xref: /optee_os/core/kernel/ldelf_loader.c (revision 546e296fc565d4711b395a8475c538f747c6b282)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2014, STMicroelectronics International N.V.
4  * Copyright (c) 2015-2020, 2022 Linaro Limited
5  * Copyright (c) 2020-2023, Arm Limited
6  */
7 
8 #include <assert.h>
9 #include <kernel/ldelf_loader.h>
10 #include <kernel/ldelf_syscalls.h>
11 #include <kernel/scall.h>
12 #include <kernel/user_access.h>
13 #include <ldelf.h>
14 #include <mm/mobj.h>
15 #include <mm/vm.h>
16 
17 #define BOUNCE_BUFFER_SIZE	4096
18 
19 extern uint8_t ldelf_data[];
20 extern const unsigned int ldelf_code_size;
21 extern const unsigned int ldelf_data_size;
22 extern const unsigned int ldelf_entry;
23 
24 /* ldelf has the same architecture/register width as the kernel */
25 #if defined(ARM32) || defined(RV32)
26 static const bool is_32bit = true;
27 #else
28 static const bool is_32bit;
29 #endif
30 
31 static TEE_Result alloc_and_map_fobj(struct user_mode_ctx *uctx, size_t sz,
32 				     uint32_t prot, uint32_t flags, vaddr_t *va)
33 {
34 	size_t num_pgs = ROUNDUP(sz, SMALL_PAGE_SIZE) / SMALL_PAGE_SIZE;
35 	struct fobj *fobj = fobj_ta_mem_alloc(num_pgs);
36 	struct mobj *mobj = mobj_with_fobj_alloc(fobj, NULL,
37 						 TEE_MATTR_MEM_TYPE_TAGGED);
38 	TEE_Result res = TEE_SUCCESS;
39 
40 	fobj_put(fobj);
41 	if (!mobj)
42 		return TEE_ERROR_OUT_OF_MEMORY;
43 	res = vm_map(uctx, va, num_pgs * SMALL_PAGE_SIZE, prot, flags, mobj, 0);
44 	mobj_put(mobj);
45 
46 	return res;
47 }
48 
49 /*
50  * This function may leave a few mappings behind on error, but that's taken
51  * care of by tee_ta_init_user_ta_session() since the entire context is
52  * removed then.
53  */
54 TEE_Result ldelf_load_ldelf(struct user_mode_ctx *uctx)
55 {
56 	TEE_Result res = TEE_SUCCESS;
57 	vaddr_t stack_addr = 0;
58 	vaddr_t code_addr = 0;
59 	vaddr_t rw_addr = 0;
60 	vaddr_t bb_addr = 0;
61 	uint32_t prot = 0;
62 
63 	uctx->is_32bit = is_32bit;
64 
65 	res = alloc_and_map_fobj(uctx, BOUNCE_BUFFER_SIZE, TEE_MATTR_PRW, 0,
66 				 &bb_addr);
67 	if (res)
68 		return res;
69 	uctx->bbuf = (void *)bb_addr;
70 	uctx->bbuf_size = BOUNCE_BUFFER_SIZE;
71 
72 	res = alloc_and_map_fobj(uctx, LDELF_STACK_SIZE,
73 				 TEE_MATTR_URW | TEE_MATTR_PRW, VM_FLAG_LDELF,
74 				 &stack_addr);
75 	if (res)
76 		return res;
77 	uctx->ldelf_stack_ptr = stack_addr + LDELF_STACK_SIZE;
78 
79 	res = alloc_and_map_fobj(uctx, ldelf_code_size, TEE_MATTR_PRW,
80 				 VM_FLAG_LDELF, &code_addr);
81 	if (res)
82 		return res;
83 	uctx->entry_func = code_addr + ldelf_entry;
84 
85 	rw_addr = ROUNDUP(code_addr + ldelf_code_size, SMALL_PAGE_SIZE);
86 	res = alloc_and_map_fobj(uctx, ldelf_data_size,
87 				 TEE_MATTR_URW | TEE_MATTR_PRW, VM_FLAG_LDELF,
88 				 &rw_addr);
89 	if (res)
90 		return res;
91 
92 	vm_set_ctx(uctx->ts_ctx);
93 
94 	memcpy((void *)code_addr, ldelf_data, ldelf_code_size);
95 
96 	res = copy_to_user((void *)rw_addr, ldelf_data + ldelf_code_size,
97 			   ldelf_data_size);
98 	if (res)
99 		return res;
100 
101 	prot = TEE_MATTR_URX;
102 	if (IS_ENABLED(CFG_CORE_BTI))
103 		prot |= TEE_MATTR_GUARDED;
104 
105 	res = vm_set_prot(uctx, code_addr,
106 			  ROUNDUP(ldelf_code_size, SMALL_PAGE_SIZE), prot);
107 	if (res)
108 		return res;
109 
110 	DMSG("ldelf load address %#"PRIxVA, code_addr);
111 
112 	return TEE_SUCCESS;
113 }
114 
115 TEE_Result ldelf_init_with_ldelf(struct ts_session *sess,
116 				 struct user_mode_ctx *uctx)
117 {
118 	TEE_Result res = TEE_SUCCESS;
119 	struct ldelf_arg *arg = NULL;
120 	uint32_t panic_code = 0;
121 	uint32_t panicked = 0;
122 	uaddr_t usr_stack = 0;
123 
124 	usr_stack = uctx->ldelf_stack_ptr;
125 	usr_stack -= ROUNDUP(sizeof(*arg), STACK_ALIGNMENT);
126 	arg = (struct ldelf_arg *)usr_stack;
127 	sess->handle_scall = scall_handle_ldelf;
128 
129 	res = clear_user(arg, sizeof(*arg));
130 	if (res)
131 		return res;
132 
133 	res = PUT_USER_SCALAR(uctx->ts_ctx->uuid, &arg->uuid);
134 	if (res)
135 		return res;
136 
137 	res = thread_enter_user_mode((vaddr_t)arg, 0, 0, 0,
138 				     usr_stack, uctx->entry_func,
139 				     is_32bit, &panicked, &panic_code);
140 
141 	sess->handle_scall = sess->ctx->ops->handle_scall;
142 	thread_user_clear_vfp(uctx);
143 	ldelf_sess_cleanup(sess);
144 
145 	if (panicked) {
146 		abort_print_current_ts();
147 		EMSG("ldelf panicked");
148 		return TEE_ERROR_GENERIC;
149 	}
150 	if (res) {
151 		EMSG("ldelf failed with res: %#"PRIx32, res);
152 		return res;
153 	}
154 
155 	res = vm_check_access_rights(uctx,
156 				     TEE_MEMORY_ACCESS_READ |
157 				     TEE_MEMORY_ACCESS_ANY_OWNER,
158 				     (uaddr_t)arg, sizeof(*arg));
159 	if (res)
160 		return res;
161 
162 	if (is_user_ta_ctx(uctx->ts_ctx)) {
163 		/*
164 		 * This is already checked by the elf loader, but since it runs
165 		 * in user mode we're not trusting it entirely.
166 		 */
167 		if (arg->flags & ~TA_FLAGS_MASK)
168 			return TEE_ERROR_BAD_FORMAT;
169 
170 		to_user_ta_ctx(uctx->ts_ctx)->ta_ctx.flags = arg->flags;
171 	}
172 
173 	uctx->is_32bit = arg->is_32bit;
174 	uctx->entry_func = arg->entry_func;
175 	uctx->load_addr = arg->load_addr;
176 	uctx->stack_ptr = arg->stack_ptr;
177 	uctx->dump_entry_func = arg->dump_entry;
178 #ifdef CFG_FTRACE_SUPPORT
179 	uctx->ftrace_entry_func = arg->ftrace_entry;
180 	sess->fbuf = arg->fbuf;
181 #endif
182 	uctx->dl_entry_func = arg->dl_entry;
183 
184 	return TEE_SUCCESS;
185 }
186 
187 TEE_Result ldelf_dump_state(struct user_mode_ctx *uctx)
188 {
189 	TEE_Result res = TEE_SUCCESS;
190 	uaddr_t usr_stack = uctx->ldelf_stack_ptr;
191 	struct dump_entry_arg *arg = NULL;
192 	uint32_t panic_code = 0;
193 	uint32_t panicked = 0;
194 	struct thread_specific_data *tsd = thread_get_tsd();
195 	struct ts_session *sess = NULL;
196 	struct vm_region *r = NULL;
197 	size_t arg_size = 0;
198 	size_t n = 0;
199 
200 	TAILQ_FOREACH(r, &uctx->vm_info.regions, link)
201 		if (r->attr & TEE_MATTR_URWX)
202 			n++;
203 
204 	arg_size = ROUNDUP(sizeof(*arg) + n * sizeof(struct dump_map),
205 			   STACK_ALIGNMENT);
206 
207 	usr_stack = uctx->ldelf_stack_ptr;
208 	usr_stack -= arg_size;
209 
210 	arg = bb_alloc(arg_size);
211 	if (!arg)
212 		return TEE_ERROR_OUT_OF_MEMORY;
213 	memset(arg, 0, arg_size);
214 
215 	arg->num_maps = n;
216 	n = 0;
217 	TAILQ_FOREACH(r, &uctx->vm_info.regions, link) {
218 		if (r->attr & TEE_MATTR_URWX) {
219 			if (r->mobj)
220 				mobj_get_pa(r->mobj, r->offset, 0,
221 					    &arg->maps[n].pa);
222 			arg->maps[n].va = r->va;
223 			arg->maps[n].sz = r->size;
224 			if (r->attr & TEE_MATTR_UR)
225 				arg->maps[n].flags |= DUMP_MAP_READ;
226 			if (r->attr & TEE_MATTR_UW)
227 				arg->maps[n].flags |= DUMP_MAP_WRITE;
228 			if (r->attr & TEE_MATTR_UX)
229 				arg->maps[n].flags |= DUMP_MAP_EXEC;
230 			if (r->attr & TEE_MATTR_SECURE)
231 				arg->maps[n].flags |= DUMP_MAP_SECURE;
232 			if (r->flags & VM_FLAG_EPHEMERAL)
233 				arg->maps[n].flags |= DUMP_MAP_EPHEM;
234 			if (r->flags & VM_FLAG_LDELF)
235 				arg->maps[n].flags |= DUMP_MAP_LDELF;
236 			n++;
237 		}
238 	}
239 
240 	arg->is_32bit = uctx->is_32bit;
241 #ifdef ARM32
242 	arg->arm32.regs[0] = tsd->abort_regs.r0;
243 	arg->arm32.regs[1] = tsd->abort_regs.r1;
244 	arg->arm32.regs[2] = tsd->abort_regs.r2;
245 	arg->arm32.regs[3] = tsd->abort_regs.r3;
246 	arg->arm32.regs[4] = tsd->abort_regs.r4;
247 	arg->arm32.regs[5] = tsd->abort_regs.r5;
248 	arg->arm32.regs[6] = tsd->abort_regs.r6;
249 	arg->arm32.regs[7] = tsd->abort_regs.r7;
250 	arg->arm32.regs[8] = tsd->abort_regs.r8;
251 	arg->arm32.regs[9] = tsd->abort_regs.r9;
252 	arg->arm32.regs[10] = tsd->abort_regs.r10;
253 	arg->arm32.regs[11] = tsd->abort_regs.r11;
254 	arg->arm32.regs[12] = tsd->abort_regs.ip;
255 	arg->arm32.regs[13] = tsd->abort_regs.usr_sp; /*SP*/
256 	arg->arm32.regs[14] = tsd->abort_regs.usr_lr; /*LR*/
257 	arg->arm32.regs[15] = tsd->abort_regs.elr; /*PC*/
258 #endif /*ARM32*/
259 #ifdef ARM64
260 	if (uctx->is_32bit) {
261 		arg->arm32.regs[0] = tsd->abort_regs.x0;
262 		arg->arm32.regs[1] = tsd->abort_regs.x1;
263 		arg->arm32.regs[2] = tsd->abort_regs.x2;
264 		arg->arm32.regs[3] = tsd->abort_regs.x3;
265 		arg->arm32.regs[4] = tsd->abort_regs.x4;
266 		arg->arm32.regs[5] = tsd->abort_regs.x5;
267 		arg->arm32.regs[6] = tsd->abort_regs.x6;
268 		arg->arm32.regs[7] = tsd->abort_regs.x7;
269 		arg->arm32.regs[8] = tsd->abort_regs.x8;
270 		arg->arm32.regs[9] = tsd->abort_regs.x9;
271 		arg->arm32.regs[10] = tsd->abort_regs.x10;
272 		arg->arm32.regs[11] = tsd->abort_regs.x11;
273 		arg->arm32.regs[12] = tsd->abort_regs.x12;
274 		arg->arm32.regs[13] = tsd->abort_regs.x13; /*SP*/
275 		arg->arm32.regs[14] = tsd->abort_regs.x14; /*LR*/
276 		arg->arm32.regs[15] = tsd->abort_regs.elr; /*PC*/
277 	} else {
278 		arg->arm64.fp = tsd->abort_regs.x29;
279 		arg->arm64.pc = tsd->abort_regs.elr;
280 		arg->arm64.sp = tsd->abort_regs.sp_el0;
281 	}
282 #endif /*ARM64*/
283 #if defined(RV64) || defined(RV32)
284 	arg->rv.fp = tsd->abort_regs.s0;
285 	arg->rv.pc = tsd->abort_regs.epc;
286 	arg->rv.sp = tsd->abort_regs.sp;
287 #endif /*RV64||RV32*/
288 
289 	res = copy_to_user((void *)usr_stack, arg, arg_size);
290 	if (res)
291 		return res;
292 
293 	sess = ts_get_current_session();
294 	sess->handle_scall = scall_handle_ldelf;
295 
296 	res = thread_enter_user_mode(usr_stack, 0, 0, 0,
297 				     usr_stack, uctx->dump_entry_func,
298 				     is_32bit, &panicked, &panic_code);
299 
300 	sess->handle_scall = sess->ctx->ops->handle_scall;
301 	thread_user_clear_vfp(uctx);
302 	ldelf_sess_cleanup(sess);
303 
304 	if (panicked) {
305 		uctx->dump_entry_func = 0;
306 		EMSG("ldelf dump function panicked");
307 		abort_print_current_ts();
308 		res = TEE_ERROR_TARGET_DEAD;
309 	}
310 
311 	return res;
312 }
313 
314 #ifdef CFG_FTRACE_SUPPORT
315 TEE_Result ldelf_dump_ftrace(struct user_mode_ctx *uctx,
316 			     void *buf, size_t *blen)
317 {
318 	uaddr_t usr_stack = uctx->ldelf_stack_ptr;
319 	TEE_Result res = TEE_SUCCESS;
320 	uint32_t panic_code = 0;
321 	uint32_t panicked = 0;
322 	size_t *arg = NULL;
323 	struct ts_session *sess = NULL;
324 
325 	if (!uctx->ftrace_entry_func)
326 		return TEE_ERROR_NOT_SUPPORTED;
327 
328 	usr_stack -= ROUNDUP(sizeof(*arg), STACK_ALIGNMENT);
329 	arg = (size_t *)usr_stack;
330 
331 	res = vm_check_access_rights(uctx,
332 				     TEE_MEMORY_ACCESS_READ |
333 				     TEE_MEMORY_ACCESS_ANY_OWNER,
334 				     (uaddr_t)arg, sizeof(*arg));
335 	if (res) {
336 		EMSG("ldelf stack is inaccessible!");
337 		return res;
338 	}
339 
340 	*arg = *blen;
341 
342 	sess = ts_get_current_session();
343 	sess->handle_scall = scall_handle_ldelf;
344 
345 	res = thread_enter_user_mode((vaddr_t)buf, (vaddr_t)arg, 0, 0,
346 				     usr_stack, uctx->ftrace_entry_func,
347 				     is_32bit, &panicked, &panic_code);
348 
349 	sess->handle_scall = sess->ctx->ops->handle_scall;
350 	thread_user_clear_vfp(uctx);
351 	ldelf_sess_cleanup(sess);
352 
353 	if (panicked) {
354 		uctx->ftrace_entry_func = 0;
355 		EMSG("ldelf ftrace function panicked");
356 		abort_print_current_ts();
357 		res = TEE_ERROR_TARGET_DEAD;
358 	}
359 
360 	if (!res) {
361 		if (*arg > *blen)
362 			res = TEE_ERROR_SHORT_BUFFER;
363 		*blen = *arg;
364 	}
365 
366 	return res;
367 }
368 #endif /*CFG_FTRACE_SUPPORT*/
369 
370 TEE_Result ldelf_dlopen(struct user_mode_ctx *uctx, TEE_UUID *uuid,
371 			uint32_t flags)
372 {
373 	uaddr_t usr_stack = uctx->ldelf_stack_ptr;
374 	TEE_Result res = TEE_ERROR_GENERIC;
375 	struct dl_entry_arg *arg = NULL;
376 	uint32_t panic_code = 0;
377 	uint32_t panicked = 0;
378 	struct ts_session *sess = NULL;
379 
380 	assert(uuid);
381 
382 	arg = bb_alloc(sizeof(*arg));
383 	if (!arg)
384 		return TEE_ERROR_OUT_OF_MEMORY;
385 
386 	memset(arg, 0, sizeof(*arg));
387 	arg->cmd = LDELF_DL_ENTRY_DLOPEN;
388 	arg->dlopen.uuid = *uuid;
389 	arg->dlopen.flags = flags;
390 
391 	usr_stack -= ROUNDUP(sizeof(*arg), STACK_ALIGNMENT);
392 
393 	res = copy_to_user((void *)usr_stack, arg, sizeof(*arg));
394 	if (res)
395 		return res;
396 
397 	sess = ts_get_current_session();
398 	sess->handle_scall = scall_handle_ldelf;
399 
400 	res = thread_enter_user_mode(usr_stack, 0, 0, 0,
401 				     usr_stack, uctx->dl_entry_func,
402 				     is_32bit, &panicked, &panic_code);
403 
404 	sess->handle_scall = sess->ctx->ops->handle_scall;
405 	ldelf_sess_cleanup(sess);
406 
407 	if (panicked) {
408 		EMSG("ldelf dl_entry function panicked");
409 		abort_print_current_ts();
410 		res = TEE_ERROR_TARGET_DEAD;
411 	}
412 	if (!res)
413 		res = arg->ret;
414 
415 	return res;
416 }
417 
418 TEE_Result ldelf_dlsym(struct user_mode_ctx *uctx, TEE_UUID *uuid,
419 		       const char *sym, size_t symlen, vaddr_t *val)
420 {
421 	uaddr_t usr_stack = uctx->ldelf_stack_ptr;
422 	TEE_Result res = TEE_ERROR_GENERIC;
423 	struct dl_entry_arg *usr_arg = NULL;
424 	struct dl_entry_arg *arg = NULL;
425 	uint32_t panic_code = 0;
426 	uint32_t panicked = 0;
427 	struct ts_session *sess = NULL;
428 
429 	usr_stack -= ROUNDUP(sizeof(*arg) + symlen + 1, STACK_ALIGNMENT);
430 	usr_arg = (void *)usr_stack;
431 	arg = bb_alloc(sizeof(*arg));
432 	if (!arg)
433 		return TEE_ERROR_OUT_OF_MEMORY;
434 	memset(arg, 0, sizeof(*arg));
435 	arg->cmd = LDELF_DL_ENTRY_DLSYM;
436 	arg->dlsym.uuid = *uuid;
437 	res = copy_to_user(usr_arg, arg, sizeof(*arg));
438 	if (res)
439 		return res;
440 	res = copy_to_user(usr_arg->dlsym.symbol, sym, symlen + 1);
441 	if (res)
442 		return res;
443 
444 	sess = ts_get_current_session();
445 	sess->handle_scall = scall_handle_ldelf;
446 
447 	res = thread_enter_user_mode((vaddr_t)usr_arg, 0, 0, 0,
448 				     usr_stack, uctx->dl_entry_func,
449 				     is_32bit, &panicked, &panic_code);
450 
451 	sess->handle_scall = sess->ctx->ops->handle_scall;
452 	ldelf_sess_cleanup(sess);
453 
454 	if (panicked) {
455 		EMSG("ldelf dl_entry function panicked");
456 		abort_print_current_ts();
457 		res = TEE_ERROR_TARGET_DEAD;
458 	}
459 	if (!res) {
460 		TEE_Result res2 = TEE_SUCCESS;
461 
462 		res2 = GET_USER_SCALAR(res, &usr_arg->ret);
463 		if (res2)
464 			res = res2;
465 		if (!res)
466 			res = GET_USER_SCALAR(*val, &usr_arg->dlsym.val);
467 	}
468 
469 	return res;
470 }
471