1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Code for replacing ftrace calls with jumps.
4 *
5 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
6 *
7 * Thanks goes out to P.A. Semi, Inc for supplying me with a PPC64 box.
8 *
9 * Added function graph tracer code, taken from x86 that was written
10 * by Frederic Weisbecker, and ported to PPC by Steven Rostedt.
11 *
12 */
13
14#define pr_fmt(fmt) "ftrace-powerpc: " fmt
15
16#include <linux/spinlock.h>
17#include <linux/hardirq.h>
18#include <linux/uaccess.h>
19#include <linux/module.h>
20#include <linux/ftrace.h>
21#include <linux/percpu.h>
22#include <linux/init.h>
23#include <linux/list.h>
24
25#include <asm/cacheflush.h>
26#include <asm/text-patching.h>
27#include <asm/ftrace.h>
28#include <asm/syscall.h>
29#include <asm/inst.h>
30#include <asm/sections.h>
31
32#define NUM_FTRACE_TRAMPS 2
33static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS];
34
35unsigned long ftrace_call_adjust(unsigned long addr)
36{
37 if (addr >= (unsigned long)__exittext_begin && addr < (unsigned long)__exittext_end)
38 return 0;
39
40 if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY) &&
41 !IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) {
42 addr += MCOUNT_INSN_SIZE;
43 if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS))
44 addr += MCOUNT_INSN_SIZE;
45 }
46
47 return addr;
48}
49
50static ppc_inst_t ftrace_create_branch_inst(unsigned long ip, unsigned long addr, int link)
51{
52 ppc_inst_t op;
53
54 WARN_ON(!is_offset_in_branch_range(addr - ip));
55 create_branch(&op, (u32 *)ip, addr, link ? BRANCH_SET_LINK : 0);
56
57 return op;
58}
59
60static inline int ftrace_read_inst(unsigned long ip, ppc_inst_t *op)
61{
62 if (copy_inst_from_kernel_nofault(op, (void *)ip)) {
63 pr_err("0x%lx: fetching instruction failed\n", ip);
64 return -EFAULT;
65 }
66
67 return 0;
68}
69
70static inline int ftrace_validate_inst(unsigned long ip, ppc_inst_t inst)
71{
72 ppc_inst_t op;
73 int ret;
74
75 ret = ftrace_read_inst(ip, &op);
76 if (!ret && !ppc_inst_equal(op, inst)) {
77 pr_err("0x%lx: expected (%08lx) != found (%08lx)\n",
78 ip, ppc_inst_as_ulong(inst), ppc_inst_as_ulong(op));
79 ret = -EINVAL;
80 }
81
82 return ret;
83}
84
85static inline int ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
86{
87 int ret = ftrace_validate_inst(ip, old);
88
89 if (!ret && !ppc_inst_equal(old, new))
90 ret = patch_instruction((u32 *)ip, new);
91
92 return ret;
93}
94
95static int is_bl_op(ppc_inst_t op)
96{
97 return (ppc_inst_val(op) & ~PPC_LI_MASK) == PPC_RAW_BL(0);
98}
99
100static unsigned long find_ftrace_tramp(unsigned long ip)
101{
102 int i;
103
104 for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
105 if (!ftrace_tramps[i])
106 continue;
107 else if (is_offset_in_branch_range(ftrace_tramps[i] - ip))
108 return ftrace_tramps[i];
109
110 return 0;
111}
112
113#ifdef CONFIG_MODULES
114static unsigned long ftrace_lookup_module_stub(unsigned long ip, unsigned long addr)
115{
116 struct module *mod = NULL;
117
118 scoped_guard(rcu)
119 mod = __module_text_address(addr: ip);
120 if (!mod)
121 pr_err("No module loaded at addr=%lx\n", ip);
122
123 return (addr == (unsigned long)ftrace_caller ? mod->arch.tramp : mod->arch.tramp_regs);
124}
125#else
126static unsigned long ftrace_lookup_module_stub(unsigned long ip, unsigned long addr)
127{
128 return 0;
129}
130#endif
131
132static unsigned long ftrace_get_ool_stub(struct dyn_ftrace *rec)
133{
134#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
135 return rec->arch.ool_stub;
136#else
137 BUILD_BUG();
138#endif
139}
140
141static int ftrace_get_call_inst(struct dyn_ftrace *rec, unsigned long addr, ppc_inst_t *call_inst)
142{
143 unsigned long ip;
144 unsigned long stub;
145
146 if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE))
147 ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE; /* second instruction in stub */
148 else
149 ip = rec->ip;
150
151 if (!is_offset_in_branch_range(addr - ip) && addr != FTRACE_ADDR &&
152 addr != FTRACE_REGS_ADDR) {
153 /* This can only happen with ftrace direct */
154 if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS)) {
155 pr_err("0x%lx (0x%lx): Unexpected target address 0x%lx\n",
156 ip, rec->ip, addr);
157 return -EINVAL;
158 }
159 addr = FTRACE_ADDR;
160 }
161
162 if (is_offset_in_branch_range(addr - ip))
163 /* Within range */
164 stub = addr;
165 else if (core_kernel_text(addr: ip))
166 /* We would be branching to one of our ftrace stubs */
167 stub = find_ftrace_tramp(ip);
168 else
169 stub = ftrace_lookup_module_stub(ip, addr);
170
171 if (!stub) {
172 pr_err("0x%lx (0x%lx): No ftrace stubs reachable\n", ip, rec->ip);
173 return -EINVAL;
174 }
175
176 *call_inst = ftrace_create_branch_inst(ip, stub, 1);
177 return 0;
178}
179
180static int ftrace_init_ool_stub(struct module *mod, struct dyn_ftrace *rec)
181{
182#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
183 static int ool_stub_text_index, ool_stub_text_end_index, ool_stub_inittext_index;
184 int ret = 0, ool_stub_count, *ool_stub_index;
185 ppc_inst_t inst;
186 /*
187 * See ftrace_entry.S if changing the below instruction sequence, as we rely on
188 * decoding the last branch instruction here to recover the correct function ip.
189 */
190 struct ftrace_ool_stub *ool_stub, ool_stub_template = {
191 .insn = {
192 PPC_RAW_MFLR(_R0),
193 PPC_RAW_NOP(), /* bl ftrace_caller */
194 PPC_RAW_MTLR(_R0),
195 PPC_RAW_NOP() /* b rec->ip + 4 */
196 }
197 };
198
199 WARN_ON(rec->arch.ool_stub);
200
201 if (is_kernel_inittext(rec->ip)) {
202 ool_stub = ftrace_ool_stub_inittext;
203 ool_stub_index = &ool_stub_inittext_index;
204 ool_stub_count = ftrace_ool_stub_inittext_count;
205 } else if (is_kernel_text(rec->ip)) {
206 /*
207 * ftrace records are sorted, so we first use up the stub area within .text
208 * (ftrace_ool_stub_text) before using the area at the end of .text
209 * (ftrace_ool_stub_text_end), unless the stub is out of range of the record.
210 */
211 if (ool_stub_text_index >= ftrace_ool_stub_text_count ||
212 !is_offset_in_branch_range((long)rec->ip -
213 (long)&ftrace_ool_stub_text[ool_stub_text_index])) {
214 ool_stub = ftrace_ool_stub_text_end;
215 ool_stub_index = &ool_stub_text_end_index;
216 ool_stub_count = ftrace_ool_stub_text_end_count;
217 } else {
218 ool_stub = ftrace_ool_stub_text;
219 ool_stub_index = &ool_stub_text_index;
220 ool_stub_count = ftrace_ool_stub_text_count;
221 }
222#ifdef CONFIG_MODULES
223 } else if (mod) {
224 ool_stub = mod->arch.ool_stubs;
225 ool_stub_index = &mod->arch.ool_stub_index;
226 ool_stub_count = mod->arch.ool_stub_count;
227#endif
228 } else {
229 return -EINVAL;
230 }
231
232 ool_stub += (*ool_stub_index)++;
233
234 if (WARN_ON(*ool_stub_index > ool_stub_count))
235 return -EINVAL;
236
237 if (!is_offset_in_branch_range((long)rec->ip - (long)&ool_stub->insn[0]) ||
238 !is_offset_in_branch_range((long)(rec->ip + MCOUNT_INSN_SIZE) -
239 (long)&ool_stub->insn[3])) {
240 pr_err("%s: ftrace ool stub out of range (%p -> %p).\n",
241 __func__, (void *)rec->ip, (void *)&ool_stub->insn[0]);
242 return -EINVAL;
243 }
244
245 rec->arch.ool_stub = (unsigned long)&ool_stub->insn[0];
246
247 /* bl ftrace_caller */
248 if (!mod)
249 ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &inst);
250#ifdef CONFIG_MODULES
251 else
252 /*
253 * We can't use ftrace_get_call_inst() since that uses
254 * __module_text_address(rec->ip) to look up the module.
255 * But, since the module is not fully formed at this stage,
256 * the lookup fails. We know the target though, so generate
257 * the branch inst directly.
258 */
259 inst = ftrace_create_branch_inst(ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE,
260 mod->arch.tramp, 1);
261#endif
262 ool_stub_template.insn[1] = ppc_inst_val(inst);
263
264 /* b rec->ip + 4 */
265 if (!ret && create_branch(&inst, &ool_stub->insn[3], rec->ip + MCOUNT_INSN_SIZE, 0))
266 return -EINVAL;
267 ool_stub_template.insn[3] = ppc_inst_val(inst);
268
269 if (!ret)
270 ret = patch_instructions((u32 *)ool_stub, (u32 *)&ool_stub_template,
271 sizeof(ool_stub_template), false);
272
273 return ret;
274#else /* !CONFIG_PPC_FTRACE_OUT_OF_LINE */
275 BUILD_BUG();
276#endif
277}
278
279#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
280static const struct ftrace_ops *powerpc_rec_get_ops(struct dyn_ftrace *rec)
281{
282 const struct ftrace_ops *ops = NULL;
283
284 if (rec->flags & FTRACE_FL_CALL_OPS_EN) {
285 ops = ftrace_find_unique_ops(rec);
286 WARN_ON_ONCE(!ops);
287 }
288
289 if (!ops)
290 ops = &ftrace_list_ops;
291
292 return ops;
293}
294
295static int ftrace_rec_set_ops(struct dyn_ftrace *rec, const struct ftrace_ops *ops)
296{
297 if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE))
298 return patch_ulong((void *)(ftrace_get_ool_stub(rec) - sizeof(unsigned long)),
299 (unsigned long)ops);
300 else
301 return patch_ulong((void *)(rec->ip - MCOUNT_INSN_SIZE - sizeof(unsigned long)),
302 (unsigned long)ops);
303}
304
305static int ftrace_rec_set_nop_ops(struct dyn_ftrace *rec)
306{
307 return ftrace_rec_set_ops(rec, &ftrace_nop_ops);
308}
309
310static int ftrace_rec_update_ops(struct dyn_ftrace *rec)
311{
312 return ftrace_rec_set_ops(rec, powerpc_rec_get_ops(rec));
313}
314#else
315static int ftrace_rec_set_nop_ops(struct dyn_ftrace *rec) { return 0; }
316static int ftrace_rec_update_ops(struct dyn_ftrace *rec) { return 0; }
317#endif
318
319#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
320int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr)
321{
322 /* This should never be called since we override ftrace_replace_code() */
323 WARN_ON(1);
324 return -EINVAL;
325}
326#endif
327
328int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
329{
330 ppc_inst_t old, new;
331 unsigned long ip = rec->ip;
332 int ret = 0;
333
334 /* This can only ever be called during module load */
335 if (WARN_ON(!IS_ENABLED(CONFIG_MODULES) || core_kernel_text(ip)))
336 return -EINVAL;
337
338 old = ppc_inst(PPC_RAW_NOP());
339 if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) {
340 ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE; /* second instruction in stub */
341 ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &old);
342 }
343
344 ret |= ftrace_get_call_inst(rec, addr, &new);
345
346 if (!ret)
347 ret = ftrace_modify_code(ip, old, new);
348
349 ret = ftrace_rec_update_ops(rec);
350 if (ret)
351 return ret;
352
353 if (!ret && IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE))
354 ret = ftrace_modify_code(rec->ip, ppc_inst(PPC_RAW_NOP()),
355 ppc_inst(PPC_RAW_BRANCH((long)ftrace_get_ool_stub(rec) - (long)rec->ip)));
356
357 return ret;
358}
359
360int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
361{
362 /*
363 * This should never be called since we override ftrace_replace_code(),
364 * as well as ftrace_init_nop()
365 */
366 WARN_ON(1);
367 return -EINVAL;
368}
369
370void ftrace_replace_code(int enable)
371{
372 ppc_inst_t old, new, call_inst, new_call_inst;
373 ppc_inst_t nop_inst = ppc_inst(PPC_RAW_NOP());
374 unsigned long ip, new_addr, addr;
375 struct ftrace_rec_iter *iter;
376 struct dyn_ftrace *rec;
377 int ret = 0, update;
378
379 for_ftrace_rec_iter(iter) {
380 rec = ftrace_rec_iter_record(iter);
381 ip = rec->ip;
382
383 if (rec->flags & FTRACE_FL_DISABLED && !(rec->flags & FTRACE_FL_ENABLED))
384 continue;
385
386 addr = ftrace_get_addr_curr(rec);
387 new_addr = ftrace_get_addr_new(rec);
388 update = ftrace_update_record(rec, enable);
389
390 if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE) && update != FTRACE_UPDATE_IGNORE) {
391 ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE;
392 ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &nop_inst);
393 if (ret)
394 goto out;
395 }
396
397 switch (update) {
398 case FTRACE_UPDATE_IGNORE:
399 default:
400 continue;
401 case FTRACE_UPDATE_MODIFY_CALL:
402 ret = ftrace_get_call_inst(rec, new_addr, &new_call_inst);
403 ret |= ftrace_get_call_inst(rec, addr, &call_inst);
404 ret |= ftrace_rec_update_ops(rec);
405 old = call_inst;
406 new = new_call_inst;
407 break;
408 case FTRACE_UPDATE_MAKE_NOP:
409 ret = ftrace_get_call_inst(rec, addr, &call_inst);
410 ret |= ftrace_rec_set_nop_ops(rec);
411 old = call_inst;
412 new = nop_inst;
413 break;
414 case FTRACE_UPDATE_MAKE_CALL:
415 ret = ftrace_get_call_inst(rec, new_addr, &call_inst);
416 ret |= ftrace_rec_update_ops(rec);
417 old = nop_inst;
418 new = call_inst;
419 break;
420 }
421
422 if (!ret)
423 ret = ftrace_modify_code(ip, old, new);
424
425 if (!ret && IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE) &&
426 (update == FTRACE_UPDATE_MAKE_NOP || update == FTRACE_UPDATE_MAKE_CALL)) {
427 /* Update the actual ftrace location */
428 call_inst = ppc_inst(PPC_RAW_BRANCH((long)ftrace_get_ool_stub(rec) -
429 (long)rec->ip));
430 nop_inst = ppc_inst(PPC_RAW_NOP());
431 ip = rec->ip;
432
433 if (update == FTRACE_UPDATE_MAKE_NOP)
434 ret = ftrace_modify_code(ip, call_inst, nop_inst);
435 else
436 ret = ftrace_modify_code(ip, nop_inst, call_inst);
437
438 if (ret)
439 goto out;
440 }
441
442 if (ret)
443 goto out;
444 }
445
446out:
447 if (ret)
448 ftrace_bug(err: ret, rec);
449 return;
450}
451
452int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
453{
454 unsigned long addr, ip = rec->ip;
455 ppc_inst_t old, new;
456 int ret = 0;
457
458 /* Verify instructions surrounding the ftrace location */
459 if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)) {
460 /* Expect nops */
461 if (!IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE))
462 ret = ftrace_validate_inst(ip - 4, ppc_inst(PPC_RAW_NOP()));
463 if (!ret)
464 ret = ftrace_validate_inst(ip, ppc_inst(PPC_RAW_NOP()));
465 } else if (IS_ENABLED(CONFIG_PPC32)) {
466 /* Expected sequence: 'mflr r0', 'stw r0,4(r1)', 'bl _mcount' */
467 ret = ftrace_validate_inst(ip - 8, ppc_inst(PPC_RAW_MFLR(_R0)));
468 if (ret)
469 return ret;
470 ret = ftrace_modify_code(ip - 4, ppc_inst(PPC_RAW_STW(_R0, _R1, 4)),
471 ppc_inst(PPC_RAW_NOP()));
472 } else if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) {
473 /* Expected sequence: 'mflr r0', ['std r0,16(r1)'], 'bl _mcount' */
474 ret = ftrace_read_inst(ip - 4, &old);
475 if (!ret && !ppc_inst_equal(old, ppc_inst(PPC_RAW_MFLR(_R0)))) {
476 /* Gcc v5.x emit the additional 'std' instruction, gcc v6.x don't */
477 ret = ftrace_validate_inst(ip - 8, ppc_inst(PPC_RAW_MFLR(_R0)));
478 if (ret)
479 return ret;
480 ret = ftrace_modify_code(ip - 4, ppc_inst(PPC_RAW_STD(_R0, _R1, 16)),
481 ppc_inst(PPC_RAW_NOP()));
482 }
483 } else {
484 return -EINVAL;
485 }
486
487 if (ret)
488 return ret;
489
490 /* Set up out-of-line stub */
491 if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) {
492 ret = ftrace_init_ool_stub(mod, rec);
493 goto out;
494 }
495
496 /* Nop-out the ftrace location */
497 new = ppc_inst(PPC_RAW_NOP());
498 addr = MCOUNT_ADDR;
499 if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)) {
500 /* we instead patch-in the 'mflr r0' */
501 old = ppc_inst(PPC_RAW_NOP());
502 new = ppc_inst(PPC_RAW_MFLR(_R0));
503 ret = ftrace_modify_code(ip - 4, old, new);
504 } else if (is_offset_in_branch_range(addr - ip)) {
505 /* Within range */
506 old = ftrace_create_branch_inst(ip, addr, 1);
507 ret = ftrace_modify_code(ip, old, new);
508 } else if (core_kernel_text(addr: ip) || (IS_ENABLED(CONFIG_MODULES) && mod)) {
509 /*
510 * We would be branching to a linker-generated stub, or to the module _mcount
511 * stub. Let's just confirm we have a 'bl' here.
512 */
513 ret = ftrace_read_inst(ip, &old);
514 if (ret)
515 return ret;
516 if (!is_bl_op(old)) {
517 pr_err("0x%lx: expected (bl) != found (%08lx)\n", ip, ppc_inst_as_ulong(old));
518 return -EINVAL;
519 }
520 ret = patch_instruction((u32 *)ip, new);
521 } else {
522 return -EINVAL;
523 }
524
525out:
526 if (!ret)
527 ret = ftrace_rec_set_nop_ops(rec);
528
529 return ret;
530}
531
532int ftrace_update_ftrace_func(ftrace_func_t func)
533{
534 unsigned long ip = (unsigned long)(&ftrace_call);
535 ppc_inst_t old, new;
536 int ret;
537
538 /*
539 * When using CALL_OPS, the function to call is associated with the
540 * call site, and we don't have a global function pointer to update.
541 */
542 if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS))
543 return 0;
544
545 old = ppc_inst_read((u32 *)&ftrace_call);
546 new = ftrace_create_branch_inst(ip, ppc_function_entry(func), 1);
547 ret = ftrace_modify_code(ip, old, new);
548
549 /* Also update the regs callback function */
550 if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !ret) {
551 ip = (unsigned long)(&ftrace_regs_call);
552 old = ppc_inst_read((u32 *)&ftrace_regs_call);
553 new = ftrace_create_branch_inst(ip, ppc_function_entry(func), 1);
554 ret = ftrace_modify_code(ip, old, new);
555 }
556
557 return ret;
558}
559
560/*
561 * Use the default ftrace_modify_all_code, but without
562 * stop_machine().
563 */
564void arch_ftrace_update_code(int command)
565{
566 ftrace_modify_all_code(command);
567}
568
569void ftrace_free_init_tramp(void)
570{
571 int i;
572
573 for (i = 0; i < NUM_FTRACE_TRAMPS && ftrace_tramps[i]; i++)
574 if (ftrace_tramps[i] == (unsigned long)ftrace_tramp_init) {
575 ftrace_tramps[i] = 0;
576 return;
577 }
578}
579
580static void __init add_ftrace_tramp(unsigned long tramp)
581{
582 int i;
583
584 for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
585 if (!ftrace_tramps[i]) {
586 ftrace_tramps[i] = tramp;
587 return;
588 }
589}
590
591int __init ftrace_dyn_arch_init(void)
592{
593 unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init };
594 unsigned long addr = FTRACE_REGS_ADDR;
595 long reladdr;
596 int i;
597 u32 stub_insns[] = {
598#ifdef CONFIG_PPC_KERNEL_PCREL
599 /* pla r12,addr */
600 PPC_PREFIX_MLS | __PPC_PRFX_R(1),
601 PPC_INST_PADDI | ___PPC_RT(_R12),
602 PPC_RAW_MTCTR(_R12),
603 PPC_RAW_BCTR()
604#elif defined(CONFIG_PPC64)
605 PPC_RAW_LD(_R12, _R13, offsetof(struct paca_struct, kernel_toc)),
606 PPC_RAW_ADDIS(_R12, _R12, 0),
607 PPC_RAW_ADDI(_R12, _R12, 0),
608 PPC_RAW_MTCTR(_R12),
609 PPC_RAW_BCTR()
610#else
611 PPC_RAW_LIS(_R12, 0),
612 PPC_RAW_ADDI(_R12, _R12, 0),
613 PPC_RAW_MTCTR(_R12),
614 PPC_RAW_BCTR()
615#endif
616 };
617
618 if (IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) {
619 for (i = 0; i < 2; i++) {
620 reladdr = addr - (unsigned long)tramp[i];
621
622 if (reladdr >= (long)SZ_8G || reladdr < -(long)SZ_8G) {
623 pr_err("Address of %ps out of range of pcrel address.\n",
624 (void *)addr);
625 return -1;
626 }
627
628 memcpy(tramp[i], stub_insns, sizeof(stub_insns));
629 tramp[i][0] |= IMM_H18(reladdr);
630 tramp[i][1] |= IMM_L(reladdr);
631 add_ftrace_tramp(tramp: (unsigned long)tramp[i]);
632 }
633 } else if (IS_ENABLED(CONFIG_PPC64)) {
634 reladdr = addr - kernel_toc_addr();
635
636 if (reladdr >= (long)SZ_2G || reladdr < -(long long)SZ_2G) {
637 pr_err("Address of %ps out of range of kernel_toc.\n",
638 (void *)addr);
639 return -1;
640 }
641
642 for (i = 0; i < 2; i++) {
643 memcpy(tramp[i], stub_insns, sizeof(stub_insns));
644 tramp[i][1] |= PPC_HA(reladdr);
645 tramp[i][2] |= PPC_LO(reladdr);
646 add_ftrace_tramp(tramp: (unsigned long)tramp[i]);
647 }
648 } else {
649 for (i = 0; i < 2; i++) {
650 memcpy(tramp[i], stub_insns, sizeof(stub_insns));
651 tramp[i][0] |= PPC_HA(addr);
652 tramp[i][1] |= PPC_LO(addr);
653 add_ftrace_tramp(tramp: (unsigned long)tramp[i]);
654 }
655 }
656
657 return 0;
658}
659
660#ifdef CONFIG_FUNCTION_GRAPH_TRACER
661void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
662 struct ftrace_ops *op, struct ftrace_regs *fregs)
663{
664 unsigned long sp = arch_ftrace_regs(fregs)->regs.gpr[1];
665
666 if (unlikely(ftrace_graph_is_dead()))
667 goto out;
668
669 if (unlikely(atomic_read(&current->tracing_graph_pause)))
670 goto out;
671
672 if (!function_graph_enter_regs(ret: parent_ip, func: ip, frame_pointer: 0, retp: (unsigned long *)sp, fregs))
673 parent_ip = ppc_function_entry(return_to_handler);
674
675out:
676 arch_ftrace_regs(fregs)->regs.link = parent_ip;
677}
678#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
679

source code of linux/arch/powerpc/kernel/trace/ftrace.c