bpf_jit_comp.c 49 KB

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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 <[email protected]>
  15. * Michael Holzheu <[email protected]>
  16. */
  17. #define KMSG_COMPONENT "bpf_jit"
  18. #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  19. #include <linux/netdevice.h>
  20. #include <linux/filter.h>
  21. #include <linux/init.h>
  22. #include <linux/bpf.h>
  23. #include <linux/mm.h>
  24. #include <linux/kernel.h>
  25. #include <asm/cacheflush.h>
  26. #include <asm/extable.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. struct bpf_jit {
  33. u32 seen; /* Flags to remember seen eBPF instructions */
  34. u32 seen_reg[16]; /* Array to remember which registers are used */
  35. u32 *addrs; /* Array with relative instruction addresses */
  36. u8 *prg_buf; /* Start of program */
  37. int size; /* Size of program and literal pool */
  38. int size_prg; /* Size of program */
  39. int prg; /* Current position in program */
  40. int lit32_start; /* Start of 32-bit literal pool */
  41. int lit32; /* Current position in 32-bit literal pool */
  42. int lit64_start; /* Start of 64-bit literal pool */
  43. int lit64; /* Current position in 64-bit literal pool */
  44. int base_ip; /* Base address for literal pool */
  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 excnt; /* Number of exception table entries */
  50. };
  51. #define SEEN_MEM BIT(0) /* use mem[] for temporary storage */
  52. #define SEEN_LITERAL BIT(1) /* code uses literals */
  53. #define SEEN_FUNC BIT(2) /* calls C functions */
  54. #define SEEN_TAIL_CALL BIT(3) /* code uses tail calls */
  55. #define SEEN_STACK (SEEN_FUNC | SEEN_MEM)
  56. /*
  57. * s390 registers
  58. */
  59. #define REG_W0 (MAX_BPF_JIT_REG + 0) /* Work register 1 (even) */
  60. #define REG_W1 (MAX_BPF_JIT_REG + 1) /* Work register 2 (odd) */
  61. #define REG_L (MAX_BPF_JIT_REG + 2) /* Literal pool register */
  62. #define REG_15 (MAX_BPF_JIT_REG + 3) /* Register 15 */
  63. #define REG_0 REG_W0 /* Register 0 */
  64. #define REG_1 REG_W1 /* Register 1 */
  65. #define REG_2 BPF_REG_1 /* Register 2 */
  66. #define REG_14 BPF_REG_0 /* Register 14 */
  67. /*
  68. * Mapping of BPF registers to s390 registers
  69. */
  70. static const int reg2hex[] = {
  71. /* Return code */
  72. [BPF_REG_0] = 14,
  73. /* Function parameters */
  74. [BPF_REG_1] = 2,
  75. [BPF_REG_2] = 3,
  76. [BPF_REG_3] = 4,
  77. [BPF_REG_4] = 5,
  78. [BPF_REG_5] = 6,
  79. /* Call saved registers */
  80. [BPF_REG_6] = 7,
  81. [BPF_REG_7] = 8,
  82. [BPF_REG_8] = 9,
  83. [BPF_REG_9] = 10,
  84. /* BPF stack pointer */
  85. [BPF_REG_FP] = 13,
  86. /* Register for blinding */
  87. [BPF_REG_AX] = 12,
  88. /* Work registers for s390x backend */
  89. [REG_W0] = 0,
  90. [REG_W1] = 1,
  91. [REG_L] = 11,
  92. [REG_15] = 15,
  93. };
  94. static inline u32 reg(u32 dst_reg, u32 src_reg)
  95. {
  96. return reg2hex[dst_reg] << 4 | reg2hex[src_reg];
  97. }
  98. static inline u32 reg_high(u32 reg)
  99. {
  100. return reg2hex[reg] << 4;
  101. }
  102. static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
  103. {
  104. u32 r1 = reg2hex[b1];
  105. if (r1 >= 6 && r1 <= 15 && !jit->seen_reg[r1])
  106. jit->seen_reg[r1] = 1;
  107. }
  108. #define REG_SET_SEEN(b1) \
  109. ({ \
  110. reg_set_seen(jit, b1); \
  111. })
  112. #define REG_SEEN(b1) jit->seen_reg[reg2hex[(b1)]]
  113. /*
  114. * EMIT macros for code generation
  115. */
  116. #define _EMIT2(op) \
  117. ({ \
  118. if (jit->prg_buf) \
  119. *(u16 *) (jit->prg_buf + jit->prg) = (op); \
  120. jit->prg += 2; \
  121. })
  122. #define EMIT2(op, b1, b2) \
  123. ({ \
  124. _EMIT2((op) | reg(b1, b2)); \
  125. REG_SET_SEEN(b1); \
  126. REG_SET_SEEN(b2); \
  127. })
  128. #define _EMIT4(op) \
  129. ({ \
  130. if (jit->prg_buf) \
  131. *(u32 *) (jit->prg_buf + jit->prg) = (op); \
  132. jit->prg += 4; \
  133. })
  134. #define EMIT4(op, b1, b2) \
  135. ({ \
  136. _EMIT4((op) | reg(b1, b2)); \
  137. REG_SET_SEEN(b1); \
  138. REG_SET_SEEN(b2); \
  139. })
  140. #define EMIT4_RRF(op, b1, b2, b3) \
  141. ({ \
  142. _EMIT4((op) | reg_high(b3) << 8 | reg(b1, b2)); \
  143. REG_SET_SEEN(b1); \
  144. REG_SET_SEEN(b2); \
  145. REG_SET_SEEN(b3); \
  146. })
  147. #define _EMIT4_DISP(op, disp) \
  148. ({ \
  149. unsigned int __disp = (disp) & 0xfff; \
  150. _EMIT4((op) | __disp); \
  151. })
  152. #define EMIT4_DISP(op, b1, b2, disp) \
  153. ({ \
  154. _EMIT4_DISP((op) | reg_high(b1) << 16 | \
  155. reg_high(b2) << 8, (disp)); \
  156. REG_SET_SEEN(b1); \
  157. REG_SET_SEEN(b2); \
  158. })
  159. #define EMIT4_IMM(op, b1, imm) \
  160. ({ \
  161. unsigned int __imm = (imm) & 0xffff; \
  162. _EMIT4((op) | reg_high(b1) << 16 | __imm); \
  163. REG_SET_SEEN(b1); \
  164. })
  165. #define EMIT4_PCREL(op, pcrel) \
  166. ({ \
  167. long __pcrel = ((pcrel) >> 1) & 0xffff; \
  168. _EMIT4((op) | __pcrel); \
  169. })
  170. #define EMIT4_PCREL_RIC(op, mask, target) \
  171. ({ \
  172. int __rel = ((target) - jit->prg) / 2; \
  173. _EMIT4((op) | (mask) << 20 | (__rel & 0xffff)); \
  174. })
  175. #define _EMIT6(op1, op2) \
  176. ({ \
  177. if (jit->prg_buf) { \
  178. *(u32 *) (jit->prg_buf + jit->prg) = (op1); \
  179. *(u16 *) (jit->prg_buf + jit->prg + 4) = (op2); \
  180. } \
  181. jit->prg += 6; \
  182. })
  183. #define _EMIT6_DISP(op1, op2, disp) \
  184. ({ \
  185. unsigned int __disp = (disp) & 0xfff; \
  186. _EMIT6((op1) | __disp, op2); \
  187. })
  188. #define _EMIT6_DISP_LH(op1, op2, disp) \
  189. ({ \
  190. u32 _disp = (u32) (disp); \
  191. unsigned int __disp_h = _disp & 0xff000; \
  192. unsigned int __disp_l = _disp & 0x00fff; \
  193. _EMIT6((op1) | __disp_l, (op2) | __disp_h >> 4); \
  194. })
  195. #define EMIT6_DISP_LH(op1, op2, b1, b2, b3, disp) \
  196. ({ \
  197. _EMIT6_DISP_LH((op1) | reg(b1, b2) << 16 | \
  198. reg_high(b3) << 8, op2, disp); \
  199. REG_SET_SEEN(b1); \
  200. REG_SET_SEEN(b2); \
  201. REG_SET_SEEN(b3); \
  202. })
  203. #define EMIT6_PCREL_RIEB(op1, op2, b1, b2, mask, target) \
  204. ({ \
  205. unsigned int rel = (int)((target) - jit->prg) / 2; \
  206. _EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), \
  207. (op2) | (mask) << 12); \
  208. REG_SET_SEEN(b1); \
  209. REG_SET_SEEN(b2); \
  210. })
  211. #define EMIT6_PCREL_RIEC(op1, op2, b1, imm, mask, target) \
  212. ({ \
  213. unsigned int rel = (int)((target) - jit->prg) / 2; \
  214. _EMIT6((op1) | (reg_high(b1) | (mask)) << 16 | \
  215. (rel & 0xffff), (op2) | ((imm) & 0xff) << 8); \
  216. REG_SET_SEEN(b1); \
  217. BUILD_BUG_ON(((unsigned long) (imm)) > 0xff); \
  218. })
  219. #define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask) \
  220. ({ \
  221. int rel = (addrs[(i) + (off) + 1] - jit->prg) / 2; \
  222. _EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), (op2) | (mask));\
  223. REG_SET_SEEN(b1); \
  224. REG_SET_SEEN(b2); \
  225. })
  226. #define EMIT6_PCREL_RILB(op, b, target) \
  227. ({ \
  228. unsigned int rel = (int)((target) - jit->prg) / 2; \
  229. _EMIT6((op) | reg_high(b) << 16 | rel >> 16, rel & 0xffff);\
  230. REG_SET_SEEN(b); \
  231. })
  232. #define EMIT6_PCREL_RIL(op, target) \
  233. ({ \
  234. unsigned int rel = (int)((target) - jit->prg) / 2; \
  235. _EMIT6((op) | rel >> 16, rel & 0xffff); \
  236. })
  237. #define EMIT6_PCREL_RILC(op, mask, target) \
  238. ({ \
  239. EMIT6_PCREL_RIL((op) | (mask) << 20, (target)); \
  240. })
  241. #define _EMIT6_IMM(op, imm) \
  242. ({ \
  243. unsigned int __imm = (imm); \
  244. _EMIT6((op) | (__imm >> 16), __imm & 0xffff); \
  245. })
  246. #define EMIT6_IMM(op, b1, imm) \
  247. ({ \
  248. _EMIT6_IMM((op) | reg_high(b1) << 16, imm); \
  249. REG_SET_SEEN(b1); \
  250. })
  251. #define _EMIT_CONST_U32(val) \
  252. ({ \
  253. unsigned int ret; \
  254. ret = jit->lit32; \
  255. if (jit->prg_buf) \
  256. *(u32 *)(jit->prg_buf + jit->lit32) = (u32)(val);\
  257. jit->lit32 += 4; \
  258. ret; \
  259. })
  260. #define EMIT_CONST_U32(val) \
  261. ({ \
  262. jit->seen |= SEEN_LITERAL; \
  263. _EMIT_CONST_U32(val) - jit->base_ip; \
  264. })
  265. #define _EMIT_CONST_U64(val) \
  266. ({ \
  267. unsigned int ret; \
  268. ret = jit->lit64; \
  269. if (jit->prg_buf) \
  270. *(u64 *)(jit->prg_buf + jit->lit64) = (u64)(val);\
  271. jit->lit64 += 8; \
  272. ret; \
  273. })
  274. #define EMIT_CONST_U64(val) \
  275. ({ \
  276. jit->seen |= SEEN_LITERAL; \
  277. _EMIT_CONST_U64(val) - jit->base_ip; \
  278. })
  279. #define EMIT_ZERO(b1) \
  280. ({ \
  281. if (!fp->aux->verifier_zext) { \
  282. /* llgfr %dst,%dst (zero extend to 64 bit) */ \
  283. EMIT4(0xb9160000, b1, b1); \
  284. REG_SET_SEEN(b1); \
  285. } \
  286. })
  287. /*
  288. * Return whether this is the first pass. The first pass is special, since we
  289. * don't know any sizes yet, and thus must be conservative.
  290. */
  291. static bool is_first_pass(struct bpf_jit *jit)
  292. {
  293. return jit->size == 0;
  294. }
  295. /*
  296. * Return whether this is the code generation pass. The code generation pass is
  297. * special, since we should change as little as possible.
  298. */
  299. static bool is_codegen_pass(struct bpf_jit *jit)
  300. {
  301. return jit->prg_buf;
  302. }
  303. /*
  304. * Return whether "rel" can be encoded as a short PC-relative offset
  305. */
  306. static bool is_valid_rel(int rel)
  307. {
  308. return rel >= -65536 && rel <= 65534;
  309. }
  310. /*
  311. * Return whether "off" can be reached using a short PC-relative offset
  312. */
  313. static bool can_use_rel(struct bpf_jit *jit, int off)
  314. {
  315. return is_valid_rel(off - jit->prg);
  316. }
  317. /*
  318. * Return whether given displacement can be encoded using
  319. * Long-Displacement Facility
  320. */
  321. static bool is_valid_ldisp(int disp)
  322. {
  323. return disp >= -524288 && disp <= 524287;
  324. }
  325. /*
  326. * Return whether the next 32-bit literal pool entry can be referenced using
  327. * Long-Displacement Facility
  328. */
  329. static bool can_use_ldisp_for_lit32(struct bpf_jit *jit)
  330. {
  331. return is_valid_ldisp(jit->lit32 - jit->base_ip);
  332. }
  333. /*
  334. * Return whether the next 64-bit literal pool entry can be referenced using
  335. * Long-Displacement Facility
  336. */
  337. static bool can_use_ldisp_for_lit64(struct bpf_jit *jit)
  338. {
  339. return is_valid_ldisp(jit->lit64 - jit->base_ip);
  340. }
  341. /*
  342. * Fill whole space with illegal instructions
  343. */
  344. static void jit_fill_hole(void *area, unsigned int size)
  345. {
  346. memset(area, 0, size);
  347. }
  348. /*
  349. * Save registers from "rs" (register start) to "re" (register end) on stack
  350. */
  351. static void save_regs(struct bpf_jit *jit, u32 rs, u32 re)
  352. {
  353. u32 off = STK_OFF_R6 + (rs - 6) * 8;
  354. if (rs == re)
  355. /* stg %rs,off(%r15) */
  356. _EMIT6(0xe300f000 | rs << 20 | off, 0x0024);
  357. else
  358. /* stmg %rs,%re,off(%r15) */
  359. _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0024, off);
  360. }
  361. /*
  362. * Restore registers from "rs" (register start) to "re" (register end) on stack
  363. */
  364. static void restore_regs(struct bpf_jit *jit, u32 rs, u32 re, u32 stack_depth)
  365. {
  366. u32 off = STK_OFF_R6 + (rs - 6) * 8;
  367. if (jit->seen & SEEN_STACK)
  368. off += STK_OFF + stack_depth;
  369. if (rs == re)
  370. /* lg %rs,off(%r15) */
  371. _EMIT6(0xe300f000 | rs << 20 | off, 0x0004);
  372. else
  373. /* lmg %rs,%re,off(%r15) */
  374. _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0004, off);
  375. }
  376. /*
  377. * Return first seen register (from start)
  378. */
  379. static int get_start(struct bpf_jit *jit, int start)
  380. {
  381. int i;
  382. for (i = start; i <= 15; i++) {
  383. if (jit->seen_reg[i])
  384. return i;
  385. }
  386. return 0;
  387. }
  388. /*
  389. * Return last seen register (from start) (gap >= 2)
  390. */
  391. static int get_end(struct bpf_jit *jit, int start)
  392. {
  393. int i;
  394. for (i = start; i < 15; i++) {
  395. if (!jit->seen_reg[i] && !jit->seen_reg[i + 1])
  396. return i - 1;
  397. }
  398. return jit->seen_reg[15] ? 15 : 14;
  399. }
  400. #define REGS_SAVE 1
  401. #define REGS_RESTORE 0
  402. /*
  403. * Save and restore clobbered registers (6-15) on stack.
  404. * We save/restore registers in chunks with gap >= 2 registers.
  405. */
  406. static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth)
  407. {
  408. const int last = 15, save_restore_size = 6;
  409. int re = 6, rs;
  410. if (is_first_pass(jit)) {
  411. /*
  412. * We don't know yet which registers are used. Reserve space
  413. * conservatively.
  414. */
  415. jit->prg += (last - re + 1) * save_restore_size;
  416. return;
  417. }
  418. do {
  419. rs = get_start(jit, re);
  420. if (!rs)
  421. break;
  422. re = get_end(jit, rs + 1);
  423. if (op == REGS_SAVE)
  424. save_regs(jit, rs, re);
  425. else
  426. restore_regs(jit, rs, re, stack_depth);
  427. re++;
  428. } while (re <= last);
  429. }
  430. static void bpf_skip(struct bpf_jit *jit, int size)
  431. {
  432. if (size >= 6 && !is_valid_rel(size)) {
  433. /* brcl 0xf,size */
  434. EMIT6_PCREL_RIL(0xc0f4000000, size);
  435. size -= 6;
  436. } else if (size >= 4 && is_valid_rel(size)) {
  437. /* brc 0xf,size */
  438. EMIT4_PCREL(0xa7f40000, size);
  439. size -= 4;
  440. }
  441. while (size >= 2) {
  442. /* bcr 0,%0 */
  443. _EMIT2(0x0700);
  444. size -= 2;
  445. }
  446. }
  447. /*
  448. * Emit function prologue
  449. *
  450. * Save registers and create stack frame if necessary.
  451. * See stack frame layout desription in "bpf_jit.h"!
  452. */
  453. static void bpf_jit_prologue(struct bpf_jit *jit, u32 stack_depth)
  454. {
  455. if (jit->seen & SEEN_TAIL_CALL) {
  456. /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */
  457. _EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT);
  458. } else {
  459. /*
  460. * There are no tail calls. Insert nops in order to have
  461. * tail_call_start at a predictable offset.
  462. */
  463. bpf_skip(jit, 6);
  464. }
  465. /* Tail calls have to skip above initialization */
  466. jit->tail_call_start = jit->prg;
  467. /* Save registers */
  468. save_restore_regs(jit, REGS_SAVE, stack_depth);
  469. /* Setup literal pool */
  470. if (is_first_pass(jit) || (jit->seen & SEEN_LITERAL)) {
  471. if (!is_first_pass(jit) &&
  472. is_valid_ldisp(jit->size - (jit->prg + 2))) {
  473. /* basr %l,0 */
  474. EMIT2(0x0d00, REG_L, REG_0);
  475. jit->base_ip = jit->prg;
  476. } else {
  477. /* larl %l,lit32_start */
  478. EMIT6_PCREL_RILB(0xc0000000, REG_L, jit->lit32_start);
  479. jit->base_ip = jit->lit32_start;
  480. }
  481. }
  482. /* Setup stack and backchain */
  483. if (is_first_pass(jit) || (jit->seen & SEEN_STACK)) {
  484. if (is_first_pass(jit) || (jit->seen & SEEN_FUNC))
  485. /* lgr %w1,%r15 (backchain) */
  486. EMIT4(0xb9040000, REG_W1, REG_15);
  487. /* la %bfp,STK_160_UNUSED(%r15) (BPF frame pointer) */
  488. EMIT4_DISP(0x41000000, BPF_REG_FP, REG_15, STK_160_UNUSED);
  489. /* aghi %r15,-STK_OFF */
  490. EMIT4_IMM(0xa70b0000, REG_15, -(STK_OFF + stack_depth));
  491. if (is_first_pass(jit) || (jit->seen & SEEN_FUNC))
  492. /* stg %w1,152(%r15) (backchain) */
  493. EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
  494. REG_15, 152);
  495. }
  496. }
  497. /*
  498. * Function epilogue
  499. */
  500. static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
  501. {
  502. jit->exit_ip = jit->prg;
  503. /* Load exit code: lgr %r2,%b0 */
  504. EMIT4(0xb9040000, REG_2, BPF_REG_0);
  505. /* Restore registers */
  506. save_restore_regs(jit, REGS_RESTORE, stack_depth);
  507. if (nospec_uses_trampoline()) {
  508. jit->r14_thunk_ip = jit->prg;
  509. /* Generate __s390_indirect_jump_r14 thunk */
  510. /* exrl %r0,.+10 */
  511. EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
  512. /* j . */
  513. EMIT4_PCREL(0xa7f40000, 0);
  514. }
  515. /* br %r14 */
  516. _EMIT2(0x07fe);
  517. if ((nospec_uses_trampoline()) &&
  518. (is_first_pass(jit) || (jit->seen & SEEN_FUNC))) {
  519. jit->r1_thunk_ip = jit->prg;
  520. /* Generate __s390_indirect_jump_r1 thunk */
  521. /* exrl %r0,.+10 */
  522. EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
  523. /* j . */
  524. EMIT4_PCREL(0xa7f40000, 0);
  525. /* br %r1 */
  526. _EMIT2(0x07f1);
  527. }
  528. }
  529. static int get_probe_mem_regno(const u8 *insn)
  530. {
  531. /*
  532. * insn must point to llgc, llgh, llgf or lg, which have destination
  533. * register at the same position.
  534. */
  535. if (insn[0] != 0xe3) /* common llgc, llgh, llgf and lg prefix */
  536. return -1;
  537. if (insn[5] != 0x90 && /* llgc */
  538. insn[5] != 0x91 && /* llgh */
  539. insn[5] != 0x16 && /* llgf */
  540. insn[5] != 0x04) /* lg */
  541. return -1;
  542. return insn[1] >> 4;
  543. }
  544. bool ex_handler_bpf(const struct exception_table_entry *x, struct pt_regs *regs)
  545. {
  546. regs->psw.addr = extable_fixup(x);
  547. regs->gprs[x->data] = 0;
  548. return true;
  549. }
  550. static int bpf_jit_probe_mem(struct bpf_jit *jit, struct bpf_prog *fp,
  551. int probe_prg, int nop_prg)
  552. {
  553. struct exception_table_entry *ex;
  554. int reg, prg;
  555. s64 delta;
  556. u8 *insn;
  557. int i;
  558. if (!fp->aux->extable)
  559. /* Do nothing during early JIT passes. */
  560. return 0;
  561. insn = jit->prg_buf + probe_prg;
  562. reg = get_probe_mem_regno(insn);
  563. if (WARN_ON_ONCE(reg < 0))
  564. /* JIT bug - unexpected probe instruction. */
  565. return -1;
  566. if (WARN_ON_ONCE(probe_prg + insn_length(*insn) != nop_prg))
  567. /* JIT bug - gap between probe and nop instructions. */
  568. return -1;
  569. for (i = 0; i < 2; i++) {
  570. if (WARN_ON_ONCE(jit->excnt >= fp->aux->num_exentries))
  571. /* Verifier bug - not enough entries. */
  572. return -1;
  573. ex = &fp->aux->extable[jit->excnt];
  574. /* Add extable entries for probe and nop instructions. */
  575. prg = i == 0 ? probe_prg : nop_prg;
  576. delta = jit->prg_buf + prg - (u8 *)&ex->insn;
  577. if (WARN_ON_ONCE(delta < INT_MIN || delta > INT_MAX))
  578. /* JIT bug - code and extable must be close. */
  579. return -1;
  580. ex->insn = delta;
  581. /*
  582. * Always land on the nop. Note that extable infrastructure
  583. * ignores fixup field, it is handled by ex_handler_bpf().
  584. */
  585. delta = jit->prg_buf + nop_prg - (u8 *)&ex->fixup;
  586. if (WARN_ON_ONCE(delta < INT_MIN || delta > INT_MAX))
  587. /* JIT bug - landing pad and extable must be close. */
  588. return -1;
  589. ex->fixup = delta;
  590. ex->type = EX_TYPE_BPF;
  591. ex->data = reg;
  592. jit->excnt++;
  593. }
  594. return 0;
  595. }
  596. /*
  597. * Compile one eBPF instruction into s390x code
  598. *
  599. * NOTE: Use noinline because for gcov (-fprofile-arcs) gcc allocates a lot of
  600. * stack space for the large switch statement.
  601. */
  602. static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
  603. int i, bool extra_pass, u32 stack_depth)
  604. {
  605. struct bpf_insn *insn = &fp->insnsi[i];
  606. u32 dst_reg = insn->dst_reg;
  607. u32 src_reg = insn->src_reg;
  608. int last, insn_count = 1;
  609. u32 *addrs = jit->addrs;
  610. s32 imm = insn->imm;
  611. s16 off = insn->off;
  612. int probe_prg = -1;
  613. unsigned int mask;
  614. int nop_prg;
  615. int err;
  616. if (BPF_CLASS(insn->code) == BPF_LDX &&
  617. BPF_MODE(insn->code) == BPF_PROBE_MEM)
  618. probe_prg = jit->prg;
  619. switch (insn->code) {
  620. /*
  621. * BPF_MOV
  622. */
  623. case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */
  624. /* llgfr %dst,%src */
  625. EMIT4(0xb9160000, dst_reg, src_reg);
  626. if (insn_is_zext(&insn[1]))
  627. insn_count = 2;
  628. break;
  629. case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
  630. /* lgr %dst,%src */
  631. EMIT4(0xb9040000, dst_reg, src_reg);
  632. break;
  633. case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
  634. /* llilf %dst,imm */
  635. EMIT6_IMM(0xc00f0000, dst_reg, imm);
  636. if (insn_is_zext(&insn[1]))
  637. insn_count = 2;
  638. break;
  639. case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */
  640. /* lgfi %dst,imm */
  641. EMIT6_IMM(0xc0010000, dst_reg, imm);
  642. break;
  643. /*
  644. * BPF_LD 64
  645. */
  646. case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
  647. {
  648. /* 16 byte instruction that uses two 'struct bpf_insn' */
  649. u64 imm64;
  650. imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32;
  651. /* lgrl %dst,imm */
  652. EMIT6_PCREL_RILB(0xc4080000, dst_reg, _EMIT_CONST_U64(imm64));
  653. insn_count = 2;
  654. break;
  655. }
  656. /*
  657. * BPF_ADD
  658. */
  659. case BPF_ALU | BPF_ADD | BPF_X: /* dst = (u32) dst + (u32) src */
  660. /* ar %dst,%src */
  661. EMIT2(0x1a00, dst_reg, src_reg);
  662. EMIT_ZERO(dst_reg);
  663. break;
  664. case BPF_ALU64 | BPF_ADD | BPF_X: /* dst = dst + src */
  665. /* agr %dst,%src */
  666. EMIT4(0xb9080000, dst_reg, src_reg);
  667. break;
  668. case BPF_ALU | BPF_ADD | BPF_K: /* dst = (u32) dst + (u32) imm */
  669. if (imm != 0) {
  670. /* alfi %dst,imm */
  671. EMIT6_IMM(0xc20b0000, dst_reg, imm);
  672. }
  673. EMIT_ZERO(dst_reg);
  674. break;
  675. case BPF_ALU64 | BPF_ADD | BPF_K: /* dst = dst + imm */
  676. if (!imm)
  677. break;
  678. /* agfi %dst,imm */
  679. EMIT6_IMM(0xc2080000, dst_reg, imm);
  680. break;
  681. /*
  682. * BPF_SUB
  683. */
  684. case BPF_ALU | BPF_SUB | BPF_X: /* dst = (u32) dst - (u32) src */
  685. /* sr %dst,%src */
  686. EMIT2(0x1b00, dst_reg, src_reg);
  687. EMIT_ZERO(dst_reg);
  688. break;
  689. case BPF_ALU64 | BPF_SUB | BPF_X: /* dst = dst - src */
  690. /* sgr %dst,%src */
  691. EMIT4(0xb9090000, dst_reg, src_reg);
  692. break;
  693. case BPF_ALU | BPF_SUB | BPF_K: /* dst = (u32) dst - (u32) imm */
  694. if (imm != 0) {
  695. /* alfi %dst,-imm */
  696. EMIT6_IMM(0xc20b0000, dst_reg, -imm);
  697. }
  698. EMIT_ZERO(dst_reg);
  699. break;
  700. case BPF_ALU64 | BPF_SUB | BPF_K: /* dst = dst - imm */
  701. if (!imm)
  702. break;
  703. if (imm == -0x80000000) {
  704. /* algfi %dst,0x80000000 */
  705. EMIT6_IMM(0xc20a0000, dst_reg, 0x80000000);
  706. } else {
  707. /* agfi %dst,-imm */
  708. EMIT6_IMM(0xc2080000, dst_reg, -imm);
  709. }
  710. break;
  711. /*
  712. * BPF_MUL
  713. */
  714. case BPF_ALU | BPF_MUL | BPF_X: /* dst = (u32) dst * (u32) src */
  715. /* msr %dst,%src */
  716. EMIT4(0xb2520000, dst_reg, src_reg);
  717. EMIT_ZERO(dst_reg);
  718. break;
  719. case BPF_ALU64 | BPF_MUL | BPF_X: /* dst = dst * src */
  720. /* msgr %dst,%src */
  721. EMIT4(0xb90c0000, dst_reg, src_reg);
  722. break;
  723. case BPF_ALU | BPF_MUL | BPF_K: /* dst = (u32) dst * (u32) imm */
  724. if (imm != 1) {
  725. /* msfi %r5,imm */
  726. EMIT6_IMM(0xc2010000, dst_reg, imm);
  727. }
  728. EMIT_ZERO(dst_reg);
  729. break;
  730. case BPF_ALU64 | BPF_MUL | BPF_K: /* dst = dst * imm */
  731. if (imm == 1)
  732. break;
  733. /* msgfi %dst,imm */
  734. EMIT6_IMM(0xc2000000, dst_reg, imm);
  735. break;
  736. /*
  737. * BPF_DIV / BPF_MOD
  738. */
  739. case BPF_ALU | BPF_DIV | BPF_X: /* dst = (u32) dst / (u32) src */
  740. case BPF_ALU | BPF_MOD | BPF_X: /* dst = (u32) dst % (u32) src */
  741. {
  742. int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
  743. /* lhi %w0,0 */
  744. EMIT4_IMM(0xa7080000, REG_W0, 0);
  745. /* lr %w1,%dst */
  746. EMIT2(0x1800, REG_W1, dst_reg);
  747. /* dlr %w0,%src */
  748. EMIT4(0xb9970000, REG_W0, src_reg);
  749. /* llgfr %dst,%rc */
  750. EMIT4(0xb9160000, dst_reg, rc_reg);
  751. if (insn_is_zext(&insn[1]))
  752. insn_count = 2;
  753. break;
  754. }
  755. case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */
  756. case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % src */
  757. {
  758. int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
  759. /* lghi %w0,0 */
  760. EMIT4_IMM(0xa7090000, REG_W0, 0);
  761. /* lgr %w1,%dst */
  762. EMIT4(0xb9040000, REG_W1, dst_reg);
  763. /* dlgr %w0,%dst */
  764. EMIT4(0xb9870000, REG_W0, src_reg);
  765. /* lgr %dst,%rc */
  766. EMIT4(0xb9040000, dst_reg, rc_reg);
  767. break;
  768. }
  769. case BPF_ALU | BPF_DIV | BPF_K: /* dst = (u32) dst / (u32) imm */
  770. case BPF_ALU | BPF_MOD | BPF_K: /* dst = (u32) dst % (u32) imm */
  771. {
  772. int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
  773. if (imm == 1) {
  774. if (BPF_OP(insn->code) == BPF_MOD)
  775. /* lhgi %dst,0 */
  776. EMIT4_IMM(0xa7090000, dst_reg, 0);
  777. else
  778. EMIT_ZERO(dst_reg);
  779. break;
  780. }
  781. /* lhi %w0,0 */
  782. EMIT4_IMM(0xa7080000, REG_W0, 0);
  783. /* lr %w1,%dst */
  784. EMIT2(0x1800, REG_W1, dst_reg);
  785. if (!is_first_pass(jit) && can_use_ldisp_for_lit32(jit)) {
  786. /* dl %w0,<d(imm)>(%l) */
  787. EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0, REG_L,
  788. EMIT_CONST_U32(imm));
  789. } else {
  790. /* lgfrl %dst,imm */
  791. EMIT6_PCREL_RILB(0xc40c0000, dst_reg,
  792. _EMIT_CONST_U32(imm));
  793. jit->seen |= SEEN_LITERAL;
  794. /* dlr %w0,%dst */
  795. EMIT4(0xb9970000, REG_W0, dst_reg);
  796. }
  797. /* llgfr %dst,%rc */
  798. EMIT4(0xb9160000, dst_reg, rc_reg);
  799. if (insn_is_zext(&insn[1]))
  800. insn_count = 2;
  801. break;
  802. }
  803. case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */
  804. case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % imm */
  805. {
  806. int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
  807. if (imm == 1) {
  808. if (BPF_OP(insn->code) == BPF_MOD)
  809. /* lhgi %dst,0 */
  810. EMIT4_IMM(0xa7090000, dst_reg, 0);
  811. break;
  812. }
  813. /* lghi %w0,0 */
  814. EMIT4_IMM(0xa7090000, REG_W0, 0);
  815. /* lgr %w1,%dst */
  816. EMIT4(0xb9040000, REG_W1, dst_reg);
  817. if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
  818. /* dlg %w0,<d(imm)>(%l) */
  819. EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L,
  820. EMIT_CONST_U64(imm));
  821. } else {
  822. /* lgrl %dst,imm */
  823. EMIT6_PCREL_RILB(0xc4080000, dst_reg,
  824. _EMIT_CONST_U64(imm));
  825. jit->seen |= SEEN_LITERAL;
  826. /* dlgr %w0,%dst */
  827. EMIT4(0xb9870000, REG_W0, dst_reg);
  828. }
  829. /* lgr %dst,%rc */
  830. EMIT4(0xb9040000, dst_reg, rc_reg);
  831. break;
  832. }
  833. /*
  834. * BPF_AND
  835. */
  836. case BPF_ALU | BPF_AND | BPF_X: /* dst = (u32) dst & (u32) src */
  837. /* nr %dst,%src */
  838. EMIT2(0x1400, dst_reg, src_reg);
  839. EMIT_ZERO(dst_reg);
  840. break;
  841. case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
  842. /* ngr %dst,%src */
  843. EMIT4(0xb9800000, dst_reg, src_reg);
  844. break;
  845. case BPF_ALU | BPF_AND | BPF_K: /* dst = (u32) dst & (u32) imm */
  846. /* nilf %dst,imm */
  847. EMIT6_IMM(0xc00b0000, dst_reg, imm);
  848. EMIT_ZERO(dst_reg);
  849. break;
  850. case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
  851. if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
  852. /* ng %dst,<d(imm)>(%l) */
  853. EMIT6_DISP_LH(0xe3000000, 0x0080,
  854. dst_reg, REG_0, REG_L,
  855. EMIT_CONST_U64(imm));
  856. } else {
  857. /* lgrl %w0,imm */
  858. EMIT6_PCREL_RILB(0xc4080000, REG_W0,
  859. _EMIT_CONST_U64(imm));
  860. jit->seen |= SEEN_LITERAL;
  861. /* ngr %dst,%w0 */
  862. EMIT4(0xb9800000, dst_reg, REG_W0);
  863. }
  864. break;
  865. /*
  866. * BPF_OR
  867. */
  868. case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
  869. /* or %dst,%src */
  870. EMIT2(0x1600, dst_reg, src_reg);
  871. EMIT_ZERO(dst_reg);
  872. break;
  873. case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
  874. /* ogr %dst,%src */
  875. EMIT4(0xb9810000, dst_reg, src_reg);
  876. break;
  877. case BPF_ALU | BPF_OR | BPF_K: /* dst = (u32) dst | (u32) imm */
  878. /* oilf %dst,imm */
  879. EMIT6_IMM(0xc00d0000, dst_reg, imm);
  880. EMIT_ZERO(dst_reg);
  881. break;
  882. case BPF_ALU64 | BPF_OR | BPF_K: /* dst = dst | imm */
  883. if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
  884. /* og %dst,<d(imm)>(%l) */
  885. EMIT6_DISP_LH(0xe3000000, 0x0081,
  886. dst_reg, REG_0, REG_L,
  887. EMIT_CONST_U64(imm));
  888. } else {
  889. /* lgrl %w0,imm */
  890. EMIT6_PCREL_RILB(0xc4080000, REG_W0,
  891. _EMIT_CONST_U64(imm));
  892. jit->seen |= SEEN_LITERAL;
  893. /* ogr %dst,%w0 */
  894. EMIT4(0xb9810000, dst_reg, REG_W0);
  895. }
  896. break;
  897. /*
  898. * BPF_XOR
  899. */
  900. case BPF_ALU | BPF_XOR | BPF_X: /* dst = (u32) dst ^ (u32) src */
  901. /* xr %dst,%src */
  902. EMIT2(0x1700, dst_reg, src_reg);
  903. EMIT_ZERO(dst_reg);
  904. break;
  905. case BPF_ALU64 | BPF_XOR | BPF_X: /* dst = dst ^ src */
  906. /* xgr %dst,%src */
  907. EMIT4(0xb9820000, dst_reg, src_reg);
  908. break;
  909. case BPF_ALU | BPF_XOR | BPF_K: /* dst = (u32) dst ^ (u32) imm */
  910. if (imm != 0) {
  911. /* xilf %dst,imm */
  912. EMIT6_IMM(0xc0070000, dst_reg, imm);
  913. }
  914. EMIT_ZERO(dst_reg);
  915. break;
  916. case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ imm */
  917. if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
  918. /* xg %dst,<d(imm)>(%l) */
  919. EMIT6_DISP_LH(0xe3000000, 0x0082,
  920. dst_reg, REG_0, REG_L,
  921. EMIT_CONST_U64(imm));
  922. } else {
  923. /* lgrl %w0,imm */
  924. EMIT6_PCREL_RILB(0xc4080000, REG_W0,
  925. _EMIT_CONST_U64(imm));
  926. jit->seen |= SEEN_LITERAL;
  927. /* xgr %dst,%w0 */
  928. EMIT4(0xb9820000, dst_reg, REG_W0);
  929. }
  930. break;
  931. /*
  932. * BPF_LSH
  933. */
  934. case BPF_ALU | BPF_LSH | BPF_X: /* dst = (u32) dst << (u32) src */
  935. /* sll %dst,0(%src) */
  936. EMIT4_DISP(0x89000000, dst_reg, src_reg, 0);
  937. EMIT_ZERO(dst_reg);
  938. break;
  939. case BPF_ALU64 | BPF_LSH | BPF_X: /* dst = dst << src */
  940. /* sllg %dst,%dst,0(%src) */
  941. EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, src_reg, 0);
  942. break;
  943. case BPF_ALU | BPF_LSH | BPF_K: /* dst = (u32) dst << (u32) imm */
  944. if (imm != 0) {
  945. /* sll %dst,imm(%r0) */
  946. EMIT4_DISP(0x89000000, dst_reg, REG_0, imm);
  947. }
  948. EMIT_ZERO(dst_reg);
  949. break;
  950. case BPF_ALU64 | BPF_LSH | BPF_K: /* dst = dst << imm */
  951. if (imm == 0)
  952. break;
  953. /* sllg %dst,%dst,imm(%r0) */
  954. EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, REG_0, imm);
  955. break;
  956. /*
  957. * BPF_RSH
  958. */
  959. case BPF_ALU | BPF_RSH | BPF_X: /* dst = (u32) dst >> (u32) src */
  960. /* srl %dst,0(%src) */
  961. EMIT4_DISP(0x88000000, dst_reg, src_reg, 0);
  962. EMIT_ZERO(dst_reg);
  963. break;
  964. case BPF_ALU64 | BPF_RSH | BPF_X: /* dst = dst >> src */
  965. /* srlg %dst,%dst,0(%src) */
  966. EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, src_reg, 0);
  967. break;
  968. case BPF_ALU | BPF_RSH | BPF_K: /* dst = (u32) dst >> (u32) imm */
  969. if (imm != 0) {
  970. /* srl %dst,imm(%r0) */
  971. EMIT4_DISP(0x88000000, dst_reg, REG_0, imm);
  972. }
  973. EMIT_ZERO(dst_reg);
  974. break;
  975. case BPF_ALU64 | BPF_RSH | BPF_K: /* dst = dst >> imm */
  976. if (imm == 0)
  977. break;
  978. /* srlg %dst,%dst,imm(%r0) */
  979. EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, REG_0, imm);
  980. break;
  981. /*
  982. * BPF_ARSH
  983. */
  984. case BPF_ALU | BPF_ARSH | BPF_X: /* ((s32) dst) >>= src */
  985. /* sra %dst,%dst,0(%src) */
  986. EMIT4_DISP(0x8a000000, dst_reg, src_reg, 0);
  987. EMIT_ZERO(dst_reg);
  988. break;
  989. case BPF_ALU64 | BPF_ARSH | BPF_X: /* ((s64) dst) >>= src */
  990. /* srag %dst,%dst,0(%src) */
  991. EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, src_reg, 0);
  992. break;
  993. case BPF_ALU | BPF_ARSH | BPF_K: /* ((s32) dst >> imm */
  994. if (imm != 0) {
  995. /* sra %dst,imm(%r0) */
  996. EMIT4_DISP(0x8a000000, dst_reg, REG_0, imm);
  997. }
  998. EMIT_ZERO(dst_reg);
  999. break;
  1000. case BPF_ALU64 | BPF_ARSH | BPF_K: /* ((s64) dst) >>= imm */
  1001. if (imm == 0)
  1002. break;
  1003. /* srag %dst,%dst,imm(%r0) */
  1004. EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, REG_0, imm);
  1005. break;
  1006. /*
  1007. * BPF_NEG
  1008. */
  1009. case BPF_ALU | BPF_NEG: /* dst = (u32) -dst */
  1010. /* lcr %dst,%dst */
  1011. EMIT2(0x1300, dst_reg, dst_reg);
  1012. EMIT_ZERO(dst_reg);
  1013. break;
  1014. case BPF_ALU64 | BPF_NEG: /* dst = -dst */
  1015. /* lcgr %dst,%dst */
  1016. EMIT4(0xb9030000, dst_reg, dst_reg);
  1017. break;
  1018. /*
  1019. * BPF_FROM_BE/LE
  1020. */
  1021. case BPF_ALU | BPF_END | BPF_FROM_BE:
  1022. /* s390 is big endian, therefore only clear high order bytes */
  1023. switch (imm) {
  1024. case 16: /* dst = (u16) cpu_to_be16(dst) */
  1025. /* llghr %dst,%dst */
  1026. EMIT4(0xb9850000, dst_reg, dst_reg);
  1027. if (insn_is_zext(&insn[1]))
  1028. insn_count = 2;
  1029. break;
  1030. case 32: /* dst = (u32) cpu_to_be32(dst) */
  1031. if (!fp->aux->verifier_zext)
  1032. /* llgfr %dst,%dst */
  1033. EMIT4(0xb9160000, dst_reg, dst_reg);
  1034. break;
  1035. case 64: /* dst = (u64) cpu_to_be64(dst) */
  1036. break;
  1037. }
  1038. break;
  1039. case BPF_ALU | BPF_END | BPF_FROM_LE:
  1040. switch (imm) {
  1041. case 16: /* dst = (u16) cpu_to_le16(dst) */
  1042. /* lrvr %dst,%dst */
  1043. EMIT4(0xb91f0000, dst_reg, dst_reg);
  1044. /* srl %dst,16(%r0) */
  1045. EMIT4_DISP(0x88000000, dst_reg, REG_0, 16);
  1046. /* llghr %dst,%dst */
  1047. EMIT4(0xb9850000, dst_reg, dst_reg);
  1048. if (insn_is_zext(&insn[1]))
  1049. insn_count = 2;
  1050. break;
  1051. case 32: /* dst = (u32) cpu_to_le32(dst) */
  1052. /* lrvr %dst,%dst */
  1053. EMIT4(0xb91f0000, dst_reg, dst_reg);
  1054. if (!fp->aux->verifier_zext)
  1055. /* llgfr %dst,%dst */
  1056. EMIT4(0xb9160000, dst_reg, dst_reg);
  1057. break;
  1058. case 64: /* dst = (u64) cpu_to_le64(dst) */
  1059. /* lrvgr %dst,%dst */
  1060. EMIT4(0xb90f0000, dst_reg, dst_reg);
  1061. break;
  1062. }
  1063. break;
  1064. /*
  1065. * BPF_NOSPEC (speculation barrier)
  1066. */
  1067. case BPF_ST | BPF_NOSPEC:
  1068. break;
  1069. /*
  1070. * BPF_ST(X)
  1071. */
  1072. case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src_reg */
  1073. /* stcy %src,off(%dst) */
  1074. EMIT6_DISP_LH(0xe3000000, 0x0072, src_reg, dst_reg, REG_0, off);
  1075. jit->seen |= SEEN_MEM;
  1076. break;
  1077. case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
  1078. /* sthy %src,off(%dst) */
  1079. EMIT6_DISP_LH(0xe3000000, 0x0070, src_reg, dst_reg, REG_0, off);
  1080. jit->seen |= SEEN_MEM;
  1081. break;
  1082. case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
  1083. /* sty %src,off(%dst) */
  1084. EMIT6_DISP_LH(0xe3000000, 0x0050, src_reg, dst_reg, REG_0, off);
  1085. jit->seen |= SEEN_MEM;
  1086. break;
  1087. case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
  1088. /* stg %src,off(%dst) */
  1089. EMIT6_DISP_LH(0xe3000000, 0x0024, src_reg, dst_reg, REG_0, off);
  1090. jit->seen |= SEEN_MEM;
  1091. break;
  1092. case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
  1093. /* lhi %w0,imm */
  1094. EMIT4_IMM(0xa7080000, REG_W0, (u8) imm);
  1095. /* stcy %w0,off(dst) */
  1096. EMIT6_DISP_LH(0xe3000000, 0x0072, REG_W0, dst_reg, REG_0, off);
  1097. jit->seen |= SEEN_MEM;
  1098. break;
  1099. case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
  1100. /* lhi %w0,imm */
  1101. EMIT4_IMM(0xa7080000, REG_W0, (u16) imm);
  1102. /* sthy %w0,off(dst) */
  1103. EMIT6_DISP_LH(0xe3000000, 0x0070, REG_W0, dst_reg, REG_0, off);
  1104. jit->seen |= SEEN_MEM;
  1105. break;
  1106. case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
  1107. /* llilf %w0,imm */
  1108. EMIT6_IMM(0xc00f0000, REG_W0, (u32) imm);
  1109. /* sty %w0,off(%dst) */
  1110. EMIT6_DISP_LH(0xe3000000, 0x0050, REG_W0, dst_reg, REG_0, off);
  1111. jit->seen |= SEEN_MEM;
  1112. break;
  1113. case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
  1114. /* lgfi %w0,imm */
  1115. EMIT6_IMM(0xc0010000, REG_W0, imm);
  1116. /* stg %w0,off(%dst) */
  1117. EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, dst_reg, REG_0, off);
  1118. jit->seen |= SEEN_MEM;
  1119. break;
  1120. /*
  1121. * BPF_ATOMIC
  1122. */
  1123. case BPF_STX | BPF_ATOMIC | BPF_DW:
  1124. case BPF_STX | BPF_ATOMIC | BPF_W:
  1125. {
  1126. bool is32 = BPF_SIZE(insn->code) == BPF_W;
  1127. switch (insn->imm) {
  1128. /* {op32|op64} {%w0|%src},%src,off(%dst) */
  1129. #define EMIT_ATOMIC(op32, op64) do { \
  1130. EMIT6_DISP_LH(0xeb000000, is32 ? (op32) : (op64), \
  1131. (insn->imm & BPF_FETCH) ? src_reg : REG_W0, \
  1132. src_reg, dst_reg, off); \
  1133. if (is32 && (insn->imm & BPF_FETCH)) \
  1134. EMIT_ZERO(src_reg); \
  1135. } while (0)
  1136. case BPF_ADD:
  1137. case BPF_ADD | BPF_FETCH:
  1138. /* {laal|laalg} */
  1139. EMIT_ATOMIC(0x00fa, 0x00ea);
  1140. break;
  1141. case BPF_AND:
  1142. case BPF_AND | BPF_FETCH:
  1143. /* {lan|lang} */
  1144. EMIT_ATOMIC(0x00f4, 0x00e4);
  1145. break;
  1146. case BPF_OR:
  1147. case BPF_OR | BPF_FETCH:
  1148. /* {lao|laog} */
  1149. EMIT_ATOMIC(0x00f6, 0x00e6);
  1150. break;
  1151. case BPF_XOR:
  1152. case BPF_XOR | BPF_FETCH:
  1153. /* {lax|laxg} */
  1154. EMIT_ATOMIC(0x00f7, 0x00e7);
  1155. break;
  1156. #undef EMIT_ATOMIC
  1157. case BPF_XCHG:
  1158. /* {ly|lg} %w0,off(%dst) */
  1159. EMIT6_DISP_LH(0xe3000000,
  1160. is32 ? 0x0058 : 0x0004, REG_W0, REG_0,
  1161. dst_reg, off);
  1162. /* 0: {csy|csg} %w0,%src,off(%dst) */
  1163. EMIT6_DISP_LH(0xeb000000, is32 ? 0x0014 : 0x0030,
  1164. REG_W0, src_reg, dst_reg, off);
  1165. /* brc 4,0b */
  1166. EMIT4_PCREL_RIC(0xa7040000, 4, jit->prg - 6);
  1167. /* {llgfr|lgr} %src,%w0 */
  1168. EMIT4(is32 ? 0xb9160000 : 0xb9040000, src_reg, REG_W0);
  1169. if (is32 && insn_is_zext(&insn[1]))
  1170. insn_count = 2;
  1171. break;
  1172. case BPF_CMPXCHG:
  1173. /* 0: {csy|csg} %b0,%src,off(%dst) */
  1174. EMIT6_DISP_LH(0xeb000000, is32 ? 0x0014 : 0x0030,
  1175. BPF_REG_0, src_reg, dst_reg, off);
  1176. break;
  1177. default:
  1178. pr_err("Unknown atomic operation %02x\n", insn->imm);
  1179. return -1;
  1180. }
  1181. jit->seen |= SEEN_MEM;
  1182. break;
  1183. }
  1184. /*
  1185. * BPF_LDX
  1186. */
  1187. case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */
  1188. case BPF_LDX | BPF_PROBE_MEM | BPF_B:
  1189. /* llgc %dst,0(off,%src) */
  1190. EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off);
  1191. jit->seen |= SEEN_MEM;
  1192. if (insn_is_zext(&insn[1]))
  1193. insn_count = 2;
  1194. break;
  1195. case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
  1196. case BPF_LDX | BPF_PROBE_MEM | BPF_H:
  1197. /* llgh %dst,0(off,%src) */
  1198. EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off);
  1199. jit->seen |= SEEN_MEM;
  1200. if (insn_is_zext(&insn[1]))
  1201. insn_count = 2;
  1202. break;
  1203. case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */
  1204. case BPF_LDX | BPF_PROBE_MEM | BPF_W:
  1205. /* llgf %dst,off(%src) */
  1206. jit->seen |= SEEN_MEM;
  1207. EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off);
  1208. if (insn_is_zext(&insn[1]))
  1209. insn_count = 2;
  1210. break;
  1211. case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
  1212. case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
  1213. /* lg %dst,0(off,%src) */
  1214. jit->seen |= SEEN_MEM;
  1215. EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, src_reg, REG_0, off);
  1216. break;
  1217. /*
  1218. * BPF_JMP / CALL
  1219. */
  1220. case BPF_JMP | BPF_CALL:
  1221. {
  1222. u64 func;
  1223. bool func_addr_fixed;
  1224. int ret;
  1225. ret = bpf_jit_get_func_addr(fp, insn, extra_pass,
  1226. &func, &func_addr_fixed);
  1227. if (ret < 0)
  1228. return -1;
  1229. REG_SET_SEEN(BPF_REG_5);
  1230. jit->seen |= SEEN_FUNC;
  1231. /* lgrl %w1,func */
  1232. EMIT6_PCREL_RILB(0xc4080000, REG_W1, _EMIT_CONST_U64(func));
  1233. if (nospec_uses_trampoline()) {
  1234. /* brasl %r14,__s390_indirect_jump_r1 */
  1235. EMIT6_PCREL_RILB(0xc0050000, REG_14, jit->r1_thunk_ip);
  1236. } else {
  1237. /* basr %r14,%w1 */
  1238. EMIT2(0x0d00, REG_14, REG_W1);
  1239. }
  1240. /* lgr %b0,%r2: load return value into %b0 */
  1241. EMIT4(0xb9040000, BPF_REG_0, REG_2);
  1242. break;
  1243. }
  1244. case BPF_JMP | BPF_TAIL_CALL: {
  1245. int patch_1_clrj, patch_2_clij, patch_3_brc;
  1246. /*
  1247. * Implicit input:
  1248. * B1: pointer to ctx
  1249. * B2: pointer to bpf_array
  1250. * B3: index in bpf_array
  1251. */
  1252. jit->seen |= SEEN_TAIL_CALL;
  1253. /*
  1254. * if (index >= array->map.max_entries)
  1255. * goto out;
  1256. */
  1257. /* llgf %w1,map.max_entries(%b2) */
  1258. EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2,
  1259. offsetof(struct bpf_array, map.max_entries));
  1260. /* if ((u32)%b3 >= (u32)%w1) goto out; */
  1261. /* clrj %b3,%w1,0xa,out */
  1262. patch_1_clrj = jit->prg;
  1263. EMIT6_PCREL_RIEB(0xec000000, 0x0077, BPF_REG_3, REG_W1, 0xa,
  1264. jit->prg);
  1265. /*
  1266. * if (tail_call_cnt++ >= MAX_TAIL_CALL_CNT)
  1267. * goto out;
  1268. */
  1269. if (jit->seen & SEEN_STACK)
  1270. off = STK_OFF_TCCNT + STK_OFF + stack_depth;
  1271. else
  1272. off = STK_OFF_TCCNT;
  1273. /* lhi %w0,1 */
  1274. EMIT4_IMM(0xa7080000, REG_W0, 1);
  1275. /* laal %w1,%w0,off(%r15) */
  1276. EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, REG_15, off);
  1277. /* clij %w1,MAX_TAIL_CALL_CNT-1,0x2,out */
  1278. patch_2_clij = jit->prg;
  1279. EMIT6_PCREL_RIEC(0xec000000, 0x007f, REG_W1, MAX_TAIL_CALL_CNT - 1,
  1280. 2, jit->prg);
  1281. /*
  1282. * prog = array->ptrs[index];
  1283. * if (prog == NULL)
  1284. * goto out;
  1285. */
  1286. /* llgfr %r1,%b3: %r1 = (u32) index */
  1287. EMIT4(0xb9160000, REG_1, BPF_REG_3);
  1288. /* sllg %r1,%r1,3: %r1 *= 8 */
  1289. EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, REG_1, REG_0, 3);
  1290. /* ltg %r1,prog(%b2,%r1) */
  1291. EMIT6_DISP_LH(0xe3000000, 0x0002, REG_1, BPF_REG_2,
  1292. REG_1, offsetof(struct bpf_array, ptrs));
  1293. /* brc 0x8,out */
  1294. patch_3_brc = jit->prg;
  1295. EMIT4_PCREL_RIC(0xa7040000, 8, jit->prg);
  1296. /*
  1297. * Restore registers before calling function
  1298. */
  1299. save_restore_regs(jit, REGS_RESTORE, stack_depth);
  1300. /*
  1301. * goto *(prog->bpf_func + tail_call_start);
  1302. */
  1303. /* lg %r1,bpf_func(%r1) */
  1304. EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, REG_1, REG_0,
  1305. offsetof(struct bpf_prog, bpf_func));
  1306. if (nospec_uses_trampoline()) {
  1307. jit->seen |= SEEN_FUNC;
  1308. /* aghi %r1,tail_call_start */
  1309. EMIT4_IMM(0xa70b0000, REG_1, jit->tail_call_start);
  1310. /* brcl 0xf,__s390_indirect_jump_r1 */
  1311. EMIT6_PCREL_RILC(0xc0040000, 0xf, jit->r1_thunk_ip);
  1312. } else {
  1313. /* bc 0xf,tail_call_start(%r1) */
  1314. _EMIT4(0x47f01000 + jit->tail_call_start);
  1315. }
  1316. /* out: */
  1317. if (jit->prg_buf) {
  1318. *(u16 *)(jit->prg_buf + patch_1_clrj + 2) =
  1319. (jit->prg - patch_1_clrj) >> 1;
  1320. *(u16 *)(jit->prg_buf + patch_2_clij + 2) =
  1321. (jit->prg - patch_2_clij) >> 1;
  1322. *(u16 *)(jit->prg_buf + patch_3_brc + 2) =
  1323. (jit->prg - patch_3_brc) >> 1;
  1324. }
  1325. break;
  1326. }
  1327. case BPF_JMP | BPF_EXIT: /* return b0 */
  1328. last = (i == fp->len - 1) ? 1 : 0;
  1329. if (last)
  1330. break;
  1331. if (!is_first_pass(jit) && can_use_rel(jit, jit->exit_ip))
  1332. /* brc 0xf, <exit> */
  1333. EMIT4_PCREL_RIC(0xa7040000, 0xf, jit->exit_ip);
  1334. else
  1335. /* brcl 0xf, <exit> */
  1336. EMIT6_PCREL_RILC(0xc0040000, 0xf, jit->exit_ip);
  1337. break;
  1338. /*
  1339. * Branch relative (number of skipped instructions) to offset on
  1340. * condition.
  1341. *
  1342. * Condition code to mask mapping:
  1343. *
  1344. * CC | Description | Mask
  1345. * ------------------------------
  1346. * 0 | Operands equal | 8
  1347. * 1 | First operand low | 4
  1348. * 2 | First operand high | 2
  1349. * 3 | Unused | 1
  1350. *
  1351. * For s390x relative branches: ip = ip + off_bytes
  1352. * For BPF relative branches: insn = insn + off_insns + 1
  1353. *
  1354. * For example for s390x with offset 0 we jump to the branch
  1355. * instruction itself (loop) and for BPF with offset 0 we
  1356. * branch to the instruction behind the branch.
  1357. */
  1358. case BPF_JMP | BPF_JA: /* if (true) */
  1359. mask = 0xf000; /* j */
  1360. goto branch_oc;
  1361. case BPF_JMP | BPF_JSGT | BPF_K: /* ((s64) dst > (s64) imm) */
  1362. case BPF_JMP32 | BPF_JSGT | BPF_K: /* ((s32) dst > (s32) imm) */
  1363. mask = 0x2000; /* jh */
  1364. goto branch_ks;
  1365. case BPF_JMP | BPF_JSLT | BPF_K: /* ((s64) dst < (s64) imm) */
  1366. case BPF_JMP32 | BPF_JSLT | BPF_K: /* ((s32) dst < (s32) imm) */
  1367. mask = 0x4000; /* jl */
  1368. goto branch_ks;
  1369. case BPF_JMP | BPF_JSGE | BPF_K: /* ((s64) dst >= (s64) imm) */
  1370. case BPF_JMP32 | BPF_JSGE | BPF_K: /* ((s32) dst >= (s32) imm) */
  1371. mask = 0xa000; /* jhe */
  1372. goto branch_ks;
  1373. case BPF_JMP | BPF_JSLE | BPF_K: /* ((s64) dst <= (s64) imm) */
  1374. case BPF_JMP32 | BPF_JSLE | BPF_K: /* ((s32) dst <= (s32) imm) */
  1375. mask = 0xc000; /* jle */
  1376. goto branch_ks;
  1377. case BPF_JMP | BPF_JGT | BPF_K: /* (dst_reg > imm) */
  1378. case BPF_JMP32 | BPF_JGT | BPF_K: /* ((u32) dst_reg > (u32) imm) */
  1379. mask = 0x2000; /* jh */
  1380. goto branch_ku;
  1381. case BPF_JMP | BPF_JLT | BPF_K: /* (dst_reg < imm) */
  1382. case BPF_JMP32 | BPF_JLT | BPF_K: /* ((u32) dst_reg < (u32) imm) */
  1383. mask = 0x4000; /* jl */
  1384. goto branch_ku;
  1385. case BPF_JMP | BPF_JGE | BPF_K: /* (dst_reg >= imm) */
  1386. case BPF_JMP32 | BPF_JGE | BPF_K: /* ((u32) dst_reg >= (u32) imm) */
  1387. mask = 0xa000; /* jhe */
  1388. goto branch_ku;
  1389. case BPF_JMP | BPF_JLE | BPF_K: /* (dst_reg <= imm) */
  1390. case BPF_JMP32 | BPF_JLE | BPF_K: /* ((u32) dst_reg <= (u32) imm) */
  1391. mask = 0xc000; /* jle */
  1392. goto branch_ku;
  1393. case BPF_JMP | BPF_JNE | BPF_K: /* (dst_reg != imm) */
  1394. case BPF_JMP32 | BPF_JNE | BPF_K: /* ((u32) dst_reg != (u32) imm) */
  1395. mask = 0x7000; /* jne */
  1396. goto branch_ku;
  1397. case BPF_JMP | BPF_JEQ | BPF_K: /* (dst_reg == imm) */
  1398. case BPF_JMP32 | BPF_JEQ | BPF_K: /* ((u32) dst_reg == (u32) imm) */
  1399. mask = 0x8000; /* je */
  1400. goto branch_ku;
  1401. case BPF_JMP | BPF_JSET | BPF_K: /* (dst_reg & imm) */
  1402. case BPF_JMP32 | BPF_JSET | BPF_K: /* ((u32) dst_reg & (u32) imm) */
  1403. mask = 0x7000; /* jnz */
  1404. if (BPF_CLASS(insn->code) == BPF_JMP32) {
  1405. /* llilf %w1,imm (load zero extend imm) */
  1406. EMIT6_IMM(0xc00f0000, REG_W1, imm);
  1407. /* nr %w1,%dst */
  1408. EMIT2(0x1400, REG_W1, dst_reg);
  1409. } else {
  1410. /* lgfi %w1,imm (load sign extend imm) */
  1411. EMIT6_IMM(0xc0010000, REG_W1, imm);
  1412. /* ngr %w1,%dst */
  1413. EMIT4(0xb9800000, REG_W1, dst_reg);
  1414. }
  1415. goto branch_oc;
  1416. case BPF_JMP | BPF_JSGT | BPF_X: /* ((s64) dst > (s64) src) */
  1417. case BPF_JMP32 | BPF_JSGT | BPF_X: /* ((s32) dst > (s32) src) */
  1418. mask = 0x2000; /* jh */
  1419. goto branch_xs;
  1420. case BPF_JMP | BPF_JSLT | BPF_X: /* ((s64) dst < (s64) src) */
  1421. case BPF_JMP32 | BPF_JSLT | BPF_X: /* ((s32) dst < (s32) src) */
  1422. mask = 0x4000; /* jl */
  1423. goto branch_xs;
  1424. case BPF_JMP | BPF_JSGE | BPF_X: /* ((s64) dst >= (s64) src) */
  1425. case BPF_JMP32 | BPF_JSGE | BPF_X: /* ((s32) dst >= (s32) src) */
  1426. mask = 0xa000; /* jhe */
  1427. goto branch_xs;
  1428. case BPF_JMP | BPF_JSLE | BPF_X: /* ((s64) dst <= (s64) src) */
  1429. case BPF_JMP32 | BPF_JSLE | BPF_X: /* ((s32) dst <= (s32) src) */
  1430. mask = 0xc000; /* jle */
  1431. goto branch_xs;
  1432. case BPF_JMP | BPF_JGT | BPF_X: /* (dst > src) */
  1433. case BPF_JMP32 | BPF_JGT | BPF_X: /* ((u32) dst > (u32) src) */
  1434. mask = 0x2000; /* jh */
  1435. goto branch_xu;
  1436. case BPF_JMP | BPF_JLT | BPF_X: /* (dst < src) */
  1437. case BPF_JMP32 | BPF_JLT | BPF_X: /* ((u32) dst < (u32) src) */
  1438. mask = 0x4000; /* jl */
  1439. goto branch_xu;
  1440. case BPF_JMP | BPF_JGE | BPF_X: /* (dst >= src) */
  1441. case BPF_JMP32 | BPF_JGE | BPF_X: /* ((u32) dst >= (u32) src) */
  1442. mask = 0xa000; /* jhe */
  1443. goto branch_xu;
  1444. case BPF_JMP | BPF_JLE | BPF_X: /* (dst <= src) */
  1445. case BPF_JMP32 | BPF_JLE | BPF_X: /* ((u32) dst <= (u32) src) */
  1446. mask = 0xc000; /* jle */
  1447. goto branch_xu;
  1448. case BPF_JMP | BPF_JNE | BPF_X: /* (dst != src) */
  1449. case BPF_JMP32 | BPF_JNE | BPF_X: /* ((u32) dst != (u32) src) */
  1450. mask = 0x7000; /* jne */
  1451. goto branch_xu;
  1452. case BPF_JMP | BPF_JEQ | BPF_X: /* (dst == src) */
  1453. case BPF_JMP32 | BPF_JEQ | BPF_X: /* ((u32) dst == (u32) src) */
  1454. mask = 0x8000; /* je */
  1455. goto branch_xu;
  1456. case BPF_JMP | BPF_JSET | BPF_X: /* (dst & src) */
  1457. case BPF_JMP32 | BPF_JSET | BPF_X: /* ((u32) dst & (u32) src) */
  1458. {
  1459. bool is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
  1460. mask = 0x7000; /* jnz */
  1461. /* nrk or ngrk %w1,%dst,%src */
  1462. EMIT4_RRF((is_jmp32 ? 0xb9f40000 : 0xb9e40000),
  1463. REG_W1, dst_reg, src_reg);
  1464. goto branch_oc;
  1465. branch_ks:
  1466. is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
  1467. /* cfi or cgfi %dst,imm */
  1468. EMIT6_IMM(is_jmp32 ? 0xc20d0000 : 0xc20c0000,
  1469. dst_reg, imm);
  1470. if (!is_first_pass(jit) &&
  1471. can_use_rel(jit, addrs[i + off + 1])) {
  1472. /* brc mask,off */
  1473. EMIT4_PCREL_RIC(0xa7040000,
  1474. mask >> 12, addrs[i + off + 1]);
  1475. } else {
  1476. /* brcl mask,off */
  1477. EMIT6_PCREL_RILC(0xc0040000,
  1478. mask >> 12, addrs[i + off + 1]);
  1479. }
  1480. break;
  1481. branch_ku:
  1482. /* lgfi %w1,imm (load sign extend imm) */
  1483. src_reg = REG_1;
  1484. EMIT6_IMM(0xc0010000, src_reg, imm);
  1485. goto branch_xu;
  1486. branch_xs:
  1487. is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
  1488. if (!is_first_pass(jit) &&
  1489. can_use_rel(jit, addrs[i + off + 1])) {
  1490. /* crj or cgrj %dst,%src,mask,off */
  1491. EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0076 : 0x0064),
  1492. dst_reg, src_reg, i, off, mask);
  1493. } else {
  1494. /* cr or cgr %dst,%src */
  1495. if (is_jmp32)
  1496. EMIT2(0x1900, dst_reg, src_reg);
  1497. else
  1498. EMIT4(0xb9200000, dst_reg, src_reg);
  1499. /* brcl mask,off */
  1500. EMIT6_PCREL_RILC(0xc0040000,
  1501. mask >> 12, addrs[i + off + 1]);
  1502. }
  1503. break;
  1504. branch_xu:
  1505. is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
  1506. if (!is_first_pass(jit) &&
  1507. can_use_rel(jit, addrs[i + off + 1])) {
  1508. /* clrj or clgrj %dst,%src,mask,off */
  1509. EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0077 : 0x0065),
  1510. dst_reg, src_reg, i, off, mask);
  1511. } else {
  1512. /* clr or clgr %dst,%src */
  1513. if (is_jmp32)
  1514. EMIT2(0x1500, dst_reg, src_reg);
  1515. else
  1516. EMIT4(0xb9210000, dst_reg, src_reg);
  1517. /* brcl mask,off */
  1518. EMIT6_PCREL_RILC(0xc0040000,
  1519. mask >> 12, addrs[i + off + 1]);
  1520. }
  1521. break;
  1522. branch_oc:
  1523. if (!is_first_pass(jit) &&
  1524. can_use_rel(jit, addrs[i + off + 1])) {
  1525. /* brc mask,off */
  1526. EMIT4_PCREL_RIC(0xa7040000,
  1527. mask >> 12, addrs[i + off + 1]);
  1528. } else {
  1529. /* brcl mask,off */
  1530. EMIT6_PCREL_RILC(0xc0040000,
  1531. mask >> 12, addrs[i + off + 1]);
  1532. }
  1533. break;
  1534. }
  1535. default: /* too complex, give up */
  1536. pr_err("Unknown opcode %02x\n", insn->code);
  1537. return -1;
  1538. }
  1539. if (probe_prg != -1) {
  1540. /*
  1541. * Handlers of certain exceptions leave psw.addr pointing to
  1542. * the instruction directly after the failing one. Therefore,
  1543. * create two exception table entries and also add a nop in
  1544. * case two probing instructions come directly after each
  1545. * other.
  1546. */
  1547. nop_prg = jit->prg;
  1548. /* bcr 0,%0 */
  1549. _EMIT2(0x0700);
  1550. err = bpf_jit_probe_mem(jit, fp, probe_prg, nop_prg);
  1551. if (err < 0)
  1552. return err;
  1553. }
  1554. return insn_count;
  1555. }
  1556. /*
  1557. * Return whether new i-th instruction address does not violate any invariant
  1558. */
  1559. static bool bpf_is_new_addr_sane(struct bpf_jit *jit, int i)
  1560. {
  1561. /* On the first pass anything goes */
  1562. if (is_first_pass(jit))
  1563. return true;
  1564. /* The codegen pass must not change anything */
  1565. if (is_codegen_pass(jit))
  1566. return jit->addrs[i] == jit->prg;
  1567. /* Passes in between must not increase code size */
  1568. return jit->addrs[i] >= jit->prg;
  1569. }
  1570. /*
  1571. * Update the address of i-th instruction
  1572. */
  1573. static int bpf_set_addr(struct bpf_jit *jit, int i)
  1574. {
  1575. int delta;
  1576. if (is_codegen_pass(jit)) {
  1577. delta = jit->prg - jit->addrs[i];
  1578. if (delta < 0)
  1579. bpf_skip(jit, -delta);
  1580. }
  1581. if (WARN_ON_ONCE(!bpf_is_new_addr_sane(jit, i)))
  1582. return -1;
  1583. jit->addrs[i] = jit->prg;
  1584. return 0;
  1585. }
  1586. /*
  1587. * Compile eBPF program into s390x code
  1588. */
  1589. static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp,
  1590. bool extra_pass, u32 stack_depth)
  1591. {
  1592. int i, insn_count, lit32_size, lit64_size;
  1593. jit->lit32 = jit->lit32_start;
  1594. jit->lit64 = jit->lit64_start;
  1595. jit->prg = 0;
  1596. jit->excnt = 0;
  1597. bpf_jit_prologue(jit, stack_depth);
  1598. if (bpf_set_addr(jit, 0) < 0)
  1599. return -1;
  1600. for (i = 0; i < fp->len; i += insn_count) {
  1601. insn_count = bpf_jit_insn(jit, fp, i, extra_pass, stack_depth);
  1602. if (insn_count < 0)
  1603. return -1;
  1604. /* Next instruction address */
  1605. if (bpf_set_addr(jit, i + insn_count) < 0)
  1606. return -1;
  1607. }
  1608. bpf_jit_epilogue(jit, stack_depth);
  1609. lit32_size = jit->lit32 - jit->lit32_start;
  1610. lit64_size = jit->lit64 - jit->lit64_start;
  1611. jit->lit32_start = jit->prg;
  1612. if (lit32_size)
  1613. jit->lit32_start = ALIGN(jit->lit32_start, 4);
  1614. jit->lit64_start = jit->lit32_start + lit32_size;
  1615. if (lit64_size)
  1616. jit->lit64_start = ALIGN(jit->lit64_start, 8);
  1617. jit->size = jit->lit64_start + lit64_size;
  1618. jit->size_prg = jit->prg;
  1619. if (WARN_ON_ONCE(fp->aux->extable &&
  1620. jit->excnt != fp->aux->num_exentries))
  1621. /* Verifier bug - too many entries. */
  1622. return -1;
  1623. return 0;
  1624. }
  1625. bool bpf_jit_needs_zext(void)
  1626. {
  1627. return true;
  1628. }
  1629. struct s390_jit_data {
  1630. struct bpf_binary_header *header;
  1631. struct bpf_jit ctx;
  1632. int pass;
  1633. };
  1634. static struct bpf_binary_header *bpf_jit_alloc(struct bpf_jit *jit,
  1635. struct bpf_prog *fp)
  1636. {
  1637. struct bpf_binary_header *header;
  1638. u32 extable_size;
  1639. u32 code_size;
  1640. /* We need two entries per insn. */
  1641. fp->aux->num_exentries *= 2;
  1642. code_size = roundup(jit->size,
  1643. __alignof__(struct exception_table_entry));
  1644. extable_size = fp->aux->num_exentries *
  1645. sizeof(struct exception_table_entry);
  1646. header = bpf_jit_binary_alloc(code_size + extable_size, &jit->prg_buf,
  1647. 8, jit_fill_hole);
  1648. if (!header)
  1649. return NULL;
  1650. fp->aux->extable = (struct exception_table_entry *)
  1651. (jit->prg_buf + code_size);
  1652. return header;
  1653. }
  1654. /*
  1655. * Compile eBPF program "fp"
  1656. */
  1657. struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
  1658. {
  1659. u32 stack_depth = round_up(fp->aux->stack_depth, 8);
  1660. struct bpf_prog *tmp, *orig_fp = fp;
  1661. struct bpf_binary_header *header;
  1662. struct s390_jit_data *jit_data;
  1663. bool tmp_blinded = false;
  1664. bool extra_pass = false;
  1665. struct bpf_jit jit;
  1666. int pass;
  1667. if (!fp->jit_requested)
  1668. return orig_fp;
  1669. tmp = bpf_jit_blind_constants(fp);
  1670. /*
  1671. * If blinding was requested and we failed during blinding,
  1672. * we must fall back to the interpreter.
  1673. */
  1674. if (IS_ERR(tmp))
  1675. return orig_fp;
  1676. if (tmp != fp) {
  1677. tmp_blinded = true;
  1678. fp = tmp;
  1679. }
  1680. jit_data = fp->aux->jit_data;
  1681. if (!jit_data) {
  1682. jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
  1683. if (!jit_data) {
  1684. fp = orig_fp;
  1685. goto out;
  1686. }
  1687. fp->aux->jit_data = jit_data;
  1688. }
  1689. if (jit_data->ctx.addrs) {
  1690. jit = jit_data->ctx;
  1691. header = jit_data->header;
  1692. extra_pass = true;
  1693. pass = jit_data->pass + 1;
  1694. goto skip_init_ctx;
  1695. }
  1696. memset(&jit, 0, sizeof(jit));
  1697. jit.addrs = kvcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
  1698. if (jit.addrs == NULL) {
  1699. fp = orig_fp;
  1700. goto free_addrs;
  1701. }
  1702. /*
  1703. * Three initial passes:
  1704. * - 1/2: Determine clobbered registers
  1705. * - 3: Calculate program size and addrs array
  1706. */
  1707. for (pass = 1; pass <= 3; pass++) {
  1708. if (bpf_jit_prog(&jit, fp, extra_pass, stack_depth)) {
  1709. fp = orig_fp;
  1710. goto free_addrs;
  1711. }
  1712. }
  1713. /*
  1714. * Final pass: Allocate and generate program
  1715. */
  1716. header = bpf_jit_alloc(&jit, fp);
  1717. if (!header) {
  1718. fp = orig_fp;
  1719. goto free_addrs;
  1720. }
  1721. skip_init_ctx:
  1722. if (bpf_jit_prog(&jit, fp, extra_pass, stack_depth)) {
  1723. bpf_jit_binary_free(header);
  1724. fp = orig_fp;
  1725. goto free_addrs;
  1726. }
  1727. if (bpf_jit_enable > 1) {
  1728. bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf);
  1729. print_fn_code(jit.prg_buf, jit.size_prg);
  1730. }
  1731. if (!fp->is_func || extra_pass) {
  1732. bpf_jit_binary_lock_ro(header);
  1733. } else {
  1734. jit_data->header = header;
  1735. jit_data->ctx = jit;
  1736. jit_data->pass = pass;
  1737. }
  1738. fp->bpf_func = (void *) jit.prg_buf;
  1739. fp->jited = 1;
  1740. fp->jited_len = jit.size;
  1741. if (!fp->is_func || extra_pass) {
  1742. bpf_prog_fill_jited_linfo(fp, jit.addrs + 1);
  1743. free_addrs:
  1744. kvfree(jit.addrs);
  1745. kfree(jit_data);
  1746. fp->aux->jit_data = NULL;
  1747. }
  1748. out:
  1749. if (tmp_blinded)
  1750. bpf_jit_prog_release_other(fp, fp == orig_fp ?
  1751. tmp : orig_fp);
  1752. return fp;
  1753. }