xref: /optee_os/core/arch/arm/kernel/thread.c (revision 5b25c76ac40f830867e3d60800120ffd7874e8dc)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2016, Linaro Limited
4  * Copyright (c) 2014, STMicroelectronics International N.V.
5  */
6 
7 #include <platform_config.h>
8 
9 #include <arm.h>
10 #include <assert.h>
11 #include <io.h>
12 #include <keep.h>
13 #include <kernel/asan.h>
14 #include <kernel/linker.h>
15 #include <kernel/lockdep.h>
16 #include <kernel/misc.h>
17 #include <kernel/panic.h>
18 #include <kernel/spinlock.h>
19 #include <kernel/tee_ta_manager.h>
20 #include <kernel/thread_defs.h>
21 #include <kernel/thread.h>
22 #include <kernel/virtualization.h>
23 #include <mm/core_memprot.h>
24 #include <mm/mobj.h>
25 #include <mm/tee_mm.h>
26 #include <mm/tee_mmu.h>
27 #include <mm/tee_pager.h>
28 #include <smccc.h>
29 #include <sm/sm.h>
30 #include <trace.h>
31 #include <util.h>
32 
33 #include "thread_private.h"
34 
35 #ifdef CFG_WITH_ARM_TRUSTED_FW
36 #define STACK_TMP_OFFS		0
37 #else
38 #define STACK_TMP_OFFS		SM_STACK_TMP_RESERVE_SIZE
39 #endif
40 
41 
42 #ifdef ARM32
43 #ifdef CFG_CORE_SANITIZE_KADDRESS
44 #define STACK_TMP_SIZE		(3072 + STACK_TMP_OFFS)
45 #else
46 #define STACK_TMP_SIZE		(2048 + STACK_TMP_OFFS)
47 #endif
48 #define STACK_THREAD_SIZE	8192
49 
50 #if defined(CFG_CORE_SANITIZE_KADDRESS) || defined(__clang__)
51 #define STACK_ABT_SIZE		3072
52 #else
53 #define STACK_ABT_SIZE		2048
54 #endif
55 
56 #endif /*ARM32*/
57 
58 #ifdef ARM64
59 #define STACK_TMP_SIZE		(2048 + STACK_TMP_OFFS)
60 #define STACK_THREAD_SIZE	8192
61 
62 #if TRACE_LEVEL > 0
63 #define STACK_ABT_SIZE		3072
64 #else
65 #define STACK_ABT_SIZE		1024
66 #endif
67 #endif /*ARM64*/
68 
69 struct thread_ctx threads[CFG_NUM_THREADS];
70 
71 struct thread_core_local thread_core_local[CFG_TEE_CORE_NB_CORE] __nex_bss;
72 
73 #ifdef CFG_WITH_STACK_CANARIES
74 #ifdef ARM32
75 #define STACK_CANARY_SIZE	(4 * sizeof(uint32_t))
76 #endif
77 #ifdef ARM64
78 #define STACK_CANARY_SIZE	(8 * sizeof(uint32_t))
79 #endif
80 #define START_CANARY_VALUE	0xdededede
81 #define END_CANARY_VALUE	0xabababab
82 #define GET_START_CANARY(name, stack_num) name[stack_num][0]
83 #define GET_END_CANARY(name, stack_num) \
84 	name[stack_num][sizeof(name[stack_num]) / sizeof(uint32_t) - 1]
85 #else
86 #define STACK_CANARY_SIZE	0
87 #endif
88 
89 #define DECLARE_STACK(name, num_stacks, stack_size, linkage) \
90 linkage uint32_t name[num_stacks] \
91 		[ROUNDUP(stack_size + STACK_CANARY_SIZE, STACK_ALIGNMENT) / \
92 		sizeof(uint32_t)] \
93 		__attribute__((section(".nozi_stack." # name), \
94 			       aligned(STACK_ALIGNMENT)))
95 
96 #define STACK_SIZE(stack) (sizeof(stack) - STACK_CANARY_SIZE / 2)
97 
98 #define GET_STACK(stack) \
99 	((vaddr_t)(stack) + STACK_SIZE(stack))
100 
101 DECLARE_STACK(stack_tmp, CFG_TEE_CORE_NB_CORE, STACK_TMP_SIZE, static);
102 DECLARE_STACK(stack_abt, CFG_TEE_CORE_NB_CORE, STACK_ABT_SIZE, static);
103 #ifndef CFG_WITH_PAGER
104 DECLARE_STACK(stack_thread, CFG_NUM_THREADS, STACK_THREAD_SIZE, static);
105 #endif
106 
107 const void *stack_tmp_export __section(".identity_map.stack_tmp_export") =
108 	(uint8_t *)stack_tmp + sizeof(stack_tmp[0]) -
109 	(STACK_TMP_OFFS + STACK_CANARY_SIZE / 2);
110 const uint32_t stack_tmp_stride __section(".identity_map.stack_tmp_stride") =
111 	sizeof(stack_tmp[0]);
112 
113 /*
114  * These stack setup info are required by secondary boot cores before they
115  * each locally enable the pager (the mmu). Hence kept in pager sections.
116  */
117 KEEP_PAGER(stack_tmp_export);
118 KEEP_PAGER(stack_tmp_stride);
119 
120 thread_pm_handler_t thread_cpu_on_handler_ptr __nex_bss;
121 thread_pm_handler_t thread_cpu_off_handler_ptr __nex_bss;
122 thread_pm_handler_t thread_cpu_suspend_handler_ptr __nex_bss;
123 thread_pm_handler_t thread_cpu_resume_handler_ptr __nex_bss;
124 thread_pm_handler_t thread_system_off_handler_ptr __nex_bss;
125 thread_pm_handler_t thread_system_reset_handler_ptr __nex_bss;
126 
127 #ifdef CFG_CORE_UNMAP_CORE_AT_EL0
128 static vaddr_t thread_user_kcode_va __nex_bss;
129 long thread_user_kcode_offset __nex_bss;
130 static size_t thread_user_kcode_size __nex_bss;
131 #endif
132 
133 #if defined(CFG_CORE_UNMAP_CORE_AT_EL0) && \
134 	defined(CFG_CORE_WORKAROUND_SPECTRE_BP_SEC) && defined(ARM64)
135 long thread_user_kdata_sp_offset __nex_bss;
136 static uint8_t thread_user_kdata_page[
137 	ROUNDUP(sizeof(thread_core_local), SMALL_PAGE_SIZE)]
138 	__aligned(SMALL_PAGE_SIZE)
139 #ifndef CFG_VIRTUALIZATION
140 	__section(".nozi.kdata_page");
141 #else
142 	__section(".nex_nozi.kdata_page");
143 #endif
144 #endif
145 
146 static unsigned int thread_global_lock __nex_bss = SPINLOCK_UNLOCK;
147 
148 static void init_canaries(void)
149 {
150 #ifdef CFG_WITH_STACK_CANARIES
151 	size_t n;
152 #define INIT_CANARY(name)						\
153 	for (n = 0; n < ARRAY_SIZE(name); n++) {			\
154 		uint32_t *start_canary = &GET_START_CANARY(name, n);	\
155 		uint32_t *end_canary = &GET_END_CANARY(name, n);	\
156 									\
157 		*start_canary = START_CANARY_VALUE;			\
158 		*end_canary = END_CANARY_VALUE;				\
159 		DMSG("#Stack canaries for %s[%zu] with top at %p",	\
160 			#name, n, (void *)(end_canary - 1));		\
161 		DMSG("watch *%p", (void *)end_canary);			\
162 	}
163 
164 	INIT_CANARY(stack_tmp);
165 	INIT_CANARY(stack_abt);
166 #if !defined(CFG_WITH_PAGER) && !defined(CFG_VIRTUALIZATION)
167 	INIT_CANARY(stack_thread);
168 #endif
169 #endif/*CFG_WITH_STACK_CANARIES*/
170 }
171 
172 #define CANARY_DIED(stack, loc, n) \
173 	do { \
174 		EMSG_RAW("Dead canary at %s of '%s[%zu]'", #loc, #stack, n); \
175 		panic(); \
176 	} while (0)
177 
178 void thread_check_canaries(void)
179 {
180 #ifdef CFG_WITH_STACK_CANARIES
181 	size_t n;
182 
183 	for (n = 0; n < ARRAY_SIZE(stack_tmp); n++) {
184 		if (GET_START_CANARY(stack_tmp, n) != START_CANARY_VALUE)
185 			CANARY_DIED(stack_tmp, start, n);
186 		if (GET_END_CANARY(stack_tmp, n) != END_CANARY_VALUE)
187 			CANARY_DIED(stack_tmp, end, n);
188 	}
189 
190 	for (n = 0; n < ARRAY_SIZE(stack_abt); n++) {
191 		if (GET_START_CANARY(stack_abt, n) != START_CANARY_VALUE)
192 			CANARY_DIED(stack_abt, start, n);
193 		if (GET_END_CANARY(stack_abt, n) != END_CANARY_VALUE)
194 			CANARY_DIED(stack_abt, end, n);
195 
196 	}
197 #if !defined(CFG_WITH_PAGER) && !defined(CFG_VIRTUALIZATION)
198 	for (n = 0; n < ARRAY_SIZE(stack_thread); n++) {
199 		if (GET_START_CANARY(stack_thread, n) != START_CANARY_VALUE)
200 			CANARY_DIED(stack_thread, start, n);
201 		if (GET_END_CANARY(stack_thread, n) != END_CANARY_VALUE)
202 			CANARY_DIED(stack_thread, end, n);
203 	}
204 #endif
205 #endif/*CFG_WITH_STACK_CANARIES*/
206 }
207 
208 void thread_lock_global(void)
209 {
210 	cpu_spin_lock(&thread_global_lock);
211 }
212 
213 void thread_unlock_global(void)
214 {
215 	cpu_spin_unlock(&thread_global_lock);
216 }
217 
218 #ifdef ARM32
219 uint32_t thread_get_exceptions(void)
220 {
221 	uint32_t cpsr = read_cpsr();
222 
223 	return (cpsr >> CPSR_F_SHIFT) & THREAD_EXCP_ALL;
224 }
225 
226 void thread_set_exceptions(uint32_t exceptions)
227 {
228 	uint32_t cpsr = read_cpsr();
229 
230 	/* Foreign interrupts must not be unmasked while holding a spinlock */
231 	if (!(exceptions & THREAD_EXCP_FOREIGN_INTR))
232 		assert_have_no_spinlock();
233 
234 	cpsr &= ~(THREAD_EXCP_ALL << CPSR_F_SHIFT);
235 	cpsr |= ((exceptions & THREAD_EXCP_ALL) << CPSR_F_SHIFT);
236 	write_cpsr(cpsr);
237 }
238 #endif /*ARM32*/
239 
240 #ifdef ARM64
241 uint32_t thread_get_exceptions(void)
242 {
243 	uint32_t daif = read_daif();
244 
245 	return (daif >> DAIF_F_SHIFT) & THREAD_EXCP_ALL;
246 }
247 
248 void thread_set_exceptions(uint32_t exceptions)
249 {
250 	uint32_t daif = read_daif();
251 
252 	/* Foreign interrupts must not be unmasked while holding a spinlock */
253 	if (!(exceptions & THREAD_EXCP_FOREIGN_INTR))
254 		assert_have_no_spinlock();
255 
256 	daif &= ~(THREAD_EXCP_ALL << DAIF_F_SHIFT);
257 	daif |= ((exceptions & THREAD_EXCP_ALL) << DAIF_F_SHIFT);
258 	write_daif(daif);
259 }
260 #endif /*ARM64*/
261 
262 uint32_t thread_mask_exceptions(uint32_t exceptions)
263 {
264 	uint32_t state = thread_get_exceptions();
265 
266 	thread_set_exceptions(state | (exceptions & THREAD_EXCP_ALL));
267 	return state;
268 }
269 
270 void thread_unmask_exceptions(uint32_t state)
271 {
272 	thread_set_exceptions(state & THREAD_EXCP_ALL);
273 }
274 
275 
276 struct thread_core_local *thread_get_core_local(void)
277 {
278 	uint32_t cpu_id = get_core_pos();
279 
280 	/*
281 	 * Foreign interrupts must be disabled before playing with core_local
282 	 * since we otherwise may be rescheduled to a different core in the
283 	 * middle of this function.
284 	 */
285 	assert(thread_get_exceptions() & THREAD_EXCP_FOREIGN_INTR);
286 
287 	assert(cpu_id < CFG_TEE_CORE_NB_CORE);
288 	return &thread_core_local[cpu_id];
289 }
290 
291 static void thread_lazy_save_ns_vfp(void)
292 {
293 #ifdef CFG_WITH_VFP
294 	struct thread_ctx *thr = threads + thread_get_id();
295 
296 	thr->vfp_state.ns_saved = false;
297 	vfp_lazy_save_state_init(&thr->vfp_state.ns);
298 #endif /*CFG_WITH_VFP*/
299 }
300 
301 static void thread_lazy_restore_ns_vfp(void)
302 {
303 #ifdef CFG_WITH_VFP
304 	struct thread_ctx *thr = threads + thread_get_id();
305 	struct thread_user_vfp_state *tuv = thr->vfp_state.uvfp;
306 
307 	assert(!thr->vfp_state.sec_lazy_saved && !thr->vfp_state.sec_saved);
308 
309 	if (tuv && tuv->lazy_saved && !tuv->saved) {
310 		vfp_lazy_save_state_final(&tuv->vfp, false /*!force_save*/);
311 		tuv->saved = true;
312 	}
313 
314 	vfp_lazy_restore_state(&thr->vfp_state.ns, thr->vfp_state.ns_saved);
315 	thr->vfp_state.ns_saved = false;
316 #endif /*CFG_WITH_VFP*/
317 }
318 
319 #ifdef ARM32
320 static void init_regs(struct thread_ctx *thread, uint32_t a0, uint32_t a1,
321 		      uint32_t a2, uint32_t a3)
322 {
323 	thread->regs.pc = (uint32_t)thread_std_smc_entry;
324 
325 	/*
326 	 * Stdcalls starts in SVC mode with masked foreign interrupts, masked
327 	 * Asynchronous abort and unmasked native interrupts.
328 	 */
329 	thread->regs.cpsr = read_cpsr() & ARM32_CPSR_E;
330 	thread->regs.cpsr |= CPSR_MODE_SVC | CPSR_A |
331 			(THREAD_EXCP_FOREIGN_INTR << ARM32_CPSR_F_SHIFT);
332 	/* Enable thumb mode if it's a thumb instruction */
333 	if (thread->regs.pc & 1)
334 		thread->regs.cpsr |= CPSR_T;
335 	/* Reinitialize stack pointer */
336 	thread->regs.svc_sp = thread->stack_va_end;
337 
338 	/*
339 	 * Copy arguments into context. This will make the
340 	 * arguments appear in r0-r7 when thread is started.
341 	 */
342 	thread->regs.r0 = a0;
343 	thread->regs.r1 = a1;
344 	thread->regs.r2 = a2;
345 	thread->regs.r3 = a3;
346 	thread->regs.r4 = 0;
347 	thread->regs.r5 = 0;
348 	thread->regs.r6 = 0;
349 	thread->regs.r7 = 0;
350 }
351 #endif /*ARM32*/
352 
353 #ifdef ARM64
354 static void init_regs(struct thread_ctx *thread, uint32_t a0, uint32_t a1,
355 		      uint32_t a2, uint32_t a3)
356 {
357 	thread->regs.pc = (uint64_t)thread_std_smc_entry;
358 
359 	/*
360 	 * Stdcalls starts in SVC mode with masked foreign interrupts, masked
361 	 * Asynchronous abort and unmasked native interrupts.
362 	 */
363 	thread->regs.cpsr = SPSR_64(SPSR_64_MODE_EL1, SPSR_64_MODE_SP_EL0,
364 				THREAD_EXCP_FOREIGN_INTR | DAIFBIT_ABT);
365 	/* Reinitialize stack pointer */
366 	thread->regs.sp = thread->stack_va_end;
367 
368 	/*
369 	 * Copy arguments into context. This will make the
370 	 * arguments appear in x0-x7 when thread is started.
371 	 */
372 	thread->regs.x[0] = a0;
373 	thread->regs.x[1] = a1;
374 	thread->regs.x[2] = a2;
375 	thread->regs.x[3] = a3;
376 	thread->regs.x[4] = 0;
377 	thread->regs.x[5] = 0;
378 	thread->regs.x[6] = 0;
379 	thread->regs.x[7] = 0;
380 
381 	/* Set up frame pointer as per the Aarch64 AAPCS */
382 	thread->regs.x[29] = 0;
383 }
384 #endif /*ARM64*/
385 
386 void thread_init_boot_thread(void)
387 {
388 	struct thread_core_local *l = thread_get_core_local();
389 
390 	thread_init_threads();
391 
392 	l->curr_thread = 0;
393 	threads[0].state = THREAD_STATE_ACTIVE;
394 }
395 
396 void thread_clr_boot_thread(void)
397 {
398 	struct thread_core_local *l = thread_get_core_local();
399 
400 	assert(l->curr_thread >= 0 && l->curr_thread < CFG_NUM_THREADS);
401 	assert(threads[l->curr_thread].state == THREAD_STATE_ACTIVE);
402 	threads[l->curr_thread].state = THREAD_STATE_FREE;
403 	l->curr_thread = -1;
404 }
405 
406 void thread_alloc_and_run(uint32_t a0, uint32_t a1, uint32_t a2, uint32_t a3)
407 {
408 	size_t n;
409 	struct thread_core_local *l = thread_get_core_local();
410 	bool found_thread = false;
411 
412 	assert(l->curr_thread == -1);
413 
414 	thread_lock_global();
415 
416 	for (n = 0; n < CFG_NUM_THREADS; n++) {
417 		if (threads[n].state == THREAD_STATE_FREE) {
418 			threads[n].state = THREAD_STATE_ACTIVE;
419 			found_thread = true;
420 			break;
421 		}
422 	}
423 
424 	thread_unlock_global();
425 
426 	if (!found_thread)
427 		return;
428 
429 	l->curr_thread = n;
430 
431 	threads[n].flags = 0;
432 	init_regs(threads + n, a0, a1, a2, a3);
433 
434 	thread_lazy_save_ns_vfp();
435 	thread_resume(&threads[n].regs);
436 	/*NOTREACHED*/
437 	panic();
438 }
439 
440 #ifdef ARM32
441 static void copy_a0_to_a3(struct thread_ctx_regs *regs, uint32_t a0,
442 			  uint32_t a1, uint32_t a2, uint32_t a3)
443 {
444 	/*
445 	 * Update returned values from RPC, values will appear in
446 	 * r0-r3 when thread is resumed.
447 	 */
448 	regs->r0 = a0;
449 	regs->r1 = a1;
450 	regs->r2 = a2;
451 	regs->r3 = a3;
452 }
453 #endif /*ARM32*/
454 
455 #ifdef ARM64
456 static void copy_a0_to_a3(struct thread_ctx_regs *regs, uint32_t a0,
457 			  uint32_t a1, uint32_t a2, uint32_t a3)
458 {
459 	/*
460 	 * Update returned values from RPC, values will appear in
461 	 * x0-x3 when thread is resumed.
462 	 */
463 	regs->x[0] = a0;
464 	regs->x[1] = a1;
465 	regs->x[2] = a2;
466 	regs->x[3] = a3;
467 }
468 #endif /*ARM64*/
469 
470 #ifdef ARM32
471 static bool is_from_user(uint32_t cpsr)
472 {
473 	return (cpsr & ARM32_CPSR_MODE_MASK) == ARM32_CPSR_MODE_USR;
474 }
475 #endif
476 
477 #ifdef ARM64
478 static bool is_from_user(uint32_t cpsr)
479 {
480 	if (cpsr & (SPSR_MODE_RW_32 << SPSR_MODE_RW_SHIFT))
481 		return true;
482 	if (((cpsr >> SPSR_64_MODE_EL_SHIFT) & SPSR_64_MODE_EL_MASK) ==
483 	     SPSR_64_MODE_EL0)
484 		return true;
485 	return false;
486 }
487 #endif
488 
489 #ifdef CFG_SYSCALL_FTRACE
490 static void __noprof ftrace_suspend(void)
491 {
492 	struct tee_ta_session *s = TAILQ_FIRST(&thread_get_tsd()->sess_stack);
493 
494 	if (!s)
495 		return;
496 
497 	if (s->fbuf)
498 		s->fbuf->syscall_trace_suspended = true;
499 }
500 
501 static void __noprof ftrace_resume(void)
502 {
503 	struct tee_ta_session *s = TAILQ_FIRST(&thread_get_tsd()->sess_stack);
504 
505 	if (!s)
506 		return;
507 
508 	if (s->fbuf)
509 		s->fbuf->syscall_trace_suspended = false;
510 }
511 #else
512 static void __noprof ftrace_suspend(void)
513 {
514 }
515 
516 static void __noprof ftrace_resume(void)
517 {
518 }
519 #endif
520 
521 static bool is_user_mode(struct thread_ctx_regs *regs)
522 {
523 	return is_from_user((uint32_t)regs->cpsr);
524 }
525 
526 void thread_resume_from_rpc(uint32_t thread_id, uint32_t a0, uint32_t a1,
527 			    uint32_t a2, uint32_t a3)
528 {
529 	size_t n = thread_id;
530 	struct thread_core_local *l = thread_get_core_local();
531 	bool found_thread = false;
532 
533 	assert(l->curr_thread == -1);
534 
535 	thread_lock_global();
536 
537 	if (n < CFG_NUM_THREADS && threads[n].state == THREAD_STATE_SUSPENDED) {
538 		threads[n].state = THREAD_STATE_ACTIVE;
539 		found_thread = true;
540 	}
541 
542 	thread_unlock_global();
543 
544 	if (!found_thread)
545 		return;
546 
547 	l->curr_thread = n;
548 
549 	if (threads[n].have_user_map) {
550 		core_mmu_set_user_map(&threads[n].user_map);
551 		if (threads[n].flags & THREAD_FLAGS_EXIT_ON_FOREIGN_INTR)
552 			tee_ta_ftrace_update_times_resume();
553 	}
554 
555 	if (is_user_mode(&threads[n].regs))
556 		tee_ta_update_session_utime_resume();
557 
558 	/*
559 	 * Return from RPC to request service of a foreign interrupt must not
560 	 * get parameters from non-secure world.
561 	 */
562 	if (threads[n].flags & THREAD_FLAGS_COPY_ARGS_ON_RETURN) {
563 		copy_a0_to_a3(&threads[n].regs, a0, a1, a2, a3);
564 		threads[n].flags &= ~THREAD_FLAGS_COPY_ARGS_ON_RETURN;
565 	}
566 
567 	thread_lazy_save_ns_vfp();
568 
569 	if (threads[n].have_user_map)
570 		ftrace_resume();
571 
572 	thread_resume(&threads[n].regs);
573 	/*NOTREACHED*/
574 	panic();
575 }
576 
577 void *thread_get_tmp_sp(void)
578 {
579 	struct thread_core_local *l = thread_get_core_local();
580 
581 	return (void *)l->tmp_stack_va_end;
582 }
583 
584 #ifdef ARM64
585 vaddr_t thread_get_saved_thread_sp(void)
586 {
587 	struct thread_core_local *l = thread_get_core_local();
588 	int ct = l->curr_thread;
589 
590 	assert(ct != -1);
591 	return threads[ct].kern_sp;
592 }
593 #endif /*ARM64*/
594 
595 vaddr_t thread_stack_start(void)
596 {
597 	struct thread_ctx *thr;
598 	int ct = thread_get_id_may_fail();
599 
600 	if (ct == -1)
601 		return 0;
602 
603 	thr = threads + ct;
604 	return thr->stack_va_end - STACK_THREAD_SIZE;
605 }
606 
607 size_t thread_stack_size(void)
608 {
609 	return STACK_THREAD_SIZE;
610 }
611 
612 bool thread_is_from_abort_mode(void)
613 {
614 	struct thread_core_local *l = thread_get_core_local();
615 
616 	return (l->flags >> THREAD_CLF_SAVED_SHIFT) & THREAD_CLF_ABORT;
617 }
618 
619 #ifdef ARM32
620 bool thread_is_in_normal_mode(void)
621 {
622 	return (read_cpsr() & ARM32_CPSR_MODE_MASK) == ARM32_CPSR_MODE_SVC;
623 }
624 #endif
625 
626 #ifdef ARM64
627 bool thread_is_in_normal_mode(void)
628 {
629 	uint32_t exceptions = thread_mask_exceptions(THREAD_EXCP_FOREIGN_INTR);
630 	struct thread_core_local *l = thread_get_core_local();
631 	bool ret;
632 
633 	/* If any bit in l->flags is set we're handling some exception. */
634 	ret = !l->flags;
635 	thread_unmask_exceptions(exceptions);
636 
637 	return ret;
638 }
639 #endif
640 
641 void thread_state_free(void)
642 {
643 	struct thread_core_local *l = thread_get_core_local();
644 	int ct = l->curr_thread;
645 
646 	assert(ct != -1);
647 
648 	thread_lazy_restore_ns_vfp();
649 	tee_pager_release_phys(
650 		(void *)(threads[ct].stack_va_end - STACK_THREAD_SIZE),
651 		STACK_THREAD_SIZE);
652 
653 	thread_lock_global();
654 
655 	assert(threads[ct].state == THREAD_STATE_ACTIVE);
656 	threads[ct].state = THREAD_STATE_FREE;
657 	threads[ct].flags = 0;
658 	l->curr_thread = -1;
659 
660 #ifdef CFG_VIRTUALIZATION
661 	virt_unset_guest();
662 #endif
663 	thread_unlock_global();
664 }
665 
666 #ifdef CFG_WITH_PAGER
667 static void release_unused_kernel_stack(struct thread_ctx *thr,
668 					uint32_t cpsr __maybe_unused)
669 {
670 #ifdef ARM64
671 	/*
672 	 * If we're from user mode then thr->regs.sp is the saved user
673 	 * stack pointer and thr->kern_sp holds the last kernel stack
674 	 * pointer. But if we're from kernel mode then thr->kern_sp isn't
675 	 * up to date so we need to read from thr->regs.sp instead.
676 	 */
677 	vaddr_t sp = is_from_user(cpsr) ?  thr->kern_sp : thr->regs.sp;
678 #else
679 	vaddr_t sp = thr->regs.svc_sp;
680 #endif
681 	vaddr_t base = thr->stack_va_end - STACK_THREAD_SIZE;
682 	size_t len = sp - base;
683 
684 	tee_pager_release_phys((void *)base, len);
685 }
686 #else
687 static void release_unused_kernel_stack(struct thread_ctx *thr __unused,
688 					uint32_t cpsr __unused)
689 {
690 }
691 #endif
692 
693 int thread_state_suspend(uint32_t flags, uint32_t cpsr, vaddr_t pc)
694 {
695 	struct thread_core_local *l = thread_get_core_local();
696 	int ct = l->curr_thread;
697 
698 	assert(ct != -1);
699 
700 	if (core_mmu_user_mapping_is_active())
701 		ftrace_suspend();
702 
703 	thread_check_canaries();
704 
705 	release_unused_kernel_stack(threads + ct, cpsr);
706 
707 	if (is_from_user(cpsr)) {
708 		thread_user_save_vfp();
709 		tee_ta_update_session_utime_suspend();
710 		tee_ta_gprof_sample_pc(pc);
711 	}
712 	thread_lazy_restore_ns_vfp();
713 
714 	thread_lock_global();
715 
716 	assert(threads[ct].state == THREAD_STATE_ACTIVE);
717 	threads[ct].flags |= flags;
718 	threads[ct].regs.cpsr = cpsr;
719 	threads[ct].regs.pc = pc;
720 	threads[ct].state = THREAD_STATE_SUSPENDED;
721 
722 	threads[ct].have_user_map = core_mmu_user_mapping_is_active();
723 	if (threads[ct].have_user_map) {
724 		if (threads[ct].flags & THREAD_FLAGS_EXIT_ON_FOREIGN_INTR)
725 			tee_ta_ftrace_update_times_suspend();
726 		core_mmu_get_user_map(&threads[ct].user_map);
727 		core_mmu_set_user_map(NULL);
728 	}
729 
730 	l->curr_thread = -1;
731 
732 #ifdef CFG_VIRTUALIZATION
733 	virt_unset_guest();
734 #endif
735 
736 	thread_unlock_global();
737 
738 	return ct;
739 }
740 
741 #ifdef ARM32
742 static void set_tmp_stack(struct thread_core_local *l, vaddr_t sp)
743 {
744 	l->tmp_stack_va_end = sp;
745 	thread_set_irq_sp(sp);
746 	thread_set_fiq_sp(sp);
747 }
748 
749 static void set_abt_stack(struct thread_core_local *l, vaddr_t sp)
750 {
751 	l->abt_stack_va_end = sp;
752 	thread_set_abt_sp((vaddr_t)l);
753 	thread_set_und_sp((vaddr_t)l);
754 }
755 #endif /*ARM32*/
756 
757 #ifdef ARM64
758 static void set_tmp_stack(struct thread_core_local *l, vaddr_t sp)
759 {
760 	/*
761 	 * We're already using the tmp stack when this function is called
762 	 * so there's no need to assign it to any stack pointer. However,
763 	 * we'll need to restore it at different times so store it here.
764 	 */
765 	l->tmp_stack_va_end = sp;
766 }
767 
768 static void set_abt_stack(struct thread_core_local *l, vaddr_t sp)
769 {
770 	l->abt_stack_va_end = sp;
771 }
772 #endif /*ARM64*/
773 
774 bool thread_init_stack(uint32_t thread_id, vaddr_t sp)
775 {
776 	if (thread_id >= CFG_NUM_THREADS)
777 		return false;
778 	threads[thread_id].stack_va_end = sp;
779 	return true;
780 }
781 
782 int thread_get_id_may_fail(void)
783 {
784 	/*
785 	 * thread_get_core_local() requires foreign interrupts to be disabled
786 	 */
787 	uint32_t exceptions = thread_mask_exceptions(THREAD_EXCP_FOREIGN_INTR);
788 	struct thread_core_local *l = thread_get_core_local();
789 	int ct = l->curr_thread;
790 
791 	thread_unmask_exceptions(exceptions);
792 	return ct;
793 }
794 
795 int thread_get_id(void)
796 {
797 	int ct = thread_get_id_may_fail();
798 
799 	assert(ct >= 0 && ct < CFG_NUM_THREADS);
800 	return ct;
801 }
802 
803 static void init_handlers(const struct thread_handlers *handlers)
804 {
805 	thread_cpu_on_handler_ptr = handlers->cpu_on;
806 	thread_cpu_off_handler_ptr = handlers->cpu_off;
807 	thread_cpu_suspend_handler_ptr = handlers->cpu_suspend;
808 	thread_cpu_resume_handler_ptr = handlers->cpu_resume;
809 	thread_system_off_handler_ptr = handlers->system_off;
810 	thread_system_reset_handler_ptr = handlers->system_reset;
811 }
812 
813 #ifdef CFG_WITH_PAGER
814 static void init_thread_stacks(void)
815 {
816 	size_t n = 0;
817 
818 	/*
819 	 * Allocate virtual memory for thread stacks.
820 	 */
821 	for (n = 0; n < CFG_NUM_THREADS; n++) {
822 		tee_mm_entry_t *mm = NULL;
823 		vaddr_t sp = 0;
824 		size_t num_pages = 0;
825 		struct fobj *fobj = NULL;
826 
827 		/* Find vmem for thread stack and its protection gap */
828 		mm = tee_mm_alloc(&tee_mm_vcore,
829 				  SMALL_PAGE_SIZE + STACK_THREAD_SIZE);
830 		assert(mm);
831 
832 		/* Claim eventual physical page */
833 		tee_pager_add_pages(tee_mm_get_smem(mm), tee_mm_get_size(mm),
834 				    true);
835 
836 		num_pages = tee_mm_get_bytes(mm) / SMALL_PAGE_SIZE - 1;
837 		fobj = fobj_locked_paged_alloc(num_pages);
838 
839 		/* Add the area to the pager */
840 		tee_pager_add_core_area(tee_mm_get_smem(mm) + SMALL_PAGE_SIZE,
841 					PAGER_AREA_TYPE_LOCK, fobj);
842 		fobj_put(fobj);
843 
844 		/* init effective stack */
845 		sp = tee_mm_get_smem(mm) + tee_mm_get_bytes(mm);
846 		asan_tag_access((void *)tee_mm_get_smem(mm), (void *)sp);
847 		if (!thread_init_stack(n, sp))
848 			panic("init stack failed");
849 	}
850 }
851 #else
852 static void init_thread_stacks(void)
853 {
854 	size_t n;
855 
856 	/* Assign the thread stacks */
857 	for (n = 0; n < CFG_NUM_THREADS; n++) {
858 		if (!thread_init_stack(n, GET_STACK(stack_thread[n])))
859 			panic("thread_init_stack failed");
860 	}
861 }
862 #endif /*CFG_WITH_PAGER*/
863 
864 static void init_user_kcode(void)
865 {
866 #ifdef CFG_CORE_UNMAP_CORE_AT_EL0
867 	vaddr_t v = (vaddr_t)thread_excp_vect;
868 	vaddr_t ve = (vaddr_t)thread_excp_vect_end;
869 
870 	thread_user_kcode_va = ROUNDDOWN(v, CORE_MMU_USER_CODE_SIZE);
871 	ve = ROUNDUP(ve, CORE_MMU_USER_CODE_SIZE);
872 	thread_user_kcode_size = ve - thread_user_kcode_va;
873 
874 	core_mmu_get_user_va_range(&v, NULL);
875 	thread_user_kcode_offset = thread_user_kcode_va - v;
876 
877 #if defined(CFG_CORE_WORKAROUND_SPECTRE_BP_SEC) && defined(ARM64)
878 	/*
879 	 * When transitioning to EL0 subtract SP with this much to point to
880 	 * this special kdata page instead. SP is restored by add this much
881 	 * while transitioning back to EL1.
882 	 */
883 	v += thread_user_kcode_size;
884 	thread_user_kdata_sp_offset = (vaddr_t)thread_core_local - v;
885 #endif
886 #endif /*CFG_CORE_UNMAP_CORE_AT_EL0*/
887 }
888 
889 void thread_init_threads(void)
890 {
891 	size_t n;
892 
893 	init_thread_stacks();
894 	pgt_init();
895 
896 	mutex_lockdep_init();
897 
898 	for (n = 0; n < CFG_NUM_THREADS; n++) {
899 		TAILQ_INIT(&threads[n].tsd.sess_stack);
900 		SLIST_INIT(&threads[n].tsd.pgt_cache);
901 	}
902 
903 	for (n = 0; n < CFG_TEE_CORE_NB_CORE; n++)
904 		thread_core_local[n].curr_thread = -1;
905 }
906 
907 void thread_init_primary(const struct thread_handlers *handlers)
908 {
909 	init_handlers(handlers);
910 
911 	/* Initialize canaries around the stacks */
912 	init_canaries();
913 
914 	init_user_kcode();
915 }
916 
917 static void init_sec_mon(size_t pos __maybe_unused)
918 {
919 #if !defined(CFG_WITH_ARM_TRUSTED_FW)
920 	/* Initialize secure monitor */
921 	sm_init(GET_STACK(stack_tmp[pos]));
922 #endif
923 }
924 
925 static uint32_t __maybe_unused get_midr_implementer(uint32_t midr)
926 {
927 	return (midr >> MIDR_IMPLEMENTER_SHIFT) & MIDR_IMPLEMENTER_MASK;
928 }
929 
930 static uint32_t __maybe_unused get_midr_primary_part(uint32_t midr)
931 {
932 	return (midr >> MIDR_PRIMARY_PART_NUM_SHIFT) &
933 	       MIDR_PRIMARY_PART_NUM_MASK;
934 }
935 
936 #ifdef ARM64
937 static bool probe_workaround_available(void)
938 {
939 	int32_t r;
940 
941 	r = thread_smc(SMCCC_VERSION, 0, 0, 0);
942 	if (r < 0)
943 		return false;
944 	if (r < 0x10001)	/* compare with version 1.1 */
945 		return false;
946 
947 	/* Version >= 1.1, so SMCCC_ARCH_FEATURES is available */
948 	r = thread_smc(SMCCC_ARCH_FEATURES, SMCCC_ARCH_WORKAROUND_1, 0, 0);
949 	return r >= 0;
950 }
951 
952 static vaddr_t __maybe_unused select_vector(vaddr_t a)
953 {
954 	if (probe_workaround_available()) {
955 		DMSG("SMCCC_ARCH_WORKAROUND_1 (%#08" PRIx32 ") available",
956 		     SMCCC_ARCH_WORKAROUND_1);
957 		DMSG("SMC Workaround for CVE-2017-5715 used");
958 		return a;
959 	}
960 
961 	DMSG("SMCCC_ARCH_WORKAROUND_1 (%#08" PRIx32 ") unavailable",
962 	     SMCCC_ARCH_WORKAROUND_1);
963 	DMSG("SMC Workaround for CVE-2017-5715 not needed (if ARM-TF is up to date)");
964 	return (vaddr_t)thread_excp_vect;
965 }
966 #else
967 static vaddr_t __maybe_unused select_vector(vaddr_t a)
968 {
969 	return a;
970 }
971 #endif
972 
973 static vaddr_t get_excp_vect(void)
974 {
975 #ifdef CFG_CORE_WORKAROUND_SPECTRE_BP_SEC
976 	uint32_t midr = read_midr();
977 
978 	if (get_midr_implementer(midr) != MIDR_IMPLEMENTER_ARM)
979 		return (vaddr_t)thread_excp_vect;
980 
981 	switch (get_midr_primary_part(midr)) {
982 #ifdef ARM32
983 	case CORTEX_A8_PART_NUM:
984 	case CORTEX_A9_PART_NUM:
985 	case CORTEX_A17_PART_NUM:
986 #endif
987 	case CORTEX_A57_PART_NUM:
988 	case CORTEX_A72_PART_NUM:
989 	case CORTEX_A73_PART_NUM:
990 	case CORTEX_A75_PART_NUM:
991 		return select_vector((vaddr_t)thread_excp_vect_workaround);
992 #ifdef ARM32
993 	case CORTEX_A15_PART_NUM:
994 		return select_vector((vaddr_t)thread_excp_vect_workaround_a15);
995 #endif
996 	default:
997 		return (vaddr_t)thread_excp_vect;
998 	}
999 #endif /*CFG_CORE_WORKAROUND_SPECTRE_BP_SEC*/
1000 
1001 	return (vaddr_t)thread_excp_vect;
1002 }
1003 
1004 void thread_init_per_cpu(void)
1005 {
1006 	size_t pos = get_core_pos();
1007 	struct thread_core_local *l = thread_get_core_local();
1008 
1009 	init_sec_mon(pos);
1010 
1011 	set_tmp_stack(l, GET_STACK(stack_tmp[pos]) - STACK_TMP_OFFS);
1012 	set_abt_stack(l, GET_STACK(stack_abt[pos]));
1013 
1014 	thread_init_vbar(get_excp_vect());
1015 
1016 #ifdef CFG_FTRACE_SUPPORT
1017 	/*
1018 	 * Enable accesses to frequency register and physical counter
1019 	 * register in EL0/PL0 required for timestamping during
1020 	 * function tracing.
1021 	 */
1022 	write_cntkctl(read_cntkctl() | CNTKCTL_PL0PCTEN);
1023 #endif
1024 }
1025 
1026 struct thread_specific_data *thread_get_tsd(void)
1027 {
1028 	return &threads[thread_get_id()].tsd;
1029 }
1030 
1031 struct thread_ctx_regs *thread_get_ctx_regs(void)
1032 {
1033 	struct thread_core_local *l = thread_get_core_local();
1034 
1035 	assert(l->curr_thread != -1);
1036 	return &threads[l->curr_thread].regs;
1037 }
1038 
1039 void thread_set_foreign_intr(bool enable)
1040 {
1041 	/* thread_get_core_local() requires foreign interrupts to be disabled */
1042 	uint32_t exceptions = thread_mask_exceptions(THREAD_EXCP_FOREIGN_INTR);
1043 	struct thread_core_local *l;
1044 
1045 	l = thread_get_core_local();
1046 
1047 	assert(l->curr_thread != -1);
1048 
1049 	if (enable) {
1050 		threads[l->curr_thread].flags |=
1051 					THREAD_FLAGS_FOREIGN_INTR_ENABLE;
1052 		thread_set_exceptions(exceptions & ~THREAD_EXCP_FOREIGN_INTR);
1053 	} else {
1054 		/*
1055 		 * No need to disable foreign interrupts here since they're
1056 		 * already disabled above.
1057 		 */
1058 		threads[l->curr_thread].flags &=
1059 					~THREAD_FLAGS_FOREIGN_INTR_ENABLE;
1060 	}
1061 }
1062 
1063 void thread_restore_foreign_intr(void)
1064 {
1065 	/* thread_get_core_local() requires foreign interrupts to be disabled */
1066 	uint32_t exceptions = thread_mask_exceptions(THREAD_EXCP_FOREIGN_INTR);
1067 	struct thread_core_local *l;
1068 
1069 	l = thread_get_core_local();
1070 
1071 	assert(l->curr_thread != -1);
1072 
1073 	if (threads[l->curr_thread].flags & THREAD_FLAGS_FOREIGN_INTR_ENABLE)
1074 		thread_set_exceptions(exceptions & ~THREAD_EXCP_FOREIGN_INTR);
1075 }
1076 
1077 #ifdef CFG_WITH_VFP
1078 uint32_t thread_kernel_enable_vfp(void)
1079 {
1080 	uint32_t exceptions = thread_mask_exceptions(THREAD_EXCP_FOREIGN_INTR);
1081 	struct thread_ctx *thr = threads + thread_get_id();
1082 	struct thread_user_vfp_state *tuv = thr->vfp_state.uvfp;
1083 
1084 	assert(!vfp_is_enabled());
1085 
1086 	if (!thr->vfp_state.ns_saved) {
1087 		vfp_lazy_save_state_final(&thr->vfp_state.ns,
1088 					  true /*force_save*/);
1089 		thr->vfp_state.ns_saved = true;
1090 	} else if (thr->vfp_state.sec_lazy_saved &&
1091 		   !thr->vfp_state.sec_saved) {
1092 		/*
1093 		 * This happens when we're handling an abort while the
1094 		 * thread was using the VFP state.
1095 		 */
1096 		vfp_lazy_save_state_final(&thr->vfp_state.sec,
1097 					  false /*!force_save*/);
1098 		thr->vfp_state.sec_saved = true;
1099 	} else if (tuv && tuv->lazy_saved && !tuv->saved) {
1100 		/*
1101 		 * This can happen either during syscall or abort
1102 		 * processing (while processing a syscall).
1103 		 */
1104 		vfp_lazy_save_state_final(&tuv->vfp, false /*!force_save*/);
1105 		tuv->saved = true;
1106 	}
1107 
1108 	vfp_enable();
1109 	return exceptions;
1110 }
1111 
1112 void thread_kernel_disable_vfp(uint32_t state)
1113 {
1114 	uint32_t exceptions;
1115 
1116 	assert(vfp_is_enabled());
1117 
1118 	vfp_disable();
1119 	exceptions = thread_get_exceptions();
1120 	assert(exceptions & THREAD_EXCP_FOREIGN_INTR);
1121 	exceptions &= ~THREAD_EXCP_FOREIGN_INTR;
1122 	exceptions |= state & THREAD_EXCP_FOREIGN_INTR;
1123 	thread_set_exceptions(exceptions);
1124 }
1125 
1126 void thread_kernel_save_vfp(void)
1127 {
1128 	struct thread_ctx *thr = threads + thread_get_id();
1129 
1130 	assert(thread_get_exceptions() & THREAD_EXCP_FOREIGN_INTR);
1131 	if (vfp_is_enabled()) {
1132 		vfp_lazy_save_state_init(&thr->vfp_state.sec);
1133 		thr->vfp_state.sec_lazy_saved = true;
1134 	}
1135 }
1136 
1137 void thread_kernel_restore_vfp(void)
1138 {
1139 	struct thread_ctx *thr = threads + thread_get_id();
1140 
1141 	assert(thread_get_exceptions() & THREAD_EXCP_FOREIGN_INTR);
1142 	assert(!vfp_is_enabled());
1143 	if (thr->vfp_state.sec_lazy_saved) {
1144 		vfp_lazy_restore_state(&thr->vfp_state.sec,
1145 				       thr->vfp_state.sec_saved);
1146 		thr->vfp_state.sec_saved = false;
1147 		thr->vfp_state.sec_lazy_saved = false;
1148 	}
1149 }
1150 
1151 void thread_user_enable_vfp(struct thread_user_vfp_state *uvfp)
1152 {
1153 	struct thread_ctx *thr = threads + thread_get_id();
1154 	struct thread_user_vfp_state *tuv = thr->vfp_state.uvfp;
1155 
1156 	assert(thread_get_exceptions() & THREAD_EXCP_FOREIGN_INTR);
1157 	assert(!vfp_is_enabled());
1158 
1159 	if (!thr->vfp_state.ns_saved) {
1160 		vfp_lazy_save_state_final(&thr->vfp_state.ns,
1161 					  true /*force_save*/);
1162 		thr->vfp_state.ns_saved = true;
1163 	} else if (tuv && uvfp != tuv) {
1164 		if (tuv->lazy_saved && !tuv->saved) {
1165 			vfp_lazy_save_state_final(&tuv->vfp,
1166 						  false /*!force_save*/);
1167 			tuv->saved = true;
1168 		}
1169 	}
1170 
1171 	if (uvfp->lazy_saved)
1172 		vfp_lazy_restore_state(&uvfp->vfp, uvfp->saved);
1173 	uvfp->lazy_saved = false;
1174 	uvfp->saved = false;
1175 
1176 	thr->vfp_state.uvfp = uvfp;
1177 	vfp_enable();
1178 }
1179 
1180 void thread_user_save_vfp(void)
1181 {
1182 	struct thread_ctx *thr = threads + thread_get_id();
1183 	struct thread_user_vfp_state *tuv = thr->vfp_state.uvfp;
1184 
1185 	assert(thread_get_exceptions() & THREAD_EXCP_FOREIGN_INTR);
1186 	if (!vfp_is_enabled())
1187 		return;
1188 
1189 	assert(tuv && !tuv->lazy_saved && !tuv->saved);
1190 	vfp_lazy_save_state_init(&tuv->vfp);
1191 	tuv->lazy_saved = true;
1192 }
1193 
1194 void thread_user_clear_vfp(struct thread_user_vfp_state *uvfp)
1195 {
1196 	struct thread_ctx *thr = threads + thread_get_id();
1197 
1198 	if (uvfp == thr->vfp_state.uvfp)
1199 		thr->vfp_state.uvfp = NULL;
1200 	uvfp->lazy_saved = false;
1201 	uvfp->saved = false;
1202 }
1203 #endif /*CFG_WITH_VFP*/
1204 
1205 #ifdef ARM32
1206 static bool get_spsr(bool is_32bit, unsigned long entry_func, uint32_t *spsr)
1207 {
1208 	uint32_t s;
1209 
1210 	if (!is_32bit)
1211 		return false;
1212 
1213 	s = read_cpsr();
1214 	s &= ~(CPSR_MODE_MASK | CPSR_T | CPSR_IT_MASK1 | CPSR_IT_MASK2);
1215 	s |= CPSR_MODE_USR;
1216 	if (entry_func & 1)
1217 		s |= CPSR_T;
1218 	*spsr = s;
1219 	return true;
1220 }
1221 #endif
1222 
1223 #ifdef ARM64
1224 static bool get_spsr(bool is_32bit, unsigned long entry_func, uint32_t *spsr)
1225 {
1226 	uint32_t s;
1227 
1228 	if (is_32bit) {
1229 		s = read_daif() & (SPSR_32_AIF_MASK << SPSR_32_AIF_SHIFT);
1230 		s |= SPSR_MODE_RW_32 << SPSR_MODE_RW_SHIFT;
1231 		s |= (entry_func & SPSR_32_T_MASK) << SPSR_32_T_SHIFT;
1232 	} else {
1233 		s = read_daif() & (SPSR_64_DAIF_MASK << SPSR_64_DAIF_SHIFT);
1234 	}
1235 
1236 	*spsr = s;
1237 	return true;
1238 }
1239 #endif
1240 
1241 static void set_ctx_regs(struct thread_ctx_regs *regs, unsigned long a0,
1242 			 unsigned long a1, unsigned long a2, unsigned long a3,
1243 			 unsigned long user_sp, unsigned long entry_func,
1244 			 uint32_t spsr)
1245 {
1246 	/*
1247 	 * First clear all registers to avoid leaking information from
1248 	 * other TAs or even the Core itself.
1249 	 */
1250 	*regs = (struct thread_ctx_regs){ };
1251 #ifdef ARM32
1252 	regs->r0 = a0;
1253 	regs->r1 = a1;
1254 	regs->r2 = a2;
1255 	regs->r3 = a3;
1256 	regs->usr_sp = user_sp;
1257 	regs->pc = entry_func;
1258 	regs->cpsr = spsr;
1259 #endif
1260 #ifdef ARM64
1261 	regs->x[0] = a0;
1262 	regs->x[1] = a1;
1263 	regs->x[2] = a2;
1264 	regs->x[3] = a3;
1265 	regs->sp = user_sp;
1266 	regs->pc = entry_func;
1267 	regs->cpsr = spsr;
1268 	regs->x[13] = user_sp;	/* Used when running TA in Aarch32 */
1269 	regs->sp = user_sp;	/* Used when running TA in Aarch64 */
1270 	/* Set frame pointer (user stack can't be unwound past this point) */
1271 	regs->x[29] = 0;
1272 #endif
1273 }
1274 
1275 uint32_t thread_enter_user_mode(unsigned long a0, unsigned long a1,
1276 		unsigned long a2, unsigned long a3, unsigned long user_sp,
1277 		unsigned long entry_func, bool is_32bit,
1278 		uint32_t *exit_status0, uint32_t *exit_status1)
1279 {
1280 	uint32_t spsr = 0;
1281 	uint32_t exceptions = 0;
1282 	uint32_t rc = 0;
1283 	struct thread_ctx_regs *regs = NULL;
1284 
1285 	tee_ta_update_session_utime_resume();
1286 
1287 	/* Derive SPSR from current CPSR/PSTATE readout. */
1288 	if (!get_spsr(is_32bit, entry_func, &spsr)) {
1289 		*exit_status0 = 1; /* panic */
1290 		*exit_status1 = 0xbadbadba;
1291 		return 0;
1292 	}
1293 
1294 	exceptions = thread_mask_exceptions(THREAD_EXCP_ALL);
1295 	/*
1296 	 * We're using the per thread location of saved context registers
1297 	 * for temporary storage. Now that exceptions are masked they will
1298 	 * not be used for any thing else until they are eventually
1299 	 * unmasked when user mode has been entered.
1300 	 */
1301 	regs = thread_get_ctx_regs();
1302 	set_ctx_regs(regs, a0, a1, a2, a3, user_sp, entry_func, spsr);
1303 	rc = __thread_enter_user_mode(regs, exit_status0, exit_status1);
1304 	thread_unmask_exceptions(exceptions);
1305 	return rc;
1306 }
1307 
1308 #ifdef CFG_CORE_UNMAP_CORE_AT_EL0
1309 void thread_get_user_kcode(struct mobj **mobj, size_t *offset,
1310 			   vaddr_t *va, size_t *sz)
1311 {
1312 	core_mmu_get_user_va_range(va, NULL);
1313 	*mobj = mobj_tee_ram;
1314 	*offset = thread_user_kcode_va - VCORE_START_VA;
1315 	*sz = thread_user_kcode_size;
1316 }
1317 #endif
1318 
1319 #if defined(CFG_CORE_UNMAP_CORE_AT_EL0) && \
1320 	defined(CFG_CORE_WORKAROUND_SPECTRE_BP_SEC) && defined(ARM64)
1321 void thread_get_user_kdata(struct mobj **mobj, size_t *offset,
1322 			   vaddr_t *va, size_t *sz)
1323 {
1324 	vaddr_t v;
1325 
1326 	core_mmu_get_user_va_range(&v, NULL);
1327 	*va = v + thread_user_kcode_size;
1328 	*mobj = mobj_tee_ram;
1329 	*offset = (vaddr_t)thread_user_kdata_page - VCORE_START_VA;
1330 	*sz = sizeof(thread_user_kdata_page);
1331 }
1332 #endif
1333 
1334 static void setup_unwind_user_mode(struct thread_svc_regs *regs)
1335 {
1336 #ifdef ARM32
1337 	regs->lr = (uintptr_t)thread_unwind_user_mode;
1338 	regs->spsr = read_cpsr();
1339 #endif
1340 #ifdef ARM64
1341 	regs->elr = (uintptr_t)thread_unwind_user_mode;
1342 	regs->spsr = SPSR_64(SPSR_64_MODE_EL1, SPSR_64_MODE_SP_EL0, 0);
1343 	regs->spsr |= read_daif();
1344 	/*
1345 	 * Regs is the value of stack pointer before calling the SVC
1346 	 * handler.  By the addition matches for the reserved space at the
1347 	 * beginning of el0_sync_svc(). This prepares the stack when
1348 	 * returning to thread_unwind_user_mode instead of a normal
1349 	 * exception return.
1350 	 */
1351 	regs->sp_el0 = (uint64_t)(regs + 1);
1352 #endif
1353 }
1354 
1355 /*
1356  * Note: this function is weak just to make it possible to exclude it from
1357  * the unpaged area.
1358  */
1359 void __weak thread_svc_handler(struct thread_svc_regs *regs)
1360 {
1361 	struct tee_ta_session *sess = NULL;
1362 	uint32_t state = 0;
1363 
1364 	/* Enable native interrupts */
1365 	state = thread_get_exceptions();
1366 	thread_unmask_exceptions(state & ~THREAD_EXCP_NATIVE_INTR);
1367 
1368 	thread_user_save_vfp();
1369 
1370 	/* TA has just entered kernel mode */
1371 	tee_ta_update_session_utime_suspend();
1372 
1373 	/* Restore foreign interrupts which are disabled on exception entry */
1374 	thread_restore_foreign_intr();
1375 
1376 	tee_ta_get_current_session(&sess);
1377 	assert(sess && sess->ctx->ops && sess->ctx->ops->handle_svc);
1378 	if (sess->ctx->ops->handle_svc(regs)) {
1379 		/* We're about to switch back to user mode */
1380 		tee_ta_update_session_utime_resume();
1381 	} else {
1382 		/* We're returning from __thread_enter_user_mode() */
1383 		setup_unwind_user_mode(regs);
1384 	}
1385 }
1386