1, offsetof(struct sk_buff, data));
423}
424
425/*
426 * Emit function prologue
427 *
428 * Save registers and create stack frame if necessary.
429 * See stack frame layout desription in "bpf_jit.h"!
430 */
431static void bpf_jit_prologue(struct bpf_jit *jit, u32 stack_depth)
432{
433 if (jit->seen & SEEN_TAIL_CALL) {
434 /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */
435 _EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT);
436 } else {
437 /* j tail_call_start: NOP if no tail calls are used */
438 EMIT4_PCREL(0xa7f40000, 6);
439 _EMIT2(0);
440 }
441 /* Tail calls have to skip above initialization */
442 jit->tail_call_start = jit->prg;
443 /* Save registers */
444 save_restore_regs(jit, REGS_SAVE, stack_depth);
445 /* Setup literal pool */
446 if (jit->seen & SEEN_LITERAL) {
447 /* basr %r13,0 */
448 EMIT2(0x0d00, REG_L, REG_0);
449 jit->base_ip = jit->prg;
450 }
451 /* Setup stack and backchain */
452 if (jit->seen & SEEN_STACK) {
453 if (jit->seen & SEEN_FUNC)
454 /* lgr %w1,%r15 (backchain) */
455 EMIT4(0xb9040000, REG_W1, REG_15);
456 /* la %bfp,STK_160_UNUSED(%r15) (BPF frame pointer) */
457 EMIT4_DISP(0x41000000, BPF_REG_FP, REG_15, STK_160_UNUSED);
458 /* aghi %r15,-STK_OFF */
459 EMIT4_IMM(0xa70b0000, REG_15, -(STK_OFF + stack_depth));
460 if (jit->seen & SEEN_FUNC)
461 /* stg %w1,152(%r15) (backchain) */
462 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
463 REG_15, 152);
464 }
465 if (jit->seen & SEEN_SKB) {
466 emit_load_skb_data_hlen(jit);
467 /* stg %b1,ST_OFF_SKBP(%r0,%r15) */
468 EMIT6_DISP_LH(0xe3000000, 0x0024, BPF_REG_1, REG_0, REG_15,
469 STK_OFF_SKBP);
470 }
471}
472
473/*
474 * Function epilogue
475 */
476static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
477{
478 /* Return 0 */
479 if (jit->seen & SEEN_RET0) {
480 jit->ret0_ip = jit->prg;
481 /* lghi %b0,0 */
482 EMIT4_IMM(0xa7090000, BPF_REG_0, 0);
483 }
484 jit->exit_ip = jit->prg;
485 /* Load exit code: lgr %r2,%b0 */
486 EMIT4(0xb9040000, REG_2, BPF_REG_0);
487 /* Restore registers */
488 save_restore_regs(jit, REGS_RESTORE, stack_depth);
489 if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable) {
490 jit->r14_thunk_ip = jit->prg;
491 /* Generate __s390_indirect_jump_r14 thunk */
492 if (test_facility(35)) {
493 /* exrl %r0,.+10 */
494 EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
495 } else {
496 /* larl %r1,.+14 */
497 EMIT6_PCREL_RILB(0xc0000000, REG_1, jit->prg + 14);
498 /* ex 0,0(%r1) */
499 EMIT4_DISP(0x44000000, REG_0, REG_1, 0);
500 }
501 /* j . */
502 EMIT4_PCREL(0xa7f40000, 0);
503 }
504 /* br %r14 */
505 _EMIT2(0x07fe);
506
507 if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable &&
508 (jit->seen & SEEN_FUNC)) {
509 jit->r1_thunk_ip = jit->prg;
510 /* Generate __s390_indirect_jump_r1 thunk */
511 if (test_facility(35)) {
512 /* exrl %r0,.+10 */
513 EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
514 /* j . */
515 EMIT4_PCREL(0xa7f40000, 0);
516 /* br %r1 */
517 _EMIT2(0x07f1);
518 } else {
519 /* larl %r1,.+14 */
520 EMIT6_PCREL_RILB(0xc0000000, REG_1, jit->prg + 14);
521 /* ex 0,S390_lowcore.br_r1_tampoline */
522 EMIT4_DISP(0x44000000, REG_0, REG_0,
523 offsetof(struct lowcore, br_r1_trampoline));
524 /* j . */
525 EMIT4_PCREL(0xa7f40000, 0);
526 }
527 }
528}
529
530/*
531 * Compile one eBPF instruction into s390x code
532 *
533 * NOTE: Use noinline because for gcov (-fprofile-arcs) gcc allocates a lot of
534 * stack space for the large switch statement.
535 */
536static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i)
537{
538 struct bpf_insn *insn = &fp->insnsi[i];
539 int jmp_off, last, insn_count = 1;
540 unsigned int func_addr, mask;
541 u32 dst_reg = insn->dst_reg;
542 u32 src_reg = insn->src_reg;
543 u32 *addrs = jit->addrs;
544 s32 imm = insn->imm;
545 s16 off = insn->off;
546
547 if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX)
548 jit->seen |= SEEN_REG_AX;
549 switch (insn->code) {
550 /*
551 * BPF_MOV
552 */
553 case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */
554 /* llgfr %dst,%src */
555 EMIT4(0xb9160000, dst_reg, src_reg);
556 break;
557 case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
558 /* lgr %dst,%src */
559 EMIT4(0xb9040000, dst_reg, src_reg);
560 break;
561 case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
562 /* llilf %dst,imm */
563 EMIT6_IMM(0xc00f0000, dst_reg, imm);
564 break;
565 case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */
566 /* lgfi %dst,imm */
567 EMIT6_IMM(0xc0010000, dst_reg, imm);
568 break;
569 /*
570 * BPF_LD 64
571 */
572 case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
573 {
574 /* 16 byte instruction that uses two 'struct bpf_insn' */
575 u64 imm64;
576
577 imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32;
578 /* lg %dst,<d(imm)>(%l) */
579 EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, REG_0, REG_L,
580 EMIT_CONST_U64(imm64));
581 insn_count = 2;
582 break;
583 }
584 /*
585 * BPF_ADD
586 */
587 case BPF_ALU | BPF_ADD | BPF_X: /* dst = (u32) dst + (u32) src */
588 /* ar %dst,%src */
589 EMIT2(0x1a00, dst_reg, src_reg);
590 EMIT_ZERO(dst_reg);
591 break;
592 case BPF_ALU64 | BPF_ADD | BPF_X: /* dst = dst + src */
593 /* agr %dst,%src */
594 EMIT4(0xb9080000, dst_reg, src_reg);
595 break;
596 case BPF_ALU | BPF_ADD | BPF_K: /* dst = (u32) dst + (u32) imm */
597 if (!imm)
598 break;
599 /* alfi %dst,imm */
600 EMIT6_IMM(0xc20b0000, dst_reg, imm);
601 EMIT_ZERO(dst_reg);
602 break;
603 case BPF_ALU64 | BPF_ADD | BPF_K: /* dst = dst + imm */
604 if (!imm)
605 break;
606 /* agfi %dst,imm */
607 EMIT6_IMM(0xc2080000, dst_reg, imm);
608 break;
609 /*
610 * BPF_SUB
611 */
612 case BPF_ALU | BPF_SUB | BPF_X: /* dst = (u32) dst - (u32) src */
613 /* sr %dst,%src */
614 EMIT2(0x1b00, dst_reg, src_reg);
615 EMIT_ZERO(dst_reg);
616 break;
617 case BPF_ALU64 | BPF_SUB | BPF_X: /* dst = dst - src */
618 /* sgr %dst,%src */
619 EMIT4(0xb9090000, dst_reg, src_reg);
620 break;
621 case BPF_ALU | BPF_SUB | BPF_K: /* dst = (u32) dst - (u32) imm */
622 if (!imm)
623 break;
624 /* alfi %dst,-imm */
625 EMIT6_IMM(0xc20b0000, dst_reg, -imm);
626 EMIT_ZERO(dst_reg);
627 break;
628 case BPF_ALU64 | BPF_SUB | BPF_K: /* dst = dst - imm */
629 if (!imm)
630 break;
631 /* agfi %dst,-imm */
632 EMIT6_IMM(0xc2080000, dst_reg, -imm);
633 break;
634 /*
635 * BPF_MUL
636 */
637 case BPF_ALU | BPF_MUL | BPF_X: /* dst = (u32) dst * (u32) src */
638 /* msr %dst,%src */
639 EMIT4(0xb2520000, dst_reg, src_reg);
640 EMIT_ZERO(dst_reg);
641 break;
642 case BPF_ALU64 | BPF_MUL | BPF_X: /* dst = dst * src */
643 /* msgr %dst,%src */
644 EMIT4(0xb90c0000, dst_reg, src_reg);
645 break;
646 case BPF_ALU | BPF_MUL | BPF_K: /* dst = (u32) dst * (u32) imm */
647 if (imm == 1)
648 break;
649 /* msfi %r5,imm */
650 EMIT6_IMM(0xc2010000, dst_reg, imm);
651 EMIT_ZERO(dst_reg);
652 break;
653 case BPF_ALU64 | BPF_MUL | BPF_K: /* dst = dst * imm */
654 if (imm == 1)
655 break;
656 /* msgfi %dst,imm */
657 EMIT6_IMM(0xc2000000, dst_reg, imm);
658 break;
659 /*
660 * BPF_DIV / BPF_MOD
661 */
662 case BPF_ALU | BPF_DIV | BPF_X: /* dst = (u32) dst / (u32) src */
663 case BPF_ALU | BPF_MOD | BPF_X: /* dst = (u32) dst % (u32) src */
664 {
665 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
666
667 /* lhi %w0,0 */
668 EMIT4_IMM(0xa7080000, REG_W0, 0);
669 /* lr %w1,%dst */
670 EMIT2(0x1800, REG_W1, dst_reg);
671 /* dlr %w0,%src */
672 EMIT4(0xb9970000, REG_W0, src_reg);
673 /* llgfr %dst,%rc */
674 EMIT4(0xb9160000, dst_reg, rc_reg);
675 break;
676 }
677 case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */
678 case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % src */
679 {
680 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
681
682 /* lghi %w0,0 */
683 EMIT4_IMM(0xa7090000, REG_W0, 0);
684 /* lgr %w1,%dst */
685 EMIT4(0xb9040000, REG_W1, dst_reg);
686 /* dlgr %w0,%dst */
687 EMIT4(0xb9870000, REG_W0, src_reg);
688 /* lgr %dst,%rc */
689 EMIT4(0xb9040000, dst_reg, rc_reg);
690 break;
691 }
692 case BPF_ALU | BPF_DIV | BPF_K: /* dst = (u32) dst / (u32) imm */
693 case BPF_ALU | BPF_MOD | BPF_K: /* dst = (u32) dst % (u32) imm */
694 {
695 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
696
697 if (imm == 1) {
698 if (BPF_OP(insn->code) == BPF_MOD)
699 /* lhgi %dst,0 */
700 EMIT4_IMM(0xa7090000, dst_reg, 0);
701 break;
702 }
703 /* lhi %w0,0 */
704 EMIT4_IMM(0xa7080000, REG_W0, 0);
705 /* lr %w1,%dst */
706 EMIT2(0x1800, REG_W1, dst_reg);
707 /* dl %w0,<d(imm)>(%l) */
708 EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0, REG_L,
709 EMIT_CONST_U32(imm));
710 /* llgfr %dst,%rc */
711 EMIT4(0xb9160000, dst_reg, rc_reg);
712 break;
713 }
714 case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */
715 case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % imm */
716 {
717 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
718
719 if (imm == 1) {
720 if (BPF_OP(insn->code) == BPF_MOD)
721 /* lhgi %dst,0 */
722 EMIT4_IMM(0xa7090000, dst_reg, 0);
723 break;
724 }
725 /* lghi %w0,0 */
726 EMIT4_IMM(0xa7090000, REG_W0, 0);
727 /* lgr %w1,%dst */
728 EMIT4(0xb9040000, REG_W1, dst_reg);
729 /* dlg %w0,<d(imm)>(%l) */
730 EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L,
731 EMIT_CONST_U64(imm));
732 /* lgr %dst,%rc */
733 EMIT4(0xb9040000, dst_reg, rc_reg);
734 break;
735 }
736 /*
737 * BPF_AND
738 */
739 case BPF_ALU | BPF_AND | BPF_X: /* dst = (u32) dst & (u32) src */
740 /* nr %dst,%src */
741 EMIT2(0x1400, dst_reg, src_reg);
742 EMIT_ZERO(dst_reg);
743 break;
744 case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
745 /* ngr %dst,%src */
746 EMIT4(0xb9800000, dst_reg, src_reg);
747 break;
748 case BPF_ALU | BPF_AND | BPF_K: /* dst = (u32) dst & (u32) imm */
749 /* nilf %dst,imm */
750 EMIT6_IMM(0xc00b0000, dst_reg, imm);
751 EMIT_ZERO(dst_reg);
752 break;
753 case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
754 /* ng %dst,<d(imm)>(%l) */
755 EMIT6_DISP_LH(0xe3000000, 0x0080, dst_reg, REG_0, REG_L,
756 EMIT_CONST_U64(imm));
757 break;
758 /*
759 * BPF_OR
760 */
761 case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
762 /* or %dst,%src */
763 EMIT2(0x1600, dst_reg, src_reg);
764 EMIT_ZERO(dst_reg);
765 break;
766 case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
767 /* ogr %dst,%src */
768 EMIT4(0xb9810000, dst_reg, src_reg);
769 break;
770 case BPF_ALU | BPF_OR | BPF_K: /* dst = (u32) dst | (u32) imm */
771 /* oilf %dst,imm */
772 EMIT6_IMM(0xc00d0000, dst_reg, imm);
773 EMIT_ZERO(dst_reg);
774 break;
775 case BPF_ALU64 | BPF_OR | BPF_K: /* dst = dst | imm */
776 /* og %dst,<d(imm)>(%l) */
777 EMIT6_DISP_LH(0xe3000000, 0x0081, dst_reg, REG_0, REG_L,
778 EMIT_CONST_U64(imm));
779 break;
780 /*
781 * BPF_XOR
782 */
783 case BPF_ALU | BPF_XOR | BPF_X: /* dst = (u32) dst ^ (u32) src */
784 /* xr %dst,%src */
785 EMIT2(0x1700, dst_reg, src_reg);
786 EMIT_ZERO(dst_reg);
787 break;
788 case BPF_ALU64 | BPF_XOR | BPF_X: /* dst = dst ^ src */
789 /* xgr %dst,%src */
790 EMIT4(0xb9820000, dst_reg, src_reg);
791 break;
792 case BPF_ALU | BPF_XOR | BPF_K: /* dst = (u32) dst ^ (u32) imm */
793 if (!imm)
794 break;
795 /* xilf %dst,imm */
796 EMIT6_IMM(0xc0070000, dst_reg, imm);
797 EMIT_ZERO(dst_reg);
798 break;
799 case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ imm */
800 /* xg %dst,<d(imm)>(%l) */
801 EMIT6_DISP_LH(0xe3000000, 0x0082, dst_reg, REG_0, REG_L,
802 EMIT_CONST_U64(imm));
803 break;
804 /*
805 * BPF_LSH
806 */
807 case BPF_ALU | BPF_LSH | BPF_X: /* dst = (u32) dst << (u32) src */
808 /* sll %dst,0(%src) */
809 EMIT4_DISP(0x89000000, dst_reg, src_reg, 0);
810 EMIT_ZERO(dst_reg);
811 break;
812 case BPF_ALU64 | BPF_LSH | BPF_X: /* dst = dst << src */
813 /* sllg %dst,%dst,0(%src) */
814 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, src_reg, 0);
815 break;
816 case BPF_ALU | BPF_LSH | BPF_K: /* dst = (u32) dst << (u32) imm */
817 if (imm == 0)
818 break;
819 /* sll %dst,imm(%r0) */
820 EMIT4_DISP(0x89000000, dst_reg, REG_0, imm);
821 EMIT_ZERO(dst_reg);
822 break;
823 case BPF_ALU64 | BPF_LSH | BPF_K: /* dst = dst << imm */
824 if (imm == 0)
825 break;
826 /* sllg %dst,%dst,imm(%r0) */
827 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, REG_0, imm);
828 break;
829 /*
830 * BPF_RSH
831 */
832 case BPF_ALU | BPF_RSH | BPF_X: /* dst = (u32) dst >> (u32) src */
833 /* srl %dst,0(%src) */
834 EMIT4_DISP(0x88000000, dst_reg, src_reg, 0);
835 EMIT_ZERO(dst_reg);
836 break;
837 case BPF_ALU64 | BPF_RSH | BPF_X: /* dst = dst >> src */
838 /* srlg %dst,%dst,0(%src) */
839 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, src_reg, 0);
840 break;
841 case BPF_ALU | BPF_RSH | BPF_K: /* dst = (u32) dst >> (u32) imm */
842 if (imm == 0)
843 break;
844 /* srl %dst,imm(%r0) */
845 EMIT4_DISP(0x88000000, dst_reg, REG_0, imm);
846 EMIT_ZERO(dst_reg);
847 break;
848 case BPF_ALU64 | BPF_RSH | BPF_K: /* dst = dst >> imm */
849 if (imm == 0)
850 break;
851 /* srlg %dst,%dst,imm(%r0) */
852 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, REG_0, imm);
853 break;
854 /*
855 * BPF_ARSH
856 */
857 case BPF_ALU64 | BPF_ARSH | BPF_X: /* ((s64) dst) >>= src */
858 /* srag %dst,%dst,0(%src) */
859 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, src_reg, 0);
860 break;
861 case BPF_ALU64 | BPF_ARSH | BPF_K: /* ((s64) dst) >>= imm */
862 if (imm == 0)
863 break;
864 /* srag %dst,%dst,imm(%r0) */
865 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, REG_0, imm);
866 break;
867 /*
868 * BPF_NEG
869 */
870 case BPF_ALU | BPF_NEG: /* dst = (u32) -dst */
871 /* lcr %dst,%dst */
872 EMIT2(0x1300, dst_reg, dst_reg);
873 EMIT_ZERO(dst_reg);
874 break;
875 case BPF_ALU64 | BPF_NEG: /* dst = -dst */
876 /* lcgr %dst,%dst */
877 EMIT4(0xb9130000, dst_reg, dst_reg);
878 break;
879 /*
880 * BPF_FROM_BE/LE
881 */
882 case BPF_ALU | BPF_END | BPF_FROM_BE:
883 /* s390 is big endian, therefore only clear high order bytes */
884 switch (imm) {
885 case 16: /* dst = (u16) cpu_to_be16(dst) */
886 /* llghr %dst,%dst */
887 EMIT4(0xb9850000, dst_reg, dst_reg);
888 break;
889 case 32: /* dst = (u32) cpu_to_be32(dst) */
890 /* llgfr %dst,%dst */
891 EMIT4(0xb9160000, dst_reg, dst_reg);
892 break;
893 case 64: /* dst = (u64) cpu_to_be64(dst) */
894 break;
895 }
896 break;
897 case BPF_ALU | BPF_END | BPF_FROM_LE:
898 switch (imm) {
899 case 16: /* dst = (u16) cpu_to_le16(dst) */
900 /* lrvr %dst,%dst */
901 EMIT4(0xb91f0000, dst_reg, dst_reg);
902 /* srl %dst,16(%r0) */
903 EMIT4_DISP(0x88000000, dst_reg, REG_0, 16);
904 /* llghr %dst,%dst */
905 EMIT4(0xb9850000, dst_reg, dst_reg);
906 break;
907 case 32: /* dst = (u32) cpu_to_le32(dst) */
908 /* lrvr %dst,%dst */
909 EMIT4(0xb91f0000, dst_reg, dst_reg);
910 /* llgfr %dst,%dst */
911 EMIT4(0xb9160000, dst_reg, dst_reg);
912 break;
913 case 64: /* dst = (u64) cpu_to_le64(dst) */
914 /* lrvgr %dst,%dst */
915 EMIT4(0xb90f0000, dst_reg, dst_reg);
916 break;
917 }
918 break;
919 /*
920 * BPF_ST(X)
921 */
922 case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src_reg */
923 /* stcy %src,off(%dst) */
924 EMIT6_DISP_LH(0xe3000000, 0x0072, src_reg, dst_reg, REG_0, off);
925 jit->seen |= SEEN_MEM;
926 break;
927 case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
928 /* sthy %src,off(%dst) */
929 EMIT6_DISP_LH(0xe3000000, 0x0070, src_reg, dst_reg, REG_0, off);
930 jit->seen |= SEEN_MEM;
931 break;
932 case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
933 /* sty %src,off(%dst) */
934 EMIT6_DISP_LH(0xe3000000, 0x0050, src_reg, dst_reg, REG_0, off);
935 jit->seen |= SEEN_MEM;
936 break;
937 case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
938 /* stg %src,off(%dst) */
939 EMIT6_DISP_LH(0xe3000000, 0x0024, src_reg, dst_reg, REG_0, off);
940 jit->seen |= SEEN_MEM;
941 break;
942 case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
943 /* lhi %w0,imm */
944 EMIT4_IMM(0xa7080000, REG_W0, (u8) imm);
945 /* stcy %w0,off(dst) */
946 EMIT6_DISP_LH(0xe3000000, 0x0072, REG_W0, dst_reg, REG_0, off);
947 jit->seen |= SEEN_MEM;
948 break;
949 case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
950 /* lhi %w0,imm */
951 EMIT4_IMM(0xa7080000, REG_W0, (u16) imm);
952 /* sthy %w0,off(dst) */
953 EMIT6_DISP_LH(0xe3000000, 0x0070, REG_W0, dst_reg, REG_0, off);
954 jit->seen |= SEEN_MEM;
955 break;
956 case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
957 /* llilf %w0,imm */
958 EMIT6_IMM(0xc00f0000, REG_W0, (u32) imm);
959 /* sty %w0,off(%dst) */
960 EMIT6_DISP_LH(0xe3000000, 0x0050, REG_W0, dst_reg, REG_0, off);
961 jit->seen |= SEEN_MEM;
962 break;
963 case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
964 /* lgfi %w0,imm */
965 EMIT6_IMM(0xc0010000, REG_W0, imm);
966 /* stg %w0,off(%dst) */
967 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, dst_reg, REG_0, off);
968 jit->seen |= SEEN_MEM;
969 break;
970 /*
971 * BPF_STX XADD (atomic_add)
972 */
973 case BPF_STX | BPF_XADD | BPF_W: /* *(u32 *)(dst + off) += src */
974 /* laal %w0,%src,off(%dst) */
975 EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W0, src_reg,
976 dst_reg, off);
977 jit->seen |= SEEN_MEM;
978 break;
979 case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */
980 /* laalg %w0,%src,off(%dst) */
981 EMIT6_DISP_LH(0xeb000000, 0x00ea, REG_W0, src_reg,
982 dst_reg, off);
983 jit->seen |= SEEN_MEM;
984 break;
985 /*
986 * BPF_LDX
987 */
988 case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */
989 /* llgc %dst,0(off,%src) */
990 EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off);
991 jit->seen |= SEEN_MEM;
992 break;
993 case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
994 /* llgh %dst,0(off,%src) */
995 EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off);
996 jit->seen |= SEEN_MEM;
997 break;
998 case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */
999 /* llgf %dst,off(%src) */
1000 jit->seen |= SEEN_MEM;
1001 EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off);
1002 break;
1003 case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
1004 /* lg %dst,0(off,%src) */
1005 jit->seen |= SEEN_MEM;
1006 EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, src_reg, REG_0, off);
1007 break;
1008 /*
1009 * BPF_JMP / CALL
1010 */
1011 case BPF_JMP | BPF_CALL:
1012 {
1013 /*
1014 * b0 = (__bpf_call_base + imm)(b1, b2, b3, b4, b5)
1015 */
1016 const u64 func = (u64)__bpf_call_base + imm;
1017
1018 REG_SET_SEEN(BPF_REG_5);
1019 jit->seen |= SEEN_FUNC;
1020 /* lg %w1,<d(imm)>(%l) */
1021 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_W1, REG_0, REG_L,
1022 EMIT_CONST_U64(func));
1023 if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable) {
1024 /* brasl %r14,__s390_indirect_jump_r1 */
1025 EMIT6_PCREL_RILB(0xc0050000, REG_14, jit->r1_thunk_ip);
1026 } else {
1027 /* basr %r14,%w1 */
1028 EMIT2(0x0d00, REG_14, REG_W1);
1029 }
1030 /* lgr %b0,%r2: load return value into %b0 */
1031 EMIT4(0xb9040000, BPF_REG_0, REG_2);
1032 if ((jit->seen & SEEN_SKB) &&
1033 bpf_helper_changes_pkt_data((void *)func)) {
1034 /* lg %b1,ST_OFF_SKBP(%r15) */
1035 EMIT6_DISP_LH(0xe3000000, 0x0004, BPF_REG_1, REG_0,
1036 REG_15, STK_OFF_SKBP);
1037 emit_load_skb_data_hlen(jit);
1038 }
1039 break;
1040 }
1041 case BPF_JMP | BPF_TAIL_CALL:
1042 /*
1043 * Implicit input:
1044 * B1: pointer to ctx
1045 * B2: pointer to bpf_array
1046 * B3: index in bpf_array
1047 */
1048 jit->seen |= SEEN_TAIL_CALL;
1049
1050 /*
1051 * if (index >= array->map.max_entries)
1052 * goto out;
1053 */
1054
1055 /* llgf %w1,map.max_entries(%b2) */
1056 EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2,
1057 offsetof(struct bpf_array, map.max_entries));
1058 /* clgrj %b3,%w1,0xa,label0: if %b3 >= %w1 goto out */
1059 EMIT6_PCREL_LABEL(0xec000000, 0x0065, BPF_REG_3,
1060 REG_W1, 0, 0xa);
1061
1062 /*
1063 * if (tail_call_cnt++ > MAX_TAIL_CALL_CNT)
1064 * goto out;
1065 */
1066
1067 if (jit->seen & SEEN_STACK)
1068 off = STK_OFF_TCCNT + STK_OFF + fp->aux->stack_depth;
1069 else
1070 off = STK_OFF_TCCNT;
1071 /* lhi %w0,1 */
1072 EMIT4_IMM(0xa7080000, REG_W0, 1);
1073 /* laal %w1,%w0,off(%r15) */
1074 EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, REG_15, off);
1075 /* clij %w1,MAX_TAIL_CALL_CNT,0x2,label0 */
1076 EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007f, REG_W1,
1077 MAX_TAIL_CALL_CNT, 0, 0x2);
1078
1079 /*
1080 * prog = array->ptrs[index];
1081 * if (prog == NULL)
1082 * goto out;
1083 */
1084
1085 /* sllg %r1,%b3,3: %r1 = index * 8 */
1086 EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, BPF_REG_3, REG_0, 3);
1087 /* lg %r1,prog(%b2,%r1) */
1088 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, BPF_REG_2,
1089 REG_1, offsetof(struct bpf_array, ptrs));
1090 /* clgij %r1,0,0x8,label0 */
1091 EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007d, REG_1, 0, 0, 0x8);
1092
1093 /*
1094 * Restore registers before calling function
1095 */
1096 save_restore_regs(jit, REGS_RESTORE, fp->aux->stack_depth);
1097
1098 /*
1099 * goto *(prog->bpf_func + tail_call_start);
1100 */
1101
1102 /* lg %r1,bpf_func(%r1) */
1103 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, REG_1, REG_0,
1104 offsetof(struct bpf_prog, bpf_func));
1105 /* bc 0xf,tail_call_start(%r1) */
1106 _EMIT4(0x47f01000 + jit->tail_call_start);
1107 /* out: */
1108 jit->labels[0] = jit->prg;
1109 break;
1110 case BPF_JMP | BPF_EXIT: /* return b0 */
1111 last = (i == fp->len - 1) ? 1 : 0;
1112 if (last && !(jit->seen & SEEN_RET0))
1113 break;
1114 /* j <exit> */
1115 EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
1116 break;
1117 /*
1118 * Branch relative (number of skipped instructions) to offset on
1119 * condition.
1120 *
1121 * Condition code to mask mapping:
1122 *
1123 * CC | Description | Mask
1124 * ------------------------------
1125 * 0 | Operands equal | 8
1126 * 1 | First operand low | 4
1127 * 2 | First operand high | 2
1128 * 3 | Unused | 1
1129 *
1130 * For s390x relative branches: ip = ip + off_bytes
1131 * For BPF relative branches: insn = insn + off_insns + 1
1132 *
1133 * For example for s390x with offset 0 we jump to the branch
1134 * instruction itself (loop) and for BPF with offset 0 we
1135 * branch to the instruction behind the branch.
1136 */
1137 case BPF_JMP | BPF_JA: /* if (true) */
1138 mask = 0xf000; /* j */
1139 goto branch_oc;
1140 case BPF_JMP | BPF_JSGT | BPF_K: /* ((s64) dst > (s64) imm) */
1141 mask = 0x2000; /* jh */
1142 goto branch_ks;
1143 case BPF_JMP | BPF_JSLT | BPF_K: /* ((s64) dst < (s64) imm) */
1144 mask = 0x4000; /* jl */
1145 goto branch_ks;
1146 case BPF_JMP | BPF_JSGE | BPF_K: /* ((s64) dst >= (s64) imm) */
1147 mask = 0xa000; /* jhe */
1148 goto branch_ks;
1149 case BPF_JMP | BPF_JSLE | BPF_K: /* ((s64) dst <= (s64) imm) */
1150 mask = 0xc000; /* jle */
1151 goto branch_ks;
1152 case BPF_JMP | BPF_JGT | BPF_K: /* (dst_reg > imm) */
1153 mask = 0x2000; /* jh */
1154 goto branch_ku;
1155 case BPF_JMP | BPF_JLT | BPF_K: /* (dst_reg < imm) */
1156 mask = 0x4000; /* jl */
1157 goto branch_ku;
1158 case BPF_JMP | BPF_JGE | BPF_K: /* (dst_reg >= imm) */
1159 mask = 0xa000; /* jhe */
1160 goto branch_ku;
1161 case BPF_JMP | BPF_JLE | BPF_K: /* (dst_reg <= imm) */
1162 mask = 0xc000; /* jle */
1163 goto branch_ku;
1164 case BPF_JMP | BPF_JNE | BPF_K: /* (dst_reg != imm) */
1165 mask = 0x7000; /* jne */
1166 goto branch_ku;
1167 case BPF_JMP | BPF_JEQ | BPF_K: /* (dst_reg == imm) */
1168 mask = 0x8000; /* je */
1169 goto branch_ku;
1170 case BPF_JMP | BPF_JSET | BPF_K: /* (dst_reg & imm) */
1171 mask = 0x7000; /* jnz */
1172 /* lgfi %w1,imm (load sign extend imm) */
1173 EMIT6_IMM(0xc0010000, REG_W1, imm);
1174 /* ngr %w1,%dst */
1175 EMIT4(0xb9800000, REG_W1, dst_reg);
1176 goto branch_oc;
1177
1178 case BPF_JMP | BPF_JSGT | BPF_X: /* ((s64) dst > (s64) src) */
1179 mask = 0x2000; /* jh */
1180 goto branch_xs;
1181 case BPF_JMP | BPF_JSLT | BPF_X: /* ((s64) dst < (s64) src) */
1182 mask = 0x4000; /* jl */
1183 goto branch_xs;
1184 case BPF_JMP | BPF_JSGE | BPF_X: /* ((s64) dst >= (s64) src) */
1185 mask = 0xa000; /* jhe */
1186 goto branch_xs;
1187 case BPF_JMP | BPF_JSLE | BPF_X: /* ((s64) dst <= (s64) src) */
1188 mask = 0xc000; /* jle */
1189 goto branch_xs;
1190 case BPF_JMP | BPF_JGT | BPF_X: /* (dst > src) */
1191 mask = 0x2000; /* jh */
1192 goto branch_xu;
1193 case BPF_JMP | BPF_JLT | BPF_X: /* (dst < src) */
1194 mask = 0x4000; /* jl */
1195 goto branch_xu;
1196 case BPF_JMP | BPF_JGE | BPF_X: /* (dst >= src) */
1197 mask = 0xa000; /* jhe */
1198 goto branch_xu;
1199 case BPF_JMP | BPF_JLE | BPF_X: /* (dst <= src) */
1200 mask = 0xc000; /* jle */
1201 goto branch_xu;
1202 case BPF_JMP | BPF_JNE | BPF_X: /* (dst != src) */
1203 mask = 0x7000; /* jne */
1204 goto branch_xu;
1205 case BPF_JMP | BPF_JEQ | BPF_X: /* (dst == src) */
1206 mask = 0x8000; /* je */
1207 goto branch_xu;
1208 case BPF_JMP | BPF_JSET | BPF_X: /* (dst & src) */
1209 mask = 0x7000; /* jnz */
1210 /* ngrk %w1,%dst,%src */
1211 EMIT4_RRF(0xb9e40000, REG_W1, dst_reg, src_reg);
1212 goto branch_oc;
1213branch_ks:
1214 /* lgfi %w1,imm (load sign extend imm) */
1215 EMIT6_IMM(0xc0010000, REG_W1, imm);
1216 /* cgrj %dst,%w1,mask,off */
1217 EMIT6_PCREL(0xec000000, 0x0064, dst_reg, REG_W1, i, off, mask);
1218 break;
1219branch_ku:
1220 /* lgfi %w1,imm (load sign extend imm) */
1221 EMIT6_IMM(0xc0010000, REG_W1, imm);
1222 /* clgrj %dst,%w1,mask,off */
1223 EMIT6_PCREL(0xec000000, 0x0065, dst_reg, REG_W1, i, off, mask);
1224 break;
1225branch_xs:
1226 /* cgrj %dst,%src,mask,off */
1227 EMIT6_PCREL(0xec000000, 0x0064, dst_reg, src_reg, i, off, mask);
1228 break;
1229branch_xu:
1230 /* clgrj %dst,%src,mask,off */
1231 EMIT6_PCREL(0xec000000, 0x0065, dst_reg, src_reg, i, off, mask);
1232 break;
1233branch_oc:
1234 /* brc mask,jmp_off (branch instruction needs 4 bytes) */
1235 jmp_off = addrs[i + off + 1] - (addrs[i + 1] - 4);
1236 EMIT4_PCREL(0xa7040000 | mask << 8, jmp_off);
1237 break;
1238 /*
1239 * BPF_LD
1240 */
1241 case BPF_LD | BPF_ABS | BPF_B: /* b0 = *(u8 *) (skb->data+imm) */
1242 case BPF_LD | BPF_IND | BPF_B: /* b0 = *(u8 *) (skb->data+imm+src) */
1243 if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
1244 func_addr = __pa(sk_load_byte_pos);
1245 else
1246 func_addr = __pa(sk_load_byte);
1247 goto call_fn;
1248 case BPF_LD | BPF_ABS | BPF_H: /* b0 = *(u16 *) (skb->data+imm) */
1249 case BPF_LD | BPF_IND | BPF_H: /* b0 = *(u16 *) (skb->data+imm+src) */
1250 if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
1251 func_addr = __pa(sk_load_half_pos);
1252 else
1253 func_addr = __pa(sk_load_half);
1254 goto call_fn;
1255 case BPF_LD | BPF_ABS | BPF_W: /* b0 = *(u32 *) (skb->data+imm) */
1256 case BPF_LD | BPF_IND | BPF_W: /* b0 = *(u32 *) (skb->data+imm+src) */
1257 if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
1258 func_addr = __pa(sk_load_word_pos);
1259 else
1260 func_addr = __pa(sk_load_word);
1261 goto call_fn;
1262call_fn:
1263 jit->seen |= SEEN_SKB | SEEN_RET0 | SEEN_FUNC;
1264 REG_SET_SEEN(REG_14); /* Return address of possible func call */
1265
1266 /*
1267 * Implicit input:
1268 * BPF_REG_6 (R7) : skb pointer
1269 * REG_SKB_DATA (R12): skb data pointer (if no BPF_REG_AX)
1270 *
1271 * Calculated input:
1272 * BPF_REG_2 (R3) : offset of byte(s) to fetch in skb
1273 * BPF_REG_5 (R6) : return address
1274 *
1275 * Output:
1276 * BPF_REG_0 (R14): data read from skb
1277 *
1278 * Scratch registers (BPF_REG_1-5)
1279 */
1280
1281 /* Call function: llilf %w1,func_addr */
1282 EMIT6_IMM(0xc00f0000, REG_W1, func_addr);
1283
1284 /* Offset: lgfi %b2,imm */
1285 EMIT6_IMM(0xc0010000, BPF_REG_2, imm);
1286 if (BPF_MODE(insn->code) == BPF_IND)
1287 /* agfr %b2,%src (%src is s32 here) */
1288 EMIT4(0xb9180000, BPF_REG_2, src_reg);
1289
1290 /* Reload REG_SKB_DATA if BPF_REG_AX is used */
1291 if (jit->seen & SEEN_REG_AX)
1292 /* lg %skb_data,data_off(%b6) */
1293 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0,
1294 BPF_REG_6, offsetof(struct sk_buff, data));
1295 /* basr %b5,%w1 (%b5 is call saved) */
1296 EMIT2(0x0d00, BPF_REG_5, REG_W1);
1297
1298 /*
1299 * Note: For fast access we jump directly after the
1300 * jnz instruction from bpf_jit.S
1301 */
1302 /* jnz <ret0> */
1303 EMIT4_PCREL(0xa7740000, jit->ret0_ip - jit->prg);
1304 break;
1305 default: /* too complex, give up */
1306 pr_err("Unknown opcode %02x\n", insn->code);
1307 return -1;
1308 }
1309 return insn_count;
1310}
1311
1312/*
1313 * Compile eBPF program into s390x code
1314 */
1315static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp)
1316{
1317 int i, insn_count;
1318
1319 jit->lit = jit->lit_start;
1320 jit->prg = 0;
1321
1322 bpf_jit_prologue(jit, fp->aux->stack_depth);
1323 for (i = 0; i < fp->len; i += insn_count) {
1324 insn_count = bpf_jit_insn(jit, fp, i);
1325 if (insn_count < 0)
1326 return -1;
1327 /* Next instruction address */
1328 jit->addrs[i + insn_count] = jit->prg;
1329 }
1330 bpf_jit_epilogue(jit, fp->aux->stack_depth);
1331
1332 jit->lit_start = jit->prg;
1333 jit->size = jit->lit;
1334 jit->size_prg = jit->prg;
1335 return 0;
1336}
1337
1338/*
1339 * Compile eBPF program "fp"
1340 */
1341struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
1342{
1343 struct bpf_prog *tmp, *orig_fp = fp;
1344 struct bpf_binary_header *header;
1345 bool tmp_blinded = false;
1346 struct bpf_jit jit;
1347 int pass;
1348
1349 if (!fp->jit_requested)
1350 return orig_fp;
1351
1352 tmp = bpf_jit_blind_constants(fp);
1353 /*
1354 * If blinding was requested and we failed during blinding,
1355 * we must fall back to the interpreter.
1356 */
1357 if (IS_ERR(tmp))
1358 return orig_fp;
1359 if (tmp != fp) {
1360 tmp_blinded = true;
1361 fp = tmp;
1362 }
1363
1364 memset(&jit, 0, sizeof(jit));
1365 jit.addrs = kcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
1366 if (jit.addrs == NULL) {
1367 fp = orig_fp;
1368 goto out;
1369 }
1370 /*
1371 * Three initial passes:
1372 * - 1/2: Determine clobbered registers
1373 * - 3: Calculate program size and addrs arrray
1374 */
1375 for (pass = 1; pass <= 3; pass++) {
1376 if (bpf_jit_prog(&jit, fp)) {
1377 fp = orig_fp;
1378 goto free_addrs;
1379 }
1380 }
1381 /*
1382 * Final pass: Allocate and generate program
1383 */
1384 if (jit.size >= BPF_SIZE_MAX) {
1385 fp = orig_fp;
1386 goto free_addrs;
1387 }
1388 header = bpf_jit_binary_alloc(jit.size, &jit.prg_buf, 2, jit_fill_hole);
1389 if (!header) {
1390 fp = orig_fp;
1391 goto free_addrs;
1392 }
1393 if (bpf_jit_prog(&jit, fp)) {
1394 fp = orig_fp;
1395 goto free_addrs;
1396 }
1397 if (bpf_jit_enable > 1) {
1398 bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf);
1399 print_fn_code(jit.prg_buf, jit.size_prg);
1400 }
1401 bpf_jit_binary_lock_ro(header);
1402 fp->bpf_func = (void *) jit.prg_buf;
1403 fp->jited = 1;
1404 fp->jited_len = jit.size;
1405free_addrs:
1406 kfree(jit.addrs);
1407out:
1408 if (tmp_blinded)
1409 bpf_jit_prog_release_other(fp, fp == orig_fp ?
1410 tmp : orig_fp);
1411 return fp;
1412}