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(struct ppc_inst * exec_addr,struct ppc_inst instr,struct ppc_inst * patch_addr)21 static int __patch_instruction(struct ppc_inst *exec_addr, struct ppc_inst instr,
22 struct ppc_inst *patch_addr)
23 {
24 if (!ppc_inst_prefixed(instr))
25 __put_user_asm_goto(ppc_inst_val(instr), patch_addr, failed, "stw");
26 else
27 __put_user_asm_goto(ppc_inst_as_u64(instr), patch_addr, failed, "std");
28
29 asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r" (patch_addr),
30 "r" (exec_addr));
31
32 return 0;
33
34 failed:
35 return -EFAULT;
36 }
37
raw_patch_instruction(struct ppc_inst * addr,struct ppc_inst instr)38 int raw_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr)
39 {
40 return __patch_instruction(addr, instr, addr);
41 }
42
43 #ifdef CONFIG_STRICT_KERNEL_RWX
44 static DEFINE_PER_CPU(struct vm_struct *, text_poke_area);
45
text_area_cpu_up(unsigned int cpu)46 static int text_area_cpu_up(unsigned int cpu)
47 {
48 struct vm_struct *area;
49
50 area = get_vm_area(PAGE_SIZE, VM_ALLOC);
51 if (!area) {
52 WARN_ONCE(1, "Failed to create text area for cpu %d\n",
53 cpu);
54 return -1;
55 }
56 this_cpu_write(text_poke_area, area);
57
58 return 0;
59 }
60
text_area_cpu_down(unsigned int cpu)61 static int text_area_cpu_down(unsigned int cpu)
62 {
63 free_vm_area(this_cpu_read(text_poke_area));
64 return 0;
65 }
66
67 /*
68 * Run as a late init call. This allows all the boot time patching to be done
69 * simply by patching the code, and then we're called here prior to
70 * mark_rodata_ro(), which happens after all init calls are run. Although
71 * BUG_ON() is rude, in this case it should only happen if ENOMEM, and we judge
72 * it as being preferable to a kernel that will crash later when someone tries
73 * to use patch_instruction().
74 */
setup_text_poke_area(void)75 static int __init setup_text_poke_area(void)
76 {
77 BUG_ON(!cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
78 "powerpc/text_poke:online", text_area_cpu_up,
79 text_area_cpu_down));
80
81 return 0;
82 }
83 late_initcall(setup_text_poke_area);
84
85 /*
86 * This can be called for kernel text or a module.
87 */
map_patch_area(void * addr,unsigned long text_poke_addr)88 static int map_patch_area(void *addr, unsigned long text_poke_addr)
89 {
90 unsigned long pfn;
91 int err;
92
93 if (is_vmalloc_or_module_addr(addr))
94 pfn = vmalloc_to_pfn(addr);
95 else
96 pfn = __pa_symbol(addr) >> PAGE_SHIFT;
97
98 err = map_kernel_page(text_poke_addr, (pfn << PAGE_SHIFT), PAGE_KERNEL);
99
100 pr_devel("Mapped addr %lx with pfn %lx:%d\n", text_poke_addr, pfn, err);
101 if (err)
102 return -1;
103
104 return 0;
105 }
106
unmap_patch_area(unsigned long addr)107 static inline int unmap_patch_area(unsigned long addr)
108 {
109 pte_t *ptep;
110 pmd_t *pmdp;
111 pud_t *pudp;
112 p4d_t *p4dp;
113 pgd_t *pgdp;
114
115 pgdp = pgd_offset_k(addr);
116 if (unlikely(!pgdp))
117 return -EINVAL;
118
119 p4dp = p4d_offset(pgdp, addr);
120 if (unlikely(!p4dp))
121 return -EINVAL;
122
123 pudp = pud_offset(p4dp, addr);
124 if (unlikely(!pudp))
125 return -EINVAL;
126
127 pmdp = pmd_offset(pudp, addr);
128 if (unlikely(!pmdp))
129 return -EINVAL;
130
131 ptep = pte_offset_kernel(pmdp, addr);
132 if (unlikely(!ptep))
133 return -EINVAL;
134
135 pr_devel("clearing mm %p, pte %p, addr %lx\n", &init_mm, ptep, addr);
136
137 /*
138 * In hash, pte_clear flushes the tlb, in radix, we have to
139 */
140 pte_clear(&init_mm, addr, ptep);
141 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
142
143 return 0;
144 }
145
do_patch_instruction(struct ppc_inst * addr,struct ppc_inst instr)146 static int do_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr)
147 {
148 int err;
149 struct ppc_inst *patch_addr = NULL;
150 unsigned long flags;
151 unsigned long text_poke_addr;
152 unsigned long kaddr = (unsigned long)addr;
153
154 /*
155 * During early early boot patch_instruction is called
156 * when text_poke_area is not ready, but we still need
157 * to allow patching. We just do the plain old patching
158 */
159 if (!this_cpu_read(text_poke_area))
160 return raw_patch_instruction(addr, instr);
161
162 local_irq_save(flags);
163
164 text_poke_addr = (unsigned long)__this_cpu_read(text_poke_area)->addr;
165 if (map_patch_area(addr, text_poke_addr)) {
166 err = -1;
167 goto out;
168 }
169
170 patch_addr = (struct ppc_inst *)(text_poke_addr + (kaddr & ~PAGE_MASK));
171
172 __patch_instruction(addr, instr, patch_addr);
173
174 err = unmap_patch_area(text_poke_addr);
175 if (err)
176 pr_warn("failed to unmap %lx\n", text_poke_addr);
177
178 out:
179 local_irq_restore(flags);
180
181 return err;
182 }
183 #else /* !CONFIG_STRICT_KERNEL_RWX */
184
do_patch_instruction(struct ppc_inst * addr,struct ppc_inst instr)185 static int do_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr)
186 {
187 return raw_patch_instruction(addr, instr);
188 }
189
190 #endif /* CONFIG_STRICT_KERNEL_RWX */
191
patch_instruction(struct ppc_inst * addr,struct ppc_inst instr)192 int patch_instruction(struct ppc_inst *addr, struct ppc_inst instr)
193 {
194 /* Make sure we aren't patching a freed init section */
195 if (init_mem_is_free && init_section_contains(addr, 4)) {
196 pr_debug("Skipping init section patching addr: 0x%px\n", addr);
197 return 0;
198 }
199 return do_patch_instruction(addr, instr);
200 }
201 NOKPROBE_SYMBOL(patch_instruction);
202
patch_branch(struct ppc_inst * addr,unsigned long target,int flags)203 int patch_branch(struct ppc_inst *addr, unsigned long target, int flags)
204 {
205 struct ppc_inst instr;
206
207 create_branch(&instr, addr, target, flags);
208 return patch_instruction(addr, instr);
209 }
210
is_offset_in_branch_range(long offset)211 bool is_offset_in_branch_range(long offset)
212 {
213 /*
214 * Powerpc branch instruction is :
215 *
216 * 0 6 30 31
217 * +---------+----------------+---+---+
218 * | opcode | LI |AA |LK |
219 * +---------+----------------+---+---+
220 * Where AA = 0 and LK = 0
221 *
222 * LI is a signed 24 bits integer. The real branch offset is computed
223 * by: imm32 = SignExtend(LI:'0b00', 32);
224 *
225 * So the maximum forward branch should be:
226 * (0x007fffff << 2) = 0x01fffffc = 0x1fffffc
227 * The maximum backward branch should be:
228 * (0xff800000 << 2) = 0xfe000000 = -0x2000000
229 */
230 return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3));
231 }
232
233 /*
234 * Helper to check if a given instruction is a conditional branch
235 * Derived from the conditional checks in analyse_instr()
236 */
is_conditional_branch(struct ppc_inst instr)237 bool is_conditional_branch(struct ppc_inst instr)
238 {
239 unsigned int opcode = ppc_inst_primary_opcode(instr);
240
241 if (opcode == 16) /* bc, bca, bcl, bcla */
242 return true;
243 if (opcode == 19) {
244 switch ((ppc_inst_val(instr) >> 1) & 0x3ff) {
245 case 16: /* bclr, bclrl */
246 case 528: /* bcctr, bcctrl */
247 case 560: /* bctar, bctarl */
248 return true;
249 }
250 }
251 return false;
252 }
253 NOKPROBE_SYMBOL(is_conditional_branch);
254
create_branch(struct ppc_inst * instr,const struct ppc_inst * addr,unsigned long target,int flags)255 int create_branch(struct ppc_inst *instr,
256 const struct ppc_inst *addr,
257 unsigned long target, int flags)
258 {
259 long offset;
260
261 *instr = ppc_inst(0);
262 offset = target;
263 if (! (flags & BRANCH_ABSOLUTE))
264 offset = offset - (unsigned long)addr;
265
266 /* Check we can represent the target in the instruction format */
267 if (!is_offset_in_branch_range(offset))
268 return 1;
269
270 /* Mask out the flags and target, so they don't step on each other. */
271 *instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC));
272
273 return 0;
274 }
275
create_cond_branch(struct ppc_inst * instr,const struct ppc_inst * addr,unsigned long target,int flags)276 int create_cond_branch(struct ppc_inst *instr, const struct ppc_inst *addr,
277 unsigned long target, int flags)
278 {
279 long offset;
280
281 offset = target;
282 if (! (flags & BRANCH_ABSOLUTE))
283 offset = offset - (unsigned long)addr;
284
285 /* Check we can represent the target in the instruction format */
286 if (offset < -0x8000 || offset > 0x7FFF || offset & 0x3)
287 return 1;
288
289 /* Mask out the flags and target, so they don't step on each other. */
290 *instr = ppc_inst(0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC));
291
292 return 0;
293 }
294
branch_opcode(struct ppc_inst instr)295 static unsigned int branch_opcode(struct ppc_inst instr)
296 {
297 return ppc_inst_primary_opcode(instr) & 0x3F;
298 }
299
instr_is_branch_iform(struct ppc_inst instr)300 static int instr_is_branch_iform(struct ppc_inst instr)
301 {
302 return branch_opcode(instr) == 18;
303 }
304
instr_is_branch_bform(struct ppc_inst instr)305 static int instr_is_branch_bform(struct ppc_inst instr)
306 {
307 return branch_opcode(instr) == 16;
308 }
309
instr_is_relative_branch(struct ppc_inst instr)310 int instr_is_relative_branch(struct ppc_inst instr)
311 {
312 if (ppc_inst_val(instr) & BRANCH_ABSOLUTE)
313 return 0;
314
315 return instr_is_branch_iform(instr) || instr_is_branch_bform(instr);
316 }
317
instr_is_relative_link_branch(struct ppc_inst instr)318 int instr_is_relative_link_branch(struct ppc_inst instr)
319 {
320 return instr_is_relative_branch(instr) && (ppc_inst_val(instr) & BRANCH_SET_LINK);
321 }
322
branch_iform_target(const struct ppc_inst * instr)323 static unsigned long branch_iform_target(const struct ppc_inst *instr)
324 {
325 signed long imm;
326
327 imm = ppc_inst_val(*instr) & 0x3FFFFFC;
328
329 /* If the top bit of the immediate value is set this is negative */
330 if (imm & 0x2000000)
331 imm -= 0x4000000;
332
333 if ((ppc_inst_val(*instr) & BRANCH_ABSOLUTE) == 0)
334 imm += (unsigned long)instr;
335
336 return (unsigned long)imm;
337 }
338
branch_bform_target(const struct ppc_inst * instr)339 static unsigned long branch_bform_target(const struct ppc_inst *instr)
340 {
341 signed long imm;
342
343 imm = ppc_inst_val(*instr) & 0xFFFC;
344
345 /* If the top bit of the immediate value is set this is negative */
346 if (imm & 0x8000)
347 imm -= 0x10000;
348
349 if ((ppc_inst_val(*instr) & BRANCH_ABSOLUTE) == 0)
350 imm += (unsigned long)instr;
351
352 return (unsigned long)imm;
353 }
354
branch_target(const struct ppc_inst * instr)355 unsigned long branch_target(const struct ppc_inst *instr)
356 {
357 if (instr_is_branch_iform(ppc_inst_read(instr)))
358 return branch_iform_target(instr);
359 else if (instr_is_branch_bform(ppc_inst_read(instr)))
360 return branch_bform_target(instr);
361
362 return 0;
363 }
364
instr_is_branch_to_addr(const struct ppc_inst * instr,unsigned long addr)365 int instr_is_branch_to_addr(const struct ppc_inst *instr, unsigned long addr)
366 {
367 if (instr_is_branch_iform(ppc_inst_read(instr)) ||
368 instr_is_branch_bform(ppc_inst_read(instr)))
369 return branch_target(instr) == addr;
370
371 return 0;
372 }
373
translate_branch(struct ppc_inst * instr,const struct ppc_inst * dest,const struct ppc_inst * src)374 int translate_branch(struct ppc_inst *instr, const struct ppc_inst *dest,
375 const struct ppc_inst *src)
376 {
377 unsigned long target;
378 target = branch_target(src);
379
380 if (instr_is_branch_iform(ppc_inst_read(src)))
381 return create_branch(instr, dest, target,
382 ppc_inst_val(ppc_inst_read(src)));
383 else if (instr_is_branch_bform(ppc_inst_read(src)))
384 return create_cond_branch(instr, dest, target,
385 ppc_inst_val(ppc_inst_read(src)));
386
387 return 1;
388 }
389
390 #ifdef CONFIG_PPC_BOOK3E_64
__patch_exception(int exc,unsigned long addr)391 void __patch_exception(int exc, unsigned long addr)
392 {
393 extern unsigned int interrupt_base_book3e;
394 unsigned int *ibase = &interrupt_base_book3e;
395
396 /* Our exceptions vectors start with a NOP and -then- a branch
397 * to deal with single stepping from userspace which stops on
398 * the second instruction. Thus we need to patch the second
399 * instruction of the exception, not the first one
400 */
401
402 patch_branch((struct ppc_inst *)(ibase + (exc / 4) + 1), addr, 0);
403 }
404 #endif
405
406 #ifdef CONFIG_CODE_PATCHING_SELFTEST
407
test_trampoline(void)408 static void __init test_trampoline(void)
409 {
410 asm ("nop;\n");
411 }
412
413 #define check(x) \
414 if (!(x)) printk("code-patching: test failed at line %d\n", __LINE__);
415
test_branch_iform(void)416 static void __init test_branch_iform(void)
417 {
418 int err;
419 struct ppc_inst instr;
420 unsigned long addr;
421
422 addr = (unsigned long)&instr;
423
424 /* The simplest case, branch to self, no flags */
425 check(instr_is_branch_iform(ppc_inst(0x48000000)));
426 /* All bits of target set, and flags */
427 check(instr_is_branch_iform(ppc_inst(0x4bffffff)));
428 /* High bit of opcode set, which is wrong */
429 check(!instr_is_branch_iform(ppc_inst(0xcbffffff)));
430 /* Middle bits of opcode set, which is wrong */
431 check(!instr_is_branch_iform(ppc_inst(0x7bffffff)));
432
433 /* Simplest case, branch to self with link */
434 check(instr_is_branch_iform(ppc_inst(0x48000001)));
435 /* All bits of targets set */
436 check(instr_is_branch_iform(ppc_inst(0x4bfffffd)));
437 /* Some bits of targets set */
438 check(instr_is_branch_iform(ppc_inst(0x4bff00fd)));
439 /* Must be a valid branch to start with */
440 check(!instr_is_branch_iform(ppc_inst(0x7bfffffd)));
441
442 /* Absolute branch to 0x100 */
443 instr = ppc_inst(0x48000103);
444 check(instr_is_branch_to_addr(&instr, 0x100));
445 /* Absolute branch to 0x420fc */
446 instr = ppc_inst(0x480420ff);
447 check(instr_is_branch_to_addr(&instr, 0x420fc));
448 /* Maximum positive relative branch, + 20MB - 4B */
449 instr = ppc_inst(0x49fffffc);
450 check(instr_is_branch_to_addr(&instr, addr + 0x1FFFFFC));
451 /* Smallest negative relative branch, - 4B */
452 instr = ppc_inst(0x4bfffffc);
453 check(instr_is_branch_to_addr(&instr, addr - 4));
454 /* Largest negative relative branch, - 32 MB */
455 instr = ppc_inst(0x4a000000);
456 check(instr_is_branch_to_addr(&instr, addr - 0x2000000));
457
458 /* Branch to self, with link */
459 err = create_branch(&instr, &instr, addr, BRANCH_SET_LINK);
460 check(instr_is_branch_to_addr(&instr, addr));
461
462 /* Branch to self - 0x100, with link */
463 err = create_branch(&instr, &instr, addr - 0x100, BRANCH_SET_LINK);
464 check(instr_is_branch_to_addr(&instr, addr - 0x100));
465
466 /* Branch to self + 0x100, no link */
467 err = create_branch(&instr, &instr, addr + 0x100, 0);
468 check(instr_is_branch_to_addr(&instr, addr + 0x100));
469
470 /* Maximum relative negative offset, - 32 MB */
471 err = create_branch(&instr, &instr, addr - 0x2000000, BRANCH_SET_LINK);
472 check(instr_is_branch_to_addr(&instr, addr - 0x2000000));
473
474 /* Out of range relative negative offset, - 32 MB + 4*/
475 err = create_branch(&instr, &instr, addr - 0x2000004, BRANCH_SET_LINK);
476 check(err);
477
478 /* Out of range relative positive offset, + 32 MB */
479 err = create_branch(&instr, &instr, addr + 0x2000000, BRANCH_SET_LINK);
480 check(err);
481
482 /* Unaligned target */
483 err = create_branch(&instr, &instr, addr + 3, BRANCH_SET_LINK);
484 check(err);
485
486 /* Check flags are masked correctly */
487 err = create_branch(&instr, &instr, addr, 0xFFFFFFFC);
488 check(instr_is_branch_to_addr(&instr, addr));
489 check(ppc_inst_equal(instr, ppc_inst(0x48000000)));
490 }
491
test_create_function_call(void)492 static void __init test_create_function_call(void)
493 {
494 struct ppc_inst *iptr;
495 unsigned long dest;
496 struct ppc_inst instr;
497
498 /* Check we can create a function call */
499 iptr = (struct ppc_inst *)ppc_function_entry(test_trampoline);
500 dest = ppc_function_entry(test_create_function_call);
501 create_branch(&instr, iptr, dest, BRANCH_SET_LINK);
502 patch_instruction(iptr, instr);
503 check(instr_is_branch_to_addr(iptr, dest));
504 }
505
test_branch_bform(void)506 static void __init test_branch_bform(void)
507 {
508 int err;
509 unsigned long addr;
510 struct ppc_inst *iptr, instr;
511 unsigned int flags;
512
513 iptr = &instr;
514 addr = (unsigned long)iptr;
515
516 /* The simplest case, branch to self, no flags */
517 check(instr_is_branch_bform(ppc_inst(0x40000000)));
518 /* All bits of target set, and flags */
519 check(instr_is_branch_bform(ppc_inst(0x43ffffff)));
520 /* High bit of opcode set, which is wrong */
521 check(!instr_is_branch_bform(ppc_inst(0xc3ffffff)));
522 /* Middle bits of opcode set, which is wrong */
523 check(!instr_is_branch_bform(ppc_inst(0x7bffffff)));
524
525 /* Absolute conditional branch to 0x100 */
526 instr = ppc_inst(0x43ff0103);
527 check(instr_is_branch_to_addr(&instr, 0x100));
528 /* Absolute conditional branch to 0x20fc */
529 instr = ppc_inst(0x43ff20ff);
530 check(instr_is_branch_to_addr(&instr, 0x20fc));
531 /* Maximum positive relative conditional branch, + 32 KB - 4B */
532 instr = ppc_inst(0x43ff7ffc);
533 check(instr_is_branch_to_addr(&instr, addr + 0x7FFC));
534 /* Smallest negative relative conditional branch, - 4B */
535 instr = ppc_inst(0x43fffffc);
536 check(instr_is_branch_to_addr(&instr, addr - 4));
537 /* Largest negative relative conditional branch, - 32 KB */
538 instr = ppc_inst(0x43ff8000);
539 check(instr_is_branch_to_addr(&instr, addr - 0x8000));
540
541 /* All condition code bits set & link */
542 flags = 0x3ff000 | BRANCH_SET_LINK;
543
544 /* Branch to self */
545 err = create_cond_branch(&instr, iptr, addr, flags);
546 check(instr_is_branch_to_addr(&instr, addr));
547
548 /* Branch to self - 0x100 */
549 err = create_cond_branch(&instr, iptr, addr - 0x100, flags);
550 check(instr_is_branch_to_addr(&instr, addr - 0x100));
551
552 /* Branch to self + 0x100 */
553 err = create_cond_branch(&instr, iptr, addr + 0x100, flags);
554 check(instr_is_branch_to_addr(&instr, addr + 0x100));
555
556 /* Maximum relative negative offset, - 32 KB */
557 err = create_cond_branch(&instr, iptr, addr - 0x8000, flags);
558 check(instr_is_branch_to_addr(&instr, addr - 0x8000));
559
560 /* Out of range relative negative offset, - 32 KB + 4*/
561 err = create_cond_branch(&instr, iptr, addr - 0x8004, flags);
562 check(err);
563
564 /* Out of range relative positive offset, + 32 KB */
565 err = create_cond_branch(&instr, iptr, addr + 0x8000, flags);
566 check(err);
567
568 /* Unaligned target */
569 err = create_cond_branch(&instr, iptr, addr + 3, flags);
570 check(err);
571
572 /* Check flags are masked correctly */
573 err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC);
574 check(instr_is_branch_to_addr(&instr, addr));
575 check(ppc_inst_equal(instr, ppc_inst(0x43FF0000)));
576 }
577
test_translate_branch(void)578 static void __init test_translate_branch(void)
579 {
580 unsigned long addr;
581 void *p, *q;
582 struct ppc_inst instr;
583 void *buf;
584
585 buf = vmalloc(PAGE_ALIGN(0x2000000 + 1));
586 check(buf);
587 if (!buf)
588 return;
589
590 /* Simple case, branch to self moved a little */
591 p = buf;
592 addr = (unsigned long)p;
593 patch_branch(p, addr, 0);
594 check(instr_is_branch_to_addr(p, addr));
595 q = p + 4;
596 translate_branch(&instr, q, p);
597 patch_instruction(q, instr);
598 check(instr_is_branch_to_addr(q, addr));
599
600 /* Maximum negative case, move b . to addr + 32 MB */
601 p = buf;
602 addr = (unsigned long)p;
603 patch_branch(p, addr, 0);
604 q = buf + 0x2000000;
605 translate_branch(&instr, q, p);
606 patch_instruction(q, instr);
607 check(instr_is_branch_to_addr(p, addr));
608 check(instr_is_branch_to_addr(q, addr));
609 check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x4a000000)));
610
611 /* Maximum positive case, move x to x - 32 MB + 4 */
612 p = buf + 0x2000000;
613 addr = (unsigned long)p;
614 patch_branch(p, addr, 0);
615 q = buf + 4;
616 translate_branch(&instr, q, p);
617 patch_instruction(q, instr);
618 check(instr_is_branch_to_addr(p, addr));
619 check(instr_is_branch_to_addr(q, addr));
620 check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x49fffffc)));
621
622 /* Jump to x + 16 MB moved to x + 20 MB */
623 p = buf;
624 addr = 0x1000000 + (unsigned long)buf;
625 patch_branch(p, addr, BRANCH_SET_LINK);
626 q = buf + 0x1400000;
627 translate_branch(&instr, q, p);
628 patch_instruction(q, instr);
629 check(instr_is_branch_to_addr(p, addr));
630 check(instr_is_branch_to_addr(q, addr));
631
632 /* Jump to x + 16 MB moved to x - 16 MB + 4 */
633 p = buf + 0x1000000;
634 addr = 0x2000000 + (unsigned long)buf;
635 patch_branch(p, addr, 0);
636 q = buf + 4;
637 translate_branch(&instr, q, p);
638 patch_instruction(q, instr);
639 check(instr_is_branch_to_addr(p, addr));
640 check(instr_is_branch_to_addr(q, addr));
641
642
643 /* Conditional branch tests */
644
645 /* Simple case, branch to self moved a little */
646 p = buf;
647 addr = (unsigned long)p;
648 create_cond_branch(&instr, p, addr, 0);
649 patch_instruction(p, instr);
650 check(instr_is_branch_to_addr(p, addr));
651 q = buf + 4;
652 translate_branch(&instr, q, p);
653 patch_instruction(q, instr);
654 check(instr_is_branch_to_addr(q, addr));
655
656 /* Maximum negative case, move b . to addr + 32 KB */
657 p = buf;
658 addr = (unsigned long)p;
659 create_cond_branch(&instr, p, addr, 0xFFFFFFFC);
660 patch_instruction(p, instr);
661 q = buf + 0x8000;
662 translate_branch(&instr, q, p);
663 patch_instruction(q, instr);
664 check(instr_is_branch_to_addr(p, addr));
665 check(instr_is_branch_to_addr(q, addr));
666 check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff8000)));
667
668 /* Maximum positive case, move x to x - 32 KB + 4 */
669 p = buf + 0x8000;
670 addr = (unsigned long)p;
671 create_cond_branch(&instr, p, addr, 0xFFFFFFFC);
672 patch_instruction(p, instr);
673 q = buf + 4;
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(0x43ff7ffc)));
679
680 /* Jump to x + 12 KB moved to x + 20 KB */
681 p = buf;
682 addr = 0x3000 + (unsigned long)buf;
683 create_cond_branch(&instr, p, addr, BRANCH_SET_LINK);
684 patch_instruction(p, instr);
685 q = buf + 0x5000;
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
691 /* Jump to x + 8 KB moved to x - 8 KB + 4 */
692 p = buf + 0x2000;
693 addr = 0x4000 + (unsigned long)buf;
694 create_cond_branch(&instr, p, addr, 0);
695 patch_instruction(p, instr);
696 q = buf + 4;
697 translate_branch(&instr, q, p);
698 patch_instruction(q, instr);
699 check(instr_is_branch_to_addr(p, addr));
700 check(instr_is_branch_to_addr(q, addr));
701
702 /* Free the buffer we were using */
703 vfree(buf);
704 }
705
706 #ifdef CONFIG_PPC64
test_prefixed_patching(void)707 static void __init test_prefixed_patching(void)
708 {
709 extern unsigned int code_patching_test1[];
710 extern unsigned int code_patching_test1_expected[];
711 extern unsigned int end_code_patching_test1[];
712
713 __patch_instruction((struct ppc_inst *)code_patching_test1,
714 ppc_inst_prefix(OP_PREFIX << 26, 0x00000000),
715 (struct ppc_inst *)code_patching_test1);
716
717 check(!memcmp(code_patching_test1,
718 code_patching_test1_expected,
719 sizeof(unsigned int) *
720 (end_code_patching_test1 - code_patching_test1)));
721 }
722 #else
test_prefixed_patching(void)723 static inline void test_prefixed_patching(void) {}
724 #endif
725
test_code_patching(void)726 static int __init test_code_patching(void)
727 {
728 printk(KERN_DEBUG "Running code patching self-tests ...\n");
729
730 test_branch_iform();
731 test_branch_bform();
732 test_create_function_call();
733 test_translate_branch();
734 test_prefixed_patching();
735
736 return 0;
737 }
738 late_initcall(test_code_patching);
739
740 #endif /* CONFIG_CODE_PATCHING_SELFTEST */
741
