xref: /optee_os/core/arch/arm/kernel/thread.c (revision 93dc6b2960b97055bffaa67f1eb4adb1b4e9bfcd)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2016-2022, Linaro Limited
4  * Copyright (c) 2014, STMicroelectronics International N.V.
5  * Copyright (c) 2020-2021, Arm Limited
6  */
7 
8 #include <platform_config.h>
9 
10 #include <arm.h>
11 #include <assert.h>
12 #include <config.h>
13 #include <io.h>
14 #include <keep.h>
15 #include <kernel/asan.h>
16 #include <kernel/boot.h>
17 #include <kernel/linker.h>
18 #include <kernel/lockdep.h>
19 #include <kernel/misc.h>
20 #include <kernel/panic.h>
21 #include <kernel/spinlock.h>
22 #include <kernel/spmc_sp_handler.h>
23 #include <kernel/tee_ta_manager.h>
24 #include <kernel/thread.h>
25 #include <kernel/thread_private.h>
26 #include <kernel/user_mode_ctx_struct.h>
27 #include <kernel/virtualization.h>
28 #include <mm/core_memprot.h>
29 #include <mm/mobj.h>
30 #include <mm/tee_mm.h>
31 #include <mm/tee_pager.h>
32 #include <mm/vm.h>
33 #include <smccc.h>
34 #include <sm/sm.h>
35 #include <trace.h>
36 #include <util.h>
37 
38 #ifdef CFG_CORE_UNMAP_CORE_AT_EL0
39 static vaddr_t thread_user_kcode_va __nex_bss;
40 long thread_user_kcode_offset __nex_bss;
41 static size_t thread_user_kcode_size __nex_bss;
42 #endif
43 
44 #if defined(CFG_CORE_UNMAP_CORE_AT_EL0) && \
45 	defined(CFG_CORE_WORKAROUND_SPECTRE_BP_SEC) && defined(ARM64)
46 long thread_user_kdata_sp_offset __nex_bss;
47 static uint8_t thread_user_kdata_page[
48 	ROUNDUP(sizeof(struct thread_core_local) * CFG_TEE_CORE_NB_CORE,
49 		SMALL_PAGE_SIZE)]
50 	__aligned(SMALL_PAGE_SIZE)
51 #ifndef CFG_VIRTUALIZATION
52 	__section(".nozi.kdata_page");
53 #else
54 	__section(".nex_nozi.kdata_page");
55 #endif
56 #endif
57 
58 #ifdef ARM32
59 uint32_t __nostackcheck thread_get_exceptions(void)
60 {
61 	uint32_t cpsr = read_cpsr();
62 
63 	return (cpsr >> CPSR_F_SHIFT) & THREAD_EXCP_ALL;
64 }
65 
66 void __nostackcheck thread_set_exceptions(uint32_t exceptions)
67 {
68 	uint32_t cpsr = read_cpsr();
69 
70 	/* Foreign interrupts must not be unmasked while holding a spinlock */
71 	if (!(exceptions & THREAD_EXCP_FOREIGN_INTR))
72 		assert_have_no_spinlock();
73 
74 	cpsr &= ~(THREAD_EXCP_ALL << CPSR_F_SHIFT);
75 	cpsr |= ((exceptions & THREAD_EXCP_ALL) << CPSR_F_SHIFT);
76 
77 	barrier();
78 	write_cpsr(cpsr);
79 	barrier();
80 }
81 #endif /*ARM32*/
82 
83 #ifdef ARM64
84 uint32_t __nostackcheck thread_get_exceptions(void)
85 {
86 	uint32_t daif = read_daif();
87 
88 	return (daif >> DAIF_F_SHIFT) & THREAD_EXCP_ALL;
89 }
90 
91 void __nostackcheck thread_set_exceptions(uint32_t exceptions)
92 {
93 	uint32_t daif = read_daif();
94 
95 	/* Foreign interrupts must not be unmasked while holding a spinlock */
96 	if (!(exceptions & THREAD_EXCP_FOREIGN_INTR))
97 		assert_have_no_spinlock();
98 
99 	daif &= ~(THREAD_EXCP_ALL << DAIF_F_SHIFT);
100 	daif |= ((exceptions & THREAD_EXCP_ALL) << DAIF_F_SHIFT);
101 
102 	barrier();
103 	write_daif(daif);
104 	barrier();
105 }
106 #endif /*ARM64*/
107 
108 uint32_t __nostackcheck thread_mask_exceptions(uint32_t exceptions)
109 {
110 	uint32_t state = thread_get_exceptions();
111 
112 	thread_set_exceptions(state | (exceptions & THREAD_EXCP_ALL));
113 	return state;
114 }
115 
116 void __nostackcheck thread_unmask_exceptions(uint32_t state)
117 {
118 	thread_set_exceptions(state & THREAD_EXCP_ALL);
119 }
120 
121 static void thread_lazy_save_ns_vfp(void)
122 {
123 #ifdef CFG_WITH_VFP
124 	struct thread_ctx *thr = threads + thread_get_id();
125 
126 	thr->vfp_state.ns_saved = false;
127 	vfp_lazy_save_state_init(&thr->vfp_state.ns);
128 #endif /*CFG_WITH_VFP*/
129 }
130 
131 static void thread_lazy_restore_ns_vfp(void)
132 {
133 #ifdef CFG_WITH_VFP
134 	struct thread_ctx *thr = threads + thread_get_id();
135 	struct thread_user_vfp_state *tuv = thr->vfp_state.uvfp;
136 
137 	assert(!thr->vfp_state.sec_lazy_saved && !thr->vfp_state.sec_saved);
138 
139 	if (tuv && tuv->lazy_saved && !tuv->saved) {
140 		vfp_lazy_save_state_final(&tuv->vfp, false /*!force_save*/);
141 		tuv->saved = true;
142 	}
143 
144 	vfp_lazy_restore_state(&thr->vfp_state.ns, thr->vfp_state.ns_saved);
145 	thr->vfp_state.ns_saved = false;
146 #endif /*CFG_WITH_VFP*/
147 }
148 
149 #ifdef ARM32
150 static void init_regs(struct thread_ctx *thread, uint32_t a0, uint32_t a1,
151 		      uint32_t a2, uint32_t a3, uint32_t a4, uint32_t a5,
152 		      uint32_t a6, uint32_t a7, void *pc)
153 {
154 	thread->regs.pc = (uint32_t)pc;
155 
156 	/*
157 	 * Stdcalls starts in SVC mode with masked foreign interrupts, masked
158 	 * Asynchronous abort and unmasked native interrupts.
159 	 */
160 	thread->regs.cpsr = read_cpsr() & ARM32_CPSR_E;
161 	thread->regs.cpsr |= CPSR_MODE_SVC | CPSR_A |
162 			(THREAD_EXCP_FOREIGN_INTR << ARM32_CPSR_F_SHIFT);
163 	/* Enable thumb mode if it's a thumb instruction */
164 	if (thread->regs.pc & 1)
165 		thread->regs.cpsr |= CPSR_T;
166 	/* Reinitialize stack pointer */
167 	thread->regs.svc_sp = thread->stack_va_end;
168 
169 	/*
170 	 * Copy arguments into context. This will make the
171 	 * arguments appear in r0-r7 when thread is started.
172 	 */
173 	thread->regs.r0 = a0;
174 	thread->regs.r1 = a1;
175 	thread->regs.r2 = a2;
176 	thread->regs.r3 = a3;
177 	thread->regs.r4 = a4;
178 	thread->regs.r5 = a5;
179 	thread->regs.r6 = a6;
180 	thread->regs.r7 = a7;
181 }
182 #endif /*ARM32*/
183 
184 #ifdef ARM64
185 static void init_regs(struct thread_ctx *thread, uint32_t a0, uint32_t a1,
186 		      uint32_t a2, uint32_t a3, uint32_t a4, uint32_t a5,
187 		      uint32_t a6, uint32_t a7, void *pc)
188 {
189 	thread->regs.pc = (uint64_t)pc;
190 
191 	/*
192 	 * Stdcalls starts in SVC mode with masked foreign interrupts, masked
193 	 * Asynchronous abort and unmasked native interrupts.
194 	 */
195 	thread->regs.cpsr = SPSR_64(SPSR_64_MODE_EL1, SPSR_64_MODE_SP_EL0,
196 				THREAD_EXCP_FOREIGN_INTR | DAIFBIT_ABT);
197 	/* Reinitialize stack pointer */
198 	thread->regs.sp = thread->stack_va_end;
199 
200 	/*
201 	 * Copy arguments into context. This will make the
202 	 * arguments appear in x0-x7 when thread is started.
203 	 */
204 	thread->regs.x[0] = a0;
205 	thread->regs.x[1] = a1;
206 	thread->regs.x[2] = a2;
207 	thread->regs.x[3] = a3;
208 	thread->regs.x[4] = a4;
209 	thread->regs.x[5] = a5;
210 	thread->regs.x[6] = a6;
211 	thread->regs.x[7] = a7;
212 
213 	/* Set up frame pointer as per the Aarch64 AAPCS */
214 	thread->regs.x[29] = 0;
215 }
216 #endif /*ARM64*/
217 
218 static void __thread_alloc_and_run(uint32_t a0, uint32_t a1, uint32_t a2,
219 				   uint32_t a3, uint32_t a4, uint32_t a5,
220 				   uint32_t a6, uint32_t a7,
221 				   void *pc)
222 {
223 	struct thread_core_local *l = thread_get_core_local();
224 	bool found_thread = false;
225 	size_t n = 0;
226 
227 	assert(l->curr_thread == THREAD_ID_INVALID);
228 
229 	thread_lock_global();
230 
231 	for (n = 0; n < CFG_NUM_THREADS; n++) {
232 		if (threads[n].state == THREAD_STATE_FREE) {
233 			threads[n].state = THREAD_STATE_ACTIVE;
234 			found_thread = true;
235 			break;
236 		}
237 	}
238 
239 	thread_unlock_global();
240 
241 	if (!found_thread)
242 		return;
243 
244 	l->curr_thread = n;
245 
246 	threads[n].flags = 0;
247 	init_regs(threads + n, a0, a1, a2, a3, a4, a5, a6, a7, pc);
248 #ifdef CFG_CORE_PAUTH
249 	/*
250 	 * Copy the APIA key into the registers to be restored with
251 	 * thread_resume().
252 	 */
253 	threads[n].regs.apiakey_hi = threads[n].keys.apia_hi;
254 	threads[n].regs.apiakey_lo = threads[n].keys.apia_lo;
255 #endif
256 
257 	thread_lazy_save_ns_vfp();
258 
259 	l->flags &= ~THREAD_CLF_TMP;
260 	thread_resume(&threads[n].regs);
261 	/*NOTREACHED*/
262 	panic();
263 }
264 
265 void thread_alloc_and_run(uint32_t a0, uint32_t a1, uint32_t a2, uint32_t a3,
266 			  uint32_t a4, uint32_t a5)
267 {
268 	__thread_alloc_and_run(a0, a1, a2, a3, a4, a5, 0, 0,
269 			       thread_std_smc_entry);
270 }
271 
272 #ifdef CFG_SECURE_PARTITION
273 void thread_sp_alloc_and_run(struct thread_smc_args *args __maybe_unused)
274 {
275 	__thread_alloc_and_run(args->a0, args->a1, args->a2, args->a3, args->a4,
276 			       args->a5, args->a6, args->a7,
277 			       spmc_sp_thread_entry);
278 }
279 #endif
280 
281 #ifdef ARM32
282 static void copy_a0_to_a3(struct thread_ctx_regs *regs, uint32_t a0,
283 			  uint32_t a1, uint32_t a2, uint32_t a3)
284 {
285 	/*
286 	 * Update returned values from RPC, values will appear in
287 	 * r0-r3 when thread is resumed.
288 	 */
289 	regs->r0 = a0;
290 	regs->r1 = a1;
291 	regs->r2 = a2;
292 	regs->r3 = a3;
293 }
294 #endif /*ARM32*/
295 
296 #ifdef ARM64
297 static void copy_a0_to_a3(struct thread_ctx_regs *regs, uint32_t a0,
298 			  uint32_t a1, uint32_t a2, uint32_t a3)
299 {
300 	/*
301 	 * Update returned values from RPC, values will appear in
302 	 * x0-x3 when thread is resumed.
303 	 */
304 	regs->x[0] = a0;
305 	regs->x[1] = a1;
306 	regs->x[2] = a2;
307 	regs->x[3] = a3;
308 }
309 #endif /*ARM64*/
310 
311 #ifdef ARM32
312 static bool is_from_user(uint32_t cpsr)
313 {
314 	return (cpsr & ARM32_CPSR_MODE_MASK) == ARM32_CPSR_MODE_USR;
315 }
316 #endif
317 
318 #ifdef ARM64
319 static bool is_from_user(uint32_t cpsr)
320 {
321 	if (cpsr & (SPSR_MODE_RW_32 << SPSR_MODE_RW_SHIFT))
322 		return true;
323 	if (((cpsr >> SPSR_64_MODE_EL_SHIFT) & SPSR_64_MODE_EL_MASK) ==
324 	     SPSR_64_MODE_EL0)
325 		return true;
326 	return false;
327 }
328 #endif
329 
330 #ifdef CFG_SYSCALL_FTRACE
331 static void __noprof ftrace_suspend(void)
332 {
333 	struct ts_session *s = TAILQ_FIRST(&thread_get_tsd()->sess_stack);
334 
335 	if (s && s->fbuf)
336 		s->fbuf->syscall_trace_suspended = true;
337 }
338 
339 static void __noprof ftrace_resume(void)
340 {
341 	struct ts_session *s = TAILQ_FIRST(&thread_get_tsd()->sess_stack);
342 
343 	if (s && s->fbuf)
344 		s->fbuf->syscall_trace_suspended = false;
345 }
346 #else
347 static void __noprof ftrace_suspend(void)
348 {
349 }
350 
351 static void __noprof ftrace_resume(void)
352 {
353 }
354 #endif
355 
356 static bool is_user_mode(struct thread_ctx_regs *regs)
357 {
358 	return is_from_user((uint32_t)regs->cpsr);
359 }
360 
361 void thread_resume_from_rpc(uint32_t thread_id, uint32_t a0, uint32_t a1,
362 			    uint32_t a2, uint32_t a3)
363 {
364 	size_t n = thread_id;
365 	struct thread_core_local *l = thread_get_core_local();
366 	bool found_thread = false;
367 
368 	assert(l->curr_thread == THREAD_ID_INVALID);
369 
370 	thread_lock_global();
371 
372 	if (n < CFG_NUM_THREADS && threads[n].state == THREAD_STATE_SUSPENDED) {
373 		threads[n].state = THREAD_STATE_ACTIVE;
374 		found_thread = true;
375 	}
376 
377 	thread_unlock_global();
378 
379 	if (!found_thread)
380 		return;
381 
382 	l->curr_thread = n;
383 
384 	if (threads[n].have_user_map) {
385 		core_mmu_set_user_map(&threads[n].user_map);
386 		if (threads[n].flags & THREAD_FLAGS_EXIT_ON_FOREIGN_INTR)
387 			tee_ta_ftrace_update_times_resume();
388 	}
389 
390 	if (is_user_mode(&threads[n].regs))
391 		tee_ta_update_session_utime_resume();
392 
393 	/*
394 	 * Return from RPC to request service of a foreign interrupt must not
395 	 * get parameters from non-secure world.
396 	 */
397 	if (threads[n].flags & THREAD_FLAGS_COPY_ARGS_ON_RETURN) {
398 		copy_a0_to_a3(&threads[n].regs, a0, a1, a2, a3);
399 		threads[n].flags &= ~THREAD_FLAGS_COPY_ARGS_ON_RETURN;
400 	}
401 
402 	thread_lazy_save_ns_vfp();
403 
404 	if (threads[n].have_user_map)
405 		ftrace_resume();
406 
407 	l->flags &= ~THREAD_CLF_TMP;
408 	thread_resume(&threads[n].regs);
409 	/*NOTREACHED*/
410 	panic();
411 }
412 
413 #ifdef ARM64
414 vaddr_t thread_get_saved_thread_sp(void)
415 {
416 	struct thread_core_local *l = thread_get_core_local();
417 	int ct = l->curr_thread;
418 
419 	assert(ct != THREAD_ID_INVALID);
420 	return threads[ct].kern_sp;
421 }
422 #endif /*ARM64*/
423 
424 #ifdef ARM32
425 bool thread_is_in_normal_mode(void)
426 {
427 	return (read_cpsr() & ARM32_CPSR_MODE_MASK) == ARM32_CPSR_MODE_SVC;
428 }
429 #endif
430 
431 void thread_state_free(void)
432 {
433 	struct thread_core_local *l = thread_get_core_local();
434 	int ct = l->curr_thread;
435 
436 	assert(ct != THREAD_ID_INVALID);
437 
438 	thread_lazy_restore_ns_vfp();
439 	tee_pager_release_phys(
440 		(void *)(threads[ct].stack_va_end - STACK_THREAD_SIZE),
441 		STACK_THREAD_SIZE);
442 
443 	thread_lock_global();
444 
445 	assert(threads[ct].state == THREAD_STATE_ACTIVE);
446 	threads[ct].state = THREAD_STATE_FREE;
447 	threads[ct].flags = 0;
448 	l->curr_thread = THREAD_ID_INVALID;
449 
450 	if (IS_ENABLED(CFG_VIRTUALIZATION))
451 		virt_unset_guest();
452 	thread_unlock_global();
453 }
454 
455 #ifdef CFG_WITH_PAGER
456 static void release_unused_kernel_stack(struct thread_ctx *thr,
457 					uint32_t cpsr __maybe_unused)
458 {
459 #ifdef ARM64
460 	/*
461 	 * If we're from user mode then thr->regs.sp is the saved user
462 	 * stack pointer and thr->kern_sp holds the last kernel stack
463 	 * pointer. But if we're from kernel mode then thr->kern_sp isn't
464 	 * up to date so we need to read from thr->regs.sp instead.
465 	 */
466 	vaddr_t sp = is_from_user(cpsr) ?  thr->kern_sp : thr->regs.sp;
467 #else
468 	vaddr_t sp = thr->regs.svc_sp;
469 #endif
470 	vaddr_t base = thr->stack_va_end - STACK_THREAD_SIZE;
471 	size_t len = sp - base;
472 
473 	tee_pager_release_phys((void *)base, len);
474 }
475 #else
476 static void release_unused_kernel_stack(struct thread_ctx *thr __unused,
477 					uint32_t cpsr __unused)
478 {
479 }
480 #endif
481 
482 int thread_state_suspend(uint32_t flags, uint32_t cpsr, vaddr_t pc)
483 {
484 	struct thread_core_local *l = thread_get_core_local();
485 	int ct = l->curr_thread;
486 
487 	assert(ct != THREAD_ID_INVALID);
488 
489 	if (core_mmu_user_mapping_is_active())
490 		ftrace_suspend();
491 
492 	thread_check_canaries();
493 
494 	release_unused_kernel_stack(threads + ct, cpsr);
495 
496 	if (is_from_user(cpsr)) {
497 		thread_user_save_vfp();
498 		tee_ta_update_session_utime_suspend();
499 		tee_ta_gprof_sample_pc(pc);
500 	}
501 	thread_lazy_restore_ns_vfp();
502 
503 	thread_lock_global();
504 
505 	assert(threads[ct].state == THREAD_STATE_ACTIVE);
506 	threads[ct].flags |= flags;
507 	threads[ct].regs.cpsr = cpsr;
508 	threads[ct].regs.pc = pc;
509 	threads[ct].state = THREAD_STATE_SUSPENDED;
510 
511 	threads[ct].have_user_map = core_mmu_user_mapping_is_active();
512 	if (threads[ct].have_user_map) {
513 		if (threads[ct].flags & THREAD_FLAGS_EXIT_ON_FOREIGN_INTR)
514 			tee_ta_ftrace_update_times_suspend();
515 		core_mmu_get_user_map(&threads[ct].user_map);
516 		core_mmu_set_user_map(NULL);
517 	}
518 
519 	l->curr_thread = THREAD_ID_INVALID;
520 
521 	if (IS_ENABLED(CFG_VIRTUALIZATION))
522 		virt_unset_guest();
523 
524 	thread_unlock_global();
525 
526 	return ct;
527 }
528 
529 bool thread_init_stack(uint32_t thread_id, vaddr_t sp)
530 {
531 	if (thread_id >= CFG_NUM_THREADS)
532 		return false;
533 	threads[thread_id].stack_va_end = sp;
534 	return true;
535 }
536 
537 static void __maybe_unused
538 set_core_local_kcode_offset(struct thread_core_local *cls, long offset)
539 {
540 	size_t n = 0;
541 
542 	for (n = 0; n < CFG_TEE_CORE_NB_CORE; n++)
543 		cls[n].kcode_offset = offset;
544 }
545 
546 static void init_user_kcode(void)
547 {
548 #ifdef CFG_CORE_UNMAP_CORE_AT_EL0
549 	vaddr_t v = (vaddr_t)thread_excp_vect;
550 	vaddr_t ve = (vaddr_t)thread_excp_vect_end;
551 
552 	thread_user_kcode_va = ROUNDDOWN(v, CORE_MMU_USER_CODE_SIZE);
553 	ve = ROUNDUP(ve, CORE_MMU_USER_CODE_SIZE);
554 	thread_user_kcode_size = ve - thread_user_kcode_va;
555 
556 	core_mmu_get_user_va_range(&v, NULL);
557 	thread_user_kcode_offset = thread_user_kcode_va - v;
558 
559 	set_core_local_kcode_offset(thread_core_local,
560 				    thread_user_kcode_offset);
561 #if defined(CFG_CORE_WORKAROUND_SPECTRE_BP_SEC) && defined(ARM64)
562 	set_core_local_kcode_offset((void *)thread_user_kdata_page,
563 				    thread_user_kcode_offset);
564 	/*
565 	 * When transitioning to EL0 subtract SP with this much to point to
566 	 * this special kdata page instead. SP is restored by add this much
567 	 * while transitioning back to EL1.
568 	 */
569 	v += thread_user_kcode_size;
570 	thread_user_kdata_sp_offset = (vaddr_t)thread_core_local - v;
571 #endif
572 #endif /*CFG_CORE_UNMAP_CORE_AT_EL0*/
573 }
574 
575 void thread_init_primary(void)
576 {
577 	/* Initialize canaries around the stacks */
578 	thread_init_canaries();
579 
580 	init_user_kcode();
581 }
582 
583 static uint32_t __maybe_unused get_midr_implementer(uint32_t midr)
584 {
585 	return (midr >> MIDR_IMPLEMENTER_SHIFT) & MIDR_IMPLEMENTER_MASK;
586 }
587 
588 static uint32_t __maybe_unused get_midr_primary_part(uint32_t midr)
589 {
590 	return (midr >> MIDR_PRIMARY_PART_NUM_SHIFT) &
591 	       MIDR_PRIMARY_PART_NUM_MASK;
592 }
593 
594 static uint32_t __maybe_unused get_midr_variant(uint32_t midr)
595 {
596 	return (midr >> MIDR_VARIANT_SHIFT) & MIDR_VARIANT_MASK;
597 }
598 
599 static uint32_t __maybe_unused get_midr_revision(uint32_t midr)
600 {
601 	return (midr >> MIDR_REVISION_SHIFT) & MIDR_REVISION_MASK;
602 }
603 
604 #ifdef ARM64
605 static bool probe_workaround_available(uint32_t wa_id)
606 {
607 	int32_t r;
608 
609 	r = thread_smc(SMCCC_VERSION, 0, 0, 0);
610 	if (r < 0)
611 		return false;
612 	if (r < 0x10001)	/* compare with version 1.1 */
613 		return false;
614 
615 	/* Version >= 1.1, so SMCCC_ARCH_FEATURES is available */
616 	r = thread_smc(SMCCC_ARCH_FEATURES, wa_id, 0, 0);
617 	return r >= 0;
618 }
619 
620 static vaddr_t __maybe_unused select_vector_wa_spectre_v2(void)
621 {
622 	if (probe_workaround_available(SMCCC_ARCH_WORKAROUND_1)) {
623 		DMSG("SMCCC_ARCH_WORKAROUND_1 (%#08" PRIx32 ") available",
624 		     SMCCC_ARCH_WORKAROUND_1);
625 		DMSG("SMC Workaround for CVE-2017-5715 used");
626 		return (vaddr_t)thread_excp_vect_wa_spectre_v2;
627 	}
628 
629 	DMSG("SMCCC_ARCH_WORKAROUND_1 (%#08" PRIx32 ") unavailable",
630 	     SMCCC_ARCH_WORKAROUND_1);
631 	DMSG("SMC Workaround for CVE-2017-5715 not needed (if ARM-TF is up to date)");
632 	return (vaddr_t)thread_excp_vect;
633 }
634 #else
635 static vaddr_t __maybe_unused select_vector_wa_spectre_v2(void)
636 {
637 	return (vaddr_t)thread_excp_vect_wa_spectre_v2;
638 }
639 #endif
640 
641 static vaddr_t __maybe_unused
642 select_vector_wa_spectre_bhb(uint8_t loop_count __maybe_unused)
643 {
644 	/*
645 	 * Spectre-BHB has only been analyzed for AArch64 so far. For
646 	 * AArch32 fall back to the Spectre-V2 workaround which is likely
647 	 * to work even if perhaps a bit more expensive than a more
648 	 * optimized workaround.
649 	 */
650 #ifdef ARM64
651 #ifdef CFG_CORE_UNMAP_CORE_AT_EL0
652 	struct thread_core_local *cl = (void *)thread_user_kdata_page;
653 
654 	cl[get_core_pos()].bhb_loop_count = loop_count;
655 #endif
656 	thread_get_core_local()->bhb_loop_count = loop_count;
657 
658 	DMSG("Spectre-BHB CVE-2022-23960 workaround enabled with \"K\" = %u",
659 	     loop_count);
660 
661 	return (vaddr_t)thread_excp_vect_wa_spectre_bhb;
662 #else
663 	return select_vector_wa_spectre_v2();
664 #endif
665 }
666 
667 static vaddr_t get_excp_vect(void)
668 {
669 #ifdef CFG_CORE_WORKAROUND_SPECTRE_BP_SEC
670 	uint32_t midr = read_midr();
671 	uint8_t vers = 0;
672 
673 	if (get_midr_implementer(midr) != MIDR_IMPLEMENTER_ARM)
674 		return (vaddr_t)thread_excp_vect;
675 	/*
676 	 * Variant rx, Revision py, for instance
677 	 * Variant 2 Revision 0 = r2p0 = 0x20
678 	 */
679 	vers = (get_midr_variant(midr) << 4) | get_midr_revision(midr);
680 
681 	/*
682 	 * Spectre-V2 (CVE-2017-5715) software workarounds covers what's
683 	 * needed for Spectre-BHB (CVE-2022-23960) too. The workaround for
684 	 * Spectre-V2 is more expensive than the one for Spectre-BHB so if
685 	 * possible select the workaround for Spectre-BHB.
686 	 */
687 	switch (get_midr_primary_part(midr)) {
688 #ifdef ARM32
689 	/* Spectre-V2 */
690 	case CORTEX_A8_PART_NUM:
691 	case CORTEX_A9_PART_NUM:
692 	case CORTEX_A17_PART_NUM:
693 #endif
694 	/* Spectre-V2 */
695 	case CORTEX_A57_PART_NUM:
696 	case CORTEX_A73_PART_NUM:
697 	case CORTEX_A75_PART_NUM:
698 		return select_vector_wa_spectre_v2();
699 #ifdef ARM32
700 	/* Spectre-V2 */
701 	case CORTEX_A15_PART_NUM:
702 		return (vaddr_t)thread_excp_vect_wa_a15_spectre_v2;
703 #endif
704 	/*
705 	 * Spectre-V2 for vers < r1p0
706 	 * Spectre-BHB for vers >= r1p0
707 	 */
708 	case CORTEX_A72_PART_NUM:
709 		if (vers < 0x10)
710 			return select_vector_wa_spectre_v2();
711 		return select_vector_wa_spectre_bhb(8);
712 
713 	/*
714 	 * Doing the more safe but expensive Spectre-V2 workaround for CPUs
715 	 * still being researched on the best mitigation sequence.
716 	 */
717 	case CORTEX_A65_PART_NUM:
718 	case CORTEX_A65AE_PART_NUM:
719 	case NEOVERSE_E1_PART_NUM:
720 		return select_vector_wa_spectre_v2();
721 
722 	/* Spectre-BHB */
723 	case CORTEX_A76_PART_NUM:
724 	case CORTEX_A76AE_PART_NUM:
725 	case CORTEX_A77_PART_NUM:
726 		return select_vector_wa_spectre_bhb(24);
727 	case CORTEX_A78_PART_NUM:
728 	case CORTEX_A78AE_PART_NUM:
729 	case CORTEX_A78C_PART_NUM:
730 	case CORTEX_A710_PART_NUM:
731 	case CORTEX_X1_PART_NUM:
732 	case CORTEX_X2_PART_NUM:
733 		return select_vector_wa_spectre_bhb(32);
734 	case NEOVERSE_N1_PART_NUM:
735 		return select_vector_wa_spectre_bhb(24);
736 	case NEOVERSE_N2_PART_NUM:
737 	case NEOVERSE_V1_PART_NUM:
738 		return select_vector_wa_spectre_bhb(32);
739 
740 	default:
741 		return (vaddr_t)thread_excp_vect;
742 	}
743 #endif /*CFG_CORE_WORKAROUND_SPECTRE_BP_SEC*/
744 
745 	return (vaddr_t)thread_excp_vect;
746 }
747 
748 void thread_init_per_cpu(void)
749 {
750 #ifdef ARM32
751 	struct thread_core_local *l = thread_get_core_local();
752 
753 #if !defined(CFG_WITH_ARM_TRUSTED_FW)
754 	/* Initialize secure monitor */
755 	sm_init(l->tmp_stack_va_end + STACK_TMP_OFFS);
756 #endif
757 	thread_set_irq_sp(l->tmp_stack_va_end);
758 	thread_set_fiq_sp(l->tmp_stack_va_end);
759 	thread_set_abt_sp((vaddr_t)l);
760 	thread_set_und_sp((vaddr_t)l);
761 #endif
762 
763 	thread_init_vbar(get_excp_vect());
764 
765 #ifdef CFG_FTRACE_SUPPORT
766 	/*
767 	 * Enable accesses to frequency register and physical counter
768 	 * register in EL0/PL0 required for timestamping during
769 	 * function tracing.
770 	 */
771 	write_cntkctl(read_cntkctl() | CNTKCTL_PL0PCTEN);
772 #endif
773 }
774 
775 #ifdef CFG_WITH_VFP
776 uint32_t thread_kernel_enable_vfp(void)
777 {
778 	uint32_t exceptions = thread_mask_exceptions(THREAD_EXCP_FOREIGN_INTR);
779 	struct thread_ctx *thr = threads + thread_get_id();
780 	struct thread_user_vfp_state *tuv = thr->vfp_state.uvfp;
781 
782 	assert(!vfp_is_enabled());
783 
784 	if (!thr->vfp_state.ns_saved) {
785 		vfp_lazy_save_state_final(&thr->vfp_state.ns,
786 					  true /*force_save*/);
787 		thr->vfp_state.ns_saved = true;
788 	} else if (thr->vfp_state.sec_lazy_saved &&
789 		   !thr->vfp_state.sec_saved) {
790 		/*
791 		 * This happens when we're handling an abort while the
792 		 * thread was using the VFP state.
793 		 */
794 		vfp_lazy_save_state_final(&thr->vfp_state.sec,
795 					  false /*!force_save*/);
796 		thr->vfp_state.sec_saved = true;
797 	} else if (tuv && tuv->lazy_saved && !tuv->saved) {
798 		/*
799 		 * This can happen either during syscall or abort
800 		 * processing (while processing a syscall).
801 		 */
802 		vfp_lazy_save_state_final(&tuv->vfp, false /*!force_save*/);
803 		tuv->saved = true;
804 	}
805 
806 	vfp_enable();
807 	return exceptions;
808 }
809 
810 void thread_kernel_disable_vfp(uint32_t state)
811 {
812 	uint32_t exceptions;
813 
814 	assert(vfp_is_enabled());
815 
816 	vfp_disable();
817 	exceptions = thread_get_exceptions();
818 	assert(exceptions & THREAD_EXCP_FOREIGN_INTR);
819 	exceptions &= ~THREAD_EXCP_FOREIGN_INTR;
820 	exceptions |= state & THREAD_EXCP_FOREIGN_INTR;
821 	thread_set_exceptions(exceptions);
822 }
823 
824 void thread_kernel_save_vfp(void)
825 {
826 	struct thread_ctx *thr = threads + thread_get_id();
827 
828 	assert(thread_get_exceptions() & THREAD_EXCP_FOREIGN_INTR);
829 	if (vfp_is_enabled()) {
830 		vfp_lazy_save_state_init(&thr->vfp_state.sec);
831 		thr->vfp_state.sec_lazy_saved = true;
832 	}
833 }
834 
835 void thread_kernel_restore_vfp(void)
836 {
837 	struct thread_ctx *thr = threads + thread_get_id();
838 
839 	assert(thread_get_exceptions() & THREAD_EXCP_FOREIGN_INTR);
840 	assert(!vfp_is_enabled());
841 	if (thr->vfp_state.sec_lazy_saved) {
842 		vfp_lazy_restore_state(&thr->vfp_state.sec,
843 				       thr->vfp_state.sec_saved);
844 		thr->vfp_state.sec_saved = false;
845 		thr->vfp_state.sec_lazy_saved = false;
846 	}
847 }
848 
849 void thread_user_enable_vfp(struct thread_user_vfp_state *uvfp)
850 {
851 	struct thread_ctx *thr = threads + thread_get_id();
852 	struct thread_user_vfp_state *tuv = thr->vfp_state.uvfp;
853 
854 	assert(thread_get_exceptions() & THREAD_EXCP_FOREIGN_INTR);
855 	assert(!vfp_is_enabled());
856 
857 	if (!thr->vfp_state.ns_saved) {
858 		vfp_lazy_save_state_final(&thr->vfp_state.ns,
859 					  true /*force_save*/);
860 		thr->vfp_state.ns_saved = true;
861 	} else if (tuv && uvfp != tuv) {
862 		if (tuv->lazy_saved && !tuv->saved) {
863 			vfp_lazy_save_state_final(&tuv->vfp,
864 						  false /*!force_save*/);
865 			tuv->saved = true;
866 		}
867 	}
868 
869 	if (uvfp->lazy_saved)
870 		vfp_lazy_restore_state(&uvfp->vfp, uvfp->saved);
871 	uvfp->lazy_saved = false;
872 	uvfp->saved = false;
873 
874 	thr->vfp_state.uvfp = uvfp;
875 	vfp_enable();
876 }
877 
878 void thread_user_save_vfp(void)
879 {
880 	struct thread_ctx *thr = threads + thread_get_id();
881 	struct thread_user_vfp_state *tuv = thr->vfp_state.uvfp;
882 
883 	assert(thread_get_exceptions() & THREAD_EXCP_FOREIGN_INTR);
884 	if (!vfp_is_enabled())
885 		return;
886 
887 	assert(tuv && !tuv->lazy_saved && !tuv->saved);
888 	vfp_lazy_save_state_init(&tuv->vfp);
889 	tuv->lazy_saved = true;
890 }
891 
892 void thread_user_clear_vfp(struct user_mode_ctx *uctx)
893 {
894 	struct thread_user_vfp_state *uvfp = &uctx->vfp;
895 	struct thread_ctx *thr = threads + thread_get_id();
896 
897 	if (uvfp == thr->vfp_state.uvfp)
898 		thr->vfp_state.uvfp = NULL;
899 	uvfp->lazy_saved = false;
900 	uvfp->saved = false;
901 }
902 #endif /*CFG_WITH_VFP*/
903 
904 #ifdef ARM32
905 static bool get_spsr(bool is_32bit, unsigned long entry_func, uint32_t *spsr)
906 {
907 	uint32_t s;
908 
909 	if (!is_32bit)
910 		return false;
911 
912 	s = read_cpsr();
913 	s &= ~(CPSR_MODE_MASK | CPSR_T | CPSR_IT_MASK1 | CPSR_IT_MASK2);
914 	s |= CPSR_MODE_USR;
915 	if (entry_func & 1)
916 		s |= CPSR_T;
917 	*spsr = s;
918 	return true;
919 }
920 #endif
921 
922 #ifdef ARM64
923 static bool get_spsr(bool is_32bit, unsigned long entry_func, uint32_t *spsr)
924 {
925 	uint32_t s;
926 
927 	if (is_32bit) {
928 		s = read_daif() & (SPSR_32_AIF_MASK << SPSR_32_AIF_SHIFT);
929 		s |= SPSR_MODE_RW_32 << SPSR_MODE_RW_SHIFT;
930 		s |= (entry_func & SPSR_32_T_MASK) << SPSR_32_T_SHIFT;
931 	} else {
932 		s = read_daif() & (SPSR_64_DAIF_MASK << SPSR_64_DAIF_SHIFT);
933 	}
934 
935 	*spsr = s;
936 	return true;
937 }
938 #endif
939 
940 static void set_ctx_regs(struct thread_ctx_regs *regs, unsigned long a0,
941 			 unsigned long a1, unsigned long a2, unsigned long a3,
942 			 unsigned long user_sp, unsigned long entry_func,
943 			 uint32_t spsr,
944 			 struct thread_pauth_keys *keys __maybe_unused)
945 {
946 	/*
947 	 * First clear all registers to avoid leaking information from
948 	 * other TAs or even the Core itself.
949 	 */
950 	*regs = (struct thread_ctx_regs){ };
951 #ifdef ARM32
952 	regs->r0 = a0;
953 	regs->r1 = a1;
954 	regs->r2 = a2;
955 	regs->r3 = a3;
956 	regs->usr_sp = user_sp;
957 	regs->pc = entry_func;
958 	regs->cpsr = spsr;
959 #endif
960 #ifdef ARM64
961 	regs->x[0] = a0;
962 	regs->x[1] = a1;
963 	regs->x[2] = a2;
964 	regs->x[3] = a3;
965 	regs->sp = user_sp;
966 	regs->pc = entry_func;
967 	regs->cpsr = spsr;
968 	regs->x[13] = user_sp;	/* Used when running TA in Aarch32 */
969 	regs->sp = user_sp;	/* Used when running TA in Aarch64 */
970 #ifdef CFG_TA_PAUTH
971 	assert(keys);
972 	regs->apiakey_hi = keys->apia_hi;
973 	regs->apiakey_lo = keys->apia_lo;
974 #endif
975 	/* Set frame pointer (user stack can't be unwound past this point) */
976 	regs->x[29] = 0;
977 #endif
978 }
979 
980 static struct thread_pauth_keys *thread_get_pauth_keys(void)
981 {
982 #if defined(CFG_TA_PAUTH)
983 	struct ts_session *s = ts_get_current_session();
984 	/* Only user TA's support the PAUTH keys */
985 	struct user_ta_ctx *utc = to_user_ta_ctx(s->ctx);
986 
987 	return &utc->uctx.keys;
988 #else
989 	return NULL;
990 #endif
991 }
992 
993 uint32_t thread_enter_user_mode(unsigned long a0, unsigned long a1,
994 		unsigned long a2, unsigned long a3, unsigned long user_sp,
995 		unsigned long entry_func, bool is_32bit,
996 		uint32_t *exit_status0, uint32_t *exit_status1)
997 {
998 	uint32_t spsr = 0;
999 	uint32_t exceptions = 0;
1000 	uint32_t rc = 0;
1001 	struct thread_ctx_regs *regs = NULL;
1002 	struct thread_pauth_keys *keys = NULL;
1003 
1004 	tee_ta_update_session_utime_resume();
1005 
1006 	keys = thread_get_pauth_keys();
1007 
1008 	/* Derive SPSR from current CPSR/PSTATE readout. */
1009 	if (!get_spsr(is_32bit, entry_func, &spsr)) {
1010 		*exit_status0 = 1; /* panic */
1011 		*exit_status1 = 0xbadbadba;
1012 		return 0;
1013 	}
1014 
1015 	exceptions = thread_mask_exceptions(THREAD_EXCP_ALL);
1016 	/*
1017 	 * We're using the per thread location of saved context registers
1018 	 * for temporary storage. Now that exceptions are masked they will
1019 	 * not be used for any thing else until they are eventually
1020 	 * unmasked when user mode has been entered.
1021 	 */
1022 	regs = thread_get_ctx_regs();
1023 	set_ctx_regs(regs, a0, a1, a2, a3, user_sp, entry_func, spsr, keys);
1024 	rc = __thread_enter_user_mode(regs, exit_status0, exit_status1);
1025 	thread_unmask_exceptions(exceptions);
1026 	return rc;
1027 }
1028 
1029 #ifdef CFG_CORE_UNMAP_CORE_AT_EL0
1030 void thread_get_user_kcode(struct mobj **mobj, size_t *offset,
1031 			   vaddr_t *va, size_t *sz)
1032 {
1033 	core_mmu_get_user_va_range(va, NULL);
1034 	*mobj = mobj_tee_ram_rx;
1035 	*sz = thread_user_kcode_size;
1036 	*offset = thread_user_kcode_va - (vaddr_t)mobj_get_va(*mobj, 0, *sz);
1037 }
1038 #endif
1039 
1040 #if defined(CFG_CORE_UNMAP_CORE_AT_EL0) && \
1041 	defined(CFG_CORE_WORKAROUND_SPECTRE_BP_SEC) && defined(ARM64)
1042 void thread_get_user_kdata(struct mobj **mobj, size_t *offset,
1043 			   vaddr_t *va, size_t *sz)
1044 {
1045 	vaddr_t v;
1046 
1047 	core_mmu_get_user_va_range(&v, NULL);
1048 	*va = v + thread_user_kcode_size;
1049 	*mobj = mobj_tee_ram_rw;
1050 	*sz = sizeof(thread_user_kdata_page);
1051 	*offset = (vaddr_t)thread_user_kdata_page -
1052 		  (vaddr_t)mobj_get_va(*mobj, 0, *sz);
1053 }
1054 #endif
1055 
1056 static void setup_unwind_user_mode(struct thread_svc_regs *regs)
1057 {
1058 #ifdef ARM32
1059 	regs->lr = (uintptr_t)thread_unwind_user_mode;
1060 	regs->spsr = read_cpsr();
1061 #endif
1062 #ifdef ARM64
1063 	regs->elr = (uintptr_t)thread_unwind_user_mode;
1064 	regs->spsr = SPSR_64(SPSR_64_MODE_EL1, SPSR_64_MODE_SP_EL0, 0);
1065 	regs->spsr |= read_daif();
1066 	/*
1067 	 * Regs is the value of stack pointer before calling the SVC
1068 	 * handler.  By the addition matches for the reserved space at the
1069 	 * beginning of el0_sync_svc(). This prepares the stack when
1070 	 * returning to thread_unwind_user_mode instead of a normal
1071 	 * exception return.
1072 	 */
1073 	regs->sp_el0 = (uint64_t)(regs + 1);
1074 #endif
1075 }
1076 
1077 static void gprof_set_status(struct ts_session *s __maybe_unused,
1078 			     enum ts_gprof_status status __maybe_unused)
1079 {
1080 #ifdef CFG_TA_GPROF_SUPPORT
1081 	if (s->ctx->ops->gprof_set_status)
1082 		s->ctx->ops->gprof_set_status(status);
1083 #endif
1084 }
1085 
1086 /*
1087  * Note: this function is weak just to make it possible to exclude it from
1088  * the unpaged area.
1089  */
1090 void __weak thread_svc_handler(struct thread_svc_regs *regs)
1091 {
1092 	struct ts_session *sess = NULL;
1093 	uint32_t state = 0;
1094 
1095 	/* Enable native interrupts */
1096 	state = thread_get_exceptions();
1097 	thread_unmask_exceptions(state & ~THREAD_EXCP_NATIVE_INTR);
1098 
1099 	thread_user_save_vfp();
1100 
1101 	sess = ts_get_current_session();
1102 	/*
1103 	 * User mode service has just entered kernel mode, suspend gprof
1104 	 * collection until we're about to switch back again.
1105 	 */
1106 	gprof_set_status(sess, TS_GPROF_SUSPEND);
1107 
1108 	/* Restore foreign interrupts which are disabled on exception entry */
1109 	thread_restore_foreign_intr();
1110 
1111 	assert(sess && sess->handle_svc);
1112 	if (sess->handle_svc(regs)) {
1113 		/* We're about to switch back to user mode */
1114 		gprof_set_status(sess, TS_GPROF_RESUME);
1115 	} else {
1116 		/* We're returning from __thread_enter_user_mode() */
1117 		setup_unwind_user_mode(regs);
1118 	}
1119 }
1120 
1121 #ifdef CFG_WITH_ARM_TRUSTED_FW
1122 /*
1123  * These five functions are __weak to allow platforms to override them if
1124  * needed.
1125  */
1126 unsigned long __weak thread_cpu_off_handler(unsigned long a0 __unused,
1127 					    unsigned long a1 __unused)
1128 {
1129 	return 0;
1130 }
1131 DECLARE_KEEP_PAGER(thread_cpu_off_handler);
1132 
1133 unsigned long __weak thread_cpu_suspend_handler(unsigned long a0 __unused,
1134 						unsigned long a1 __unused)
1135 {
1136 	return 0;
1137 }
1138 DECLARE_KEEP_PAGER(thread_cpu_suspend_handler);
1139 
1140 unsigned long __weak thread_cpu_resume_handler(unsigned long a0 __unused,
1141 					       unsigned long a1 __unused)
1142 {
1143 	return 0;
1144 }
1145 DECLARE_KEEP_PAGER(thread_cpu_resume_handler);
1146 
1147 unsigned long __weak thread_system_off_handler(unsigned long a0 __unused,
1148 					       unsigned long a1 __unused)
1149 {
1150 	return 0;
1151 }
1152 DECLARE_KEEP_PAGER(thread_system_off_handler);
1153 
1154 unsigned long __weak thread_system_reset_handler(unsigned long a0 __unused,
1155 						 unsigned long a1 __unused)
1156 {
1157 	return 0;
1158 }
1159 DECLARE_KEEP_PAGER(thread_system_reset_handler);
1160 #endif /*CFG_WITH_ARM_TRUSTED_FW*/
1161