~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/sparc/net/bpf_jit_comp.c

Version: ~ [ linux-5.6-rc3 ] ~ [ linux-5.5.6 ] ~ [ linux-5.4.22 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.106 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.171 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.214 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.214 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.82 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 #include <linux/moduleloader.h>
  2 #include <linux/workqueue.h>
  3 #include <linux/netdevice.h>
  4 #include <linux/filter.h>
  5 #include <linux/cache.h>
  6 #include <linux/if_vlan.h>
  7 
  8 #include <asm/cacheflush.h>
  9 #include <asm/ptrace.h>
 10 
 11 #include "bpf_jit.h"
 12 
 13 int bpf_jit_enable __read_mostly;
 14 
 15 static inline bool is_simm13(unsigned int value)
 16 {
 17         return value + 0x1000 < 0x2000;
 18 }
 19 
 20 static void bpf_flush_icache(void *start_, void *end_)
 21 {
 22 #ifdef CONFIG_SPARC64
 23         /* Cheetah's I-cache is fully coherent.  */
 24         if (tlb_type == spitfire) {
 25                 unsigned long start = (unsigned long) start_;
 26                 unsigned long end = (unsigned long) end_;
 27 
 28                 start &= ~7UL;
 29                 end = (end + 7UL) & ~7UL;
 30                 while (start < end) {
 31                         flushi(start);
 32                         start += 32;
 33                 }
 34         }
 35 #endif
 36 }
 37 
 38 #define SEEN_DATAREF 1 /* might call external helpers */
 39 #define SEEN_XREG    2 /* ebx is used */
 40 #define SEEN_MEM     4 /* use mem[] for temporary storage */
 41 
 42 #define S13(X)          ((X) & 0x1fff)
 43 #define IMMED           0x00002000
 44 #define RD(X)           ((X) << 25)
 45 #define RS1(X)          ((X) << 14)
 46 #define RS2(X)          ((X))
 47 #define OP(X)           ((X) << 30)
 48 #define OP2(X)          ((X) << 22)
 49 #define OP3(X)          ((X) << 19)
 50 #define COND(X)         ((X) << 25)
 51 #define F1(X)           OP(X)
 52 #define F2(X, Y)        (OP(X) | OP2(Y))
 53 #define F3(X, Y)        (OP(X) | OP3(Y))
 54 
 55 #define CONDN           COND(0x0)
 56 #define CONDE           COND(0x1)
 57 #define CONDLE          COND(0x2)
 58 #define CONDL           COND(0x3)
 59 #define CONDLEU         COND(0x4)
 60 #define CONDCS          COND(0x5)
 61 #define CONDNEG         COND(0x6)
 62 #define CONDVC          COND(0x7)
 63 #define CONDA           COND(0x8)
 64 #define CONDNE          COND(0x9)
 65 #define CONDG           COND(0xa)
 66 #define CONDGE          COND(0xb)
 67 #define CONDGU          COND(0xc)
 68 #define CONDCC          COND(0xd)
 69 #define CONDPOS         COND(0xe)
 70 #define CONDVS          COND(0xf)
 71 
 72 #define CONDGEU         CONDCC
 73 #define CONDLU          CONDCS
 74 
 75 #define WDISP22(X)      (((X) >> 2) & 0x3fffff)
 76 
 77 #define BA              (F2(0, 2) | CONDA)
 78 #define BGU             (F2(0, 2) | CONDGU)
 79 #define BLEU            (F2(0, 2) | CONDLEU)
 80 #define BGEU            (F2(0, 2) | CONDGEU)
 81 #define BLU             (F2(0, 2) | CONDLU)
 82 #define BE              (F2(0, 2) | CONDE)
 83 #define BNE             (F2(0, 2) | CONDNE)
 84 
 85 #ifdef CONFIG_SPARC64
 86 #define BNE_PTR         (F2(0, 1) | CONDNE | (2 << 20))
 87 #else
 88 #define BNE_PTR         BNE
 89 #endif
 90 
 91 #define SETHI(K, REG)   \
 92         (F2(0, 0x4) | RD(REG) | (((K) >> 10) & 0x3fffff))
 93 #define OR_LO(K, REG)   \
 94         (F3(2, 0x02) | IMMED | RS1(REG) | ((K) & 0x3ff) | RD(REG))
 95 
 96 #define ADD             F3(2, 0x00)
 97 #define AND             F3(2, 0x01)
 98 #define ANDCC           F3(2, 0x11)
 99 #define OR              F3(2, 0x02)
100 #define XOR             F3(2, 0x03)
101 #define SUB             F3(2, 0x04)
102 #define SUBCC           F3(2, 0x14)
103 #define MUL             F3(2, 0x0a)     /* umul */
104 #define DIV             F3(2, 0x0e)     /* udiv */
105 #define SLL             F3(2, 0x25)
106 #define SRL             F3(2, 0x26)
107 #define JMPL            F3(2, 0x38)
108 #define CALL            F1(1)
109 #define BR              F2(0, 0x01)
110 #define RD_Y            F3(2, 0x28)
111 #define WR_Y            F3(2, 0x30)
112 
113 #define LD32            F3(3, 0x00)
114 #define LD8             F3(3, 0x01)
115 #define LD16            F3(3, 0x02)
116 #define LD64            F3(3, 0x0b)
117 #define ST32            F3(3, 0x04)
118 
119 #ifdef CONFIG_SPARC64
120 #define LDPTR           LD64
121 #define BASE_STACKFRAME 176
122 #else
123 #define LDPTR           LD32
124 #define BASE_STACKFRAME 96
125 #endif
126 
127 #define LD32I           (LD32 | IMMED)
128 #define LD8I            (LD8 | IMMED)
129 #define LD16I           (LD16 | IMMED)
130 #define LD64I           (LD64 | IMMED)
131 #define LDPTRI          (LDPTR | IMMED)
132 #define ST32I           (ST32 | IMMED)
133 
134 #define emit_nop()              \
135 do {                            \
136         *prog++ = SETHI(0, G0); \
137 } while (0)
138 
139 #define emit_neg()                                      \
140 do {    /* sub %g0, r_A, r_A */                         \
141         *prog++ = SUB | RS1(G0) | RS2(r_A) | RD(r_A);   \
142 } while (0)
143 
144 #define emit_reg_move(FROM, TO)                         \
145 do {    /* or %g0, FROM, TO */                          \
146         *prog++ = OR | RS1(G0) | RS2(FROM) | RD(TO);    \
147 } while (0)
148 
149 #define emit_clear(REG)                                 \
150 do {    /* or %g0, %g0, REG */                          \
151         *prog++ = OR | RS1(G0) | RS2(G0) | RD(REG);     \
152 } while (0)
153 
154 #define emit_set_const(K, REG)                                  \
155 do {    /* sethi %hi(K), REG */                                 \
156         *prog++ = SETHI(K, REG);                                \
157         /* or REG, %lo(K), REG */                               \
158         *prog++ = OR_LO(K, REG);                                \
159 } while (0)
160 
161         /* Emit
162          *
163          *      OP      r_A, r_X, r_A
164          */
165 #define emit_alu_X(OPCODE)                                      \
166 do {                                                            \
167         seen |= SEEN_XREG;                                      \
168         *prog++ = OPCODE | RS1(r_A) | RS2(r_X) | RD(r_A);       \
169 } while (0)
170 
171         /* Emit either:
172          *
173          *      OP      r_A, K, r_A
174          *
175          * or
176          *
177          *      sethi   %hi(K), r_TMP
178          *      or      r_TMP, %lo(K), r_TMP
179          *      OP      r_A, r_TMP, r_A
180          *
181          * depending upon whether K fits in a signed 13-bit
182          * immediate instruction field.  Emit nothing if K
183          * is zero.
184          */
185 #define emit_alu_K(OPCODE, K)                                   \
186 do {                                                            \
187         if (K) {                                                \
188                 unsigned int _insn = OPCODE;                    \
189                 _insn |= RS1(r_A) | RD(r_A);                    \
190                 if (is_simm13(K)) {                             \
191                         *prog++ = _insn | IMMED | S13(K);       \
192                 } else {                                        \
193                         emit_set_const(K, r_TMP);               \
194                         *prog++ = _insn | RS2(r_TMP);           \
195                 }                                               \
196         }                                                       \
197 } while (0)
198 
199 #define emit_loadimm(K, DEST)                                           \
200 do {                                                                    \
201         if (is_simm13(K)) {                                             \
202                 /* or %g0, K, DEST */                                   \
203                 *prog++ = OR | IMMED | RS1(G0) | S13(K) | RD(DEST);     \
204         } else {                                                        \
205                 emit_set_const(K, DEST);                                \
206         }                                                               \
207 } while (0)
208 
209 #define emit_loadptr(BASE, STRUCT, FIELD, DEST)                         \
210 do {    unsigned int _off = offsetof(STRUCT, FIELD);                    \
211         BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(void *));    \
212         *prog++ = LDPTRI | RS1(BASE) | S13(_off) | RD(DEST);            \
213 } while (0)
214 
215 #define emit_load32(BASE, STRUCT, FIELD, DEST)                          \
216 do {    unsigned int _off = offsetof(STRUCT, FIELD);                    \
217         BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u32));       \
218         *prog++ = LD32I | RS1(BASE) | S13(_off) | RD(DEST);             \
219 } while (0)
220 
221 #define emit_load16(BASE, STRUCT, FIELD, DEST)                          \
222 do {    unsigned int _off = offsetof(STRUCT, FIELD);                    \
223         BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u16));       \
224         *prog++ = LD16I | RS1(BASE) | S13(_off) | RD(DEST);             \
225 } while (0)
226 
227 #define __emit_load8(BASE, STRUCT, FIELD, DEST)                         \
228 do {    unsigned int _off = offsetof(STRUCT, FIELD);                    \
229         *prog++ = LD8I | RS1(BASE) | S13(_off) | RD(DEST);              \
230 } while (0)
231 
232 #define emit_load8(BASE, STRUCT, FIELD, DEST)                           \
233 do {    BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u8));        \
234         __emit_load8(BASE, STRUCT, FIELD, DEST);                        \
235 } while (0)
236 
237 #define emit_ldmem(OFF, DEST)                                   \
238 do {    *prog++ = LD32I | RS1(FP) | S13(-(OFF)) | RD(DEST);     \
239 } while (0)
240 
241 #define emit_stmem(OFF, SRC)                                    \
242 do {    *prog++ = LD32I | RS1(FP) | S13(-(OFF)) | RD(SRC);      \
243 } while (0)
244 
245 #ifdef CONFIG_SMP
246 #ifdef CONFIG_SPARC64
247 #define emit_load_cpu(REG)                                              \
248         emit_load16(G6, struct thread_info, cpu, REG)
249 #else
250 #define emit_load_cpu(REG)                                              \
251         emit_load32(G6, struct thread_info, cpu, REG)
252 #endif
253 #else
254 #define emit_load_cpu(REG)      emit_clear(REG)
255 #endif
256 
257 #define emit_skb_loadptr(FIELD, DEST) \
258         emit_loadptr(r_SKB, struct sk_buff, FIELD, DEST)
259 #define emit_skb_load32(FIELD, DEST) \
260         emit_load32(r_SKB, struct sk_buff, FIELD, DEST)
261 #define emit_skb_load16(FIELD, DEST) \
262         emit_load16(r_SKB, struct sk_buff, FIELD, DEST)
263 #define __emit_skb_load8(FIELD, DEST) \
264         __emit_load8(r_SKB, struct sk_buff, FIELD, DEST)
265 #define emit_skb_load8(FIELD, DEST) \
266         emit_load8(r_SKB, struct sk_buff, FIELD, DEST)
267 
268 #define emit_jmpl(BASE, IMM_OFF, LREG) \
269         *prog++ = (JMPL | IMMED | RS1(BASE) | S13(IMM_OFF) | RD(LREG))
270 
271 #define emit_call(FUNC)                                 \
272 do {    void *_here = image + addrs[i] - 8;             \
273         unsigned int _off = (void *)(FUNC) - _here;     \
274         *prog++ = CALL | (((_off) >> 2) & 0x3fffffff);  \
275         emit_nop();                                     \
276 } while (0)
277 
278 #define emit_branch(BR_OPC, DEST)                       \
279 do {    unsigned int _here = addrs[i] - 8;              \
280         *prog++ = BR_OPC | WDISP22((DEST) - _here);     \
281 } while (0)
282 
283 #define emit_branch_off(BR_OPC, OFF)                    \
284 do {    *prog++ = BR_OPC | WDISP22(OFF);                \
285 } while (0)
286 
287 #define emit_jump(DEST)         emit_branch(BA, DEST)
288 
289 #define emit_read_y(REG)        *prog++ = RD_Y | RD(REG)
290 #define emit_write_y(REG)       *prog++ = WR_Y | IMMED | RS1(REG) | S13(0)
291 
292 #define emit_cmp(R1, R2) \
293         *prog++ = (SUBCC | RS1(R1) | RS2(R2) | RD(G0))
294 
295 #define emit_cmpi(R1, IMM) \
296         *prog++ = (SUBCC | IMMED | RS1(R1) | S13(IMM) | RD(G0));
297 
298 #define emit_btst(R1, R2) \
299         *prog++ = (ANDCC | RS1(R1) | RS2(R2) | RD(G0))
300 
301 #define emit_btsti(R1, IMM) \
302         *prog++ = (ANDCC | IMMED | RS1(R1) | S13(IMM) | RD(G0));
303 
304 #define emit_sub(R1, R2, R3) \
305         *prog++ = (SUB | RS1(R1) | RS2(R2) | RD(R3))
306 
307 #define emit_subi(R1, IMM, R3) \
308         *prog++ = (SUB | IMMED | RS1(R1) | S13(IMM) | RD(R3))
309 
310 #define emit_add(R1, R2, R3) \
311         *prog++ = (ADD | RS1(R1) | RS2(R2) | RD(R3))
312 
313 #define emit_addi(R1, IMM, R3) \
314         *prog++ = (ADD | IMMED | RS1(R1) | S13(IMM) | RD(R3))
315 
316 #define emit_and(R1, R2, R3) \
317         *prog++ = (AND | RS1(R1) | RS2(R2) | RD(R3))
318 
319 #define emit_andi(R1, IMM, R3) \
320         *prog++ = (AND | IMMED | RS1(R1) | S13(IMM) | RD(R3))
321 
322 #define emit_alloc_stack(SZ) \
323         *prog++ = (SUB | IMMED | RS1(SP) | S13(SZ) | RD(SP))
324 
325 #define emit_release_stack(SZ) \
326         *prog++ = (ADD | IMMED | RS1(SP) | S13(SZ) | RD(SP))
327 
328 /* A note about branch offset calculations.  The addrs[] array,
329  * indexed by BPF instruction, records the address after all the
330  * sparc instructions emitted for that BPF instruction.
331  *
332  * The most common case is to emit a branch at the end of such
333  * a code sequence.  So this would be two instructions, the
334  * branch and it's delay slot.
335  *
336  * Therefore by default the branch emitters calculate the branch
337  * offset field as:
338  *
339  *      destination - (addrs[i] - 8)
340  *
341  * This "addrs[i] - 8" is the address of the branch itself or
342  * what "." would be in assembler notation.  The "8" part is
343  * how we take into consideration the branch and it's delay
344  * slot mentioned above.
345  *
346  * Sometimes we need to emit a branch earlier in the code
347  * sequence.  And in these situations we adjust "destination"
348  * to accomodate this difference.  For example, if we needed
349  * to emit a branch (and it's delay slot) right before the
350  * final instruction emitted for a BPF opcode, we'd use
351  * "destination + 4" instead of just plain "destination" above.
352  *
353  * This is why you see all of these funny emit_branch() and
354  * emit_jump() calls with adjusted offsets.
355  */
356 
357 void bpf_jit_compile(struct sk_filter *fp)
358 {
359         unsigned int cleanup_addr, proglen, oldproglen = 0;
360         u32 temp[8], *prog, *func, seen = 0, pass;
361         const struct sock_filter *filter = fp->insns;
362         int i, flen = fp->len, pc_ret0 = -1;
363         unsigned int *addrs;
364         void *image;
365 
366         if (!bpf_jit_enable)
367                 return;
368 
369         addrs = kmalloc(flen * sizeof(*addrs), GFP_KERNEL);
370         if (addrs == NULL)
371                 return;
372 
373         /* Before first pass, make a rough estimation of addrs[]
374          * each bpf instruction is translated to less than 64 bytes
375          */
376         for (proglen = 0, i = 0; i < flen; i++) {
377                 proglen += 64;
378                 addrs[i] = proglen;
379         }
380         cleanup_addr = proglen; /* epilogue address */
381         image = NULL;
382         for (pass = 0; pass < 10; pass++) {
383                 u8 seen_or_pass0 = (pass == 0) ? (SEEN_XREG | SEEN_DATAREF | SEEN_MEM) : seen;
384 
385                 /* no prologue/epilogue for trivial filters (RET something) */
386                 proglen = 0;
387                 prog = temp;
388 
389                 /* Prologue */
390                 if (seen_or_pass0) {
391                         if (seen_or_pass0 & SEEN_MEM) {
392                                 unsigned int sz = BASE_STACKFRAME;
393                                 sz += BPF_MEMWORDS * sizeof(u32);
394                                 emit_alloc_stack(sz);
395                         }
396 
397                         /* Make sure we dont leek kernel memory. */
398                         if (seen_or_pass0 & SEEN_XREG)
399                                 emit_clear(r_X);
400 
401                         /* If this filter needs to access skb data,
402                          * load %o4 and %o5 with:
403                          *  %o4 = skb->len - skb->data_len
404                          *  %o5 = skb->data
405                          * And also back up %o7 into r_saved_O7 so we can
406                          * invoke the stubs using 'call'.
407                          */
408                         if (seen_or_pass0 & SEEN_DATAREF) {
409                                 emit_load32(r_SKB, struct sk_buff, len, r_HEADLEN);
410                                 emit_load32(r_SKB, struct sk_buff, data_len, r_TMP);
411                                 emit_sub(r_HEADLEN, r_TMP, r_HEADLEN);
412                                 emit_loadptr(r_SKB, struct sk_buff, data, r_SKB_DATA);
413                         }
414                 }
415                 emit_reg_move(O7, r_saved_O7);
416 
417                 switch (filter[0].code) {
418                 case BPF_S_RET_K:
419                 case BPF_S_LD_W_LEN:
420                 case BPF_S_ANC_PROTOCOL:
421                 case BPF_S_ANC_PKTTYPE:
422                 case BPF_S_ANC_IFINDEX:
423                 case BPF_S_ANC_MARK:
424                 case BPF_S_ANC_RXHASH:
425                 case BPF_S_ANC_VLAN_TAG:
426                 case BPF_S_ANC_VLAN_TAG_PRESENT:
427                 case BPF_S_ANC_CPU:
428                 case BPF_S_ANC_QUEUE:
429                 case BPF_S_LD_W_ABS:
430                 case BPF_S_LD_H_ABS:
431                 case BPF_S_LD_B_ABS:
432                         /* The first instruction sets the A register (or is
433                          * a "RET 'constant'")
434                          */
435                         break;
436                 default:
437                         /* Make sure we dont leak kernel information to the
438                          * user.
439                          */
440                         emit_clear(r_A); /* A = 0 */
441                 }
442 
443                 for (i = 0; i < flen; i++) {
444                         unsigned int K = filter[i].k;
445                         unsigned int t_offset;
446                         unsigned int f_offset;
447                         u32 t_op, f_op;
448                         int ilen;
449 
450                         switch (filter[i].code) {
451                         case BPF_S_ALU_ADD_X:   /* A += X; */
452                                 emit_alu_X(ADD);
453                                 break;
454                         case BPF_S_ALU_ADD_K:   /* A += K; */
455                                 emit_alu_K(ADD, K);
456                                 break;
457                         case BPF_S_ALU_SUB_X:   /* A -= X; */
458                                 emit_alu_X(SUB);
459                                 break;
460                         case BPF_S_ALU_SUB_K:   /* A -= K */
461                                 emit_alu_K(SUB, K);
462                                 break;
463                         case BPF_S_ALU_AND_X:   /* A &= X */
464                                 emit_alu_X(AND);
465                                 break;
466                         case BPF_S_ALU_AND_K:   /* A &= K */
467                                 emit_alu_K(AND, K);
468                                 break;
469                         case BPF_S_ALU_OR_X:    /* A |= X */
470                                 emit_alu_X(OR);
471                                 break;
472                         case BPF_S_ALU_OR_K:    /* A |= K */
473                                 emit_alu_K(OR, K);
474                                 break;
475                         case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */
476                         case BPF_S_ALU_XOR_X:
477                                 emit_alu_X(XOR);
478                                 break;
479                         case BPF_S_ALU_XOR_K:   /* A ^= K */
480                                 emit_alu_K(XOR, K);
481                                 break;
482                         case BPF_S_ALU_LSH_X:   /* A <<= X */
483                                 emit_alu_X(SLL);
484                                 break;
485                         case BPF_S_ALU_LSH_K:   /* A <<= K */
486                                 emit_alu_K(SLL, K);
487                                 break;
488                         case BPF_S_ALU_RSH_X:   /* A >>= X */
489                                 emit_alu_X(SRL);
490                                 break;
491                         case BPF_S_ALU_RSH_K:   /* A >>= K */
492                                 emit_alu_K(SRL, K);
493                                 break;
494                         case BPF_S_ALU_MUL_X:   /* A *= X; */
495                                 emit_alu_X(MUL);
496                                 break;
497                         case BPF_S_ALU_MUL_K:   /* A *= K */
498                                 emit_alu_K(MUL, K);
499                                 break;
500                         case BPF_S_ALU_DIV_K:   /* A /= K */
501                                 emit_alu_K(MUL, K);
502                                 emit_read_y(r_A);
503                                 break;
504                         case BPF_S_ALU_DIV_X:   /* A /= X; */
505                                 emit_cmpi(r_X, 0);
506                                 if (pc_ret0 > 0) {
507                                         t_offset = addrs[pc_ret0 - 1];
508 #ifdef CONFIG_SPARC32
509                                         emit_branch(BE, t_offset + 20);
510 #else
511                                         emit_branch(BE, t_offset + 8);
512 #endif
513                                         emit_nop(); /* delay slot */
514                                 } else {
515                                         emit_branch_off(BNE, 16);
516                                         emit_nop();
517 #ifdef CONFIG_SPARC32
518                                         emit_jump(cleanup_addr + 20);
519 #else
520                                         emit_jump(cleanup_addr + 8);
521 #endif
522                                         emit_clear(r_A);
523                                 }
524                                 emit_write_y(G0);
525 #ifdef CONFIG_SPARC32
526                                 /* The Sparc v8 architecture requires
527                                  * three instructions between a %y
528                                  * register write and the first use.
529                                  */
530                                 emit_nop();
531                                 emit_nop();
532                                 emit_nop();
533 #endif
534                                 emit_alu_X(DIV);
535                                 break;
536                         case BPF_S_ALU_NEG:
537                                 emit_neg();
538                                 break;
539                         case BPF_S_RET_K:
540                                 if (!K) {
541                                         if (pc_ret0 == -1)
542                                                 pc_ret0 = i;
543                                         emit_clear(r_A);
544                                 } else {
545                                         emit_loadimm(K, r_A);
546                                 }
547                                 /* Fallthrough */
548                         case BPF_S_RET_A:
549                                 if (seen_or_pass0) {
550                                         if (i != flen - 1) {
551                                                 emit_jump(cleanup_addr);
552                                                 emit_nop();
553                                                 break;
554                                         }
555                                         if (seen_or_pass0 & SEEN_MEM) {
556                                                 unsigned int sz = BASE_STACKFRAME;
557                                                 sz += BPF_MEMWORDS * sizeof(u32);
558                                                 emit_release_stack(sz);
559                                         }
560                                 }
561                                 /* jmpl %r_saved_O7 + 8, %g0 */
562                                 emit_jmpl(r_saved_O7, 8, G0);
563                                 emit_reg_move(r_A, O0); /* delay slot */
564                                 break;
565                         case BPF_S_MISC_TAX:
566                                 seen |= SEEN_XREG;
567                                 emit_reg_move(r_A, r_X);
568                                 break;
569                         case BPF_S_MISC_TXA:
570                                 seen |= SEEN_XREG;
571                                 emit_reg_move(r_X, r_A);
572                                 break;
573                         case BPF_S_ANC_CPU:
574                                 emit_load_cpu(r_A);
575                                 break;
576                         case BPF_S_ANC_PROTOCOL:
577                                 emit_skb_load16(protocol, r_A);
578                                 break;
579 #if 0
580                                 /* GCC won't let us take the address of
581                                  * a bit field even though we very much
582                                  * know what we are doing here.
583                                  */
584                         case BPF_S_ANC_PKTTYPE:
585                                 __emit_skb_load8(pkt_type, r_A);
586                                 emit_alu_K(SRL, 5);
587                                 break;
588 #endif
589                         case BPF_S_ANC_IFINDEX:
590                                 emit_skb_loadptr(dev, r_A);
591                                 emit_cmpi(r_A, 0);
592                                 emit_branch(BNE_PTR, cleanup_addr + 4);
593                                 emit_nop();
594                                 emit_load32(r_A, struct net_device, ifindex, r_A);
595                                 break;
596                         case BPF_S_ANC_MARK:
597                                 emit_skb_load32(mark, r_A);
598                                 break;
599                         case BPF_S_ANC_QUEUE:
600                                 emit_skb_load16(queue_mapping, r_A);
601                                 break;
602                         case BPF_S_ANC_HATYPE:
603                                 emit_skb_loadptr(dev, r_A);
604                                 emit_cmpi(r_A, 0);
605                                 emit_branch(BNE_PTR, cleanup_addr + 4);
606                                 emit_nop();
607                                 emit_load16(r_A, struct net_device, type, r_A);
608                                 break;
609                         case BPF_S_ANC_RXHASH:
610                                 emit_skb_load32(rxhash, r_A);
611                                 break;
612                         case BPF_S_ANC_VLAN_TAG:
613                         case BPF_S_ANC_VLAN_TAG_PRESENT:
614                                 emit_skb_load16(vlan_tci, r_A);
615                                 if (filter[i].code == BPF_S_ANC_VLAN_TAG) {
616                                         emit_andi(r_A, VLAN_VID_MASK, r_A);
617                                 } else {
618                                         emit_loadimm(VLAN_TAG_PRESENT, r_TMP);
619                                         emit_and(r_A, r_TMP, r_A);
620                                 }
621                                 break;
622 
623                         case BPF_S_LD_IMM:
624                                 emit_loadimm(K, r_A);
625                                 break;
626                         case BPF_S_LDX_IMM:
627                                 emit_loadimm(K, r_X);
628                                 break;
629                         case BPF_S_LD_MEM:
630                                 emit_ldmem(K * 4, r_A);
631                                 break;
632                         case BPF_S_LDX_MEM:
633                                 emit_ldmem(K * 4, r_X);
634                                 break;
635                         case BPF_S_ST:
636                                 emit_stmem(K * 4, r_A);
637                                 break;
638                         case BPF_S_STX:
639                                 emit_stmem(K * 4, r_X);
640                                 break;
641 
642 #define CHOOSE_LOAD_FUNC(K, func) \
643         ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
644 
645                         case BPF_S_LD_W_ABS:
646                                 func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_word);
647 common_load:                    seen |= SEEN_DATAREF;
648                                 emit_loadimm(K, r_OFF);
649                                 emit_call(func);
650                                 break;
651                         case BPF_S_LD_H_ABS:
652                                 func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_half);
653                                 goto common_load;
654                         case BPF_S_LD_B_ABS:
655                                 func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte);
656                                 goto common_load;
657                         case BPF_S_LDX_B_MSH:
658                                 func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte_msh);
659                                 goto common_load;
660                         case BPF_S_LD_W_IND:
661                                 func = bpf_jit_load_word;
662 common_load_ind:                seen |= SEEN_DATAREF | SEEN_XREG;
663                                 if (K) {
664                                         if (is_simm13(K)) {
665                                                 emit_addi(r_X, K, r_OFF);
666                                         } else {
667                                                 emit_loadimm(K, r_TMP);
668                                                 emit_add(r_X, r_TMP, r_OFF);
669                                         }
670                                 } else {
671                                         emit_reg_move(r_X, r_OFF);
672                                 }
673                                 emit_call(func);
674                                 break;
675                         case BPF_S_LD_H_IND:
676                                 func = bpf_jit_load_half;
677                                 goto common_load_ind;
678                         case BPF_S_LD_B_IND:
679                                 func = bpf_jit_load_byte;
680                                 goto common_load_ind;
681                         case BPF_S_JMP_JA:
682                                 emit_jump(addrs[i + K]);
683                                 emit_nop();
684                                 break;
685 
686 #define COND_SEL(CODE, TOP, FOP)        \
687         case CODE:                      \
688                 t_op = TOP;             \
689                 f_op = FOP;             \
690                 goto cond_branch
691 
692                         COND_SEL(BPF_S_JMP_JGT_K, BGU, BLEU);
693                         COND_SEL(BPF_S_JMP_JGE_K, BGEU, BLU);
694                         COND_SEL(BPF_S_JMP_JEQ_K, BE, BNE);
695                         COND_SEL(BPF_S_JMP_JSET_K, BNE, BE);
696                         COND_SEL(BPF_S_JMP_JGT_X, BGU, BLEU);
697                         COND_SEL(BPF_S_JMP_JGE_X, BGEU, BLU);
698                         COND_SEL(BPF_S_JMP_JEQ_X, BE, BNE);
699                         COND_SEL(BPF_S_JMP_JSET_X, BNE, BE);
700 
701 cond_branch:                    f_offset = addrs[i + filter[i].jf];
702                                 t_offset = addrs[i + filter[i].jt];
703 
704                                 /* same targets, can avoid doing the test :) */
705                                 if (filter[i].jt == filter[i].jf) {
706                                         emit_jump(t_offset);
707                                         emit_nop();
708                                         break;
709                                 }
710 
711                                 switch (filter[i].code) {
712                                 case BPF_S_JMP_JGT_X:
713                                 case BPF_S_JMP_JGE_X:
714                                 case BPF_S_JMP_JEQ_X:
715                                         seen |= SEEN_XREG;
716                                         emit_cmp(r_A, r_X);
717                                         break;
718                                 case BPF_S_JMP_JSET_X:
719                                         seen |= SEEN_XREG;
720                                         emit_btst(r_A, r_X);
721                                         break;
722                                 case BPF_S_JMP_JEQ_K:
723                                 case BPF_S_JMP_JGT_K:
724                                 case BPF_S_JMP_JGE_K:
725                                         if (is_simm13(K)) {
726                                                 emit_cmpi(r_A, K);
727                                         } else {
728                                                 emit_loadimm(K, r_TMP);
729                                                 emit_cmp(r_A, r_TMP);
730                                         }
731                                         break;
732                                 case BPF_S_JMP_JSET_K:
733                                         if (is_simm13(K)) {
734                                                 emit_btsti(r_A, K);
735                                         } else {
736                                                 emit_loadimm(K, r_TMP);
737                                                 emit_btst(r_A, r_TMP);
738                                         }
739                                         break;
740                                 }
741                                 if (filter[i].jt != 0) {
742                                         if (filter[i].jf)
743                                                 t_offset += 8;
744                                         emit_branch(t_op, t_offset);
745                                         emit_nop(); /* delay slot */
746                                         if (filter[i].jf) {
747                                                 emit_jump(f_offset);
748                                                 emit_nop();
749                                         }
750                                         break;
751                                 }
752                                 emit_branch(f_op, f_offset);
753                                 emit_nop(); /* delay slot */
754                                 break;
755 
756                         default:
757                                 /* hmm, too complex filter, give up with jit compiler */
758                                 goto out;
759                         }
760                         ilen = (void *) prog - (void *) temp;
761                         if (image) {
762                                 if (unlikely(proglen + ilen > oldproglen)) {
763                                         pr_err("bpb_jit_compile fatal error\n");
764                                         kfree(addrs);
765                                         module_free(NULL, image);
766                                         return;
767                                 }
768                                 memcpy(image + proglen, temp, ilen);
769                         }
770                         proglen += ilen;
771                         addrs[i] = proglen;
772                         prog = temp;
773                 }
774                 /* last bpf instruction is always a RET :
775                  * use it to give the cleanup instruction(s) addr
776                  */
777                 cleanup_addr = proglen - 8; /* jmpl; mov r_A,%o0; */
778                 if (seen_or_pass0 & SEEN_MEM)
779                         cleanup_addr -= 4; /* add %sp, X, %sp; */
780 
781                 if (image) {
782                         if (proglen != oldproglen)
783                                 pr_err("bpb_jit_compile proglen=%u != oldproglen=%u\n",
784                                        proglen, oldproglen);
785                         break;
786                 }
787                 if (proglen == oldproglen) {
788                         image = module_alloc(max_t(unsigned int,
789                                                    proglen,
790                                                    sizeof(struct work_struct)));
791                         if (!image)
792                                 goto out;
793                 }
794                 oldproglen = proglen;
795         }
796 
797         if (bpf_jit_enable > 1)
798                 pr_err("flen=%d proglen=%u pass=%d image=%p\n",
799                        flen, proglen, pass, image);
800 
801         if (image) {
802                 if (bpf_jit_enable > 1)
803                         print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_ADDRESS,
804                                        16, 1, image, proglen, false);
805                 bpf_flush_icache(image, image + proglen);
806                 fp->bpf_func = (void *)image;
807         }
808 out:
809         kfree(addrs);
810         return;
811 }
812 
813 static void jit_free_defer(struct work_struct *arg)
814 {
815         module_free(NULL, arg);
816 }
817 
818 /* run from softirq, we must use a work_struct to call
819  * module_free() from process context
820  */
821 void bpf_jit_free(struct sk_filter *fp)
822 {
823         if (fp->bpf_func != sk_run_filter) {
824                 struct work_struct *work = (struct work_struct *)fp->bpf_func;
825 
826                 INIT_WORK(work, jit_free_defer);
827                 schedule_work(work);
828         }
829 }
830 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp