1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright 2008 Michael Ellerman, IBM Corporation.
4 */
5
6 #include <linux/kernel.h>
7 #include <linux/kprobes.h>
8 #include <linux/vmalloc.h>
9 #include <linux/init.h>
10 #include <linux/mm.h>
11 #include <linux/cpuhotplug.h>
12 #include <linux/slab.h>
13 #include <linux/uaccess.h>
14
15 #include <asm/tlbflush.h>
16 #include <asm/page.h>
17 #include <asm/code-patching.h>
18 #include <asm/setup.h>
19 #include <asm/inst.h>
20
__patch_instruction(u32 * exec_addr,struct ppc_inst instr,u32 * patch_addr)21 static int __patch_instruction(u32 *exec_addr, struct ppc_inst instr, u32 *patch_addr)
22 {
23 if (!ppc_inst_prefixed(instr)) {
24 u32 val = ppc_inst_val(instr);
25
26 __put_kernel_nofault(patch_addr, &val, u32, failed);
27 } else {
28 u64 val = ppc_inst_as_ulong(instr);
29
30 __put_kernel_nofault(patch_addr, &val, u64, failed);
31 }
32
33 asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r" (patch_addr),
34 "r" (exec_addr));
35
36 return 0;
37
38 failed:
39 return -EFAULT;
40 }
41
raw_patch_instruction(u32 * addr,struct ppc_inst instr)42 int raw_patch_instruction(u32 *addr, struct ppc_inst instr)
43 {
44 return __patch_instruction(addr, instr, addr);
45 }
46
47 #ifdef CONFIG_STRICT_KERNEL_RWX
48 static DEFINE_PER_CPU(struct vm_struct *, text_poke_area);
49
text_area_cpu_up(unsigned int cpu)50 static int text_area_cpu_up(unsigned int cpu)
51 {
52 struct vm_struct *area;
53
54 area = get_vm_area(PAGE_SIZE, VM_ALLOC);
55 if (!area) {
56 WARN_ONCE(1, "Failed to create text area for cpu %d\n",
57 cpu);
58 return -1;
59 }
60 this_cpu_write(text_poke_area, area);
61
62 return 0;
63 }
64
text_area_cpu_down(unsigned int cpu)65 static int text_area_cpu_down(unsigned int cpu)
66 {
67 free_vm_area(this_cpu_read(text_poke_area));
68 return 0;
69 }
70
71 /*
72 * Although BUG_ON() is rude, in this case it should only happen if ENOMEM, and
73 * we judge it as being preferable to a kernel that will crash later when
74 * someone tries to use patch_instruction().
75 */
poking_init(void)76 void __init poking_init(void)
77 {
78 BUG_ON(!cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
79 "powerpc/text_poke:online", text_area_cpu_up,
80 text_area_cpu_down));
81 }
82
83 /*
84 * This can be called for kernel text or a module.
85 */
map_patch_area(void * addr,unsigned long text_poke_addr)86 static int map_patch_area(void *addr, unsigned long text_poke_addr)
87 {
88 unsigned long pfn;
89 int err;
90
91 if (is_vmalloc_or_module_addr(addr))
92 pfn = vmalloc_to_pfn(addr);
93 else
94 pfn = __pa_symbol(addr) >> PAGE_SHIFT;
95
96 err = map_kernel_page(text_poke_addr, (pfn << PAGE_SHIFT), PAGE_KERNEL);
97
98 pr_devel("Mapped addr %lx with pfn %lx:%d\n", text_poke_addr, pfn, err);
99 if (err)
100 return -1;
101
102 return 0;
103 }
104
unmap_patch_area(unsigned long addr)105 static inline int unmap_patch_area(unsigned long addr)
106 {
107 pte_t *ptep;
108 pmd_t *pmdp;
109 pud_t *pudp;
110 p4d_t *p4dp;
111 pgd_t *pgdp;
112
113 pgdp = pgd_offset_k(addr);
114 if (unlikely(!pgdp))
115 return -EINVAL;
116
117 p4dp = p4d_offset(pgdp, addr);
118 if (unlikely(!p4dp))
119 return -EINVAL;
120
121 pudp = pud_offset(p4dp, addr);
122 if (unlikely(!pudp))
123 return -EINVAL;
124
125 pmdp = pmd_offset(pudp, addr);
126 if (unlikely(!pmdp))
127 return -EINVAL;
128
129 ptep = pte_offset_kernel(pmdp, addr);
130 if (unlikely(!ptep))
131 return -EINVAL;
132
133 pr_devel("clearing mm %p, pte %p, addr %lx\n", &init_mm, ptep, addr);
134
135 /*
136 * In hash, pte_clear flushes the tlb, in radix, we have to
137 */
138 pte_clear(&init_mm, addr, ptep);
139 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
140
141 return 0;
142 }
143
do_patch_instruction(u32 * addr,struct ppc_inst instr)144 static int do_patch_instruction(u32 *addr, struct ppc_inst instr)
145 {
146 int err;
147 u32 *patch_addr = NULL;
148 unsigned long flags;
149 unsigned long text_poke_addr;
150 unsigned long kaddr = (unsigned long)addr;
151
152 /*
153 * During early early boot patch_instruction is called
154 * when text_poke_area is not ready, but we still need
155 * to allow patching. We just do the plain old patching
156 */
157 if (!this_cpu_read(text_poke_area))
158 return raw_patch_instruction(addr, instr);
159
160 local_irq_save(flags);
161
162 text_poke_addr = (unsigned long)__this_cpu_read(text_poke_area)->addr;
163 if (map_patch_area(addr, text_poke_addr)) {
164 err = -1;
165 goto out;
166 }
167
168 patch_addr = (u32 *)(text_poke_addr + (kaddr & ~PAGE_MASK));
169
170 __patch_instruction(addr, instr, patch_addr);
171
172 err = unmap_patch_area(text_poke_addr);
173 if (err)
174 pr_warn("failed to unmap %lx\n", text_poke_addr);
175
176 out:
177 local_irq_restore(flags);
178
179 return err;
180 }
181 #else /* !CONFIG_STRICT_KERNEL_RWX */
182
do_patch_instruction(u32 * addr,struct ppc_inst instr)183 static int do_patch_instruction(u32 *addr, struct ppc_inst instr)
184 {
185 return raw_patch_instruction(addr, instr);
186 }
187
188 #endif /* CONFIG_STRICT_KERNEL_RWX */
189
patch_instruction(u32 * addr,struct ppc_inst instr)190 int patch_instruction(u32 *addr, struct ppc_inst instr)
191 {
192 /* Make sure we aren't patching a freed init section */
193 if (init_mem_is_free && init_section_contains(addr, 4)) {
194 pr_debug("Skipping init section patching addr: 0x%px\n", addr);
195 return 0;
196 }
197 return do_patch_instruction(addr, instr);
198 }
199 NOKPROBE_SYMBOL(patch_instruction);
200
patch_branch(u32 * addr,unsigned long target,int flags)201 int patch_branch(u32 *addr, unsigned long target, int flags)
202 {
203 struct ppc_inst instr;
204
205 create_branch(&instr, addr, target, flags);
206 return patch_instruction(addr, instr);
207 }
208
is_offset_in_branch_range(long offset)209 bool is_offset_in_branch_range(long offset)
210 {
211 /*
212 * Powerpc branch instruction is :
213 *
214 * 0 6 30 31
215 * +---------+----------------+---+---+
216 * | opcode | LI |AA |LK |
217 * +---------+----------------+---+---+
218 * Where AA = 0 and LK = 0
219 *
220 * LI is a signed 24 bits integer. The real branch offset is computed
221 * by: imm32 = SignExtend(LI:'0b00', 32);
222 *
223 * So the maximum forward branch should be:
224 * (0x007fffff << 2) = 0x01fffffc = 0x1fffffc
225 * The maximum backward branch should be:
226 * (0xff800000 << 2) = 0xfe000000 = -0x2000000
227 */
228 return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3));
229 }
230
is_offset_in_cond_branch_range(long offset)231 bool is_offset_in_cond_branch_range(long offset)
232 {
233 return offset >= -0x8000 && offset <= 0x7fff && !(offset & 0x3);
234 }
235
236 /*
237 * Helper to check if a given instruction is a conditional branch
238 * Derived from the conditional checks in analyse_instr()
239 */
is_conditional_branch(struct ppc_inst instr)240 bool is_conditional_branch(struct ppc_inst instr)
241 {
242 unsigned int opcode = ppc_inst_primary_opcode(instr);
243
244 if (opcode == 16) /* bc, bca, bcl, bcla */
245 return true;
246 if (opcode == 19) {
247 switch ((ppc_inst_val(instr) >> 1) & 0x3ff) {
248 case 16: /* bclr, bclrl */
249 case 528: /* bcctr, bcctrl */
250 case 560: /* bctar, bctarl */
251 return true;
252 }
253 }
254 return false;
255 }
256 NOKPROBE_SYMBOL(is_conditional_branch);
257
create_branch(struct ppc_inst * instr,const u32 * addr,unsigned long target,int flags)258 int create_branch(struct ppc_inst *instr, const u32 *addr,
259 unsigned long target, int flags)
260 {
261 long offset;
262
263 *instr = ppc_inst(0);
264 offset = target;
265 if (! (flags & BRANCH_ABSOLUTE))
266 offset = offset - (unsigned long)addr;
267
268 /* Check we can represent the target in the instruction format */
269 if (!is_offset_in_branch_range(offset))
270 return 1;
271
272 /* Mask out the flags and target, so they don't step on each other. */
273 *instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC));
274
275 return 0;
276 }
277
create_cond_branch(struct ppc_inst * instr,const u32 * addr,unsigned long target,int flags)278 int create_cond_branch(struct ppc_inst *instr, const u32 *addr,
279 unsigned long target, int flags)
280 {
281 long offset;
282
283 offset = target;
284 if (! (flags & BRANCH_ABSOLUTE))
285 offset = offset - (unsigned long)addr;
286
287 /* Check we can represent the target in the instruction format */
288 if (!is_offset_in_cond_branch_range(offset))
289 return 1;
290
291 /* Mask out the flags and target, so they don't step on each other. */
292 *instr = ppc_inst(0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC));
293
294 return 0;
295 }
296
branch_opcode(struct ppc_inst instr)297 static unsigned int branch_opcode(struct ppc_inst instr)
298 {
299 return ppc_inst_primary_opcode(instr) & 0x3F;
300 }
301
instr_is_branch_iform(struct ppc_inst instr)302 static int instr_is_branch_iform(struct ppc_inst instr)
303 {
304 return branch_opcode(instr) == 18;
305 }
306
instr_is_branch_bform(struct ppc_inst instr)307 static int instr_is_branch_bform(struct ppc_inst instr)
308 {
309 return branch_opcode(instr) == 16;
310 }
311
instr_is_relative_branch(struct ppc_inst instr)312 int instr_is_relative_branch(struct ppc_inst instr)
313 {
314 if (ppc_inst_val(instr) & BRANCH_ABSOLUTE)
315 return 0;
316
317 return instr_is_branch_iform(instr) || instr_is_branch_bform(instr);
318 }
319
instr_is_relative_link_branch(struct ppc_inst instr)320 int instr_is_relative_link_branch(struct ppc_inst instr)
321 {
322 return instr_is_relative_branch(instr) && (ppc_inst_val(instr) & BRANCH_SET_LINK);
323 }
324
branch_iform_target(const u32 * instr)325 static unsigned long branch_iform_target(const u32 *instr)
326 {
327 signed long imm;
328
329 imm = ppc_inst_val(ppc_inst_read(instr)) & 0x3FFFFFC;
330
331 /* If the top bit of the immediate value is set this is negative */
332 if (imm & 0x2000000)
333 imm -= 0x4000000;
334
335 if ((ppc_inst_val(ppc_inst_read(instr)) & BRANCH_ABSOLUTE) == 0)
336 imm += (unsigned long)instr;
337
338 return (unsigned long)imm;
339 }
340
branch_bform_target(const u32 * instr)341 static unsigned long branch_bform_target(const u32 *instr)
342 {
343 signed long imm;
344
345 imm = ppc_inst_val(ppc_inst_read(instr)) & 0xFFFC;
346
347 /* If the top bit of the immediate value is set this is negative */
348 if (imm & 0x8000)
349 imm -= 0x10000;
350
351 if ((ppc_inst_val(ppc_inst_read(instr)) & BRANCH_ABSOLUTE) == 0)
352 imm += (unsigned long)instr;
353
354 return (unsigned long)imm;
355 }
356
branch_target(const u32 * instr)357 unsigned long branch_target(const u32 *instr)
358 {
359 if (instr_is_branch_iform(ppc_inst_read(instr)))
360 return branch_iform_target(instr);
361 else if (instr_is_branch_bform(ppc_inst_read(instr)))
362 return branch_bform_target(instr);
363
364 return 0;
365 }
366
translate_branch(struct ppc_inst * instr,const u32 * dest,const u32 * src)367 int translate_branch(struct ppc_inst *instr, const u32 *dest, const u32 *src)
368 {
369 unsigned long target;
370 target = branch_target(src);
371
372 if (instr_is_branch_iform(ppc_inst_read(src)))
373 return create_branch(instr, dest, target,
374 ppc_inst_val(ppc_inst_read(src)));
375 else if (instr_is_branch_bform(ppc_inst_read(src)))
376 return create_cond_branch(instr, dest, target,
377 ppc_inst_val(ppc_inst_read(src)));
378
379 return 1;
380 }
381
382 #ifdef CONFIG_PPC_BOOK3E_64
__patch_exception(int exc,unsigned long addr)383 void __patch_exception(int exc, unsigned long addr)
384 {
385 extern unsigned int interrupt_base_book3e;
386 unsigned int *ibase = &interrupt_base_book3e;
387
388 /* Our exceptions vectors start with a NOP and -then- a branch
389 * to deal with single stepping from userspace which stops on
390 * the second instruction. Thus we need to patch the second
391 * instruction of the exception, not the first one
392 */
393
394 patch_branch(ibase + (exc / 4) + 1, addr, 0);
395 }
396 #endif
397
398 #ifdef CONFIG_CODE_PATCHING_SELFTEST
399
instr_is_branch_to_addr(const u32 * instr,unsigned long addr)400 static int instr_is_branch_to_addr(const u32 *instr, unsigned long addr)
401 {
402 if (instr_is_branch_iform(ppc_inst_read(instr)) ||
403 instr_is_branch_bform(ppc_inst_read(instr)))
404 return branch_target(instr) == addr;
405
406 return 0;
407 }
408
test_trampoline(void)409 static void __init test_trampoline(void)
410 {
411 asm ("nop;\n");
412 }
413
414 #define check(x) \
415 if (!(x)) printk("code-patching: test failed at line %d\n", __LINE__);
416
test_branch_iform(void)417 static void __init test_branch_iform(void)
418 {
419 int err;
420 struct ppc_inst instr;
421 u32 tmp[2];
422 u32 *iptr = tmp;
423 unsigned long addr = (unsigned long)tmp;
424
425 /* The simplest case, branch to self, no flags */
426 check(instr_is_branch_iform(ppc_inst(0x48000000)));
427 /* All bits of target set, and flags */
428 check(instr_is_branch_iform(ppc_inst(0x4bffffff)));
429 /* High bit of opcode set, which is wrong */
430 check(!instr_is_branch_iform(ppc_inst(0xcbffffff)));
431 /* Middle bits of opcode set, which is wrong */
432 check(!instr_is_branch_iform(ppc_inst(0x7bffffff)));
433
434 /* Simplest case, branch to self with link */
435 check(instr_is_branch_iform(ppc_inst(0x48000001)));
436 /* All bits of targets set */
437 check(instr_is_branch_iform(ppc_inst(0x4bfffffd)));
438 /* Some bits of targets set */
439 check(instr_is_branch_iform(ppc_inst(0x4bff00fd)));
440 /* Must be a valid branch to start with */
441 check(!instr_is_branch_iform(ppc_inst(0x7bfffffd)));
442
443 /* Absolute branch to 0x100 */
444 patch_instruction(iptr, ppc_inst(0x48000103));
445 check(instr_is_branch_to_addr(iptr, 0x100));
446 /* Absolute branch to 0x420fc */
447 patch_instruction(iptr, ppc_inst(0x480420ff));
448 check(instr_is_branch_to_addr(iptr, 0x420fc));
449 /* Maximum positive relative branch, + 20MB - 4B */
450 patch_instruction(iptr, ppc_inst(0x49fffffc));
451 check(instr_is_branch_to_addr(iptr, addr + 0x1FFFFFC));
452 /* Smallest negative relative branch, - 4B */
453 patch_instruction(iptr, ppc_inst(0x4bfffffc));
454 check(instr_is_branch_to_addr(iptr, addr - 4));
455 /* Largest negative relative branch, - 32 MB */
456 patch_instruction(iptr, ppc_inst(0x4a000000));
457 check(instr_is_branch_to_addr(iptr, addr - 0x2000000));
458
459 /* Branch to self, with link */
460 err = create_branch(&instr, iptr, addr, BRANCH_SET_LINK);
461 patch_instruction(iptr, instr);
462 check(instr_is_branch_to_addr(iptr, addr));
463
464 /* Branch to self - 0x100, with link */
465 err = create_branch(&instr, iptr, addr - 0x100, BRANCH_SET_LINK);
466 patch_instruction(iptr, instr);
467 check(instr_is_branch_to_addr(iptr, addr - 0x100));
468
469 /* Branch to self + 0x100, no link */
470 err = create_branch(&instr, iptr, addr + 0x100, 0);
471 patch_instruction(iptr, instr);
472 check(instr_is_branch_to_addr(iptr, addr + 0x100));
473
474 /* Maximum relative negative offset, - 32 MB */
475 err = create_branch(&instr, iptr, addr - 0x2000000, BRANCH_SET_LINK);
476 patch_instruction(iptr, instr);
477 check(instr_is_branch_to_addr(iptr, addr - 0x2000000));
478
479 /* Out of range relative negative offset, - 32 MB + 4*/
480 err = create_branch(&instr, iptr, addr - 0x2000004, BRANCH_SET_LINK);
481 check(err);
482
483 /* Out of range relative positive offset, + 32 MB */
484 err = create_branch(&instr, iptr, addr + 0x2000000, BRANCH_SET_LINK);
485 check(err);
486
487 /* Unaligned target */
488 err = create_branch(&instr, iptr, addr + 3, BRANCH_SET_LINK);
489 check(err);
490
491 /* Check flags are masked correctly */
492 err = create_branch(&instr, iptr, addr, 0xFFFFFFFC);
493 patch_instruction(iptr, instr);
494 check(instr_is_branch_to_addr(iptr, addr));
495 check(ppc_inst_equal(instr, ppc_inst(0x48000000)));
496 }
497
test_create_function_call(void)498 static void __init test_create_function_call(void)
499 {
500 u32 *iptr;
501 unsigned long dest;
502 struct ppc_inst instr;
503
504 /* Check we can create a function call */
505 iptr = (u32 *)ppc_function_entry(test_trampoline);
506 dest = ppc_function_entry(test_create_function_call);
507 create_branch(&instr, iptr, dest, BRANCH_SET_LINK);
508 patch_instruction(iptr, instr);
509 check(instr_is_branch_to_addr(iptr, dest));
510 }
511
test_branch_bform(void)512 static void __init test_branch_bform(void)
513 {
514 int err;
515 unsigned long addr;
516 struct ppc_inst instr;
517 u32 tmp[2];
518 u32 *iptr = tmp;
519 unsigned int flags;
520
521 addr = (unsigned long)iptr;
522
523 /* The simplest case, branch to self, no flags */
524 check(instr_is_branch_bform(ppc_inst(0x40000000)));
525 /* All bits of target set, and flags */
526 check(instr_is_branch_bform(ppc_inst(0x43ffffff)));
527 /* High bit of opcode set, which is wrong */
528 check(!instr_is_branch_bform(ppc_inst(0xc3ffffff)));
529 /* Middle bits of opcode set, which is wrong */
530 check(!instr_is_branch_bform(ppc_inst(0x7bffffff)));
531
532 /* Absolute conditional branch to 0x100 */
533 patch_instruction(iptr, ppc_inst(0x43ff0103));
534 check(instr_is_branch_to_addr(iptr, 0x100));
535 /* Absolute conditional branch to 0x20fc */
536 patch_instruction(iptr, ppc_inst(0x43ff20ff));
537 check(instr_is_branch_to_addr(iptr, 0x20fc));
538 /* Maximum positive relative conditional branch, + 32 KB - 4B */
539 patch_instruction(iptr, ppc_inst(0x43ff7ffc));
540 check(instr_is_branch_to_addr(iptr, addr + 0x7FFC));
541 /* Smallest negative relative conditional branch, - 4B */
542 patch_instruction(iptr, ppc_inst(0x43fffffc));
543 check(instr_is_branch_to_addr(iptr, addr - 4));
544 /* Largest negative relative conditional branch, - 32 KB */
545 patch_instruction(iptr, ppc_inst(0x43ff8000));
546 check(instr_is_branch_to_addr(iptr, addr - 0x8000));
547
548 /* All condition code bits set & link */
549 flags = 0x3ff000 | BRANCH_SET_LINK;
550
551 /* Branch to self */
552 err = create_cond_branch(&instr, iptr, addr, flags);
553 patch_instruction(iptr, instr);
554 check(instr_is_branch_to_addr(iptr, addr));
555
556 /* Branch to self - 0x100 */
557 err = create_cond_branch(&instr, iptr, addr - 0x100, flags);
558 patch_instruction(iptr, instr);
559 check(instr_is_branch_to_addr(iptr, addr - 0x100));
560
561 /* Branch to self + 0x100 */
562 err = create_cond_branch(&instr, iptr, addr + 0x100, flags);
563 patch_instruction(iptr, instr);
564 check(instr_is_branch_to_addr(iptr, addr + 0x100));
565
566 /* Maximum relative negative offset, - 32 KB */
567 err = create_cond_branch(&instr, iptr, addr - 0x8000, flags);
568 patch_instruction(iptr, instr);
569 check(instr_is_branch_to_addr(iptr, addr - 0x8000));
570
571 /* Out of range relative negative offset, - 32 KB + 4*/
572 err = create_cond_branch(&instr, iptr, addr - 0x8004, flags);
573 check(err);
574
575 /* Out of range relative positive offset, + 32 KB */
576 err = create_cond_branch(&instr, iptr, addr + 0x8000, flags);
577 check(err);
578
579 /* Unaligned target */
580 err = create_cond_branch(&instr, iptr, addr + 3, flags);
581 check(err);
582
583 /* Check flags are masked correctly */
584 err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC);
585 patch_instruction(iptr, instr);
586 check(instr_is_branch_to_addr(iptr, addr));
587 check(ppc_inst_equal(instr, ppc_inst(0x43FF0000)));
588 }
589
test_translate_branch(void)590 static void __init test_translate_branch(void)
591 {
592 unsigned long addr;
593 void *p, *q;
594 struct ppc_inst instr;
595 void *buf;
596
597 buf = vmalloc(PAGE_ALIGN(0x2000000 + 1));
598 check(buf);
599 if (!buf)
600 return;
601
602 /* Simple case, branch to self moved a little */
603 p = buf;
604 addr = (unsigned long)p;
605 patch_branch(p, addr, 0);
606 check(instr_is_branch_to_addr(p, addr));
607 q = p + 4;
608 translate_branch(&instr, q, p);
609 patch_instruction(q, instr);
610 check(instr_is_branch_to_addr(q, addr));
611
612 /* Maximum negative case, move b . to addr + 32 MB */
613 p = buf;
614 addr = (unsigned long)p;
615 patch_branch(p, addr, 0);
616 q = buf + 0x2000000;
617 translate_branch(&instr, q, p);
618 patch_instruction(q, instr);
619 check(instr_is_branch_to_addr(p, addr));
620 check(instr_is_branch_to_addr(q, addr));
621 check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x4a000000)));
622
623 /* Maximum positive case, move x to x - 32 MB + 4 */
624 p = buf + 0x2000000;
625 addr = (unsigned long)p;
626 patch_branch(p, addr, 0);
627 q = buf + 4;
628 translate_branch(&instr, q, p);
629 patch_instruction(q, instr);
630 check(instr_is_branch_to_addr(p, addr));
631 check(instr_is_branch_to_addr(q, addr));
632 check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x49fffffc)));
633
634 /* Jump to x + 16 MB moved to x + 20 MB */
635 p = buf;
636 addr = 0x1000000 + (unsigned long)buf;
637 patch_branch(p, addr, BRANCH_SET_LINK);
638 q = buf + 0x1400000;
639 translate_branch(&instr, q, p);
640 patch_instruction(q, instr);
641 check(instr_is_branch_to_addr(p, addr));
642 check(instr_is_branch_to_addr(q, addr));
643
644 /* Jump to x + 16 MB moved to x - 16 MB + 4 */
645 p = buf + 0x1000000;
646 addr = 0x2000000 + (unsigned long)buf;
647 patch_branch(p, addr, 0);
648 q = buf + 4;
649 translate_branch(&instr, q, p);
650 patch_instruction(q, instr);
651 check(instr_is_branch_to_addr(p, addr));
652 check(instr_is_branch_to_addr(q, addr));
653
654
655 /* Conditional branch tests */
656
657 /* Simple case, branch to self moved a little */
658 p = buf;
659 addr = (unsigned long)p;
660 create_cond_branch(&instr, p, addr, 0);
661 patch_instruction(p, instr);
662 check(instr_is_branch_to_addr(p, addr));
663 q = buf + 4;
664 translate_branch(&instr, q, p);
665 patch_instruction(q, instr);
666 check(instr_is_branch_to_addr(q, addr));
667
668 /* Maximum negative case, move b . to addr + 32 KB */
669 p = buf;
670 addr = (unsigned long)p;
671 create_cond_branch(&instr, p, addr, 0xFFFFFFFC);
672 patch_instruction(p, instr);
673 q = buf + 0x8000;
674 translate_branch(&instr, q, p);
675 patch_instruction(q, instr);
676 check(instr_is_branch_to_addr(p, addr));
677 check(instr_is_branch_to_addr(q, addr));
678 check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff8000)));
679
680 /* Maximum positive case, move x to x - 32 KB + 4 */
681 p = buf + 0x8000;
682 addr = (unsigned long)p;
683 create_cond_branch(&instr, p, addr, 0xFFFFFFFC);
684 patch_instruction(p, instr);
685 q = buf + 4;
686 translate_branch(&instr, q, p);
687 patch_instruction(q, instr);
688 check(instr_is_branch_to_addr(p, addr));
689 check(instr_is_branch_to_addr(q, addr));
690 check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff7ffc)));
691
692 /* Jump to x + 12 KB moved to x + 20 KB */
693 p = buf;
694 addr = 0x3000 + (unsigned long)buf;
695 create_cond_branch(&instr, p, addr, BRANCH_SET_LINK);
696 patch_instruction(p, instr);
697 q = buf + 0x5000;
698 translate_branch(&instr, q, p);
699 patch_instruction(q, instr);
700 check(instr_is_branch_to_addr(p, addr));
701 check(instr_is_branch_to_addr(q, addr));
702
703 /* Jump to x + 8 KB moved to x - 8 KB + 4 */
704 p = buf + 0x2000;
705 addr = 0x4000 + (unsigned long)buf;
706 create_cond_branch(&instr, p, addr, 0);
707 patch_instruction(p, instr);
708 q = buf + 4;
709 translate_branch(&instr, q, p);
710 patch_instruction(q, instr);
711 check(instr_is_branch_to_addr(p, addr));
712 check(instr_is_branch_to_addr(q, addr));
713
714 /* Free the buffer we were using */
715 vfree(buf);
716 }
717
718 #ifdef CONFIG_PPC64
test_prefixed_patching(void)719 static void __init test_prefixed_patching(void)
720 {
721 extern unsigned int code_patching_test1[];
722 extern unsigned int code_patching_test1_expected[];
723 extern unsigned int end_code_patching_test1[];
724
725 __patch_instruction(code_patching_test1,
726 ppc_inst_prefix(OP_PREFIX << 26, 0x00000000),
727 code_patching_test1);
728
729 check(!memcmp(code_patching_test1,
730 code_patching_test1_expected,
731 sizeof(unsigned int) *
732 (end_code_patching_test1 - code_patching_test1)));
733 }
734 #else
test_prefixed_patching(void)735 static inline void test_prefixed_patching(void) {}
736 #endif
737
test_code_patching(void)738 static int __init test_code_patching(void)
739 {
740 printk(KERN_DEBUG "Running code patching self-tests ...\n");
741
742 test_branch_iform();
743 test_branch_bform();
744 test_create_function_call();
745 test_translate_branch();
746 test_prefixed_patching();
747
748 return 0;
749 }
750 late_initcall(test_code_patching);
751
752 #endif /* CONFIG_CODE_PATCHING_SELFTEST */
753