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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * bpf_jit_comp64.c: eBPF JIT compiler
4 *
5 * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
6 * IBM Corporation
7 *
8 * Based on the powerpc classic BPF JIT compiler by Matt Evans
9 */
10#include <linux/moduleloader.h>
11#include <asm/cacheflush.h>
12#include <asm/asm-compat.h>
13#include <linux/netdevice.h>
14#include <linux/filter.h>
15#include <linux/if_vlan.h>
16#include <asm/kprobes.h>
17#include <linux/bpf.h>
18#include <asm/security_features.h>
19
20#include "bpf_jit.h"
21
22/*
23 * Stack layout:
24 * Ensure the top half (upto local_tmp_var) stays consistent
25 * with our redzone usage.
26 *
27 * [ prev sp ] <-------------
28 * [ nv gpr save area ] 5*8 |
29 * [ tail_call_cnt ] 8 |
30 * [ local_tmp_var ] 16 |
31 * fp (r31) --> [ ebpf stack space ] upto 512 |
32 * [ frame header ] 32/112 |
33 * sp (r1) ---> [ stack pointer ] --------------
34 */
35
36/* for gpr non volatile registers BPG_REG_6 to 10 */
37#define BPF_PPC_STACK_SAVE (5*8)
38/* for bpf JIT code internal usage */
39#define BPF_PPC_STACK_LOCALS 24
40/* stack frame excluding BPF stack, ensure this is quadword aligned */
41#define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + \
42 BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE)
43
44/* BPF register usage */
45#define TMP_REG_1 (MAX_BPF_JIT_REG + 0)
46#define TMP_REG_2 (MAX_BPF_JIT_REG + 1)
47
48/* BPF to ppc register mappings */
49void bpf_jit_init_reg_mapping(struct codegen_context *ctx)
50{
51 /* function return value */
52 ctx->b2p[BPF_REG_0] = _R8;
53 /* function arguments */
54 ctx->b2p[BPF_REG_1] = _R3;
55 ctx->b2p[BPF_REG_2] = _R4;
56 ctx->b2p[BPF_REG_3] = _R5;
57 ctx->b2p[BPF_REG_4] = _R6;
58 ctx->b2p[BPF_REG_5] = _R7;
59 /* non volatile registers */
60 ctx->b2p[BPF_REG_6] = _R27;
61 ctx->b2p[BPF_REG_7] = _R28;
62 ctx->b2p[BPF_REG_8] = _R29;
63 ctx->b2p[BPF_REG_9] = _R30;
64 /* frame pointer aka BPF_REG_10 */
65 ctx->b2p[BPF_REG_FP] = _R31;
66 /* eBPF jit internal registers */
67 ctx->b2p[BPF_REG_AX] = _R12;
68 ctx->b2p[TMP_REG_1] = _R9;
69 ctx->b2p[TMP_REG_2] = _R10;
70}
71
72/* PPC NVR range -- update this if we ever use NVRs below r27 */
73#define BPF_PPC_NVR_MIN _R27
74
75static inline bool bpf_has_stack_frame(struct codegen_context *ctx)
76{
77 /*
78 * We only need a stack frame if:
79 * - we call other functions (kernel helpers), or
80 * - the bpf program uses its stack area
81 * The latter condition is deduced from the usage of BPF_REG_FP
82 */
83 return ctx->seen & SEEN_FUNC || bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP));
84}
85
86/*
87 * When not setting up our own stackframe, the redzone usage is:
88 *
89 * [ prev sp ] <-------------
90 * [ ... ] |
91 * sp (r1) ---> [ stack pointer ] --------------
92 * [ nv gpr save area ] 5*8
93 * [ tail_call_cnt ] 8
94 * [ local_tmp_var ] 16
95 * [ unused red zone ] 208 bytes protected
96 */
97static int bpf_jit_stack_local(struct codegen_context *ctx)
98{
99 if (bpf_has_stack_frame(ctx))
100 return STACK_FRAME_MIN_SIZE + ctx->stack_size;
101 else
102 return -(BPF_PPC_STACK_SAVE + 24);
103}
104
105static int bpf_jit_stack_tailcallcnt(struct codegen_context *ctx)
106{
107 return bpf_jit_stack_local(ctx) + 16;
108}
109
110static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
111{
112 if (reg >= BPF_PPC_NVR_MIN && reg < 32)
113 return (bpf_has_stack_frame(ctx) ?
114 (BPF_PPC_STACKFRAME + ctx->stack_size) : 0)
115 - (8 * (32 - reg));
116
117 pr_err("BPF JIT is asking about unknown registers");
118 BUG();
119}
120
121void bpf_jit_realloc_regs(struct codegen_context *ctx)
122{
123}
124
125void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
126{
127 int i;
128
129#ifndef CONFIG_PPC_KERNEL_PCREL
130 if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
131 EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc)));
132#endif
133
134 /*
135 * Initialize tail_call_cnt if we do tail calls.
136 * Otherwise, put in NOPs so that it can be skipped when we are
137 * invoked through a tail call.
138 */
139 if (ctx->seen & SEEN_TAILCALL) {
140 EMIT(PPC_RAW_LI(bpf_to_ppc(TMP_REG_1), 0));
141 /* this goes in the redzone */
142 EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, -(BPF_PPC_STACK_SAVE + 8)));
143 } else {
144 EMIT(PPC_RAW_NOP());
145 EMIT(PPC_RAW_NOP());
146 }
147
148 if (bpf_has_stack_frame(ctx)) {
149 /*
150 * We need a stack frame, but we don't necessarily need to
151 * save/restore LR unless we call other functions
152 */
153 if (ctx->seen & SEEN_FUNC) {
154 EMIT(PPC_RAW_MFLR(_R0));
155 EMIT(PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF));
156 }
157
158 EMIT(PPC_RAW_STDU(_R1, _R1, -(BPF_PPC_STACKFRAME + ctx->stack_size)));
159 }
160
161 /*
162 * Back up non-volatile regs -- BPF registers 6-10
163 * If we haven't created our own stack frame, we save these
164 * in the protected zone below the previous stack frame
165 */
166 for (i = BPF_REG_6; i <= BPF_REG_10; i++)
167 if (bpf_is_seen_register(ctx, bpf_to_ppc(i)))
168 EMIT(PPC_RAW_STD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i))));
169
170 /* Setup frame pointer to point to the bpf stack area */
171 if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP)))
172 EMIT(PPC_RAW_ADDI(bpf_to_ppc(BPF_REG_FP), _R1,
173 STACK_FRAME_MIN_SIZE + ctx->stack_size));
174}
175
176static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx)
177{
178 int i;
179
180 /* Restore NVRs */
181 for (i = BPF_REG_6; i <= BPF_REG_10; i++)
182 if (bpf_is_seen_register(ctx, bpf_to_ppc(i)))
183 EMIT(PPC_RAW_LD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i))));
184
185 /* Tear down our stack frame */
186 if (bpf_has_stack_frame(ctx)) {
187 EMIT(PPC_RAW_ADDI(_R1, _R1, BPF_PPC_STACKFRAME + ctx->stack_size));
188 if (ctx->seen & SEEN_FUNC) {
189 EMIT(PPC_RAW_LD(_R0, _R1, PPC_LR_STKOFF));
190 EMIT(PPC_RAW_MTLR(_R0));
191 }
192 }
193}
194
195void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
196{
197 bpf_jit_emit_common_epilogue(image, ctx);
198
199 /* Move result to r3 */
200 EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_0)));
201
202 EMIT(PPC_RAW_BLR());
203}
204
205static int bpf_jit_emit_func_call_hlp(u32 *image, struct codegen_context *ctx, u64 func)
206{
207 unsigned long func_addr = func ? ppc_function_entry((void *)func) : 0;
208 long reladdr;
209
210 if (WARN_ON_ONCE(!core_kernel_text(func_addr)))
211 return -EINVAL;
212
213 if (IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) {
214 reladdr = func_addr - CTX_NIA(ctx);
215
216 if (reladdr >= (long)SZ_8G || reladdr < -(long)SZ_8G) {
217 pr_err("eBPF: address of %ps out of range of pcrel address.\n",
218 (void *)func);
219 return -ERANGE;
220 }
221 /* pla r12,addr */
222 EMIT(PPC_PREFIX_MLS | __PPC_PRFX_R(1) | IMM_H18(reladdr));
223 EMIT(PPC_INST_PADDI | ___PPC_RT(_R12) | IMM_L(reladdr));
224 EMIT(PPC_RAW_MTCTR(_R12));
225 EMIT(PPC_RAW_BCTR());
226
227 } else {
228 reladdr = func_addr - kernel_toc_addr();
229 if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
230 pr_err("eBPF: address of %ps out of range of kernel_toc.\n", (void *)func);
231 return -ERANGE;
232 }
233
234 EMIT(PPC_RAW_ADDIS(_R12, _R2, PPC_HA(reladdr)));
235 EMIT(PPC_RAW_ADDI(_R12, _R12, PPC_LO(reladdr)));
236 EMIT(PPC_RAW_MTCTR(_R12));
237 EMIT(PPC_RAW_BCTRL());
238 }
239
240 return 0;
241}
242
243int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *ctx, u64 func)
244{
245 unsigned int i, ctx_idx = ctx->idx;
246
247 if (WARN_ON_ONCE(func && is_module_text_address(func)))
248 return -EINVAL;
249
250 /* skip past descriptor if elf v1 */
251 func += FUNCTION_DESCR_SIZE;
252
253 /* Load function address into r12 */
254 PPC_LI64(_R12, func);
255
256 /* For bpf-to-bpf function calls, the callee's address is unknown
257 * until the last extra pass. As seen above, we use PPC_LI64() to
258 * load the callee's address, but this may optimize the number of
259 * instructions required based on the nature of the address.
260 *
261 * Since we don't want the number of instructions emitted to increase,
262 * we pad the optimized PPC_LI64() call with NOPs to guarantee that
263 * we always have a five-instruction sequence, which is the maximum
264 * that PPC_LI64() can emit.
265 */
266 if (!image)
267 for (i = ctx->idx - ctx_idx; i < 5; i++)
268 EMIT(PPC_RAW_NOP());
269
270 EMIT(PPC_RAW_MTCTR(_R12));
271 EMIT(PPC_RAW_BCTRL());
272
273 return 0;
274}
275
276static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out)
277{
278 /*
279 * By now, the eBPF program has already setup parameters in r3, r4 and r5
280 * r3/BPF_REG_1 - pointer to ctx -- passed as is to the next bpf program
281 * r4/BPF_REG_2 - pointer to bpf_array
282 * r5/BPF_REG_3 - index in bpf_array
283 */
284 int b2p_bpf_array = bpf_to_ppc(BPF_REG_2);
285 int b2p_index = bpf_to_ppc(BPF_REG_3);
286 int bpf_tailcall_prologue_size = 8;
287
288 if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
289 bpf_tailcall_prologue_size += 4; /* skip past the toc load */
290
291 /*
292 * if (index >= array->map.max_entries)
293 * goto out;
294 */
295 EMIT(PPC_RAW_LWZ(bpf_to_ppc(TMP_REG_1), b2p_bpf_array, offsetof(struct bpf_array, map.max_entries)));
296 EMIT(PPC_RAW_RLWINM(b2p_index, b2p_index, 0, 0, 31));
297 EMIT(PPC_RAW_CMPLW(b2p_index, bpf_to_ppc(TMP_REG_1)));
298 PPC_BCC_SHORT(COND_GE, out);
299
300 /*
301 * if (tail_call_cnt >= MAX_TAIL_CALL_CNT)
302 * goto out;
303 */
304 EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx)));
305 EMIT(PPC_RAW_CMPLWI(bpf_to_ppc(TMP_REG_1), MAX_TAIL_CALL_CNT));
306 PPC_BCC_SHORT(COND_GE, out);
307
308 /*
309 * tail_call_cnt++;
310 */
311 EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), 1));
312 EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx)));
313
314 /* prog = array->ptrs[index]; */
315 EMIT(PPC_RAW_MULI(bpf_to_ppc(TMP_REG_1), b2p_index, 8));
316 EMIT(PPC_RAW_ADD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), b2p_bpf_array));
317 EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_array, ptrs)));
318
319 /*
320 * if (prog == NULL)
321 * goto out;
322 */
323 EMIT(PPC_RAW_CMPLDI(bpf_to_ppc(TMP_REG_1), 0));
324 PPC_BCC_SHORT(COND_EQ, out);
325
326 /* goto *(prog->bpf_func + prologue_size); */
327 EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_prog, bpf_func)));
328 EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1),
329 FUNCTION_DESCR_SIZE + bpf_tailcall_prologue_size));
330 EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_1)));
331
332 /* tear down stack, restore NVRs, ... */
333 bpf_jit_emit_common_epilogue(image, ctx);
334
335 EMIT(PPC_RAW_BCTR());
336
337 /* out: */
338 return 0;
339}
340
341/*
342 * We spill into the redzone always, even if the bpf program has its own stackframe.
343 * Offsets hardcoded based on BPF_PPC_STACK_SAVE -- see bpf_jit_stack_local()
344 */
345void bpf_stf_barrier(void);
346
347asm (
348" .global bpf_stf_barrier ;"
349" bpf_stf_barrier: ;"
350" std 21,-64(1) ;"
351" std 22,-56(1) ;"
352" sync ;"
353" ld 21,-64(1) ;"
354" ld 22,-56(1) ;"
355" ori 31,31,0 ;"
356" .rept 14 ;"
357" b 1f ;"
358" 1: ;"
359" .endr ;"
360" blr ;"
361);
362
363/* Assemble the body code between the prologue & epilogue */
364int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx,
365 u32 *addrs, int pass, bool extra_pass)
366{
367 enum stf_barrier_type stf_barrier = stf_barrier_type_get();
368 const struct bpf_insn *insn = fp->insnsi;
369 int flen = fp->len;
370 int i, ret;
371
372 /* Start of epilogue code - will only be valid 2nd pass onwards */
373 u32 exit_addr = addrs[flen];
374
375 for (i = 0; i < flen; i++) {
376 u32 code = insn[i].code;
377 u32 dst_reg = bpf_to_ppc(insn[i].dst_reg);
378 u32 src_reg = bpf_to_ppc(insn[i].src_reg);
379 u32 size = BPF_SIZE(code);
380 u32 tmp1_reg = bpf_to_ppc(TMP_REG_1);
381 u32 tmp2_reg = bpf_to_ppc(TMP_REG_2);
382 u32 save_reg, ret_reg;
383 s16 off = insn[i].off;
384 s32 imm = insn[i].imm;
385 bool func_addr_fixed;
386 u64 func_addr;
387 u64 imm64;
388 u32 true_cond;
389 u32 tmp_idx;
390 int j;
391
392 /*
393 * addrs[] maps a BPF bytecode address into a real offset from
394 * the start of the body code.
395 */
396 addrs[i] = ctx->idx * 4;
397
398 /*
399 * As an optimization, we note down which non-volatile registers
400 * are used so that we can only save/restore those in our
401 * prologue and epilogue. We do this here regardless of whether
402 * the actual BPF instruction uses src/dst registers or not
403 * (for instance, BPF_CALL does not use them). The expectation
404 * is that those instructions will have src_reg/dst_reg set to
405 * 0. Even otherwise, we just lose some prologue/epilogue
406 * optimization but everything else should work without
407 * any issues.
408 */
409 if (dst_reg >= BPF_PPC_NVR_MIN && dst_reg < 32)
410 bpf_set_seen_register(ctx, dst_reg);
411 if (src_reg >= BPF_PPC_NVR_MIN && src_reg < 32)
412 bpf_set_seen_register(ctx, src_reg);
413
414 switch (code) {
415 /*
416 * Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG
417 */
418 case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */
419 case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */
420 EMIT(PPC_RAW_ADD(dst_reg, dst_reg, src_reg));
421 goto bpf_alu32_trunc;
422 case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */
423 case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */
424 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, src_reg));
425 goto bpf_alu32_trunc;
426 case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */
427 case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */
428 if (!imm) {
429 goto bpf_alu32_trunc;
430 } else if (imm >= -32768 && imm < 32768) {
431 EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(imm)));
432 } else {
433 PPC_LI32(tmp1_reg, imm);
434 EMIT(PPC_RAW_ADD(dst_reg, dst_reg, tmp1_reg));
435 }
436 goto bpf_alu32_trunc;
437 case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */
438 case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */
439 if (!imm) {
440 goto bpf_alu32_trunc;
441 } else if (imm > -32768 && imm <= 32768) {
442 EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(-imm)));
443 } else {
444 PPC_LI32(tmp1_reg, imm);
445 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
446 }
447 goto bpf_alu32_trunc;
448 case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */
449 case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */
450 if (BPF_CLASS(code) == BPF_ALU)
451 EMIT(PPC_RAW_MULW(dst_reg, dst_reg, src_reg));
452 else
453 EMIT(PPC_RAW_MULD(dst_reg, dst_reg, src_reg));
454 goto bpf_alu32_trunc;
455 case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */
456 case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */
457 if (imm >= -32768 && imm < 32768)
458 EMIT(PPC_RAW_MULI(dst_reg, dst_reg, IMM_L(imm)));
459 else {
460 PPC_LI32(tmp1_reg, imm);
461 if (BPF_CLASS(code) == BPF_ALU)
462 EMIT(PPC_RAW_MULW(dst_reg, dst_reg, tmp1_reg));
463 else
464 EMIT(PPC_RAW_MULD(dst_reg, dst_reg, tmp1_reg));
465 }
466 goto bpf_alu32_trunc;
467 case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */
468 case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */
469 if (BPF_OP(code) == BPF_MOD) {
470 EMIT(PPC_RAW_DIVWU(tmp1_reg, dst_reg, src_reg));
471 EMIT(PPC_RAW_MULW(tmp1_reg, src_reg, tmp1_reg));
472 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
473 } else
474 EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, src_reg));
475 goto bpf_alu32_trunc;
476 case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */
477 case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */
478 if (BPF_OP(code) == BPF_MOD) {
479 EMIT(PPC_RAW_DIVDU(tmp1_reg, dst_reg, src_reg));
480 EMIT(PPC_RAW_MULD(tmp1_reg, src_reg, tmp1_reg));
481 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
482 } else
483 EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, src_reg));
484 break;
485 case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */
486 case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */
487 case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */
488 case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */
489 if (imm == 0)
490 return -EINVAL;
491 if (imm == 1) {
492 if (BPF_OP(code) == BPF_DIV) {
493 goto bpf_alu32_trunc;
494 } else {
495 EMIT(PPC_RAW_LI(dst_reg, 0));
496 break;
497 }
498 }
499
500 PPC_LI32(tmp1_reg, imm);
501 switch (BPF_CLASS(code)) {
502 case BPF_ALU:
503 if (BPF_OP(code) == BPF_MOD) {
504 EMIT(PPC_RAW_DIVWU(tmp2_reg, dst_reg, tmp1_reg));
505 EMIT(PPC_RAW_MULW(tmp1_reg, tmp1_reg, tmp2_reg));
506 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
507 } else
508 EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, tmp1_reg));
509 break;
510 case BPF_ALU64:
511 if (BPF_OP(code) == BPF_MOD) {
512 EMIT(PPC_RAW_DIVDU(tmp2_reg, dst_reg, tmp1_reg));
513 EMIT(PPC_RAW_MULD(tmp1_reg, tmp1_reg, tmp2_reg));
514 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
515 } else
516 EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, tmp1_reg));
517 break;
518 }
519 goto bpf_alu32_trunc;
520 case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */
521 case BPF_ALU64 | BPF_NEG: /* dst = -dst */
522 EMIT(PPC_RAW_NEG(dst_reg, dst_reg));
523 goto bpf_alu32_trunc;
524
525 /*
526 * Logical operations: AND/OR/XOR/[A]LSH/[A]RSH
527 */
528 case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */
529 case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
530 EMIT(PPC_RAW_AND(dst_reg, dst_reg, src_reg));
531 goto bpf_alu32_trunc;
532 case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */
533 case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
534 if (!IMM_H(imm))
535 EMIT(PPC_RAW_ANDI(dst_reg, dst_reg, IMM_L(imm)));
536 else {
537 /* Sign-extended */
538 PPC_LI32(tmp1_reg, imm);
539 EMIT(PPC_RAW_AND(dst_reg, dst_reg, tmp1_reg));
540 }
541 goto bpf_alu32_trunc;
542 case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
543 case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
544 EMIT(PPC_RAW_OR(dst_reg, dst_reg, src_reg));
545 goto bpf_alu32_trunc;
546 case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */
547 case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */
548 if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
549 /* Sign-extended */
550 PPC_LI32(tmp1_reg, imm);
551 EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp1_reg));
552 } else {
553 if (IMM_L(imm))
554 EMIT(PPC_RAW_ORI(dst_reg, dst_reg, IMM_L(imm)));
555 if (IMM_H(imm))
556 EMIT(PPC_RAW_ORIS(dst_reg, dst_reg, IMM_H(imm)));
557 }
558 goto bpf_alu32_trunc;
559 case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */
560 case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */
561 EMIT(PPC_RAW_XOR(dst_reg, dst_reg, src_reg));
562 goto bpf_alu32_trunc;
563 case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */
564 case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */
565 if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
566 /* Sign-extended */
567 PPC_LI32(tmp1_reg, imm);
568 EMIT(PPC_RAW_XOR(dst_reg, dst_reg, tmp1_reg));
569 } else {
570 if (IMM_L(imm))
571 EMIT(PPC_RAW_XORI(dst_reg, dst_reg, IMM_L(imm)));
572 if (IMM_H(imm))
573 EMIT(PPC_RAW_XORIS(dst_reg, dst_reg, IMM_H(imm)));
574 }
575 goto bpf_alu32_trunc;
576 case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */
577 /* slw clears top 32 bits */
578 EMIT(PPC_RAW_SLW(dst_reg, dst_reg, src_reg));
579 /* skip zero extension move, but set address map. */
580 if (insn_is_zext(&insn[i + 1]))
581 addrs[++i] = ctx->idx * 4;
582 break;
583 case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */
584 EMIT(PPC_RAW_SLD(dst_reg, dst_reg, src_reg));
585 break;
586 case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<== (u32) imm */
587 /* with imm 0, we still need to clear top 32 bits */
588 EMIT(PPC_RAW_SLWI(dst_reg, dst_reg, imm));
589 if (insn_is_zext(&insn[i + 1]))
590 addrs[++i] = ctx->idx * 4;
591 break;
592 case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<== imm */
593 if (imm != 0)
594 EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, imm));
595 break;
596 case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */
597 EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg));
598 if (insn_is_zext(&insn[i + 1]))
599 addrs[++i] = ctx->idx * 4;
600 break;
601 case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */
602 EMIT(PPC_RAW_SRD(dst_reg, dst_reg, src_reg));
603 break;
604 case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */
605 EMIT(PPC_RAW_SRWI(dst_reg, dst_reg, imm));
606 if (insn_is_zext(&insn[i + 1]))
607 addrs[++i] = ctx->idx * 4;
608 break;
609 case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */
610 if (imm != 0)
611 EMIT(PPC_RAW_SRDI(dst_reg, dst_reg, imm));
612 break;
613 case BPF_ALU | BPF_ARSH | BPF_X: /* (s32) dst >>= src */
614 EMIT(PPC_RAW_SRAW(dst_reg, dst_reg, src_reg));
615 goto bpf_alu32_trunc;
616 case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */
617 EMIT(PPC_RAW_SRAD(dst_reg, dst_reg, src_reg));
618 break;
619 case BPF_ALU | BPF_ARSH | BPF_K: /* (s32) dst >>= imm */
620 EMIT(PPC_RAW_SRAWI(dst_reg, dst_reg, imm));
621 goto bpf_alu32_trunc;
622 case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */
623 if (imm != 0)
624 EMIT(PPC_RAW_SRADI(dst_reg, dst_reg, imm));
625 break;
626
627 /*
628 * MOV
629 */
630 case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */
631 case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
632 if (imm == 1) {
633 /* special mov32 for zext */
634 EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31));
635 break;
636 }
637 EMIT(PPC_RAW_MR(dst_reg, src_reg));
638 goto bpf_alu32_trunc;
639 case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */
640 case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */
641 PPC_LI32(dst_reg, imm);
642 if (imm < 0)
643 goto bpf_alu32_trunc;
644 else if (insn_is_zext(&insn[i + 1]))
645 addrs[++i] = ctx->idx * 4;
646 break;
647
648bpf_alu32_trunc:
649 /* Truncate to 32-bits */
650 if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext)
651 EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31));
652 break;
653
654 /*
655 * BPF_FROM_BE/LE
656 */
657 case BPF_ALU | BPF_END | BPF_FROM_LE:
658 case BPF_ALU | BPF_END | BPF_FROM_BE:
659#ifdef __BIG_ENDIAN__
660 if (BPF_SRC(code) == BPF_FROM_BE)
661 goto emit_clear;
662#else /* !__BIG_ENDIAN__ */
663 if (BPF_SRC(code) == BPF_FROM_LE)
664 goto emit_clear;
665#endif
666 switch (imm) {
667 case 16:
668 /* Rotate 8 bits left & mask with 0x0000ff00 */
669 EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 16, 23));
670 /* Rotate 8 bits right & insert LSB to reg */
671 EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 24, 31));
672 /* Move result back to dst_reg */
673 EMIT(PPC_RAW_MR(dst_reg, tmp1_reg));
674 break;
675 case 32:
676 /*
677 * Rotate word left by 8 bits:
678 * 2 bytes are already in their final position
679 * -- byte 2 and 4 (of bytes 1, 2, 3 and 4)
680 */
681 EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 0, 31));
682 /* Rotate 24 bits and insert byte 1 */
683 EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 0, 7));
684 /* Rotate 24 bits and insert byte 3 */
685 EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 16, 23));
686 EMIT(PPC_RAW_MR(dst_reg, tmp1_reg));
687 break;
688 case 64:
689 /* Store the value to stack and then use byte-reverse loads */
690 EMIT(PPC_RAW_STD(dst_reg, _R1, bpf_jit_stack_local(ctx)));
691 EMIT(PPC_RAW_ADDI(tmp1_reg, _R1, bpf_jit_stack_local(ctx)));
692 if (cpu_has_feature(CPU_FTR_ARCH_206)) {
693 EMIT(PPC_RAW_LDBRX(dst_reg, 0, tmp1_reg));
694 } else {
695 EMIT(PPC_RAW_LWBRX(dst_reg, 0, tmp1_reg));
696 if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN))
697 EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, 32));
698 EMIT(PPC_RAW_LI(tmp2_reg, 4));
699 EMIT(PPC_RAW_LWBRX(tmp2_reg, tmp2_reg, tmp1_reg));
700 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
701 EMIT(PPC_RAW_SLDI(tmp2_reg, tmp2_reg, 32));
702 EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp2_reg));
703 }
704 break;
705 }
706 break;
707
708emit_clear:
709 switch (imm) {
710 case 16:
711 /* zero-extend 16 bits into 64 bits */
712 EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 48));
713 if (insn_is_zext(&insn[i + 1]))
714 addrs[++i] = ctx->idx * 4;
715 break;
716 case 32:
717 if (!fp->aux->verifier_zext)
718 /* zero-extend 32 bits into 64 bits */
719 EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 32));
720 break;
721 case 64:
722 /* nop */
723 break;
724 }
725 break;
726
727 /*
728 * BPF_ST NOSPEC (speculation barrier)
729 */
730 case BPF_ST | BPF_NOSPEC:
731 if (!security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) ||
732 !security_ftr_enabled(SEC_FTR_STF_BARRIER))
733 break;
734
735 switch (stf_barrier) {
736 case STF_BARRIER_EIEIO:
737 EMIT(PPC_RAW_EIEIO() | 0x02000000);
738 break;
739 case STF_BARRIER_SYNC_ORI:
740 EMIT(PPC_RAW_SYNC());
741 EMIT(PPC_RAW_LD(tmp1_reg, _R13, 0));
742 EMIT(PPC_RAW_ORI(_R31, _R31, 0));
743 break;
744 case STF_BARRIER_FALLBACK:
745 ctx->seen |= SEEN_FUNC;
746 PPC_LI64(_R12, dereference_kernel_function_descriptor(bpf_stf_barrier));
747 EMIT(PPC_RAW_MTCTR(_R12));
748 EMIT(PPC_RAW_BCTRL());
749 break;
750 case STF_BARRIER_NONE:
751 break;
752 }
753 break;
754
755 /*
756 * BPF_ST(X)
757 */
758 case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */
759 case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
760 if (BPF_CLASS(code) == BPF_ST) {
761 EMIT(PPC_RAW_LI(tmp1_reg, imm));
762 src_reg = tmp1_reg;
763 }
764 EMIT(PPC_RAW_STB(src_reg, dst_reg, off));
765 break;
766 case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
767 case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
768 if (BPF_CLASS(code) == BPF_ST) {
769 EMIT(PPC_RAW_LI(tmp1_reg, imm));
770 src_reg = tmp1_reg;
771 }
772 EMIT(PPC_RAW_STH(src_reg, dst_reg, off));
773 break;
774 case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
775 case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
776 if (BPF_CLASS(code) == BPF_ST) {
777 PPC_LI32(tmp1_reg, imm);
778 src_reg = tmp1_reg;
779 }
780 EMIT(PPC_RAW_STW(src_reg, dst_reg, off));
781 break;
782 case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
783 case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
784 if (BPF_CLASS(code) == BPF_ST) {
785 PPC_LI32(tmp1_reg, imm);
786 src_reg = tmp1_reg;
787 }
788 if (off % 4) {
789 EMIT(PPC_RAW_LI(tmp2_reg, off));
790 EMIT(PPC_RAW_STDX(src_reg, dst_reg, tmp2_reg));
791 } else {
792 EMIT(PPC_RAW_STD(src_reg, dst_reg, off));
793 }
794 break;
795
796 /*
797 * BPF_STX ATOMIC (atomic ops)
798 */
799 case BPF_STX | BPF_ATOMIC | BPF_W:
800 case BPF_STX | BPF_ATOMIC | BPF_DW:
801 save_reg = tmp2_reg;
802 ret_reg = src_reg;
803
804 /* Get offset into TMP_REG_1 */
805 EMIT(PPC_RAW_LI(tmp1_reg, off));
806 tmp_idx = ctx->idx * 4;
807 /* load value from memory into TMP_REG_2 */
808 if (size == BPF_DW)
809 EMIT(PPC_RAW_LDARX(tmp2_reg, tmp1_reg, dst_reg, 0));
810 else
811 EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0));
812
813 /* Save old value in _R0 */
814 if (imm & BPF_FETCH)
815 EMIT(PPC_RAW_MR(_R0, tmp2_reg));
816
817 switch (imm) {
818 case BPF_ADD:
819 case BPF_ADD | BPF_FETCH:
820 EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg));
821 break;
822 case BPF_AND:
823 case BPF_AND | BPF_FETCH:
824 EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg));
825 break;
826 case BPF_OR:
827 case BPF_OR | BPF_FETCH:
828 EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg));
829 break;
830 case BPF_XOR:
831 case BPF_XOR | BPF_FETCH:
832 EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg));
833 break;
834 case BPF_CMPXCHG:
835 /*
836 * Return old value in BPF_REG_0 for BPF_CMPXCHG &
837 * in src_reg for other cases.
838 */
839 ret_reg = bpf_to_ppc(BPF_REG_0);
840
841 /* Compare with old value in BPF_R0 */
842 if (size == BPF_DW)
843 EMIT(PPC_RAW_CMPD(bpf_to_ppc(BPF_REG_0), tmp2_reg));
844 else
845 EMIT(PPC_RAW_CMPW(bpf_to_ppc(BPF_REG_0), tmp2_reg));
846 /* Don't set if different from old value */
847 PPC_BCC_SHORT(COND_NE, (ctx->idx + 3) * 4);
848 fallthrough;
849 case BPF_XCHG:
850 save_reg = src_reg;
851 break;
852 default:
853 pr_err_ratelimited(
854 "eBPF filter atomic op code %02x (@%d) unsupported\n",
855 code, i);
856 return -EOPNOTSUPP;
857 }
858
859 /* store new value */
860 if (size == BPF_DW)
861 EMIT(PPC_RAW_STDCX(save_reg, tmp1_reg, dst_reg));
862 else
863 EMIT(PPC_RAW_STWCX(save_reg, tmp1_reg, dst_reg));
864 /* we're done if this succeeded */
865 PPC_BCC_SHORT(COND_NE, tmp_idx);
866
867 if (imm & BPF_FETCH) {
868 EMIT(PPC_RAW_MR(ret_reg, _R0));
869 /*
870 * Skip unnecessary zero-extension for 32-bit cmpxchg.
871 * For context, see commit 39491867ace5.
872 */
873 if (size != BPF_DW && imm == BPF_CMPXCHG &&
874 insn_is_zext(&insn[i + 1]))
875 addrs[++i] = ctx->idx * 4;
876 }
877 break;
878
879 /*
880 * BPF_LDX
881 */
882 /* dst = *(u8 *)(ul) (src + off) */
883 case BPF_LDX | BPF_MEM | BPF_B:
884 case BPF_LDX | BPF_PROBE_MEM | BPF_B:
885 /* dst = *(u16 *)(ul) (src + off) */
886 case BPF_LDX | BPF_MEM | BPF_H:
887 case BPF_LDX | BPF_PROBE_MEM | BPF_H:
888 /* dst = *(u32 *)(ul) (src + off) */
889 case BPF_LDX | BPF_MEM | BPF_W:
890 case BPF_LDX | BPF_PROBE_MEM | BPF_W:
891 /* dst = *(u64 *)(ul) (src + off) */
892 case BPF_LDX | BPF_MEM | BPF_DW:
893 case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
894 /*
895 * As PTR_TO_BTF_ID that uses BPF_PROBE_MEM mode could either be a valid
896 * kernel pointer or NULL but not a userspace address, execute BPF_PROBE_MEM
897 * load only if addr is kernel address (see is_kernel_addr()), otherwise
898 * set dst_reg=0 and move on.
899 */
900 if (BPF_MODE(code) == BPF_PROBE_MEM) {
901 EMIT(PPC_RAW_ADDI(tmp1_reg, src_reg, off));
902 if (IS_ENABLED(CONFIG_PPC_BOOK3E_64))
903 PPC_LI64(tmp2_reg, 0x8000000000000000ul);
904 else /* BOOK3S_64 */
905 PPC_LI64(tmp2_reg, PAGE_OFFSET);
906 EMIT(PPC_RAW_CMPLD(tmp1_reg, tmp2_reg));
907 PPC_BCC_SHORT(COND_GT, (ctx->idx + 3) * 4);
908 EMIT(PPC_RAW_LI(dst_reg, 0));
909 /*
910 * Check if 'off' is word aligned for BPF_DW, because
911 * we might generate two instructions.
912 */
913 if (BPF_SIZE(code) == BPF_DW && (off & 3))
914 PPC_JMP((ctx->idx + 3) * 4);
915 else
916 PPC_JMP((ctx->idx + 2) * 4);
917 }
918
919 switch (size) {
920 case BPF_B:
921 EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off));
922 break;
923 case BPF_H:
924 EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off));
925 break;
926 case BPF_W:
927 EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off));
928 break;
929 case BPF_DW:
930 if (off % 4) {
931 EMIT(PPC_RAW_LI(tmp1_reg, off));
932 EMIT(PPC_RAW_LDX(dst_reg, src_reg, tmp1_reg));
933 } else {
934 EMIT(PPC_RAW_LD(dst_reg, src_reg, off));
935 }
936 break;
937 }
938
939 if (size != BPF_DW && insn_is_zext(&insn[i + 1]))
940 addrs[++i] = ctx->idx * 4;
941
942 if (BPF_MODE(code) == BPF_PROBE_MEM) {
943 ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx,
944 ctx->idx - 1, 4, dst_reg);
945 if (ret)
946 return ret;
947 }
948 break;
949
950 /*
951 * Doubleword load
952 * 16 byte instruction that uses two 'struct bpf_insn'
953 */
954 case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
955 imm64 = ((u64)(u32) insn[i].imm) |
956 (((u64)(u32) insn[i+1].imm) << 32);
957 tmp_idx = ctx->idx;
958 PPC_LI64(dst_reg, imm64);
959 /* padding to allow full 5 instructions for later patching */
960 if (!image)
961 for (j = ctx->idx - tmp_idx; j < 5; j++)
962 EMIT(PPC_RAW_NOP());
963 /* Adjust for two bpf instructions */
964 addrs[++i] = ctx->idx * 4;
965 break;
966
967 /*
968 * Return/Exit
969 */
970 case BPF_JMP | BPF_EXIT:
971 /*
972 * If this isn't the very last instruction, branch to
973 * the epilogue. If we _are_ the last instruction,
974 * we'll just fall through to the epilogue.
975 */
976 if (i != flen - 1) {
977 ret = bpf_jit_emit_exit_insn(image, ctx, tmp1_reg, exit_addr);
978 if (ret)
979 return ret;
980 }
981 /* else fall through to the epilogue */
982 break;
983
984 /*
985 * Call kernel helper or bpf function
986 */
987 case BPF_JMP | BPF_CALL:
988 ctx->seen |= SEEN_FUNC;
989
990 ret = bpf_jit_get_func_addr(fp, &insn[i], extra_pass,
991 &func_addr, &func_addr_fixed);
992 if (ret < 0)
993 return ret;
994
995 if (func_addr_fixed)
996 ret = bpf_jit_emit_func_call_hlp(image, ctx, func_addr);
997 else
998 ret = bpf_jit_emit_func_call_rel(image, fimage, ctx, func_addr);
999
1000 if (ret)
1001 return ret;
1002
1003 /* move return value from r3 to BPF_REG_0 */
1004 EMIT(PPC_RAW_MR(bpf_to_ppc(BPF_REG_0), _R3));
1005 break;
1006
1007 /*
1008 * Jumps and branches
1009 */
1010 case BPF_JMP | BPF_JA:
1011 PPC_JMP(addrs[i + 1 + off]);
1012 break;
1013
1014 case BPF_JMP | BPF_JGT | BPF_K:
1015 case BPF_JMP | BPF_JGT | BPF_X:
1016 case BPF_JMP | BPF_JSGT | BPF_K:
1017 case BPF_JMP | BPF_JSGT | BPF_X:
1018 case BPF_JMP32 | BPF_JGT | BPF_K:
1019 case BPF_JMP32 | BPF_JGT | BPF_X:
1020 case BPF_JMP32 | BPF_JSGT | BPF_K:
1021 case BPF_JMP32 | BPF_JSGT | BPF_X:
1022 true_cond = COND_GT;
1023 goto cond_branch;
1024 case BPF_JMP | BPF_JLT | BPF_K:
1025 case BPF_JMP | BPF_JLT | BPF_X:
1026 case BPF_JMP | BPF_JSLT | BPF_K:
1027 case BPF_JMP | BPF_JSLT | BPF_X:
1028 case BPF_JMP32 | BPF_JLT | BPF_K:
1029 case BPF_JMP32 | BPF_JLT | BPF_X:
1030 case BPF_JMP32 | BPF_JSLT | BPF_K:
1031 case BPF_JMP32 | BPF_JSLT | BPF_X:
1032 true_cond = COND_LT;
1033 goto cond_branch;
1034 case BPF_JMP | BPF_JGE | BPF_K:
1035 case BPF_JMP | BPF_JGE | BPF_X:
1036 case BPF_JMP | BPF_JSGE | BPF_K:
1037 case BPF_JMP | BPF_JSGE | BPF_X:
1038 case BPF_JMP32 | BPF_JGE | BPF_K:
1039 case BPF_JMP32 | BPF_JGE | BPF_X:
1040 case BPF_JMP32 | BPF_JSGE | BPF_K:
1041 case BPF_JMP32 | BPF_JSGE | BPF_X:
1042 true_cond = COND_GE;
1043 goto cond_branch;
1044 case BPF_JMP | BPF_JLE | BPF_K:
1045 case BPF_JMP | BPF_JLE | BPF_X:
1046 case BPF_JMP | BPF_JSLE | BPF_K:
1047 case BPF_JMP | BPF_JSLE | BPF_X:
1048 case BPF_JMP32 | BPF_JLE | BPF_K:
1049 case BPF_JMP32 | BPF_JLE | BPF_X:
1050 case BPF_JMP32 | BPF_JSLE | BPF_K:
1051 case BPF_JMP32 | BPF_JSLE | BPF_X:
1052 true_cond = COND_LE;
1053 goto cond_branch;
1054 case BPF_JMP | BPF_JEQ | BPF_K:
1055 case BPF_JMP | BPF_JEQ | BPF_X:
1056 case BPF_JMP32 | BPF_JEQ | BPF_K:
1057 case BPF_JMP32 | BPF_JEQ | BPF_X:
1058 true_cond = COND_EQ;
1059 goto cond_branch;
1060 case BPF_JMP | BPF_JNE | BPF_K:
1061 case BPF_JMP | BPF_JNE | BPF_X:
1062 case BPF_JMP32 | BPF_JNE | BPF_K:
1063 case BPF_JMP32 | BPF_JNE | BPF_X:
1064 true_cond = COND_NE;
1065 goto cond_branch;
1066 case BPF_JMP | BPF_JSET | BPF_K:
1067 case BPF_JMP | BPF_JSET | BPF_X:
1068 case BPF_JMP32 | BPF_JSET | BPF_K:
1069 case BPF_JMP32 | BPF_JSET | BPF_X:
1070 true_cond = COND_NE;
1071 /* Fall through */
1072
1073cond_branch:
1074 switch (code) {
1075 case BPF_JMP | BPF_JGT | BPF_X:
1076 case BPF_JMP | BPF_JLT | BPF_X:
1077 case BPF_JMP | BPF_JGE | BPF_X:
1078 case BPF_JMP | BPF_JLE | BPF_X:
1079 case BPF_JMP | BPF_JEQ | BPF_X:
1080 case BPF_JMP | BPF_JNE | BPF_X:
1081 case BPF_JMP32 | BPF_JGT | BPF_X:
1082 case BPF_JMP32 | BPF_JLT | BPF_X:
1083 case BPF_JMP32 | BPF_JGE | BPF_X:
1084 case BPF_JMP32 | BPF_JLE | BPF_X:
1085 case BPF_JMP32 | BPF_JEQ | BPF_X:
1086 case BPF_JMP32 | BPF_JNE | BPF_X:
1087 /* unsigned comparison */
1088 if (BPF_CLASS(code) == BPF_JMP32)
1089 EMIT(PPC_RAW_CMPLW(dst_reg, src_reg));
1090 else
1091 EMIT(PPC_RAW_CMPLD(dst_reg, src_reg));
1092 break;
1093 case BPF_JMP | BPF_JSGT | BPF_X:
1094 case BPF_JMP | BPF_JSLT | BPF_X:
1095 case BPF_JMP | BPF_JSGE | BPF_X:
1096 case BPF_JMP | BPF_JSLE | BPF_X:
1097 case BPF_JMP32 | BPF_JSGT | BPF_X:
1098 case BPF_JMP32 | BPF_JSLT | BPF_X:
1099 case BPF_JMP32 | BPF_JSGE | BPF_X:
1100 case BPF_JMP32 | BPF_JSLE | BPF_X:
1101 /* signed comparison */
1102 if (BPF_CLASS(code) == BPF_JMP32)
1103 EMIT(PPC_RAW_CMPW(dst_reg, src_reg));
1104 else
1105 EMIT(PPC_RAW_CMPD(dst_reg, src_reg));
1106 break;
1107 case BPF_JMP | BPF_JSET | BPF_X:
1108 case BPF_JMP32 | BPF_JSET | BPF_X:
1109 if (BPF_CLASS(code) == BPF_JMP) {
1110 EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg, src_reg));
1111 } else {
1112 EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, src_reg));
1113 EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg, 0, 0, 31));
1114 }
1115 break;
1116 case BPF_JMP | BPF_JNE | BPF_K:
1117 case BPF_JMP | BPF_JEQ | BPF_K:
1118 case BPF_JMP | BPF_JGT | BPF_K:
1119 case BPF_JMP | BPF_JLT | BPF_K:
1120 case BPF_JMP | BPF_JGE | BPF_K:
1121 case BPF_JMP | BPF_JLE | BPF_K:
1122 case BPF_JMP32 | BPF_JNE | BPF_K:
1123 case BPF_JMP32 | BPF_JEQ | BPF_K:
1124 case BPF_JMP32 | BPF_JGT | BPF_K:
1125 case BPF_JMP32 | BPF_JLT | BPF_K:
1126 case BPF_JMP32 | BPF_JGE | BPF_K:
1127 case BPF_JMP32 | BPF_JLE | BPF_K:
1128 {
1129 bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32;
1130
1131 /*
1132 * Need sign-extended load, so only positive
1133 * values can be used as imm in cmpldi
1134 */
1135 if (imm >= 0 && imm < 32768) {
1136 if (is_jmp32)
1137 EMIT(PPC_RAW_CMPLWI(dst_reg, imm));
1138 else
1139 EMIT(PPC_RAW_CMPLDI(dst_reg, imm));
1140 } else {
1141 /* sign-extending load */
1142 PPC_LI32(tmp1_reg, imm);
1143 /* ... but unsigned comparison */
1144 if (is_jmp32)
1145 EMIT(PPC_RAW_CMPLW(dst_reg, tmp1_reg));
1146 else
1147 EMIT(PPC_RAW_CMPLD(dst_reg, tmp1_reg));
1148 }
1149 break;
1150 }
1151 case BPF_JMP | BPF_JSGT | BPF_K:
1152 case BPF_JMP | BPF_JSLT | BPF_K:
1153 case BPF_JMP | BPF_JSGE | BPF_K:
1154 case BPF_JMP | BPF_JSLE | BPF_K:
1155 case BPF_JMP32 | BPF_JSGT | BPF_K:
1156 case BPF_JMP32 | BPF_JSLT | BPF_K:
1157 case BPF_JMP32 | BPF_JSGE | BPF_K:
1158 case BPF_JMP32 | BPF_JSLE | BPF_K:
1159 {
1160 bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32;
1161
1162 /*
1163 * signed comparison, so any 16-bit value
1164 * can be used in cmpdi
1165 */
1166 if (imm >= -32768 && imm < 32768) {
1167 if (is_jmp32)
1168 EMIT(PPC_RAW_CMPWI(dst_reg, imm));
1169 else
1170 EMIT(PPC_RAW_CMPDI(dst_reg, imm));
1171 } else {
1172 PPC_LI32(tmp1_reg, imm);
1173 if (is_jmp32)
1174 EMIT(PPC_RAW_CMPW(dst_reg, tmp1_reg));
1175 else
1176 EMIT(PPC_RAW_CMPD(dst_reg, tmp1_reg));
1177 }
1178 break;
1179 }
1180 case BPF_JMP | BPF_JSET | BPF_K:
1181 case BPF_JMP32 | BPF_JSET | BPF_K:
1182 /* andi does not sign-extend the immediate */
1183 if (imm >= 0 && imm < 32768)
1184 /* PPC_ANDI is _only/always_ dot-form */
1185 EMIT(PPC_RAW_ANDI(tmp1_reg, dst_reg, imm));
1186 else {
1187 PPC_LI32(tmp1_reg, imm);
1188 if (BPF_CLASS(code) == BPF_JMP) {
1189 EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg,
1190 tmp1_reg));
1191 } else {
1192 EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, tmp1_reg));
1193 EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg,
1194 0, 0, 31));
1195 }
1196 }
1197 break;
1198 }
1199 PPC_BCC(true_cond, addrs[i + 1 + off]);
1200 break;
1201
1202 /*
1203 * Tail call
1204 */
1205 case BPF_JMP | BPF_TAIL_CALL:
1206 ctx->seen |= SEEN_TAILCALL;
1207 ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]);
1208 if (ret < 0)
1209 return ret;
1210 break;
1211
1212 default:
1213 /*
1214 * The filter contains something cruel & unusual.
1215 * We don't handle it, but also there shouldn't be
1216 * anything missing from our list.
1217 */
1218 pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n",
1219 code, i);
1220 return -ENOTSUPP;
1221 }
1222 }
1223
1224 /* Set end-of-body-code address for exit. */
1225 addrs[i] = ctx->idx * 4;
1226
1227 return 0;
1228}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * bpf_jit_comp64.c: eBPF JIT compiler
4 *
5 * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
6 * IBM Corporation
7 *
8 * Based on the powerpc classic BPF JIT compiler by Matt Evans
9 */
10#include <linux/moduleloader.h>
11#include <asm/cacheflush.h>
12#include <asm/asm-compat.h>
13#include <linux/netdevice.h>
14#include <linux/filter.h>
15#include <linux/if_vlan.h>
16#include <asm/kprobes.h>
17#include <linux/bpf.h>
18#include <asm/security_features.h>
19
20#include "bpf_jit.h"
21
22/*
23 * Stack layout:
24 * Ensure the top half (upto local_tmp_var) stays consistent
25 * with our redzone usage.
26 *
27 * [ prev sp ] <-------------
28 * [ nv gpr save area ] 5*8 |
29 * [ tail_call_cnt ] 8 |
30 * [ local_tmp_var ] 16 |
31 * fp (r31) --> [ ebpf stack space ] upto 512 |
32 * [ frame header ] 32/112 |
33 * sp (r1) ---> [ stack pointer ] --------------
34 */
35
36/* for gpr non volatile registers BPG_REG_6 to 10 */
37#define BPF_PPC_STACK_SAVE (5*8)
38/* for bpf JIT code internal usage */
39#define BPF_PPC_STACK_LOCALS 24
40/* stack frame excluding BPF stack, ensure this is quadword aligned */
41#define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + \
42 BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE)
43
44/* BPF register usage */
45#define TMP_REG_1 (MAX_BPF_JIT_REG + 0)
46#define TMP_REG_2 (MAX_BPF_JIT_REG + 1)
47
48/* BPF to ppc register mappings */
49void bpf_jit_init_reg_mapping(struct codegen_context *ctx)
50{
51 /* function return value */
52 ctx->b2p[BPF_REG_0] = _R8;
53 /* function arguments */
54 ctx->b2p[BPF_REG_1] = _R3;
55 ctx->b2p[BPF_REG_2] = _R4;
56 ctx->b2p[BPF_REG_3] = _R5;
57 ctx->b2p[BPF_REG_4] = _R6;
58 ctx->b2p[BPF_REG_5] = _R7;
59 /* non volatile registers */
60 ctx->b2p[BPF_REG_6] = _R27;
61 ctx->b2p[BPF_REG_7] = _R28;
62 ctx->b2p[BPF_REG_8] = _R29;
63 ctx->b2p[BPF_REG_9] = _R30;
64 /* frame pointer aka BPF_REG_10 */
65 ctx->b2p[BPF_REG_FP] = _R31;
66 /* eBPF jit internal registers */
67 ctx->b2p[BPF_REG_AX] = _R12;
68 ctx->b2p[TMP_REG_1] = _R9;
69 ctx->b2p[TMP_REG_2] = _R10;
70}
71
72/* PPC NVR range -- update this if we ever use NVRs below r27 */
73#define BPF_PPC_NVR_MIN _R27
74
75static inline bool bpf_has_stack_frame(struct codegen_context *ctx)
76{
77 /*
78 * We only need a stack frame if:
79 * - we call other functions (kernel helpers), or
80 * - the bpf program uses its stack area
81 * The latter condition is deduced from the usage of BPF_REG_FP
82 */
83 return ctx->seen & SEEN_FUNC || bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP));
84}
85
86/*
87 * When not setting up our own stackframe, the redzone usage is:
88 *
89 * [ prev sp ] <-------------
90 * [ ... ] |
91 * sp (r1) ---> [ stack pointer ] --------------
92 * [ nv gpr save area ] 5*8
93 * [ tail_call_cnt ] 8
94 * [ local_tmp_var ] 16
95 * [ unused red zone ] 208 bytes protected
96 */
97static int bpf_jit_stack_local(struct codegen_context *ctx)
98{
99 if (bpf_has_stack_frame(ctx))
100 return STACK_FRAME_MIN_SIZE + ctx->stack_size;
101 else
102 return -(BPF_PPC_STACK_SAVE + 24);
103}
104
105static int bpf_jit_stack_tailcallcnt(struct codegen_context *ctx)
106{
107 return bpf_jit_stack_local(ctx) + 16;
108}
109
110static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
111{
112 if (reg >= BPF_PPC_NVR_MIN && reg < 32)
113 return (bpf_has_stack_frame(ctx) ?
114 (BPF_PPC_STACKFRAME + ctx->stack_size) : 0)
115 - (8 * (32 - reg));
116
117 pr_err("BPF JIT is asking about unknown registers");
118 BUG();
119}
120
121void bpf_jit_realloc_regs(struct codegen_context *ctx)
122{
123}
124
125void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
126{
127 int i;
128
129 if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
130 EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc)));
131
132 /*
133 * Initialize tail_call_cnt if we do tail calls.
134 * Otherwise, put in NOPs so that it can be skipped when we are
135 * invoked through a tail call.
136 */
137 if (ctx->seen & SEEN_TAILCALL) {
138 EMIT(PPC_RAW_LI(bpf_to_ppc(TMP_REG_1), 0));
139 /* this goes in the redzone */
140 EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, -(BPF_PPC_STACK_SAVE + 8)));
141 } else {
142 EMIT(PPC_RAW_NOP());
143 EMIT(PPC_RAW_NOP());
144 }
145
146 if (bpf_has_stack_frame(ctx)) {
147 /*
148 * We need a stack frame, but we don't necessarily need to
149 * save/restore LR unless we call other functions
150 */
151 if (ctx->seen & SEEN_FUNC) {
152 EMIT(PPC_RAW_MFLR(_R0));
153 EMIT(PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF));
154 }
155
156 EMIT(PPC_RAW_STDU(_R1, _R1, -(BPF_PPC_STACKFRAME + ctx->stack_size)));
157 }
158
159 /*
160 * Back up non-volatile regs -- BPF registers 6-10
161 * If we haven't created our own stack frame, we save these
162 * in the protected zone below the previous stack frame
163 */
164 for (i = BPF_REG_6; i <= BPF_REG_10; i++)
165 if (bpf_is_seen_register(ctx, bpf_to_ppc(i)))
166 EMIT(PPC_RAW_STD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i))));
167
168 /* Setup frame pointer to point to the bpf stack area */
169 if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP)))
170 EMIT(PPC_RAW_ADDI(bpf_to_ppc(BPF_REG_FP), _R1,
171 STACK_FRAME_MIN_SIZE + ctx->stack_size));
172}
173
174static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx)
175{
176 int i;
177
178 /* Restore NVRs */
179 for (i = BPF_REG_6; i <= BPF_REG_10; i++)
180 if (bpf_is_seen_register(ctx, bpf_to_ppc(i)))
181 EMIT(PPC_RAW_LD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i))));
182
183 /* Tear down our stack frame */
184 if (bpf_has_stack_frame(ctx)) {
185 EMIT(PPC_RAW_ADDI(_R1, _R1, BPF_PPC_STACKFRAME + ctx->stack_size));
186 if (ctx->seen & SEEN_FUNC) {
187 EMIT(PPC_RAW_LD(_R0, _R1, PPC_LR_STKOFF));
188 EMIT(PPC_RAW_MTLR(_R0));
189 }
190 }
191}
192
193void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
194{
195 bpf_jit_emit_common_epilogue(image, ctx);
196
197 /* Move result to r3 */
198 EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_0)));
199
200 EMIT(PPC_RAW_BLR());
201}
202
203static int bpf_jit_emit_func_call_hlp(u32 *image, struct codegen_context *ctx, u64 func)
204{
205 unsigned long func_addr = func ? ppc_function_entry((void *)func) : 0;
206 long reladdr;
207
208 if (WARN_ON_ONCE(!core_kernel_text(func_addr)))
209 return -EINVAL;
210
211 reladdr = func_addr - kernel_toc_addr();
212 if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
213 pr_err("eBPF: address of %ps out of range of kernel_toc.\n", (void *)func);
214 return -ERANGE;
215 }
216
217 EMIT(PPC_RAW_ADDIS(_R12, _R2, PPC_HA(reladdr)));
218 EMIT(PPC_RAW_ADDI(_R12, _R12, PPC_LO(reladdr)));
219 EMIT(PPC_RAW_MTCTR(_R12));
220 EMIT(PPC_RAW_BCTRL());
221
222 return 0;
223}
224
225int bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func)
226{
227 unsigned int i, ctx_idx = ctx->idx;
228
229 if (WARN_ON_ONCE(func && is_module_text_address(func)))
230 return -EINVAL;
231
232 /* skip past descriptor if elf v1 */
233 func += FUNCTION_DESCR_SIZE;
234
235 /* Load function address into r12 */
236 PPC_LI64(_R12, func);
237
238 /* For bpf-to-bpf function calls, the callee's address is unknown
239 * until the last extra pass. As seen above, we use PPC_LI64() to
240 * load the callee's address, but this may optimize the number of
241 * instructions required based on the nature of the address.
242 *
243 * Since we don't want the number of instructions emitted to change,
244 * we pad the optimized PPC_LI64() call with NOPs to guarantee that
245 * we always have a five-instruction sequence, which is the maximum
246 * that PPC_LI64() can emit.
247 */
248 for (i = ctx->idx - ctx_idx; i < 5; i++)
249 EMIT(PPC_RAW_NOP());
250
251 EMIT(PPC_RAW_MTCTR(_R12));
252 EMIT(PPC_RAW_BCTRL());
253
254 return 0;
255}
256
257static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out)
258{
259 /*
260 * By now, the eBPF program has already setup parameters in r3, r4 and r5
261 * r3/BPF_REG_1 - pointer to ctx -- passed as is to the next bpf program
262 * r4/BPF_REG_2 - pointer to bpf_array
263 * r5/BPF_REG_3 - index in bpf_array
264 */
265 int b2p_bpf_array = bpf_to_ppc(BPF_REG_2);
266 int b2p_index = bpf_to_ppc(BPF_REG_3);
267 int bpf_tailcall_prologue_size = 8;
268
269 if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
270 bpf_tailcall_prologue_size += 4; /* skip past the toc load */
271
272 /*
273 * if (index >= array->map.max_entries)
274 * goto out;
275 */
276 EMIT(PPC_RAW_LWZ(bpf_to_ppc(TMP_REG_1), b2p_bpf_array, offsetof(struct bpf_array, map.max_entries)));
277 EMIT(PPC_RAW_RLWINM(b2p_index, b2p_index, 0, 0, 31));
278 EMIT(PPC_RAW_CMPLW(b2p_index, bpf_to_ppc(TMP_REG_1)));
279 PPC_BCC_SHORT(COND_GE, out);
280
281 /*
282 * if (tail_call_cnt >= MAX_TAIL_CALL_CNT)
283 * goto out;
284 */
285 EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx)));
286 EMIT(PPC_RAW_CMPLWI(bpf_to_ppc(TMP_REG_1), MAX_TAIL_CALL_CNT));
287 PPC_BCC_SHORT(COND_GE, out);
288
289 /*
290 * tail_call_cnt++;
291 */
292 EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), 1));
293 EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx)));
294
295 /* prog = array->ptrs[index]; */
296 EMIT(PPC_RAW_MULI(bpf_to_ppc(TMP_REG_1), b2p_index, 8));
297 EMIT(PPC_RAW_ADD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), b2p_bpf_array));
298 EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_array, ptrs)));
299
300 /*
301 * if (prog == NULL)
302 * goto out;
303 */
304 EMIT(PPC_RAW_CMPLDI(bpf_to_ppc(TMP_REG_1), 0));
305 PPC_BCC_SHORT(COND_EQ, out);
306
307 /* goto *(prog->bpf_func + prologue_size); */
308 EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_prog, bpf_func)));
309 EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1),
310 FUNCTION_DESCR_SIZE + bpf_tailcall_prologue_size));
311 EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_1)));
312
313 /* tear down stack, restore NVRs, ... */
314 bpf_jit_emit_common_epilogue(image, ctx);
315
316 EMIT(PPC_RAW_BCTR());
317
318 /* out: */
319 return 0;
320}
321
322/*
323 * We spill into the redzone always, even if the bpf program has its own stackframe.
324 * Offsets hardcoded based on BPF_PPC_STACK_SAVE -- see bpf_jit_stack_local()
325 */
326void bpf_stf_barrier(void);
327
328asm (
329" .global bpf_stf_barrier ;"
330" bpf_stf_barrier: ;"
331" std 21,-64(1) ;"
332" std 22,-56(1) ;"
333" sync ;"
334" ld 21,-64(1) ;"
335" ld 22,-56(1) ;"
336" ori 31,31,0 ;"
337" .rept 14 ;"
338" b 1f ;"
339" 1: ;"
340" .endr ;"
341" blr ;"
342);
343
344/* Assemble the body code between the prologue & epilogue */
345int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx,
346 u32 *addrs, int pass)
347{
348 enum stf_barrier_type stf_barrier = stf_barrier_type_get();
349 const struct bpf_insn *insn = fp->insnsi;
350 int flen = fp->len;
351 int i, ret;
352
353 /* Start of epilogue code - will only be valid 2nd pass onwards */
354 u32 exit_addr = addrs[flen];
355
356 for (i = 0; i < flen; i++) {
357 u32 code = insn[i].code;
358 u32 dst_reg = bpf_to_ppc(insn[i].dst_reg);
359 u32 src_reg = bpf_to_ppc(insn[i].src_reg);
360 u32 size = BPF_SIZE(code);
361 u32 tmp1_reg = bpf_to_ppc(TMP_REG_1);
362 u32 tmp2_reg = bpf_to_ppc(TMP_REG_2);
363 u32 save_reg, ret_reg;
364 s16 off = insn[i].off;
365 s32 imm = insn[i].imm;
366 bool func_addr_fixed;
367 u64 func_addr;
368 u64 imm64;
369 u32 true_cond;
370 u32 tmp_idx;
371 int j;
372
373 /*
374 * addrs[] maps a BPF bytecode address into a real offset from
375 * the start of the body code.
376 */
377 addrs[i] = ctx->idx * 4;
378
379 /*
380 * As an optimization, we note down which non-volatile registers
381 * are used so that we can only save/restore those in our
382 * prologue and epilogue. We do this here regardless of whether
383 * the actual BPF instruction uses src/dst registers or not
384 * (for instance, BPF_CALL does not use them). The expectation
385 * is that those instructions will have src_reg/dst_reg set to
386 * 0. Even otherwise, we just lose some prologue/epilogue
387 * optimization but everything else should work without
388 * any issues.
389 */
390 if (dst_reg >= BPF_PPC_NVR_MIN && dst_reg < 32)
391 bpf_set_seen_register(ctx, dst_reg);
392 if (src_reg >= BPF_PPC_NVR_MIN && src_reg < 32)
393 bpf_set_seen_register(ctx, src_reg);
394
395 switch (code) {
396 /*
397 * Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG
398 */
399 case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */
400 case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */
401 EMIT(PPC_RAW_ADD(dst_reg, dst_reg, src_reg));
402 goto bpf_alu32_trunc;
403 case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */
404 case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */
405 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, src_reg));
406 goto bpf_alu32_trunc;
407 case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */
408 case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */
409 if (!imm) {
410 goto bpf_alu32_trunc;
411 } else if (imm >= -32768 && imm < 32768) {
412 EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(imm)));
413 } else {
414 PPC_LI32(tmp1_reg, imm);
415 EMIT(PPC_RAW_ADD(dst_reg, dst_reg, tmp1_reg));
416 }
417 goto bpf_alu32_trunc;
418 case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */
419 case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */
420 if (!imm) {
421 goto bpf_alu32_trunc;
422 } else if (imm > -32768 && imm <= 32768) {
423 EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(-imm)));
424 } else {
425 PPC_LI32(tmp1_reg, imm);
426 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
427 }
428 goto bpf_alu32_trunc;
429 case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */
430 case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */
431 if (BPF_CLASS(code) == BPF_ALU)
432 EMIT(PPC_RAW_MULW(dst_reg, dst_reg, src_reg));
433 else
434 EMIT(PPC_RAW_MULD(dst_reg, dst_reg, src_reg));
435 goto bpf_alu32_trunc;
436 case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */
437 case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */
438 if (imm >= -32768 && imm < 32768)
439 EMIT(PPC_RAW_MULI(dst_reg, dst_reg, IMM_L(imm)));
440 else {
441 PPC_LI32(tmp1_reg, imm);
442 if (BPF_CLASS(code) == BPF_ALU)
443 EMIT(PPC_RAW_MULW(dst_reg, dst_reg, tmp1_reg));
444 else
445 EMIT(PPC_RAW_MULD(dst_reg, dst_reg, tmp1_reg));
446 }
447 goto bpf_alu32_trunc;
448 case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */
449 case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */
450 if (BPF_OP(code) == BPF_MOD) {
451 EMIT(PPC_RAW_DIVWU(tmp1_reg, dst_reg, src_reg));
452 EMIT(PPC_RAW_MULW(tmp1_reg, src_reg, tmp1_reg));
453 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
454 } else
455 EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, src_reg));
456 goto bpf_alu32_trunc;
457 case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */
458 case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */
459 if (BPF_OP(code) == BPF_MOD) {
460 EMIT(PPC_RAW_DIVDU(tmp1_reg, dst_reg, src_reg));
461 EMIT(PPC_RAW_MULD(tmp1_reg, src_reg, tmp1_reg));
462 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
463 } else
464 EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, src_reg));
465 break;
466 case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */
467 case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */
468 case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */
469 case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */
470 if (imm == 0)
471 return -EINVAL;
472 if (imm == 1) {
473 if (BPF_OP(code) == BPF_DIV) {
474 goto bpf_alu32_trunc;
475 } else {
476 EMIT(PPC_RAW_LI(dst_reg, 0));
477 break;
478 }
479 }
480
481 PPC_LI32(tmp1_reg, imm);
482 switch (BPF_CLASS(code)) {
483 case BPF_ALU:
484 if (BPF_OP(code) == BPF_MOD) {
485 EMIT(PPC_RAW_DIVWU(tmp2_reg, dst_reg, tmp1_reg));
486 EMIT(PPC_RAW_MULW(tmp1_reg, tmp1_reg, tmp2_reg));
487 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
488 } else
489 EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, tmp1_reg));
490 break;
491 case BPF_ALU64:
492 if (BPF_OP(code) == BPF_MOD) {
493 EMIT(PPC_RAW_DIVDU(tmp2_reg, dst_reg, tmp1_reg));
494 EMIT(PPC_RAW_MULD(tmp1_reg, tmp1_reg, tmp2_reg));
495 EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
496 } else
497 EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, tmp1_reg));
498 break;
499 }
500 goto bpf_alu32_trunc;
501 case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */
502 case BPF_ALU64 | BPF_NEG: /* dst = -dst */
503 EMIT(PPC_RAW_NEG(dst_reg, dst_reg));
504 goto bpf_alu32_trunc;
505
506 /*
507 * Logical operations: AND/OR/XOR/[A]LSH/[A]RSH
508 */
509 case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */
510 case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
511 EMIT(PPC_RAW_AND(dst_reg, dst_reg, src_reg));
512 goto bpf_alu32_trunc;
513 case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */
514 case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
515 if (!IMM_H(imm))
516 EMIT(PPC_RAW_ANDI(dst_reg, dst_reg, IMM_L(imm)));
517 else {
518 /* Sign-extended */
519 PPC_LI32(tmp1_reg, imm);
520 EMIT(PPC_RAW_AND(dst_reg, dst_reg, tmp1_reg));
521 }
522 goto bpf_alu32_trunc;
523 case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
524 case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
525 EMIT(PPC_RAW_OR(dst_reg, dst_reg, src_reg));
526 goto bpf_alu32_trunc;
527 case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */
528 case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */
529 if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
530 /* Sign-extended */
531 PPC_LI32(tmp1_reg, imm);
532 EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp1_reg));
533 } else {
534 if (IMM_L(imm))
535 EMIT(PPC_RAW_ORI(dst_reg, dst_reg, IMM_L(imm)));
536 if (IMM_H(imm))
537 EMIT(PPC_RAW_ORIS(dst_reg, dst_reg, IMM_H(imm)));
538 }
539 goto bpf_alu32_trunc;
540 case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */
541 case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */
542 EMIT(PPC_RAW_XOR(dst_reg, dst_reg, src_reg));
543 goto bpf_alu32_trunc;
544 case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */
545 case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */
546 if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
547 /* Sign-extended */
548 PPC_LI32(tmp1_reg, imm);
549 EMIT(PPC_RAW_XOR(dst_reg, dst_reg, tmp1_reg));
550 } else {
551 if (IMM_L(imm))
552 EMIT(PPC_RAW_XORI(dst_reg, dst_reg, IMM_L(imm)));
553 if (IMM_H(imm))
554 EMIT(PPC_RAW_XORIS(dst_reg, dst_reg, IMM_H(imm)));
555 }
556 goto bpf_alu32_trunc;
557 case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */
558 /* slw clears top 32 bits */
559 EMIT(PPC_RAW_SLW(dst_reg, dst_reg, src_reg));
560 /* skip zero extension move, but set address map. */
561 if (insn_is_zext(&insn[i + 1]))
562 addrs[++i] = ctx->idx * 4;
563 break;
564 case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */
565 EMIT(PPC_RAW_SLD(dst_reg, dst_reg, src_reg));
566 break;
567 case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<== (u32) imm */
568 /* with imm 0, we still need to clear top 32 bits */
569 EMIT(PPC_RAW_SLWI(dst_reg, dst_reg, imm));
570 if (insn_is_zext(&insn[i + 1]))
571 addrs[++i] = ctx->idx * 4;
572 break;
573 case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<== imm */
574 if (imm != 0)
575 EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, imm));
576 break;
577 case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */
578 EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg));
579 if (insn_is_zext(&insn[i + 1]))
580 addrs[++i] = ctx->idx * 4;
581 break;
582 case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */
583 EMIT(PPC_RAW_SRD(dst_reg, dst_reg, src_reg));
584 break;
585 case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */
586 EMIT(PPC_RAW_SRWI(dst_reg, dst_reg, imm));
587 if (insn_is_zext(&insn[i + 1]))
588 addrs[++i] = ctx->idx * 4;
589 break;
590 case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */
591 if (imm != 0)
592 EMIT(PPC_RAW_SRDI(dst_reg, dst_reg, imm));
593 break;
594 case BPF_ALU | BPF_ARSH | BPF_X: /* (s32) dst >>= src */
595 EMIT(PPC_RAW_SRAW(dst_reg, dst_reg, src_reg));
596 goto bpf_alu32_trunc;
597 case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */
598 EMIT(PPC_RAW_SRAD(dst_reg, dst_reg, src_reg));
599 break;
600 case BPF_ALU | BPF_ARSH | BPF_K: /* (s32) dst >>= imm */
601 EMIT(PPC_RAW_SRAWI(dst_reg, dst_reg, imm));
602 goto bpf_alu32_trunc;
603 case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */
604 if (imm != 0)
605 EMIT(PPC_RAW_SRADI(dst_reg, dst_reg, imm));
606 break;
607
608 /*
609 * MOV
610 */
611 case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */
612 case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
613 if (imm == 1) {
614 /* special mov32 for zext */
615 EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31));
616 break;
617 }
618 EMIT(PPC_RAW_MR(dst_reg, src_reg));
619 goto bpf_alu32_trunc;
620 case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */
621 case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */
622 PPC_LI32(dst_reg, imm);
623 if (imm < 0)
624 goto bpf_alu32_trunc;
625 else if (insn_is_zext(&insn[i + 1]))
626 addrs[++i] = ctx->idx * 4;
627 break;
628
629bpf_alu32_trunc:
630 /* Truncate to 32-bits */
631 if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext)
632 EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31));
633 break;
634
635 /*
636 * BPF_FROM_BE/LE
637 */
638 case BPF_ALU | BPF_END | BPF_FROM_LE:
639 case BPF_ALU | BPF_END | BPF_FROM_BE:
640#ifdef __BIG_ENDIAN__
641 if (BPF_SRC(code) == BPF_FROM_BE)
642 goto emit_clear;
643#else /* !__BIG_ENDIAN__ */
644 if (BPF_SRC(code) == BPF_FROM_LE)
645 goto emit_clear;
646#endif
647 switch (imm) {
648 case 16:
649 /* Rotate 8 bits left & mask with 0x0000ff00 */
650 EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 16, 23));
651 /* Rotate 8 bits right & insert LSB to reg */
652 EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 24, 31));
653 /* Move result back to dst_reg */
654 EMIT(PPC_RAW_MR(dst_reg, tmp1_reg));
655 break;
656 case 32:
657 /*
658 * Rotate word left by 8 bits:
659 * 2 bytes are already in their final position
660 * -- byte 2 and 4 (of bytes 1, 2, 3 and 4)
661 */
662 EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 0, 31));
663 /* Rotate 24 bits and insert byte 1 */
664 EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 0, 7));
665 /* Rotate 24 bits and insert byte 3 */
666 EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 16, 23));
667 EMIT(PPC_RAW_MR(dst_reg, tmp1_reg));
668 break;
669 case 64:
670 /* Store the value to stack and then use byte-reverse loads */
671 EMIT(PPC_RAW_STD(dst_reg, _R1, bpf_jit_stack_local(ctx)));
672 EMIT(PPC_RAW_ADDI(tmp1_reg, _R1, bpf_jit_stack_local(ctx)));
673 if (cpu_has_feature(CPU_FTR_ARCH_206)) {
674 EMIT(PPC_RAW_LDBRX(dst_reg, 0, tmp1_reg));
675 } else {
676 EMIT(PPC_RAW_LWBRX(dst_reg, 0, tmp1_reg));
677 if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN))
678 EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, 32));
679 EMIT(PPC_RAW_LI(tmp2_reg, 4));
680 EMIT(PPC_RAW_LWBRX(tmp2_reg, tmp2_reg, tmp1_reg));
681 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
682 EMIT(PPC_RAW_SLDI(tmp2_reg, tmp2_reg, 32));
683 EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp2_reg));
684 }
685 break;
686 }
687 break;
688
689emit_clear:
690 switch (imm) {
691 case 16:
692 /* zero-extend 16 bits into 64 bits */
693 EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 48));
694 if (insn_is_zext(&insn[i + 1]))
695 addrs[++i] = ctx->idx * 4;
696 break;
697 case 32:
698 if (!fp->aux->verifier_zext)
699 /* zero-extend 32 bits into 64 bits */
700 EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 32));
701 break;
702 case 64:
703 /* nop */
704 break;
705 }
706 break;
707
708 /*
709 * BPF_ST NOSPEC (speculation barrier)
710 */
711 case BPF_ST | BPF_NOSPEC:
712 if (!security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) ||
713 !security_ftr_enabled(SEC_FTR_STF_BARRIER))
714 break;
715
716 switch (stf_barrier) {
717 case STF_BARRIER_EIEIO:
718 EMIT(PPC_RAW_EIEIO() | 0x02000000);
719 break;
720 case STF_BARRIER_SYNC_ORI:
721 EMIT(PPC_RAW_SYNC());
722 EMIT(PPC_RAW_LD(tmp1_reg, _R13, 0));
723 EMIT(PPC_RAW_ORI(_R31, _R31, 0));
724 break;
725 case STF_BARRIER_FALLBACK:
726 ctx->seen |= SEEN_FUNC;
727 PPC_LI64(_R12, dereference_kernel_function_descriptor(bpf_stf_barrier));
728 EMIT(PPC_RAW_MTCTR(_R12));
729 EMIT(PPC_RAW_BCTRL());
730 break;
731 case STF_BARRIER_NONE:
732 break;
733 }
734 break;
735
736 /*
737 * BPF_ST(X)
738 */
739 case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */
740 case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
741 if (BPF_CLASS(code) == BPF_ST) {
742 EMIT(PPC_RAW_LI(tmp1_reg, imm));
743 src_reg = tmp1_reg;
744 }
745 EMIT(PPC_RAW_STB(src_reg, dst_reg, off));
746 break;
747 case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
748 case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
749 if (BPF_CLASS(code) == BPF_ST) {
750 EMIT(PPC_RAW_LI(tmp1_reg, imm));
751 src_reg = tmp1_reg;
752 }
753 EMIT(PPC_RAW_STH(src_reg, dst_reg, off));
754 break;
755 case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
756 case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
757 if (BPF_CLASS(code) == BPF_ST) {
758 PPC_LI32(tmp1_reg, imm);
759 src_reg = tmp1_reg;
760 }
761 EMIT(PPC_RAW_STW(src_reg, dst_reg, off));
762 break;
763 case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
764 case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
765 if (BPF_CLASS(code) == BPF_ST) {
766 PPC_LI32(tmp1_reg, imm);
767 src_reg = tmp1_reg;
768 }
769 if (off % 4) {
770 EMIT(PPC_RAW_LI(tmp2_reg, off));
771 EMIT(PPC_RAW_STDX(src_reg, dst_reg, tmp2_reg));
772 } else {
773 EMIT(PPC_RAW_STD(src_reg, dst_reg, off));
774 }
775 break;
776
777 /*
778 * BPF_STX ATOMIC (atomic ops)
779 */
780 case BPF_STX | BPF_ATOMIC | BPF_W:
781 case BPF_STX | BPF_ATOMIC | BPF_DW:
782 save_reg = tmp2_reg;
783 ret_reg = src_reg;
784
785 /* Get offset into TMP_REG_1 */
786 EMIT(PPC_RAW_LI(tmp1_reg, off));
787 tmp_idx = ctx->idx * 4;
788 /* load value from memory into TMP_REG_2 */
789 if (size == BPF_DW)
790 EMIT(PPC_RAW_LDARX(tmp2_reg, tmp1_reg, dst_reg, 0));
791 else
792 EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0));
793
794 /* Save old value in _R0 */
795 if (imm & BPF_FETCH)
796 EMIT(PPC_RAW_MR(_R0, tmp2_reg));
797
798 switch (imm) {
799 case BPF_ADD:
800 case BPF_ADD | BPF_FETCH:
801 EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg));
802 break;
803 case BPF_AND:
804 case BPF_AND | BPF_FETCH:
805 EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg));
806 break;
807 case BPF_OR:
808 case BPF_OR | BPF_FETCH:
809 EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg));
810 break;
811 case BPF_XOR:
812 case BPF_XOR | BPF_FETCH:
813 EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg));
814 break;
815 case BPF_CMPXCHG:
816 /*
817 * Return old value in BPF_REG_0 for BPF_CMPXCHG &
818 * in src_reg for other cases.
819 */
820 ret_reg = bpf_to_ppc(BPF_REG_0);
821
822 /* Compare with old value in BPF_R0 */
823 if (size == BPF_DW)
824 EMIT(PPC_RAW_CMPD(bpf_to_ppc(BPF_REG_0), tmp2_reg));
825 else
826 EMIT(PPC_RAW_CMPW(bpf_to_ppc(BPF_REG_0), tmp2_reg));
827 /* Don't set if different from old value */
828 PPC_BCC_SHORT(COND_NE, (ctx->idx + 3) * 4);
829 fallthrough;
830 case BPF_XCHG:
831 save_reg = src_reg;
832 break;
833 default:
834 pr_err_ratelimited(
835 "eBPF filter atomic op code %02x (@%d) unsupported\n",
836 code, i);
837 return -EOPNOTSUPP;
838 }
839
840 /* store new value */
841 if (size == BPF_DW)
842 EMIT(PPC_RAW_STDCX(save_reg, tmp1_reg, dst_reg));
843 else
844 EMIT(PPC_RAW_STWCX(save_reg, tmp1_reg, dst_reg));
845 /* we're done if this succeeded */
846 PPC_BCC_SHORT(COND_NE, tmp_idx);
847
848 if (imm & BPF_FETCH) {
849 EMIT(PPC_RAW_MR(ret_reg, _R0));
850 /*
851 * Skip unnecessary zero-extension for 32-bit cmpxchg.
852 * For context, see commit 39491867ace5.
853 */
854 if (size != BPF_DW && imm == BPF_CMPXCHG &&
855 insn_is_zext(&insn[i + 1]))
856 addrs[++i] = ctx->idx * 4;
857 }
858 break;
859
860 /*
861 * BPF_LDX
862 */
863 /* dst = *(u8 *)(ul) (src + off) */
864 case BPF_LDX | BPF_MEM | BPF_B:
865 case BPF_LDX | BPF_PROBE_MEM | BPF_B:
866 /* dst = *(u16 *)(ul) (src + off) */
867 case BPF_LDX | BPF_MEM | BPF_H:
868 case BPF_LDX | BPF_PROBE_MEM | BPF_H:
869 /* dst = *(u32 *)(ul) (src + off) */
870 case BPF_LDX | BPF_MEM | BPF_W:
871 case BPF_LDX | BPF_PROBE_MEM | BPF_W:
872 /* dst = *(u64 *)(ul) (src + off) */
873 case BPF_LDX | BPF_MEM | BPF_DW:
874 case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
875 /*
876 * As PTR_TO_BTF_ID that uses BPF_PROBE_MEM mode could either be a valid
877 * kernel pointer or NULL but not a userspace address, execute BPF_PROBE_MEM
878 * load only if addr is kernel address (see is_kernel_addr()), otherwise
879 * set dst_reg=0 and move on.
880 */
881 if (BPF_MODE(code) == BPF_PROBE_MEM) {
882 EMIT(PPC_RAW_ADDI(tmp1_reg, src_reg, off));
883 if (IS_ENABLED(CONFIG_PPC_BOOK3E_64))
884 PPC_LI64(tmp2_reg, 0x8000000000000000ul);
885 else /* BOOK3S_64 */
886 PPC_LI64(tmp2_reg, PAGE_OFFSET);
887 EMIT(PPC_RAW_CMPLD(tmp1_reg, tmp2_reg));
888 PPC_BCC_SHORT(COND_GT, (ctx->idx + 3) * 4);
889 EMIT(PPC_RAW_LI(dst_reg, 0));
890 /*
891 * Check if 'off' is word aligned for BPF_DW, because
892 * we might generate two instructions.
893 */
894 if (BPF_SIZE(code) == BPF_DW && (off & 3))
895 PPC_JMP((ctx->idx + 3) * 4);
896 else
897 PPC_JMP((ctx->idx + 2) * 4);
898 }
899
900 switch (size) {
901 case BPF_B:
902 EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off));
903 break;
904 case BPF_H:
905 EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off));
906 break;
907 case BPF_W:
908 EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off));
909 break;
910 case BPF_DW:
911 if (off % 4) {
912 EMIT(PPC_RAW_LI(tmp1_reg, off));
913 EMIT(PPC_RAW_LDX(dst_reg, src_reg, tmp1_reg));
914 } else {
915 EMIT(PPC_RAW_LD(dst_reg, src_reg, off));
916 }
917 break;
918 }
919
920 if (size != BPF_DW && insn_is_zext(&insn[i + 1]))
921 addrs[++i] = ctx->idx * 4;
922
923 if (BPF_MODE(code) == BPF_PROBE_MEM) {
924 ret = bpf_add_extable_entry(fp, image, pass, ctx, ctx->idx - 1,
925 4, dst_reg);
926 if (ret)
927 return ret;
928 }
929 break;
930
931 /*
932 * Doubleword load
933 * 16 byte instruction that uses two 'struct bpf_insn'
934 */
935 case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
936 imm64 = ((u64)(u32) insn[i].imm) |
937 (((u64)(u32) insn[i+1].imm) << 32);
938 tmp_idx = ctx->idx;
939 PPC_LI64(dst_reg, imm64);
940 /* padding to allow full 5 instructions for later patching */
941 for (j = ctx->idx - tmp_idx; j < 5; j++)
942 EMIT(PPC_RAW_NOP());
943 /* Adjust for two bpf instructions */
944 addrs[++i] = ctx->idx * 4;
945 break;
946
947 /*
948 * Return/Exit
949 */
950 case BPF_JMP | BPF_EXIT:
951 /*
952 * If this isn't the very last instruction, branch to
953 * the epilogue. If we _are_ the last instruction,
954 * we'll just fall through to the epilogue.
955 */
956 if (i != flen - 1) {
957 ret = bpf_jit_emit_exit_insn(image, ctx, tmp1_reg, exit_addr);
958 if (ret)
959 return ret;
960 }
961 /* else fall through to the epilogue */
962 break;
963
964 /*
965 * Call kernel helper or bpf function
966 */
967 case BPF_JMP | BPF_CALL:
968 ctx->seen |= SEEN_FUNC;
969
970 ret = bpf_jit_get_func_addr(fp, &insn[i], false,
971 &func_addr, &func_addr_fixed);
972 if (ret < 0)
973 return ret;
974
975 if (func_addr_fixed)
976 ret = bpf_jit_emit_func_call_hlp(image, ctx, func_addr);
977 else
978 ret = bpf_jit_emit_func_call_rel(image, ctx, func_addr);
979
980 if (ret)
981 return ret;
982
983 /* move return value from r3 to BPF_REG_0 */
984 EMIT(PPC_RAW_MR(bpf_to_ppc(BPF_REG_0), _R3));
985 break;
986
987 /*
988 * Jumps and branches
989 */
990 case BPF_JMP | BPF_JA:
991 PPC_JMP(addrs[i + 1 + off]);
992 break;
993
994 case BPF_JMP | BPF_JGT | BPF_K:
995 case BPF_JMP | BPF_JGT | BPF_X:
996 case BPF_JMP | BPF_JSGT | BPF_K:
997 case BPF_JMP | BPF_JSGT | BPF_X:
998 case BPF_JMP32 | BPF_JGT | BPF_K:
999 case BPF_JMP32 | BPF_JGT | BPF_X:
1000 case BPF_JMP32 | BPF_JSGT | BPF_K:
1001 case BPF_JMP32 | BPF_JSGT | BPF_X:
1002 true_cond = COND_GT;
1003 goto cond_branch;
1004 case BPF_JMP | BPF_JLT | BPF_K:
1005 case BPF_JMP | BPF_JLT | BPF_X:
1006 case BPF_JMP | BPF_JSLT | BPF_K:
1007 case BPF_JMP | BPF_JSLT | BPF_X:
1008 case BPF_JMP32 | BPF_JLT | BPF_K:
1009 case BPF_JMP32 | BPF_JLT | BPF_X:
1010 case BPF_JMP32 | BPF_JSLT | BPF_K:
1011 case BPF_JMP32 | BPF_JSLT | BPF_X:
1012 true_cond = COND_LT;
1013 goto cond_branch;
1014 case BPF_JMP | BPF_JGE | BPF_K:
1015 case BPF_JMP | BPF_JGE | BPF_X:
1016 case BPF_JMP | BPF_JSGE | BPF_K:
1017 case BPF_JMP | BPF_JSGE | BPF_X:
1018 case BPF_JMP32 | BPF_JGE | BPF_K:
1019 case BPF_JMP32 | BPF_JGE | BPF_X:
1020 case BPF_JMP32 | BPF_JSGE | BPF_K:
1021 case BPF_JMP32 | BPF_JSGE | BPF_X:
1022 true_cond = COND_GE;
1023 goto cond_branch;
1024 case BPF_JMP | BPF_JLE | BPF_K:
1025 case BPF_JMP | BPF_JLE | BPF_X:
1026 case BPF_JMP | BPF_JSLE | BPF_K:
1027 case BPF_JMP | BPF_JSLE | BPF_X:
1028 case BPF_JMP32 | BPF_JLE | BPF_K:
1029 case BPF_JMP32 | BPF_JLE | BPF_X:
1030 case BPF_JMP32 | BPF_JSLE | BPF_K:
1031 case BPF_JMP32 | BPF_JSLE | BPF_X:
1032 true_cond = COND_LE;
1033 goto cond_branch;
1034 case BPF_JMP | BPF_JEQ | BPF_K:
1035 case BPF_JMP | BPF_JEQ | BPF_X:
1036 case BPF_JMP32 | BPF_JEQ | BPF_K:
1037 case BPF_JMP32 | BPF_JEQ | BPF_X:
1038 true_cond = COND_EQ;
1039 goto cond_branch;
1040 case BPF_JMP | BPF_JNE | BPF_K:
1041 case BPF_JMP | BPF_JNE | BPF_X:
1042 case BPF_JMP32 | BPF_JNE | BPF_K:
1043 case BPF_JMP32 | BPF_JNE | BPF_X:
1044 true_cond = COND_NE;
1045 goto cond_branch;
1046 case BPF_JMP | BPF_JSET | BPF_K:
1047 case BPF_JMP | BPF_JSET | BPF_X:
1048 case BPF_JMP32 | BPF_JSET | BPF_K:
1049 case BPF_JMP32 | BPF_JSET | BPF_X:
1050 true_cond = COND_NE;
1051 /* Fall through */
1052
1053cond_branch:
1054 switch (code) {
1055 case BPF_JMP | BPF_JGT | BPF_X:
1056 case BPF_JMP | BPF_JLT | BPF_X:
1057 case BPF_JMP | BPF_JGE | BPF_X:
1058 case BPF_JMP | BPF_JLE | BPF_X:
1059 case BPF_JMP | BPF_JEQ | BPF_X:
1060 case BPF_JMP | BPF_JNE | BPF_X:
1061 case BPF_JMP32 | BPF_JGT | BPF_X:
1062 case BPF_JMP32 | BPF_JLT | BPF_X:
1063 case BPF_JMP32 | BPF_JGE | BPF_X:
1064 case BPF_JMP32 | BPF_JLE | BPF_X:
1065 case BPF_JMP32 | BPF_JEQ | BPF_X:
1066 case BPF_JMP32 | BPF_JNE | BPF_X:
1067 /* unsigned comparison */
1068 if (BPF_CLASS(code) == BPF_JMP32)
1069 EMIT(PPC_RAW_CMPLW(dst_reg, src_reg));
1070 else
1071 EMIT(PPC_RAW_CMPLD(dst_reg, src_reg));
1072 break;
1073 case BPF_JMP | BPF_JSGT | BPF_X:
1074 case BPF_JMP | BPF_JSLT | BPF_X:
1075 case BPF_JMP | BPF_JSGE | BPF_X:
1076 case BPF_JMP | BPF_JSLE | BPF_X:
1077 case BPF_JMP32 | BPF_JSGT | BPF_X:
1078 case BPF_JMP32 | BPF_JSLT | BPF_X:
1079 case BPF_JMP32 | BPF_JSGE | BPF_X:
1080 case BPF_JMP32 | BPF_JSLE | BPF_X:
1081 /* signed comparison */
1082 if (BPF_CLASS(code) == BPF_JMP32)
1083 EMIT(PPC_RAW_CMPW(dst_reg, src_reg));
1084 else
1085 EMIT(PPC_RAW_CMPD(dst_reg, src_reg));
1086 break;
1087 case BPF_JMP | BPF_JSET | BPF_X:
1088 case BPF_JMP32 | BPF_JSET | BPF_X:
1089 if (BPF_CLASS(code) == BPF_JMP) {
1090 EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg, src_reg));
1091 } else {
1092 EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, src_reg));
1093 EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg, 0, 0, 31));
1094 }
1095 break;
1096 case BPF_JMP | BPF_JNE | BPF_K:
1097 case BPF_JMP | BPF_JEQ | BPF_K:
1098 case BPF_JMP | BPF_JGT | BPF_K:
1099 case BPF_JMP | BPF_JLT | BPF_K:
1100 case BPF_JMP | BPF_JGE | BPF_K:
1101 case BPF_JMP | BPF_JLE | BPF_K:
1102 case BPF_JMP32 | BPF_JNE | BPF_K:
1103 case BPF_JMP32 | BPF_JEQ | BPF_K:
1104 case BPF_JMP32 | BPF_JGT | BPF_K:
1105 case BPF_JMP32 | BPF_JLT | BPF_K:
1106 case BPF_JMP32 | BPF_JGE | BPF_K:
1107 case BPF_JMP32 | BPF_JLE | BPF_K:
1108 {
1109 bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32;
1110
1111 /*
1112 * Need sign-extended load, so only positive
1113 * values can be used as imm in cmpldi
1114 */
1115 if (imm >= 0 && imm < 32768) {
1116 if (is_jmp32)
1117 EMIT(PPC_RAW_CMPLWI(dst_reg, imm));
1118 else
1119 EMIT(PPC_RAW_CMPLDI(dst_reg, imm));
1120 } else {
1121 /* sign-extending load */
1122 PPC_LI32(tmp1_reg, imm);
1123 /* ... but unsigned comparison */
1124 if (is_jmp32)
1125 EMIT(PPC_RAW_CMPLW(dst_reg, tmp1_reg));
1126 else
1127 EMIT(PPC_RAW_CMPLD(dst_reg, tmp1_reg));
1128 }
1129 break;
1130 }
1131 case BPF_JMP | BPF_JSGT | BPF_K:
1132 case BPF_JMP | BPF_JSLT | BPF_K:
1133 case BPF_JMP | BPF_JSGE | BPF_K:
1134 case BPF_JMP | BPF_JSLE | BPF_K:
1135 case BPF_JMP32 | BPF_JSGT | BPF_K:
1136 case BPF_JMP32 | BPF_JSLT | BPF_K:
1137 case BPF_JMP32 | BPF_JSGE | BPF_K:
1138 case BPF_JMP32 | BPF_JSLE | BPF_K:
1139 {
1140 bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32;
1141
1142 /*
1143 * signed comparison, so any 16-bit value
1144 * can be used in cmpdi
1145 */
1146 if (imm >= -32768 && imm < 32768) {
1147 if (is_jmp32)
1148 EMIT(PPC_RAW_CMPWI(dst_reg, imm));
1149 else
1150 EMIT(PPC_RAW_CMPDI(dst_reg, imm));
1151 } else {
1152 PPC_LI32(tmp1_reg, imm);
1153 if (is_jmp32)
1154 EMIT(PPC_RAW_CMPW(dst_reg, tmp1_reg));
1155 else
1156 EMIT(PPC_RAW_CMPD(dst_reg, tmp1_reg));
1157 }
1158 break;
1159 }
1160 case BPF_JMP | BPF_JSET | BPF_K:
1161 case BPF_JMP32 | BPF_JSET | BPF_K:
1162 /* andi does not sign-extend the immediate */
1163 if (imm >= 0 && imm < 32768)
1164 /* PPC_ANDI is _only/always_ dot-form */
1165 EMIT(PPC_RAW_ANDI(tmp1_reg, dst_reg, imm));
1166 else {
1167 PPC_LI32(tmp1_reg, imm);
1168 if (BPF_CLASS(code) == BPF_JMP) {
1169 EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg,
1170 tmp1_reg));
1171 } else {
1172 EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, tmp1_reg));
1173 EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg,
1174 0, 0, 31));
1175 }
1176 }
1177 break;
1178 }
1179 PPC_BCC(true_cond, addrs[i + 1 + off]);
1180 break;
1181
1182 /*
1183 * Tail call
1184 */
1185 case BPF_JMP | BPF_TAIL_CALL:
1186 ctx->seen |= SEEN_TAILCALL;
1187 ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]);
1188 if (ret < 0)
1189 return ret;
1190 break;
1191
1192 default:
1193 /*
1194 * The filter contains something cruel & unusual.
1195 * We don't handle it, but also there shouldn't be
1196 * anything missing from our list.
1197 */
1198 pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n",
1199 code, i);
1200 return -ENOTSUPP;
1201 }
1202 }
1203
1204 /* Set end-of-body-code address for exit. */
1205 addrs[i] = ctx->idx * 4;
1206
1207 return 0;
1208}