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7aab5a8c PMD |
1 | /* |
2 | * ARM generic helpers. | |
3 | * | |
4 | * This code is licensed under the GNU GPL v2 or later. | |
5 | * | |
6 | * SPDX-License-Identifier: GPL-2.0-or-later | |
7 | */ | |
db725815 | 8 | |
7aab5a8c PMD |
9 | #include "qemu/osdep.h" |
10 | #include "qemu/units.h" | |
11 | #include "target/arm/idau.h" | |
12 | #include "trace.h" | |
13 | #include "cpu.h" | |
14 | #include "internals.h" | |
15 | #include "exec/gdbstub.h" | |
16 | #include "exec/helper-proto.h" | |
17 | #include "qemu/host-utils.h" | |
db725815 | 18 | #include "qemu/main-loop.h" |
7aab5a8c PMD |
19 | #include "qemu/bitops.h" |
20 | #include "qemu/crc32c.h" | |
21 | #include "qemu/qemu-print.h" | |
22 | #include "exec/exec-all.h" | |
23 | #include <zlib.h> /* For crc32 */ | |
24 | #include "hw/semihosting/semihost.h" | |
25 | #include "sysemu/cpus.h" | |
26 | #include "sysemu/kvm.h" | |
27 | #include "qemu/range.h" | |
28 | #include "qapi/qapi-commands-machine-target.h" | |
29 | #include "qapi/error.h" | |
30 | #include "qemu/guest-random.h" | |
31 | #ifdef CONFIG_TCG | |
32 | #include "arm_ldst.h" | |
33 | #include "exec/cpu_ldst.h" | |
34 | #endif | |
35 | ||
36 | #ifdef CONFIG_USER_ONLY | |
37 | ||
38 | /* These should probably raise undefined insn exceptions. */ | |
39 | void HELPER(v7m_msr)(CPUARMState *env, uint32_t reg, uint32_t val) | |
40 | { | |
41 | ARMCPU *cpu = env_archcpu(env); | |
42 | ||
43 | cpu_abort(CPU(cpu), "v7m_msr %d\n", reg); | |
44 | } | |
45 | ||
46 | uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg) | |
47 | { | |
48 | ARMCPU *cpu = env_archcpu(env); | |
49 | ||
50 | cpu_abort(CPU(cpu), "v7m_mrs %d\n", reg); | |
51 | return 0; | |
52 | } | |
53 | ||
54 | void HELPER(v7m_bxns)(CPUARMState *env, uint32_t dest) | |
55 | { | |
56 | /* translate.c should never generate calls here in user-only mode */ | |
57 | g_assert_not_reached(); | |
58 | } | |
59 | ||
60 | void HELPER(v7m_blxns)(CPUARMState *env, uint32_t dest) | |
61 | { | |
62 | /* translate.c should never generate calls here in user-only mode */ | |
63 | g_assert_not_reached(); | |
64 | } | |
65 | ||
66 | void HELPER(v7m_preserve_fp_state)(CPUARMState *env) | |
67 | { | |
68 | /* translate.c should never generate calls here in user-only mode */ | |
69 | g_assert_not_reached(); | |
70 | } | |
71 | ||
72 | void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr) | |
73 | { | |
74 | /* translate.c should never generate calls here in user-only mode */ | |
75 | g_assert_not_reached(); | |
76 | } | |
77 | ||
78 | void HELPER(v7m_vlldm)(CPUARMState *env, uint32_t fptr) | |
79 | { | |
80 | /* translate.c should never generate calls here in user-only mode */ | |
81 | g_assert_not_reached(); | |
82 | } | |
83 | ||
84 | uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op) | |
85 | { | |
86 | /* | |
87 | * The TT instructions can be used by unprivileged code, but in | |
88 | * user-only emulation we don't have the MPU. | |
89 | * Luckily since we know we are NonSecure unprivileged (and that in | |
90 | * turn means that the A flag wasn't specified), all the bits in the | |
91 | * register must be zero: | |
92 | * IREGION: 0 because IRVALID is 0 | |
93 | * IRVALID: 0 because NS | |
94 | * S: 0 because NS | |
95 | * NSRW: 0 because NS | |
96 | * NSR: 0 because NS | |
97 | * RW: 0 because unpriv and A flag not set | |
98 | * R: 0 because unpriv and A flag not set | |
99 | * SRVALID: 0 because NS | |
100 | * MRVALID: 0 because unpriv and A flag not set | |
101 | * SREGION: 0 becaus SRVALID is 0 | |
102 | * MREGION: 0 because MRVALID is 0 | |
103 | */ | |
104 | return 0; | |
105 | } | |
106 | ||
107 | #else | |
108 | ||
109 | /* | |
110 | * What kind of stack write are we doing? This affects how exceptions | |
111 | * generated during the stacking are treated. | |
112 | */ | |
113 | typedef enum StackingMode { | |
114 | STACK_NORMAL, | |
115 | STACK_IGNFAULTS, | |
116 | STACK_LAZYFP, | |
117 | } StackingMode; | |
118 | ||
119 | static bool v7m_stack_write(ARMCPU *cpu, uint32_t addr, uint32_t value, | |
120 | ARMMMUIdx mmu_idx, StackingMode mode) | |
121 | { | |
122 | CPUState *cs = CPU(cpu); | |
123 | CPUARMState *env = &cpu->env; | |
124 | MemTxAttrs attrs = {}; | |
125 | MemTxResult txres; | |
126 | target_ulong page_size; | |
127 | hwaddr physaddr; | |
128 | int prot; | |
129 | ARMMMUFaultInfo fi = {}; | |
130 | bool secure = mmu_idx & ARM_MMU_IDX_M_S; | |
131 | int exc; | |
132 | bool exc_secure; | |
133 | ||
134 | if (get_phys_addr(env, addr, MMU_DATA_STORE, mmu_idx, &physaddr, | |
135 | &attrs, &prot, &page_size, &fi, NULL)) { | |
136 | /* MPU/SAU lookup failed */ | |
137 | if (fi.type == ARMFault_QEMU_SFault) { | |
138 | if (mode == STACK_LAZYFP) { | |
139 | qemu_log_mask(CPU_LOG_INT, | |
140 | "...SecureFault with SFSR.LSPERR " | |
141 | "during lazy stacking\n"); | |
142 | env->v7m.sfsr |= R_V7M_SFSR_LSPERR_MASK; | |
143 | } else { | |
144 | qemu_log_mask(CPU_LOG_INT, | |
145 | "...SecureFault with SFSR.AUVIOL " | |
146 | "during stacking\n"); | |
147 | env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK; | |
148 | } | |
149 | env->v7m.sfsr |= R_V7M_SFSR_SFARVALID_MASK; | |
150 | env->v7m.sfar = addr; | |
151 | exc = ARMV7M_EXCP_SECURE; | |
152 | exc_secure = false; | |
153 | } else { | |
154 | if (mode == STACK_LAZYFP) { | |
155 | qemu_log_mask(CPU_LOG_INT, | |
156 | "...MemManageFault with CFSR.MLSPERR\n"); | |
157 | env->v7m.cfsr[secure] |= R_V7M_CFSR_MLSPERR_MASK; | |
158 | } else { | |
159 | qemu_log_mask(CPU_LOG_INT, | |
160 | "...MemManageFault with CFSR.MSTKERR\n"); | |
161 | env->v7m.cfsr[secure] |= R_V7M_CFSR_MSTKERR_MASK; | |
162 | } | |
163 | exc = ARMV7M_EXCP_MEM; | |
164 | exc_secure = secure; | |
165 | } | |
166 | goto pend_fault; | |
167 | } | |
168 | address_space_stl_le(arm_addressspace(cs, attrs), physaddr, value, | |
169 | attrs, &txres); | |
170 | if (txres != MEMTX_OK) { | |
171 | /* BusFault trying to write the data */ | |
172 | if (mode == STACK_LAZYFP) { | |
173 | qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.LSPERR\n"); | |
174 | env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_LSPERR_MASK; | |
175 | } else { | |
176 | qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.STKERR\n"); | |
177 | env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_STKERR_MASK; | |
178 | } | |
179 | exc = ARMV7M_EXCP_BUS; | |
180 | exc_secure = false; | |
181 | goto pend_fault; | |
182 | } | |
183 | return true; | |
184 | ||
185 | pend_fault: | |
186 | /* | |
187 | * By pending the exception at this point we are making | |
188 | * the IMPDEF choice "overridden exceptions pended" (see the | |
189 | * MergeExcInfo() pseudocode). The other choice would be to not | |
190 | * pend them now and then make a choice about which to throw away | |
191 | * later if we have two derived exceptions. | |
192 | * The only case when we must not pend the exception but instead | |
193 | * throw it away is if we are doing the push of the callee registers | |
194 | * and we've already generated a derived exception (this is indicated | |
195 | * by the caller passing STACK_IGNFAULTS). Even in this case we will | |
196 | * still update the fault status registers. | |
197 | */ | |
198 | switch (mode) { | |
199 | case STACK_NORMAL: | |
200 | armv7m_nvic_set_pending_derived(env->nvic, exc, exc_secure); | |
201 | break; | |
202 | case STACK_LAZYFP: | |
203 | armv7m_nvic_set_pending_lazyfp(env->nvic, exc, exc_secure); | |
204 | break; | |
205 | case STACK_IGNFAULTS: | |
206 | break; | |
207 | } | |
208 | return false; | |
209 | } | |
210 | ||
211 | static bool v7m_stack_read(ARMCPU *cpu, uint32_t *dest, uint32_t addr, | |
212 | ARMMMUIdx mmu_idx) | |
213 | { | |
214 | CPUState *cs = CPU(cpu); | |
215 | CPUARMState *env = &cpu->env; | |
216 | MemTxAttrs attrs = {}; | |
217 | MemTxResult txres; | |
218 | target_ulong page_size; | |
219 | hwaddr physaddr; | |
220 | int prot; | |
221 | ARMMMUFaultInfo fi = {}; | |
222 | bool secure = mmu_idx & ARM_MMU_IDX_M_S; | |
223 | int exc; | |
224 | bool exc_secure; | |
225 | uint32_t value; | |
226 | ||
227 | if (get_phys_addr(env, addr, MMU_DATA_LOAD, mmu_idx, &physaddr, | |
228 | &attrs, &prot, &page_size, &fi, NULL)) { | |
229 | /* MPU/SAU lookup failed */ | |
230 | if (fi.type == ARMFault_QEMU_SFault) { | |
231 | qemu_log_mask(CPU_LOG_INT, | |
232 | "...SecureFault with SFSR.AUVIOL during unstack\n"); | |
233 | env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK | R_V7M_SFSR_SFARVALID_MASK; | |
234 | env->v7m.sfar = addr; | |
235 | exc = ARMV7M_EXCP_SECURE; | |
236 | exc_secure = false; | |
237 | } else { | |
238 | qemu_log_mask(CPU_LOG_INT, | |
239 | "...MemManageFault with CFSR.MUNSTKERR\n"); | |
240 | env->v7m.cfsr[secure] |= R_V7M_CFSR_MUNSTKERR_MASK; | |
241 | exc = ARMV7M_EXCP_MEM; | |
242 | exc_secure = secure; | |
243 | } | |
244 | goto pend_fault; | |
245 | } | |
246 | ||
247 | value = address_space_ldl(arm_addressspace(cs, attrs), physaddr, | |
248 | attrs, &txres); | |
249 | if (txres != MEMTX_OK) { | |
250 | /* BusFault trying to read the data */ | |
251 | qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.UNSTKERR\n"); | |
252 | env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_UNSTKERR_MASK; | |
253 | exc = ARMV7M_EXCP_BUS; | |
254 | exc_secure = false; | |
255 | goto pend_fault; | |
256 | } | |
257 | ||
258 | *dest = value; | |
259 | return true; | |
260 | ||
261 | pend_fault: | |
262 | /* | |
263 | * By pending the exception at this point we are making | |
264 | * the IMPDEF choice "overridden exceptions pended" (see the | |
265 | * MergeExcInfo() pseudocode). The other choice would be to not | |
266 | * pend them now and then make a choice about which to throw away | |
267 | * later if we have two derived exceptions. | |
268 | */ | |
269 | armv7m_nvic_set_pending(env->nvic, exc, exc_secure); | |
270 | return false; | |
271 | } | |
272 | ||
273 | void HELPER(v7m_preserve_fp_state)(CPUARMState *env) | |
274 | { | |
275 | /* | |
276 | * Preserve FP state (because LSPACT was set and we are about | |
277 | * to execute an FP instruction). This corresponds to the | |
278 | * PreserveFPState() pseudocode. | |
279 | * We may throw an exception if the stacking fails. | |
280 | */ | |
281 | ARMCPU *cpu = env_archcpu(env); | |
282 | bool is_secure = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK; | |
283 | bool negpri = !(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_HFRDY_MASK); | |
284 | bool is_priv = !(env->v7m.fpccr[is_secure] & R_V7M_FPCCR_USER_MASK); | |
285 | bool splimviol = env->v7m.fpccr[is_secure] & R_V7M_FPCCR_SPLIMVIOL_MASK; | |
286 | uint32_t fpcar = env->v7m.fpcar[is_secure]; | |
287 | bool stacked_ok = true; | |
288 | bool ts = is_secure && (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK); | |
289 | bool take_exception; | |
290 | ||
291 | /* Take the iothread lock as we are going to touch the NVIC */ | |
292 | qemu_mutex_lock_iothread(); | |
293 | ||
294 | /* Check the background context had access to the FPU */ | |
295 | if (!v7m_cpacr_pass(env, is_secure, is_priv)) { | |
296 | armv7m_nvic_set_pending_lazyfp(env->nvic, ARMV7M_EXCP_USAGE, is_secure); | |
297 | env->v7m.cfsr[is_secure] |= R_V7M_CFSR_NOCP_MASK; | |
298 | stacked_ok = false; | |
299 | } else if (!is_secure && !extract32(env->v7m.nsacr, 10, 1)) { | |
300 | armv7m_nvic_set_pending_lazyfp(env->nvic, ARMV7M_EXCP_USAGE, M_REG_S); | |
301 | env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_NOCP_MASK; | |
302 | stacked_ok = false; | |
303 | } | |
304 | ||
305 | if (!splimviol && stacked_ok) { | |
306 | /* We only stack if the stack limit wasn't violated */ | |
307 | int i; | |
308 | ARMMMUIdx mmu_idx; | |
309 | ||
310 | mmu_idx = arm_v7m_mmu_idx_all(env, is_secure, is_priv, negpri); | |
311 | for (i = 0; i < (ts ? 32 : 16); i += 2) { | |
312 | uint64_t dn = *aa32_vfp_dreg(env, i / 2); | |
313 | uint32_t faddr = fpcar + 4 * i; | |
314 | uint32_t slo = extract64(dn, 0, 32); | |
315 | uint32_t shi = extract64(dn, 32, 32); | |
316 | ||
317 | if (i >= 16) { | |
318 | faddr += 8; /* skip the slot for the FPSCR */ | |
319 | } | |
320 | stacked_ok = stacked_ok && | |
321 | v7m_stack_write(cpu, faddr, slo, mmu_idx, STACK_LAZYFP) && | |
322 | v7m_stack_write(cpu, faddr + 4, shi, mmu_idx, STACK_LAZYFP); | |
323 | } | |
324 | ||
325 | stacked_ok = stacked_ok && | |
326 | v7m_stack_write(cpu, fpcar + 0x40, | |
327 | vfp_get_fpscr(env), mmu_idx, STACK_LAZYFP); | |
328 | } | |
329 | ||
330 | /* | |
331 | * We definitely pended an exception, but it's possible that it | |
332 | * might not be able to be taken now. If its priority permits us | |
333 | * to take it now, then we must not update the LSPACT or FP regs, | |
334 | * but instead jump out to take the exception immediately. | |
335 | * If it's just pending and won't be taken until the current | |
336 | * handler exits, then we do update LSPACT and the FP regs. | |
337 | */ | |
338 | take_exception = !stacked_ok && | |
339 | armv7m_nvic_can_take_pending_exception(env->nvic); | |
340 | ||
341 | qemu_mutex_unlock_iothread(); | |
342 | ||
343 | if (take_exception) { | |
344 | raise_exception_ra(env, EXCP_LAZYFP, 0, 1, GETPC()); | |
345 | } | |
346 | ||
347 | env->v7m.fpccr[is_secure] &= ~R_V7M_FPCCR_LSPACT_MASK; | |
348 | ||
349 | if (ts) { | |
350 | /* Clear s0 to s31 and the FPSCR */ | |
351 | int i; | |
352 | ||
353 | for (i = 0; i < 32; i += 2) { | |
354 | *aa32_vfp_dreg(env, i / 2) = 0; | |
355 | } | |
356 | vfp_set_fpscr(env, 0); | |
357 | } | |
358 | /* | |
359 | * Otherwise s0 to s15 and FPSCR are UNKNOWN; we choose to leave them | |
360 | * unchanged. | |
361 | */ | |
362 | } | |
363 | ||
364 | /* | |
365 | * Write to v7M CONTROL.SPSEL bit for the specified security bank. | |
366 | * This may change the current stack pointer between Main and Process | |
367 | * stack pointers if it is done for the CONTROL register for the current | |
368 | * security state. | |
369 | */ | |
370 | static void write_v7m_control_spsel_for_secstate(CPUARMState *env, | |
371 | bool new_spsel, | |
372 | bool secstate) | |
373 | { | |
374 | bool old_is_psp = v7m_using_psp(env); | |
375 | ||
376 | env->v7m.control[secstate] = | |
377 | deposit32(env->v7m.control[secstate], | |
378 | R_V7M_CONTROL_SPSEL_SHIFT, | |
379 | R_V7M_CONTROL_SPSEL_LENGTH, new_spsel); | |
380 | ||
381 | if (secstate == env->v7m.secure) { | |
382 | bool new_is_psp = v7m_using_psp(env); | |
383 | uint32_t tmp; | |
384 | ||
385 | if (old_is_psp != new_is_psp) { | |
386 | tmp = env->v7m.other_sp; | |
387 | env->v7m.other_sp = env->regs[13]; | |
388 | env->regs[13] = tmp; | |
389 | } | |
390 | } | |
391 | } | |
392 | ||
393 | /* | |
394 | * Write to v7M CONTROL.SPSEL bit. This may change the current | |
395 | * stack pointer between Main and Process stack pointers. | |
396 | */ | |
397 | static void write_v7m_control_spsel(CPUARMState *env, bool new_spsel) | |
398 | { | |
399 | write_v7m_control_spsel_for_secstate(env, new_spsel, env->v7m.secure); | |
400 | } | |
401 | ||
402 | void write_v7m_exception(CPUARMState *env, uint32_t new_exc) | |
403 | { | |
404 | /* | |
405 | * Write a new value to v7m.exception, thus transitioning into or out | |
406 | * of Handler mode; this may result in a change of active stack pointer. | |
407 | */ | |
408 | bool new_is_psp, old_is_psp = v7m_using_psp(env); | |
409 | uint32_t tmp; | |
410 | ||
411 | env->v7m.exception = new_exc; | |
412 | ||
413 | new_is_psp = v7m_using_psp(env); | |
414 | ||
415 | if (old_is_psp != new_is_psp) { | |
416 | tmp = env->v7m.other_sp; | |
417 | env->v7m.other_sp = env->regs[13]; | |
418 | env->regs[13] = tmp; | |
419 | } | |
420 | } | |
421 | ||
422 | /* Switch M profile security state between NS and S */ | |
423 | static void switch_v7m_security_state(CPUARMState *env, bool new_secstate) | |
424 | { | |
425 | uint32_t new_ss_msp, new_ss_psp; | |
426 | ||
427 | if (env->v7m.secure == new_secstate) { | |
428 | return; | |
429 | } | |
430 | ||
431 | /* | |
432 | * All the banked state is accessed by looking at env->v7m.secure | |
433 | * except for the stack pointer; rearrange the SP appropriately. | |
434 | */ | |
435 | new_ss_msp = env->v7m.other_ss_msp; | |
436 | new_ss_psp = env->v7m.other_ss_psp; | |
437 | ||
438 | if (v7m_using_psp(env)) { | |
439 | env->v7m.other_ss_psp = env->regs[13]; | |
440 | env->v7m.other_ss_msp = env->v7m.other_sp; | |
441 | } else { | |
442 | env->v7m.other_ss_msp = env->regs[13]; | |
443 | env->v7m.other_ss_psp = env->v7m.other_sp; | |
444 | } | |
445 | ||
446 | env->v7m.secure = new_secstate; | |
447 | ||
448 | if (v7m_using_psp(env)) { | |
449 | env->regs[13] = new_ss_psp; | |
450 | env->v7m.other_sp = new_ss_msp; | |
451 | } else { | |
452 | env->regs[13] = new_ss_msp; | |
453 | env->v7m.other_sp = new_ss_psp; | |
454 | } | |
455 | } | |
456 | ||
457 | void HELPER(v7m_bxns)(CPUARMState *env, uint32_t dest) | |
458 | { | |
459 | /* | |
460 | * Handle v7M BXNS: | |
461 | * - if the return value is a magic value, do exception return (like BX) | |
462 | * - otherwise bit 0 of the return value is the target security state | |
463 | */ | |
464 | uint32_t min_magic; | |
465 | ||
466 | if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { | |
467 | /* Covers FNC_RETURN and EXC_RETURN magic */ | |
468 | min_magic = FNC_RETURN_MIN_MAGIC; | |
469 | } else { | |
470 | /* EXC_RETURN magic only */ | |
471 | min_magic = EXC_RETURN_MIN_MAGIC; | |
472 | } | |
473 | ||
474 | if (dest >= min_magic) { | |
475 | /* | |
476 | * This is an exception return magic value; put it where | |
477 | * do_v7m_exception_exit() expects and raise EXCEPTION_EXIT. | |
478 | * Note that if we ever add gen_ss_advance() singlestep support to | |
479 | * M profile this should count as an "instruction execution complete" | |
480 | * event (compare gen_bx_excret_final_code()). | |
481 | */ | |
482 | env->regs[15] = dest & ~1; | |
483 | env->thumb = dest & 1; | |
484 | HELPER(exception_internal)(env, EXCP_EXCEPTION_EXIT); | |
485 | /* notreached */ | |
486 | } | |
487 | ||
488 | /* translate.c should have made BXNS UNDEF unless we're secure */ | |
489 | assert(env->v7m.secure); | |
490 | ||
491 | if (!(dest & 1)) { | |
492 | env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK; | |
493 | } | |
494 | switch_v7m_security_state(env, dest & 1); | |
495 | env->thumb = 1; | |
496 | env->regs[15] = dest & ~1; | |
497 | } | |
498 | ||
499 | void HELPER(v7m_blxns)(CPUARMState *env, uint32_t dest) | |
500 | { | |
501 | /* | |
502 | * Handle v7M BLXNS: | |
503 | * - bit 0 of the destination address is the target security state | |
504 | */ | |
505 | ||
506 | /* At this point regs[15] is the address just after the BLXNS */ | |
507 | uint32_t nextinst = env->regs[15] | 1; | |
508 | uint32_t sp = env->regs[13] - 8; | |
509 | uint32_t saved_psr; | |
510 | ||
511 | /* translate.c will have made BLXNS UNDEF unless we're secure */ | |
512 | assert(env->v7m.secure); | |
513 | ||
514 | if (dest & 1) { | |
515 | /* | |
516 | * Target is Secure, so this is just a normal BLX, | |
517 | * except that the low bit doesn't indicate Thumb/not. | |
518 | */ | |
519 | env->regs[14] = nextinst; | |
520 | env->thumb = 1; | |
521 | env->regs[15] = dest & ~1; | |
522 | return; | |
523 | } | |
524 | ||
525 | /* Target is non-secure: first push a stack frame */ | |
526 | if (!QEMU_IS_ALIGNED(sp, 8)) { | |
527 | qemu_log_mask(LOG_GUEST_ERROR, | |
528 | "BLXNS with misaligned SP is UNPREDICTABLE\n"); | |
529 | } | |
530 | ||
531 | if (sp < v7m_sp_limit(env)) { | |
532 | raise_exception(env, EXCP_STKOF, 0, 1); | |
533 | } | |
534 | ||
535 | saved_psr = env->v7m.exception; | |
536 | if (env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK) { | |
537 | saved_psr |= XPSR_SFPA; | |
538 | } | |
539 | ||
540 | /* Note that these stores can throw exceptions on MPU faults */ | |
2884fbb6 PM |
541 | cpu_stl_data_ra(env, sp, nextinst, GETPC()); |
542 | cpu_stl_data_ra(env, sp + 4, saved_psr, GETPC()); | |
7aab5a8c PMD |
543 | |
544 | env->regs[13] = sp; | |
545 | env->regs[14] = 0xfeffffff; | |
546 | if (arm_v7m_is_handler_mode(env)) { | |
547 | /* | |
548 | * Write a dummy value to IPSR, to avoid leaking the current secure | |
549 | * exception number to non-secure code. This is guaranteed not | |
550 | * to cause write_v7m_exception() to actually change stacks. | |
551 | */ | |
552 | write_v7m_exception(env, 1); | |
553 | } | |
554 | env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK; | |
555 | switch_v7m_security_state(env, 0); | |
556 | env->thumb = 1; | |
557 | env->regs[15] = dest; | |
558 | } | |
559 | ||
560 | static uint32_t *get_v7m_sp_ptr(CPUARMState *env, bool secure, bool threadmode, | |
561 | bool spsel) | |
562 | { | |
563 | /* | |
564 | * Return a pointer to the location where we currently store the | |
565 | * stack pointer for the requested security state and thread mode. | |
566 | * This pointer will become invalid if the CPU state is updated | |
567 | * such that the stack pointers are switched around (eg changing | |
568 | * the SPSEL control bit). | |
569 | * Compare the v8M ARM ARM pseudocode LookUpSP_with_security_mode(). | |
570 | * Unlike that pseudocode, we require the caller to pass us in the | |
571 | * SPSEL control bit value; this is because we also use this | |
572 | * function in handling of pushing of the callee-saves registers | |
573 | * part of the v8M stack frame (pseudocode PushCalleeStack()), | |
574 | * and in the tailchain codepath the SPSEL bit comes from the exception | |
575 | * return magic LR value from the previous exception. The pseudocode | |
576 | * opencodes the stack-selection in PushCalleeStack(), but we prefer | |
577 | * to make this utility function generic enough to do the job. | |
578 | */ | |
579 | bool want_psp = threadmode && spsel; | |
580 | ||
581 | if (secure == env->v7m.secure) { | |
582 | if (want_psp == v7m_using_psp(env)) { | |
583 | return &env->regs[13]; | |
584 | } else { | |
585 | return &env->v7m.other_sp; | |
586 | } | |
587 | } else { | |
588 | if (want_psp) { | |
589 | return &env->v7m.other_ss_psp; | |
590 | } else { | |
591 | return &env->v7m.other_ss_msp; | |
592 | } | |
593 | } | |
594 | } | |
595 | ||
596 | static bool arm_v7m_load_vector(ARMCPU *cpu, int exc, bool targets_secure, | |
597 | uint32_t *pvec) | |
598 | { | |
599 | CPUState *cs = CPU(cpu); | |
600 | CPUARMState *env = &cpu->env; | |
601 | MemTxResult result; | |
602 | uint32_t addr = env->v7m.vecbase[targets_secure] + exc * 4; | |
603 | uint32_t vector_entry; | |
604 | MemTxAttrs attrs = {}; | |
605 | ARMMMUIdx mmu_idx; | |
606 | bool exc_secure; | |
607 | ||
608 | mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, targets_secure, true); | |
609 | ||
610 | /* | |
611 | * We don't do a get_phys_addr() here because the rules for vector | |
612 | * loads are special: they always use the default memory map, and | |
613 | * the default memory map permits reads from all addresses. | |
614 | * Since there's no easy way to pass through to pmsav8_mpu_lookup() | |
615 | * that we want this special case which would always say "yes", | |
616 | * we just do the SAU lookup here followed by a direct physical load. | |
617 | */ | |
618 | attrs.secure = targets_secure; | |
619 | attrs.user = false; | |
620 | ||
621 | if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { | |
622 | V8M_SAttributes sattrs = {}; | |
623 | ||
624 | v8m_security_lookup(env, addr, MMU_DATA_LOAD, mmu_idx, &sattrs); | |
625 | if (sattrs.ns) { | |
626 | attrs.secure = false; | |
627 | } else if (!targets_secure) { | |
51c9122e PM |
628 | /* |
629 | * NS access to S memory: the underlying exception which we escalate | |
630 | * to HardFault is SecureFault, which always targets Secure. | |
631 | */ | |
632 | exc_secure = true; | |
7aab5a8c PMD |
633 | goto load_fail; |
634 | } | |
635 | } | |
636 | ||
637 | vector_entry = address_space_ldl(arm_addressspace(cs, attrs), addr, | |
638 | attrs, &result); | |
639 | if (result != MEMTX_OK) { | |
51c9122e PM |
640 | /* |
641 | * Underlying exception is BusFault: its target security state | |
642 | * depends on BFHFNMINS. | |
643 | */ | |
644 | exc_secure = !(cpu->env.v7m.aircr & R_V7M_AIRCR_BFHFNMINS_MASK); | |
7aab5a8c PMD |
645 | goto load_fail; |
646 | } | |
647 | *pvec = vector_entry; | |
648 | return true; | |
649 | ||
650 | load_fail: | |
651 | /* | |
652 | * All vector table fetch fails are reported as HardFault, with | |
653 | * HFSR.VECTTBL and .FORCED set. (FORCED is set because | |
51c9122e | 654 | * technically the underlying exception is a SecureFault or BusFault |
7aab5a8c PMD |
655 | * that is escalated to HardFault.) This is a terminal exception, |
656 | * so we will either take the HardFault immediately or else enter | |
657 | * lockup (the latter case is handled in armv7m_nvic_set_pending_derived()). | |
51c9122e PM |
658 | * The HardFault is Secure if BFHFNMINS is 0 (meaning that all HFs are |
659 | * secure); otherwise it targets the same security state as the | |
660 | * underlying exception. | |
7aab5a8c | 661 | */ |
51c9122e PM |
662 | if (!(cpu->env.v7m.aircr & R_V7M_AIRCR_BFHFNMINS_MASK)) { |
663 | exc_secure = true; | |
664 | } | |
7aab5a8c PMD |
665 | env->v7m.hfsr |= R_V7M_HFSR_VECTTBL_MASK | R_V7M_HFSR_FORCED_MASK; |
666 | armv7m_nvic_set_pending_derived(env->nvic, ARMV7M_EXCP_HARD, exc_secure); | |
667 | return false; | |
668 | } | |
669 | ||
670 | static uint32_t v7m_integrity_sig(CPUARMState *env, uint32_t lr) | |
671 | { | |
672 | /* | |
673 | * Return the integrity signature value for the callee-saves | |
674 | * stack frame section. @lr is the exception return payload/LR value | |
675 | * whose FType bit forms bit 0 of the signature if FP is present. | |
676 | */ | |
677 | uint32_t sig = 0xfefa125a; | |
678 | ||
679 | if (!arm_feature(env, ARM_FEATURE_VFP) || (lr & R_V7M_EXCRET_FTYPE_MASK)) { | |
680 | sig |= 1; | |
681 | } | |
682 | return sig; | |
683 | } | |
684 | ||
685 | static bool v7m_push_callee_stack(ARMCPU *cpu, uint32_t lr, bool dotailchain, | |
686 | bool ignore_faults) | |
687 | { | |
688 | /* | |
689 | * For v8M, push the callee-saves register part of the stack frame. | |
690 | * Compare the v8M pseudocode PushCalleeStack(). | |
691 | * In the tailchaining case this may not be the current stack. | |
692 | */ | |
693 | CPUARMState *env = &cpu->env; | |
694 | uint32_t *frame_sp_p; | |
695 | uint32_t frameptr; | |
696 | ARMMMUIdx mmu_idx; | |
697 | bool stacked_ok; | |
698 | uint32_t limit; | |
699 | bool want_psp; | |
700 | uint32_t sig; | |
701 | StackingMode smode = ignore_faults ? STACK_IGNFAULTS : STACK_NORMAL; | |
702 | ||
703 | if (dotailchain) { | |
704 | bool mode = lr & R_V7M_EXCRET_MODE_MASK; | |
705 | bool priv = !(env->v7m.control[M_REG_S] & R_V7M_CONTROL_NPRIV_MASK) || | |
706 | !mode; | |
707 | ||
708 | mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, M_REG_S, priv); | |
709 | frame_sp_p = get_v7m_sp_ptr(env, M_REG_S, mode, | |
710 | lr & R_V7M_EXCRET_SPSEL_MASK); | |
711 | want_psp = mode && (lr & R_V7M_EXCRET_SPSEL_MASK); | |
712 | if (want_psp) { | |
713 | limit = env->v7m.psplim[M_REG_S]; | |
714 | } else { | |
715 | limit = env->v7m.msplim[M_REG_S]; | |
716 | } | |
717 | } else { | |
718 | mmu_idx = arm_mmu_idx(env); | |
719 | frame_sp_p = &env->regs[13]; | |
720 | limit = v7m_sp_limit(env); | |
721 | } | |
722 | ||
723 | frameptr = *frame_sp_p - 0x28; | |
724 | if (frameptr < limit) { | |
725 | /* | |
726 | * Stack limit failure: set SP to the limit value, and generate | |
727 | * STKOF UsageFault. Stack pushes below the limit must not be | |
728 | * performed. It is IMPDEF whether pushes above the limit are | |
729 | * performed; we choose not to. | |
730 | */ | |
731 | qemu_log_mask(CPU_LOG_INT, | |
732 | "...STKOF during callee-saves register stacking\n"); | |
733 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_STKOF_MASK; | |
734 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, | |
735 | env->v7m.secure); | |
736 | *frame_sp_p = limit; | |
737 | return true; | |
738 | } | |
739 | ||
740 | /* | |
741 | * Write as much of the stack frame as we can. A write failure may | |
742 | * cause us to pend a derived exception. | |
743 | */ | |
744 | sig = v7m_integrity_sig(env, lr); | |
745 | stacked_ok = | |
746 | v7m_stack_write(cpu, frameptr, sig, mmu_idx, smode) && | |
747 | v7m_stack_write(cpu, frameptr + 0x8, env->regs[4], mmu_idx, smode) && | |
748 | v7m_stack_write(cpu, frameptr + 0xc, env->regs[5], mmu_idx, smode) && | |
749 | v7m_stack_write(cpu, frameptr + 0x10, env->regs[6], mmu_idx, smode) && | |
750 | v7m_stack_write(cpu, frameptr + 0x14, env->regs[7], mmu_idx, smode) && | |
751 | v7m_stack_write(cpu, frameptr + 0x18, env->regs[8], mmu_idx, smode) && | |
752 | v7m_stack_write(cpu, frameptr + 0x1c, env->regs[9], mmu_idx, smode) && | |
753 | v7m_stack_write(cpu, frameptr + 0x20, env->regs[10], mmu_idx, smode) && | |
754 | v7m_stack_write(cpu, frameptr + 0x24, env->regs[11], mmu_idx, smode); | |
755 | ||
756 | /* Update SP regardless of whether any of the stack accesses failed. */ | |
757 | *frame_sp_p = frameptr; | |
758 | ||
759 | return !stacked_ok; | |
760 | } | |
761 | ||
762 | static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr, bool dotailchain, | |
763 | bool ignore_stackfaults) | |
764 | { | |
765 | /* | |
766 | * Do the "take the exception" parts of exception entry, | |
767 | * but not the pushing of state to the stack. This is | |
768 | * similar to the pseudocode ExceptionTaken() function. | |
769 | */ | |
770 | CPUARMState *env = &cpu->env; | |
771 | uint32_t addr; | |
772 | bool targets_secure; | |
773 | int exc; | |
774 | bool push_failed = false; | |
775 | ||
776 | armv7m_nvic_get_pending_irq_info(env->nvic, &exc, &targets_secure); | |
777 | qemu_log_mask(CPU_LOG_INT, "...taking pending %s exception %d\n", | |
778 | targets_secure ? "secure" : "nonsecure", exc); | |
779 | ||
780 | if (dotailchain) { | |
781 | /* Sanitize LR FType and PREFIX bits */ | |
782 | if (!arm_feature(env, ARM_FEATURE_VFP)) { | |
783 | lr |= R_V7M_EXCRET_FTYPE_MASK; | |
784 | } | |
785 | lr = deposit32(lr, 24, 8, 0xff); | |
786 | } | |
787 | ||
788 | if (arm_feature(env, ARM_FEATURE_V8)) { | |
789 | if (arm_feature(env, ARM_FEATURE_M_SECURITY) && | |
790 | (lr & R_V7M_EXCRET_S_MASK)) { | |
791 | /* | |
792 | * The background code (the owner of the registers in the | |
793 | * exception frame) is Secure. This means it may either already | |
794 | * have or now needs to push callee-saves registers. | |
795 | */ | |
796 | if (targets_secure) { | |
797 | if (dotailchain && !(lr & R_V7M_EXCRET_ES_MASK)) { | |
798 | /* | |
799 | * We took an exception from Secure to NonSecure | |
800 | * (which means the callee-saved registers got stacked) | |
801 | * and are now tailchaining to a Secure exception. | |
802 | * Clear DCRS so eventual return from this Secure | |
803 | * exception unstacks the callee-saved registers. | |
804 | */ | |
805 | lr &= ~R_V7M_EXCRET_DCRS_MASK; | |
806 | } | |
807 | } else { | |
808 | /* | |
809 | * We're going to a non-secure exception; push the | |
810 | * callee-saves registers to the stack now, if they're | |
811 | * not already saved. | |
812 | */ | |
813 | if (lr & R_V7M_EXCRET_DCRS_MASK && | |
814 | !(dotailchain && !(lr & R_V7M_EXCRET_ES_MASK))) { | |
815 | push_failed = v7m_push_callee_stack(cpu, lr, dotailchain, | |
816 | ignore_stackfaults); | |
817 | } | |
818 | lr |= R_V7M_EXCRET_DCRS_MASK; | |
819 | } | |
820 | } | |
821 | ||
822 | lr &= ~R_V7M_EXCRET_ES_MASK; | |
823 | if (targets_secure || !arm_feature(env, ARM_FEATURE_M_SECURITY)) { | |
824 | lr |= R_V7M_EXCRET_ES_MASK; | |
825 | } | |
826 | lr &= ~R_V7M_EXCRET_SPSEL_MASK; | |
827 | if (env->v7m.control[targets_secure] & R_V7M_CONTROL_SPSEL_MASK) { | |
828 | lr |= R_V7M_EXCRET_SPSEL_MASK; | |
829 | } | |
830 | ||
831 | /* | |
832 | * Clear registers if necessary to prevent non-secure exception | |
833 | * code being able to see register values from secure code. | |
834 | * Where register values become architecturally UNKNOWN we leave | |
835 | * them with their previous values. | |
836 | */ | |
837 | if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { | |
838 | if (!targets_secure) { | |
839 | /* | |
840 | * Always clear the caller-saved registers (they have been | |
841 | * pushed to the stack earlier in v7m_push_stack()). | |
842 | * Clear callee-saved registers if the background code is | |
843 | * Secure (in which case these regs were saved in | |
844 | * v7m_push_callee_stack()). | |
845 | */ | |
846 | int i; | |
847 | ||
848 | for (i = 0; i < 13; i++) { | |
849 | /* r4..r11 are callee-saves, zero only if EXCRET.S == 1 */ | |
850 | if (i < 4 || i > 11 || (lr & R_V7M_EXCRET_S_MASK)) { | |
851 | env->regs[i] = 0; | |
852 | } | |
853 | } | |
854 | /* Clear EAPSR */ | |
855 | xpsr_write(env, 0, XPSR_NZCV | XPSR_Q | XPSR_GE | XPSR_IT); | |
856 | } | |
857 | } | |
858 | } | |
859 | ||
860 | if (push_failed && !ignore_stackfaults) { | |
861 | /* | |
862 | * Derived exception on callee-saves register stacking: | |
863 | * we might now want to take a different exception which | |
864 | * targets a different security state, so try again from the top. | |
865 | */ | |
866 | qemu_log_mask(CPU_LOG_INT, | |
867 | "...derived exception on callee-saves register stacking"); | |
868 | v7m_exception_taken(cpu, lr, true, true); | |
869 | return; | |
870 | } | |
871 | ||
872 | if (!arm_v7m_load_vector(cpu, exc, targets_secure, &addr)) { | |
873 | /* Vector load failed: derived exception */ | |
874 | qemu_log_mask(CPU_LOG_INT, "...derived exception on vector table load"); | |
875 | v7m_exception_taken(cpu, lr, true, true); | |
876 | return; | |
877 | } | |
878 | ||
879 | /* | |
880 | * Now we've done everything that might cause a derived exception | |
881 | * we can go ahead and activate whichever exception we're going to | |
882 | * take (which might now be the derived exception). | |
883 | */ | |
884 | armv7m_nvic_acknowledge_irq(env->nvic); | |
885 | ||
886 | /* Switch to target security state -- must do this before writing SPSEL */ | |
887 | switch_v7m_security_state(env, targets_secure); | |
888 | write_v7m_control_spsel(env, 0); | |
889 | arm_clear_exclusive(env); | |
890 | /* Clear SFPA and FPCA (has no effect if no FPU) */ | |
891 | env->v7m.control[M_REG_S] &= | |
892 | ~(R_V7M_CONTROL_FPCA_MASK | R_V7M_CONTROL_SFPA_MASK); | |
893 | /* Clear IT bits */ | |
894 | env->condexec_bits = 0; | |
895 | env->regs[14] = lr; | |
896 | env->regs[15] = addr & 0xfffffffe; | |
897 | env->thumb = addr & 1; | |
898 | } | |
899 | ||
900 | static void v7m_update_fpccr(CPUARMState *env, uint32_t frameptr, | |
901 | bool apply_splim) | |
902 | { | |
903 | /* | |
904 | * Like the pseudocode UpdateFPCCR: save state in FPCAR and FPCCR | |
905 | * that we will need later in order to do lazy FP reg stacking. | |
906 | */ | |
907 | bool is_secure = env->v7m.secure; | |
908 | void *nvic = env->nvic; | |
909 | /* | |
910 | * Some bits are unbanked and live always in fpccr[M_REG_S]; some bits | |
911 | * are banked and we want to update the bit in the bank for the | |
912 | * current security state; and in one case we want to specifically | |
913 | * update the NS banked version of a bit even if we are secure. | |
914 | */ | |
915 | uint32_t *fpccr_s = &env->v7m.fpccr[M_REG_S]; | |
916 | uint32_t *fpccr_ns = &env->v7m.fpccr[M_REG_NS]; | |
917 | uint32_t *fpccr = &env->v7m.fpccr[is_secure]; | |
918 | bool hfrdy, bfrdy, mmrdy, ns_ufrdy, s_ufrdy, sfrdy, monrdy; | |
919 | ||
920 | env->v7m.fpcar[is_secure] = frameptr & ~0x7; | |
921 | ||
922 | if (apply_splim && arm_feature(env, ARM_FEATURE_V8)) { | |
923 | bool splimviol; | |
924 | uint32_t splim = v7m_sp_limit(env); | |
925 | bool ign = armv7m_nvic_neg_prio_requested(nvic, is_secure) && | |
926 | (env->v7m.ccr[is_secure] & R_V7M_CCR_STKOFHFNMIGN_MASK); | |
927 | ||
928 | splimviol = !ign && frameptr < splim; | |
929 | *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, SPLIMVIOL, splimviol); | |
930 | } | |
931 | ||
932 | *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, LSPACT, 1); | |
933 | ||
934 | *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, S, is_secure); | |
935 | ||
936 | *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, USER, arm_current_el(env) == 0); | |
937 | ||
938 | *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, THREAD, | |
939 | !arm_v7m_is_handler_mode(env)); | |
940 | ||
941 | hfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_HARD, false); | |
942 | *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, HFRDY, hfrdy); | |
943 | ||
944 | bfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_BUS, false); | |
945 | *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, BFRDY, bfrdy); | |
946 | ||
947 | mmrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_MEM, is_secure); | |
948 | *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, MMRDY, mmrdy); | |
949 | ||
950 | ns_ufrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_USAGE, false); | |
951 | *fpccr_ns = FIELD_DP32(*fpccr_ns, V7M_FPCCR, UFRDY, ns_ufrdy); | |
952 | ||
953 | monrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_DEBUG, false); | |
954 | *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, MONRDY, monrdy); | |
955 | ||
956 | if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { | |
957 | s_ufrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_USAGE, true); | |
958 | *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, UFRDY, s_ufrdy); | |
959 | ||
960 | sfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_SECURE, false); | |
961 | *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, SFRDY, sfrdy); | |
962 | } | |
963 | } | |
964 | ||
965 | void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr) | |
966 | { | |
967 | /* fptr is the value of Rn, the frame pointer we store the FP regs to */ | |
968 | bool s = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK; | |
969 | bool lspact = env->v7m.fpccr[s] & R_V7M_FPCCR_LSPACT_MASK; | |
2884fbb6 | 970 | uintptr_t ra = GETPC(); |
7aab5a8c PMD |
971 | |
972 | assert(env->v7m.secure); | |
973 | ||
974 | if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) { | |
975 | return; | |
976 | } | |
977 | ||
978 | /* Check access to the coprocessor is permitted */ | |
979 | if (!v7m_cpacr_pass(env, true, arm_current_el(env) != 0)) { | |
980 | raise_exception_ra(env, EXCP_NOCP, 0, 1, GETPC()); | |
981 | } | |
982 | ||
983 | if (lspact) { | |
984 | /* LSPACT should not be active when there is active FP state */ | |
985 | raise_exception_ra(env, EXCP_LSERR, 0, 1, GETPC()); | |
986 | } | |
987 | ||
988 | if (fptr & 7) { | |
989 | raise_exception_ra(env, EXCP_UNALIGNED, 0, 1, GETPC()); | |
990 | } | |
991 | ||
992 | /* | |
993 | * Note that we do not use v7m_stack_write() here, because the | |
994 | * accesses should not set the FSR bits for stacking errors if they | |
995 | * fail. (In pseudocode terms, they are AccType_NORMAL, not AccType_STACK | |
2884fbb6 | 996 | * or AccType_LAZYFP). Faults in cpu_stl_data_ra() will throw exceptions |
7aab5a8c PMD |
997 | * and longjmp out. |
998 | */ | |
999 | if (!(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPEN_MASK)) { | |
1000 | bool ts = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK; | |
1001 | int i; | |
1002 | ||
1003 | for (i = 0; i < (ts ? 32 : 16); i += 2) { | |
1004 | uint64_t dn = *aa32_vfp_dreg(env, i / 2); | |
1005 | uint32_t faddr = fptr + 4 * i; | |
1006 | uint32_t slo = extract64(dn, 0, 32); | |
1007 | uint32_t shi = extract64(dn, 32, 32); | |
1008 | ||
1009 | if (i >= 16) { | |
1010 | faddr += 8; /* skip the slot for the FPSCR */ | |
1011 | } | |
2884fbb6 PM |
1012 | cpu_stl_data_ra(env, faddr, slo, ra); |
1013 | cpu_stl_data_ra(env, faddr + 4, shi, ra); | |
7aab5a8c | 1014 | } |
2884fbb6 | 1015 | cpu_stl_data_ra(env, fptr + 0x40, vfp_get_fpscr(env), ra); |
7aab5a8c PMD |
1016 | |
1017 | /* | |
1018 | * If TS is 0 then s0 to s15 and FPSCR are UNKNOWN; we choose to | |
1019 | * leave them unchanged, matching our choice in v7m_preserve_fp_state. | |
1020 | */ | |
1021 | if (ts) { | |
1022 | for (i = 0; i < 32; i += 2) { | |
1023 | *aa32_vfp_dreg(env, i / 2) = 0; | |
1024 | } | |
1025 | vfp_set_fpscr(env, 0); | |
1026 | } | |
1027 | } else { | |
1028 | v7m_update_fpccr(env, fptr, false); | |
1029 | } | |
1030 | ||
1031 | env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK; | |
1032 | } | |
1033 | ||
1034 | void HELPER(v7m_vlldm)(CPUARMState *env, uint32_t fptr) | |
1035 | { | |
2884fbb6 PM |
1036 | uintptr_t ra = GETPC(); |
1037 | ||
7aab5a8c PMD |
1038 | /* fptr is the value of Rn, the frame pointer we load the FP regs from */ |
1039 | assert(env->v7m.secure); | |
1040 | ||
1041 | if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) { | |
1042 | return; | |
1043 | } | |
1044 | ||
1045 | /* Check access to the coprocessor is permitted */ | |
1046 | if (!v7m_cpacr_pass(env, true, arm_current_el(env) != 0)) { | |
1047 | raise_exception_ra(env, EXCP_NOCP, 0, 1, GETPC()); | |
1048 | } | |
1049 | ||
1050 | if (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK) { | |
1051 | /* State in FP is still valid */ | |
1052 | env->v7m.fpccr[M_REG_S] &= ~R_V7M_FPCCR_LSPACT_MASK; | |
1053 | } else { | |
1054 | bool ts = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK; | |
1055 | int i; | |
1056 | uint32_t fpscr; | |
1057 | ||
1058 | if (fptr & 7) { | |
1059 | raise_exception_ra(env, EXCP_UNALIGNED, 0, 1, GETPC()); | |
1060 | } | |
1061 | ||
1062 | for (i = 0; i < (ts ? 32 : 16); i += 2) { | |
1063 | uint32_t slo, shi; | |
1064 | uint64_t dn; | |
1065 | uint32_t faddr = fptr + 4 * i; | |
1066 | ||
1067 | if (i >= 16) { | |
1068 | faddr += 8; /* skip the slot for the FPSCR */ | |
1069 | } | |
1070 | ||
2884fbb6 PM |
1071 | slo = cpu_ldl_data_ra(env, faddr, ra); |
1072 | shi = cpu_ldl_data_ra(env, faddr + 4, ra); | |
7aab5a8c PMD |
1073 | |
1074 | dn = (uint64_t) shi << 32 | slo; | |
1075 | *aa32_vfp_dreg(env, i / 2) = dn; | |
1076 | } | |
2884fbb6 | 1077 | fpscr = cpu_ldl_data_ra(env, fptr + 0x40, ra); |
7aab5a8c PMD |
1078 | vfp_set_fpscr(env, fpscr); |
1079 | } | |
1080 | ||
1081 | env->v7m.control[M_REG_S] |= R_V7M_CONTROL_FPCA_MASK; | |
1082 | } | |
1083 | ||
1084 | static bool v7m_push_stack(ARMCPU *cpu) | |
1085 | { | |
1086 | /* | |
1087 | * Do the "set up stack frame" part of exception entry, | |
1088 | * similar to pseudocode PushStack(). | |
1089 | * Return true if we generate a derived exception (and so | |
1090 | * should ignore further stack faults trying to process | |
1091 | * that derived exception.) | |
1092 | */ | |
1093 | bool stacked_ok = true, limitviol = false; | |
1094 | CPUARMState *env = &cpu->env; | |
1095 | uint32_t xpsr = xpsr_read(env); | |
1096 | uint32_t frameptr = env->regs[13]; | |
1097 | ARMMMUIdx mmu_idx = arm_mmu_idx(env); | |
1098 | uint32_t framesize; | |
1099 | bool nsacr_cp10 = extract32(env->v7m.nsacr, 10, 1); | |
1100 | ||
1101 | if ((env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK) && | |
1102 | (env->v7m.secure || nsacr_cp10)) { | |
1103 | if (env->v7m.secure && | |
1104 | env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK) { | |
1105 | framesize = 0xa8; | |
1106 | } else { | |
1107 | framesize = 0x68; | |
1108 | } | |
1109 | } else { | |
1110 | framesize = 0x20; | |
1111 | } | |
1112 | ||
1113 | /* Align stack pointer if the guest wants that */ | |
1114 | if ((frameptr & 4) && | |
1115 | (env->v7m.ccr[env->v7m.secure] & R_V7M_CCR_STKALIGN_MASK)) { | |
1116 | frameptr -= 4; | |
1117 | xpsr |= XPSR_SPREALIGN; | |
1118 | } | |
1119 | ||
1120 | xpsr &= ~XPSR_SFPA; | |
1121 | if (env->v7m.secure && | |
1122 | (env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) { | |
1123 | xpsr |= XPSR_SFPA; | |
1124 | } | |
1125 | ||
1126 | frameptr -= framesize; | |
1127 | ||
1128 | if (arm_feature(env, ARM_FEATURE_V8)) { | |
1129 | uint32_t limit = v7m_sp_limit(env); | |
1130 | ||
1131 | if (frameptr < limit) { | |
1132 | /* | |
1133 | * Stack limit failure: set SP to the limit value, and generate | |
1134 | * STKOF UsageFault. Stack pushes below the limit must not be | |
1135 | * performed. It is IMPDEF whether pushes above the limit are | |
1136 | * performed; we choose not to. | |
1137 | */ | |
1138 | qemu_log_mask(CPU_LOG_INT, | |
1139 | "...STKOF during stacking\n"); | |
1140 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_STKOF_MASK; | |
1141 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, | |
1142 | env->v7m.secure); | |
1143 | env->regs[13] = limit; | |
1144 | /* | |
1145 | * We won't try to perform any further memory accesses but | |
1146 | * we must continue through the following code to check for | |
1147 | * permission faults during FPU state preservation, and we | |
1148 | * must update FPCCR if lazy stacking is enabled. | |
1149 | */ | |
1150 | limitviol = true; | |
1151 | stacked_ok = false; | |
1152 | } | |
1153 | } | |
1154 | ||
1155 | /* | |
1156 | * Write as much of the stack frame as we can. If we fail a stack | |
1157 | * write this will result in a derived exception being pended | |
1158 | * (which may be taken in preference to the one we started with | |
1159 | * if it has higher priority). | |
1160 | */ | |
1161 | stacked_ok = stacked_ok && | |
1162 | v7m_stack_write(cpu, frameptr, env->regs[0], mmu_idx, STACK_NORMAL) && | |
1163 | v7m_stack_write(cpu, frameptr + 4, env->regs[1], | |
1164 | mmu_idx, STACK_NORMAL) && | |
1165 | v7m_stack_write(cpu, frameptr + 8, env->regs[2], | |
1166 | mmu_idx, STACK_NORMAL) && | |
1167 | v7m_stack_write(cpu, frameptr + 12, env->regs[3], | |
1168 | mmu_idx, STACK_NORMAL) && | |
1169 | v7m_stack_write(cpu, frameptr + 16, env->regs[12], | |
1170 | mmu_idx, STACK_NORMAL) && | |
1171 | v7m_stack_write(cpu, frameptr + 20, env->regs[14], | |
1172 | mmu_idx, STACK_NORMAL) && | |
1173 | v7m_stack_write(cpu, frameptr + 24, env->regs[15], | |
1174 | mmu_idx, STACK_NORMAL) && | |
1175 | v7m_stack_write(cpu, frameptr + 28, xpsr, mmu_idx, STACK_NORMAL); | |
1176 | ||
1177 | if (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK) { | |
1178 | /* FPU is active, try to save its registers */ | |
1179 | bool fpccr_s = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK; | |
1180 | bool lspact = env->v7m.fpccr[fpccr_s] & R_V7M_FPCCR_LSPACT_MASK; | |
1181 | ||
1182 | if (lspact && arm_feature(env, ARM_FEATURE_M_SECURITY)) { | |
1183 | qemu_log_mask(CPU_LOG_INT, | |
1184 | "...SecureFault because LSPACT and FPCA both set\n"); | |
1185 | env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK; | |
1186 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); | |
1187 | } else if (!env->v7m.secure && !nsacr_cp10) { | |
1188 | qemu_log_mask(CPU_LOG_INT, | |
1189 | "...Secure UsageFault with CFSR.NOCP because " | |
1190 | "NSACR.CP10 prevents stacking FP regs\n"); | |
1191 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, M_REG_S); | |
1192 | env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_NOCP_MASK; | |
1193 | } else { | |
1194 | if (!(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPEN_MASK)) { | |
1195 | /* Lazy stacking disabled, save registers now */ | |
1196 | int i; | |
1197 | bool cpacr_pass = v7m_cpacr_pass(env, env->v7m.secure, | |
1198 | arm_current_el(env) != 0); | |
1199 | ||
1200 | if (stacked_ok && !cpacr_pass) { | |
1201 | /* | |
1202 | * Take UsageFault if CPACR forbids access. The pseudocode | |
1203 | * here does a full CheckCPEnabled() but we know the NSACR | |
1204 | * check can never fail as we have already handled that. | |
1205 | */ | |
1206 | qemu_log_mask(CPU_LOG_INT, | |
1207 | "...UsageFault with CFSR.NOCP because " | |
1208 | "CPACR.CP10 prevents stacking FP regs\n"); | |
1209 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, | |
1210 | env->v7m.secure); | |
1211 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_NOCP_MASK; | |
1212 | stacked_ok = false; | |
1213 | } | |
1214 | ||
1215 | for (i = 0; i < ((framesize == 0xa8) ? 32 : 16); i += 2) { | |
1216 | uint64_t dn = *aa32_vfp_dreg(env, i / 2); | |
1217 | uint32_t faddr = frameptr + 0x20 + 4 * i; | |
1218 | uint32_t slo = extract64(dn, 0, 32); | |
1219 | uint32_t shi = extract64(dn, 32, 32); | |
1220 | ||
1221 | if (i >= 16) { | |
1222 | faddr += 8; /* skip the slot for the FPSCR */ | |
1223 | } | |
1224 | stacked_ok = stacked_ok && | |
1225 | v7m_stack_write(cpu, faddr, slo, | |
1226 | mmu_idx, STACK_NORMAL) && | |
1227 | v7m_stack_write(cpu, faddr + 4, shi, | |
1228 | mmu_idx, STACK_NORMAL); | |
1229 | } | |
1230 | stacked_ok = stacked_ok && | |
1231 | v7m_stack_write(cpu, frameptr + 0x60, | |
1232 | vfp_get_fpscr(env), mmu_idx, STACK_NORMAL); | |
1233 | if (cpacr_pass) { | |
1234 | for (i = 0; i < ((framesize == 0xa8) ? 32 : 16); i += 2) { | |
1235 | *aa32_vfp_dreg(env, i / 2) = 0; | |
1236 | } | |
1237 | vfp_set_fpscr(env, 0); | |
1238 | } | |
1239 | } else { | |
1240 | /* Lazy stacking enabled, save necessary info to stack later */ | |
1241 | v7m_update_fpccr(env, frameptr + 0x20, true); | |
1242 | } | |
1243 | } | |
1244 | } | |
1245 | ||
1246 | /* | |
1247 | * If we broke a stack limit then SP was already updated earlier; | |
1248 | * otherwise we update SP regardless of whether any of the stack | |
1249 | * accesses failed or we took some other kind of fault. | |
1250 | */ | |
1251 | if (!limitviol) { | |
1252 | env->regs[13] = frameptr; | |
1253 | } | |
1254 | ||
1255 | return !stacked_ok; | |
1256 | } | |
1257 | ||
1258 | static void do_v7m_exception_exit(ARMCPU *cpu) | |
1259 | { | |
1260 | CPUARMState *env = &cpu->env; | |
1261 | uint32_t excret; | |
1262 | uint32_t xpsr, xpsr_mask; | |
1263 | bool ufault = false; | |
1264 | bool sfault = false; | |
1265 | bool return_to_sp_process; | |
1266 | bool return_to_handler; | |
1267 | bool rettobase = false; | |
1268 | bool exc_secure = false; | |
1269 | bool return_to_secure; | |
1270 | bool ftype; | |
1271 | bool restore_s16_s31; | |
1272 | ||
1273 | /* | |
1274 | * If we're not in Handler mode then jumps to magic exception-exit | |
1275 | * addresses don't have magic behaviour. However for the v8M | |
1276 | * security extensions the magic secure-function-return has to | |
1277 | * work in thread mode too, so to avoid doing an extra check in | |
1278 | * the generated code we allow exception-exit magic to also cause the | |
1279 | * internal exception and bring us here in thread mode. Correct code | |
1280 | * will never try to do this (the following insn fetch will always | |
1281 | * fault) so we the overhead of having taken an unnecessary exception | |
1282 | * doesn't matter. | |
1283 | */ | |
1284 | if (!arm_v7m_is_handler_mode(env)) { | |
1285 | return; | |
1286 | } | |
1287 | ||
1288 | /* | |
1289 | * In the spec pseudocode ExceptionReturn() is called directly | |
1290 | * from BXWritePC() and gets the full target PC value including | |
1291 | * bit zero. In QEMU's implementation we treat it as a normal | |
1292 | * jump-to-register (which is then caught later on), and so split | |
1293 | * the target value up between env->regs[15] and env->thumb in | |
1294 | * gen_bx(). Reconstitute it. | |
1295 | */ | |
1296 | excret = env->regs[15]; | |
1297 | if (env->thumb) { | |
1298 | excret |= 1; | |
1299 | } | |
1300 | ||
1301 | qemu_log_mask(CPU_LOG_INT, "Exception return: magic PC %" PRIx32 | |
1302 | " previous exception %d\n", | |
1303 | excret, env->v7m.exception); | |
1304 | ||
1305 | if ((excret & R_V7M_EXCRET_RES1_MASK) != R_V7M_EXCRET_RES1_MASK) { | |
1306 | qemu_log_mask(LOG_GUEST_ERROR, "M profile: zero high bits in exception " | |
1307 | "exit PC value 0x%" PRIx32 " are UNPREDICTABLE\n", | |
1308 | excret); | |
1309 | } | |
1310 | ||
1311 | ftype = excret & R_V7M_EXCRET_FTYPE_MASK; | |
1312 | ||
1313 | if (!arm_feature(env, ARM_FEATURE_VFP) && !ftype) { | |
1314 | qemu_log_mask(LOG_GUEST_ERROR, "M profile: zero FTYPE in exception " | |
1315 | "exit PC value 0x%" PRIx32 " is UNPREDICTABLE " | |
1316 | "if FPU not present\n", | |
1317 | excret); | |
1318 | ftype = true; | |
1319 | } | |
1320 | ||
1321 | if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { | |
1322 | /* | |
1323 | * EXC_RETURN.ES validation check (R_SMFL). We must do this before | |
1324 | * we pick which FAULTMASK to clear. | |
1325 | */ | |
1326 | if (!env->v7m.secure && | |
1327 | ((excret & R_V7M_EXCRET_ES_MASK) || | |
1328 | !(excret & R_V7M_EXCRET_DCRS_MASK))) { | |
1329 | sfault = 1; | |
1330 | /* For all other purposes, treat ES as 0 (R_HXSR) */ | |
1331 | excret &= ~R_V7M_EXCRET_ES_MASK; | |
1332 | } | |
1333 | exc_secure = excret & R_V7M_EXCRET_ES_MASK; | |
1334 | } | |
1335 | ||
1336 | if (env->v7m.exception != ARMV7M_EXCP_NMI) { | |
1337 | /* | |
1338 | * Auto-clear FAULTMASK on return from other than NMI. | |
1339 | * If the security extension is implemented then this only | |
1340 | * happens if the raw execution priority is >= 0; the | |
1341 | * value of the ES bit in the exception return value indicates | |
1342 | * which security state's faultmask to clear. (v8M ARM ARM R_KBNF.) | |
1343 | */ | |
1344 | if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { | |
1345 | if (armv7m_nvic_raw_execution_priority(env->nvic) >= 0) { | |
1346 | env->v7m.faultmask[exc_secure] = 0; | |
1347 | } | |
1348 | } else { | |
1349 | env->v7m.faultmask[M_REG_NS] = 0; | |
1350 | } | |
1351 | } | |
1352 | ||
1353 | switch (armv7m_nvic_complete_irq(env->nvic, env->v7m.exception, | |
1354 | exc_secure)) { | |
1355 | case -1: | |
1356 | /* attempt to exit an exception that isn't active */ | |
1357 | ufault = true; | |
1358 | break; | |
1359 | case 0: | |
1360 | /* still an irq active now */ | |
1361 | break; | |
1362 | case 1: | |
1363 | /* | |
1364 | * We returned to base exception level, no nesting. | |
1365 | * (In the pseudocode this is written using "NestedActivation != 1" | |
1366 | * where we have 'rettobase == false'.) | |
1367 | */ | |
1368 | rettobase = true; | |
1369 | break; | |
1370 | default: | |
1371 | g_assert_not_reached(); | |
1372 | } | |
1373 | ||
1374 | return_to_handler = !(excret & R_V7M_EXCRET_MODE_MASK); | |
1375 | return_to_sp_process = excret & R_V7M_EXCRET_SPSEL_MASK; | |
1376 | return_to_secure = arm_feature(env, ARM_FEATURE_M_SECURITY) && | |
1377 | (excret & R_V7M_EXCRET_S_MASK); | |
1378 | ||
1379 | if (arm_feature(env, ARM_FEATURE_V8)) { | |
1380 | if (!arm_feature(env, ARM_FEATURE_M_SECURITY)) { | |
1381 | /* | |
1382 | * UNPREDICTABLE if S == 1 or DCRS == 0 or ES == 1 (R_XLCP); | |
1383 | * we choose to take the UsageFault. | |
1384 | */ | |
1385 | if ((excret & R_V7M_EXCRET_S_MASK) || | |
1386 | (excret & R_V7M_EXCRET_ES_MASK) || | |
1387 | !(excret & R_V7M_EXCRET_DCRS_MASK)) { | |
1388 | ufault = true; | |
1389 | } | |
1390 | } | |
1391 | if (excret & R_V7M_EXCRET_RES0_MASK) { | |
1392 | ufault = true; | |
1393 | } | |
1394 | } else { | |
1395 | /* For v7M we only recognize certain combinations of the low bits */ | |
1396 | switch (excret & 0xf) { | |
1397 | case 1: /* Return to Handler */ | |
1398 | break; | |
1399 | case 13: /* Return to Thread using Process stack */ | |
1400 | case 9: /* Return to Thread using Main stack */ | |
1401 | /* | |
1402 | * We only need to check NONBASETHRDENA for v7M, because in | |
1403 | * v8M this bit does not exist (it is RES1). | |
1404 | */ | |
1405 | if (!rettobase && | |
1406 | !(env->v7m.ccr[env->v7m.secure] & | |
1407 | R_V7M_CCR_NONBASETHRDENA_MASK)) { | |
1408 | ufault = true; | |
1409 | } | |
1410 | break; | |
1411 | default: | |
1412 | ufault = true; | |
1413 | } | |
1414 | } | |
1415 | ||
1416 | /* | |
1417 | * Set CONTROL.SPSEL from excret.SPSEL. Since we're still in | |
1418 | * Handler mode (and will be until we write the new XPSR.Interrupt | |
1419 | * field) this does not switch around the current stack pointer. | |
1420 | * We must do this before we do any kind of tailchaining, including | |
1421 | * for the derived exceptions on integrity check failures, or we will | |
1422 | * give the guest an incorrect EXCRET.SPSEL value on exception entry. | |
1423 | */ | |
1424 | write_v7m_control_spsel_for_secstate(env, return_to_sp_process, exc_secure); | |
1425 | ||
1426 | /* | |
1427 | * Clear scratch FP values left in caller saved registers; this | |
1428 | * must happen before any kind of tail chaining. | |
1429 | */ | |
1430 | if ((env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_CLRONRET_MASK) && | |
1431 | (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK)) { | |
1432 | if (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK) { | |
1433 | env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK; | |
1434 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); | |
1435 | qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing " | |
1436 | "stackframe: error during lazy state deactivation\n"); | |
1437 | v7m_exception_taken(cpu, excret, true, false); | |
1438 | return; | |
1439 | } else { | |
1440 | /* Clear s0..s15 and FPSCR */ | |
1441 | int i; | |
1442 | ||
1443 | for (i = 0; i < 16; i += 2) { | |
1444 | *aa32_vfp_dreg(env, i / 2) = 0; | |
1445 | } | |
1446 | vfp_set_fpscr(env, 0); | |
1447 | } | |
1448 | } | |
1449 | ||
1450 | if (sfault) { | |
1451 | env->v7m.sfsr |= R_V7M_SFSR_INVER_MASK; | |
1452 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); | |
1453 | qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing " | |
1454 | "stackframe: failed EXC_RETURN.ES validity check\n"); | |
1455 | v7m_exception_taken(cpu, excret, true, false); | |
1456 | return; | |
1457 | } | |
1458 | ||
1459 | if (ufault) { | |
1460 | /* | |
1461 | * Bad exception return: instead of popping the exception | |
1462 | * stack, directly take a usage fault on the current stack. | |
1463 | */ | |
1464 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK; | |
1465 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); | |
1466 | qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing " | |
1467 | "stackframe: failed exception return integrity check\n"); | |
1468 | v7m_exception_taken(cpu, excret, true, false); | |
1469 | return; | |
1470 | } | |
1471 | ||
1472 | /* | |
1473 | * Tailchaining: if there is currently a pending exception that | |
1474 | * is high enough priority to preempt execution at the level we're | |
1475 | * about to return to, then just directly take that exception now, | |
1476 | * avoiding an unstack-and-then-stack. Note that now we have | |
1477 | * deactivated the previous exception by calling armv7m_nvic_complete_irq() | |
1478 | * our current execution priority is already the execution priority we are | |
1479 | * returning to -- none of the state we would unstack or set based on | |
1480 | * the EXCRET value affects it. | |
1481 | */ | |
1482 | if (armv7m_nvic_can_take_pending_exception(env->nvic)) { | |
1483 | qemu_log_mask(CPU_LOG_INT, "...tailchaining to pending exception\n"); | |
1484 | v7m_exception_taken(cpu, excret, true, false); | |
1485 | return; | |
1486 | } | |
1487 | ||
1488 | switch_v7m_security_state(env, return_to_secure); | |
1489 | ||
1490 | { | |
1491 | /* | |
1492 | * The stack pointer we should be reading the exception frame from | |
1493 | * depends on bits in the magic exception return type value (and | |
1494 | * for v8M isn't necessarily the stack pointer we will eventually | |
1495 | * end up resuming execution with). Get a pointer to the location | |
1496 | * in the CPU state struct where the SP we need is currently being | |
1497 | * stored; we will use and modify it in place. | |
1498 | * We use this limited C variable scope so we don't accidentally | |
1499 | * use 'frame_sp_p' after we do something that makes it invalid. | |
1500 | */ | |
1501 | uint32_t *frame_sp_p = get_v7m_sp_ptr(env, | |
1502 | return_to_secure, | |
1503 | !return_to_handler, | |
1504 | return_to_sp_process); | |
1505 | uint32_t frameptr = *frame_sp_p; | |
1506 | bool pop_ok = true; | |
1507 | ARMMMUIdx mmu_idx; | |
1508 | bool return_to_priv = return_to_handler || | |
1509 | !(env->v7m.control[return_to_secure] & R_V7M_CONTROL_NPRIV_MASK); | |
1510 | ||
1511 | mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, return_to_secure, | |
1512 | return_to_priv); | |
1513 | ||
1514 | if (!QEMU_IS_ALIGNED(frameptr, 8) && | |
1515 | arm_feature(env, ARM_FEATURE_V8)) { | |
1516 | qemu_log_mask(LOG_GUEST_ERROR, | |
1517 | "M profile exception return with non-8-aligned SP " | |
1518 | "for destination state is UNPREDICTABLE\n"); | |
1519 | } | |
1520 | ||
1521 | /* Do we need to pop callee-saved registers? */ | |
1522 | if (return_to_secure && | |
1523 | ((excret & R_V7M_EXCRET_ES_MASK) == 0 || | |
1524 | (excret & R_V7M_EXCRET_DCRS_MASK) == 0)) { | |
1525 | uint32_t actual_sig; | |
1526 | ||
1527 | pop_ok = v7m_stack_read(cpu, &actual_sig, frameptr, mmu_idx); | |
1528 | ||
1529 | if (pop_ok && v7m_integrity_sig(env, excret) != actual_sig) { | |
1530 | /* Take a SecureFault on the current stack */ | |
1531 | env->v7m.sfsr |= R_V7M_SFSR_INVIS_MASK; | |
1532 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); | |
1533 | qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing " | |
1534 | "stackframe: failed exception return integrity " | |
1535 | "signature check\n"); | |
1536 | v7m_exception_taken(cpu, excret, true, false); | |
1537 | return; | |
1538 | } | |
1539 | ||
1540 | pop_ok = pop_ok && | |
1541 | v7m_stack_read(cpu, &env->regs[4], frameptr + 0x8, mmu_idx) && | |
1542 | v7m_stack_read(cpu, &env->regs[5], frameptr + 0xc, mmu_idx) && | |
1543 | v7m_stack_read(cpu, &env->regs[6], frameptr + 0x10, mmu_idx) && | |
1544 | v7m_stack_read(cpu, &env->regs[7], frameptr + 0x14, mmu_idx) && | |
1545 | v7m_stack_read(cpu, &env->regs[8], frameptr + 0x18, mmu_idx) && | |
1546 | v7m_stack_read(cpu, &env->regs[9], frameptr + 0x1c, mmu_idx) && | |
1547 | v7m_stack_read(cpu, &env->regs[10], frameptr + 0x20, mmu_idx) && | |
1548 | v7m_stack_read(cpu, &env->regs[11], frameptr + 0x24, mmu_idx); | |
1549 | ||
1550 | frameptr += 0x28; | |
1551 | } | |
1552 | ||
1553 | /* Pop registers */ | |
1554 | pop_ok = pop_ok && | |
1555 | v7m_stack_read(cpu, &env->regs[0], frameptr, mmu_idx) && | |
1556 | v7m_stack_read(cpu, &env->regs[1], frameptr + 0x4, mmu_idx) && | |
1557 | v7m_stack_read(cpu, &env->regs[2], frameptr + 0x8, mmu_idx) && | |
1558 | v7m_stack_read(cpu, &env->regs[3], frameptr + 0xc, mmu_idx) && | |
1559 | v7m_stack_read(cpu, &env->regs[12], frameptr + 0x10, mmu_idx) && | |
1560 | v7m_stack_read(cpu, &env->regs[14], frameptr + 0x14, mmu_idx) && | |
1561 | v7m_stack_read(cpu, &env->regs[15], frameptr + 0x18, mmu_idx) && | |
1562 | v7m_stack_read(cpu, &xpsr, frameptr + 0x1c, mmu_idx); | |
1563 | ||
1564 | if (!pop_ok) { | |
1565 | /* | |
1566 | * v7m_stack_read() pended a fault, so take it (as a tail | |
1567 | * chained exception on the same stack frame) | |
1568 | */ | |
1569 | qemu_log_mask(CPU_LOG_INT, "...derived exception on unstacking\n"); | |
1570 | v7m_exception_taken(cpu, excret, true, false); | |
1571 | return; | |
1572 | } | |
1573 | ||
1574 | /* | |
1575 | * Returning from an exception with a PC with bit 0 set is defined | |
1576 | * behaviour on v8M (bit 0 is ignored), but for v7M it was specified | |
1577 | * to be UNPREDICTABLE. In practice actual v7M hardware seems to ignore | |
1578 | * the lsbit, and there are several RTOSes out there which incorrectly | |
1579 | * assume the r15 in the stack frame should be a Thumb-style "lsbit | |
1580 | * indicates ARM/Thumb" value, so ignore the bit on v7M as well, but | |
1581 | * complain about the badly behaved guest. | |
1582 | */ | |
1583 | if (env->regs[15] & 1) { | |
1584 | env->regs[15] &= ~1U; | |
1585 | if (!arm_feature(env, ARM_FEATURE_V8)) { | |
1586 | qemu_log_mask(LOG_GUEST_ERROR, | |
1587 | "M profile return from interrupt with misaligned " | |
1588 | "PC is UNPREDICTABLE on v7M\n"); | |
1589 | } | |
1590 | } | |
1591 | ||
1592 | if (arm_feature(env, ARM_FEATURE_V8)) { | |
1593 | /* | |
1594 | * For v8M we have to check whether the xPSR exception field | |
1595 | * matches the EXCRET value for return to handler/thread | |
1596 | * before we commit to changing the SP and xPSR. | |
1597 | */ | |
1598 | bool will_be_handler = (xpsr & XPSR_EXCP) != 0; | |
1599 | if (return_to_handler != will_be_handler) { | |
1600 | /* | |
1601 | * Take an INVPC UsageFault on the current stack. | |
1602 | * By this point we will have switched to the security state | |
1603 | * for the background state, so this UsageFault will target | |
1604 | * that state. | |
1605 | */ | |
1606 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, | |
1607 | env->v7m.secure); | |
1608 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK; | |
1609 | qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing " | |
1610 | "stackframe: failed exception return integrity " | |
1611 | "check\n"); | |
1612 | v7m_exception_taken(cpu, excret, true, false); | |
1613 | return; | |
1614 | } | |
1615 | } | |
1616 | ||
1617 | if (!ftype) { | |
1618 | /* FP present and we need to handle it */ | |
1619 | if (!return_to_secure && | |
1620 | (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK)) { | |
1621 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); | |
1622 | env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK; | |
1623 | qemu_log_mask(CPU_LOG_INT, | |
1624 | "...taking SecureFault on existing stackframe: " | |
1625 | "Secure LSPACT set but exception return is " | |
1626 | "not to secure state\n"); | |
1627 | v7m_exception_taken(cpu, excret, true, false); | |
1628 | return; | |
1629 | } | |
1630 | ||
1631 | restore_s16_s31 = return_to_secure && | |
1632 | (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK); | |
1633 | ||
1634 | if (env->v7m.fpccr[return_to_secure] & R_V7M_FPCCR_LSPACT_MASK) { | |
1635 | /* State in FPU is still valid, just clear LSPACT */ | |
1636 | env->v7m.fpccr[return_to_secure] &= ~R_V7M_FPCCR_LSPACT_MASK; | |
1637 | } else { | |
1638 | int i; | |
1639 | uint32_t fpscr; | |
1640 | bool cpacr_pass, nsacr_pass; | |
1641 | ||
1642 | cpacr_pass = v7m_cpacr_pass(env, return_to_secure, | |
1643 | return_to_priv); | |
1644 | nsacr_pass = return_to_secure || | |
1645 | extract32(env->v7m.nsacr, 10, 1); | |
1646 | ||
1647 | if (!cpacr_pass) { | |
1648 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, | |
1649 | return_to_secure); | |
1650 | env->v7m.cfsr[return_to_secure] |= R_V7M_CFSR_NOCP_MASK; | |
1651 | qemu_log_mask(CPU_LOG_INT, | |
1652 | "...taking UsageFault on existing " | |
1653 | "stackframe: CPACR.CP10 prevents unstacking " | |
1654 | "FP regs\n"); | |
1655 | v7m_exception_taken(cpu, excret, true, false); | |
1656 | return; | |
1657 | } else if (!nsacr_pass) { | |
1658 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, true); | |
1659 | env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_INVPC_MASK; | |
1660 | qemu_log_mask(CPU_LOG_INT, | |
1661 | "...taking Secure UsageFault on existing " | |
1662 | "stackframe: NSACR.CP10 prevents unstacking " | |
1663 | "FP regs\n"); | |
1664 | v7m_exception_taken(cpu, excret, true, false); | |
1665 | return; | |
1666 | } | |
1667 | ||
1668 | for (i = 0; i < (restore_s16_s31 ? 32 : 16); i += 2) { | |
1669 | uint32_t slo, shi; | |
1670 | uint64_t dn; | |
1671 | uint32_t faddr = frameptr + 0x20 + 4 * i; | |
1672 | ||
1673 | if (i >= 16) { | |
1674 | faddr += 8; /* Skip the slot for the FPSCR */ | |
1675 | } | |
1676 | ||
1677 | pop_ok = pop_ok && | |
1678 | v7m_stack_read(cpu, &slo, faddr, mmu_idx) && | |
1679 | v7m_stack_read(cpu, &shi, faddr + 4, mmu_idx); | |
1680 | ||
1681 | if (!pop_ok) { | |
1682 | break; | |
1683 | } | |
1684 | ||
1685 | dn = (uint64_t)shi << 32 | slo; | |
1686 | *aa32_vfp_dreg(env, i / 2) = dn; | |
1687 | } | |
1688 | pop_ok = pop_ok && | |
1689 | v7m_stack_read(cpu, &fpscr, frameptr + 0x60, mmu_idx); | |
1690 | if (pop_ok) { | |
1691 | vfp_set_fpscr(env, fpscr); | |
1692 | } | |
1693 | if (!pop_ok) { | |
1694 | /* | |
1695 | * These regs are 0 if security extension present; | |
1696 | * otherwise merely UNKNOWN. We zero always. | |
1697 | */ | |
1698 | for (i = 0; i < (restore_s16_s31 ? 32 : 16); i += 2) { | |
1699 | *aa32_vfp_dreg(env, i / 2) = 0; | |
1700 | } | |
1701 | vfp_set_fpscr(env, 0); | |
1702 | } | |
1703 | } | |
1704 | } | |
1705 | env->v7m.control[M_REG_S] = FIELD_DP32(env->v7m.control[M_REG_S], | |
1706 | V7M_CONTROL, FPCA, !ftype); | |
1707 | ||
1708 | /* Commit to consuming the stack frame */ | |
1709 | frameptr += 0x20; | |
1710 | if (!ftype) { | |
1711 | frameptr += 0x48; | |
1712 | if (restore_s16_s31) { | |
1713 | frameptr += 0x40; | |
1714 | } | |
1715 | } | |
1716 | /* | |
1717 | * Undo stack alignment (the SPREALIGN bit indicates that the original | |
1718 | * pre-exception SP was not 8-aligned and we added a padding word to | |
1719 | * align it, so we undo this by ORing in the bit that increases it | |
1720 | * from the current 8-aligned value to the 8-unaligned value. (Adding 4 | |
1721 | * would work too but a logical OR is how the pseudocode specifies it.) | |
1722 | */ | |
1723 | if (xpsr & XPSR_SPREALIGN) { | |
1724 | frameptr |= 4; | |
1725 | } | |
1726 | *frame_sp_p = frameptr; | |
1727 | } | |
1728 | ||
1729 | xpsr_mask = ~(XPSR_SPREALIGN | XPSR_SFPA); | |
1730 | if (!arm_feature(env, ARM_FEATURE_THUMB_DSP)) { | |
1731 | xpsr_mask &= ~XPSR_GE; | |
1732 | } | |
1733 | /* This xpsr_write() will invalidate frame_sp_p as it may switch stack */ | |
1734 | xpsr_write(env, xpsr, xpsr_mask); | |
1735 | ||
1736 | if (env->v7m.secure) { | |
1737 | bool sfpa = xpsr & XPSR_SFPA; | |
1738 | ||
1739 | env->v7m.control[M_REG_S] = FIELD_DP32(env->v7m.control[M_REG_S], | |
1740 | V7M_CONTROL, SFPA, sfpa); | |
1741 | } | |
1742 | ||
1743 | /* | |
1744 | * The restored xPSR exception field will be zero if we're | |
1745 | * resuming in Thread mode. If that doesn't match what the | |
1746 | * exception return excret specified then this is a UsageFault. | |
1747 | * v7M requires we make this check here; v8M did it earlier. | |
1748 | */ | |
1749 | if (return_to_handler != arm_v7m_is_handler_mode(env)) { | |
1750 | /* | |
1751 | * Take an INVPC UsageFault by pushing the stack again; | |
1752 | * we know we're v7M so this is never a Secure UsageFault. | |
1753 | */ | |
1754 | bool ignore_stackfaults; | |
1755 | ||
1756 | assert(!arm_feature(env, ARM_FEATURE_V8)); | |
1757 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, false); | |
1758 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK; | |
1759 | ignore_stackfaults = v7m_push_stack(cpu); | |
1760 | qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on new stackframe: " | |
1761 | "failed exception return integrity check\n"); | |
1762 | v7m_exception_taken(cpu, excret, false, ignore_stackfaults); | |
1763 | return; | |
1764 | } | |
1765 | ||
1766 | /* Otherwise, we have a successful exception exit. */ | |
1767 | arm_clear_exclusive(env); | |
1768 | qemu_log_mask(CPU_LOG_INT, "...successful exception return\n"); | |
1769 | } | |
1770 | ||
1771 | static bool do_v7m_function_return(ARMCPU *cpu) | |
1772 | { | |
1773 | /* | |
1774 | * v8M security extensions magic function return. | |
1775 | * We may either: | |
1776 | * (1) throw an exception (longjump) | |
1777 | * (2) return true if we successfully handled the function return | |
1778 | * (3) return false if we failed a consistency check and have | |
1779 | * pended a UsageFault that needs to be taken now | |
1780 | * | |
1781 | * At this point the magic return value is split between env->regs[15] | |
1782 | * and env->thumb. We don't bother to reconstitute it because we don't | |
1783 | * need it (all values are handled the same way). | |
1784 | */ | |
1785 | CPUARMState *env = &cpu->env; | |
1786 | uint32_t newpc, newpsr, newpsr_exc; | |
1787 | ||
1788 | qemu_log_mask(CPU_LOG_INT, "...really v7M secure function return\n"); | |
1789 | ||
1790 | { | |
1791 | bool threadmode, spsel; | |
1792 | TCGMemOpIdx oi; | |
1793 | ARMMMUIdx mmu_idx; | |
1794 | uint32_t *frame_sp_p; | |
1795 | uint32_t frameptr; | |
1796 | ||
1797 | /* Pull the return address and IPSR from the Secure stack */ | |
1798 | threadmode = !arm_v7m_is_handler_mode(env); | |
1799 | spsel = env->v7m.control[M_REG_S] & R_V7M_CONTROL_SPSEL_MASK; | |
1800 | ||
1801 | frame_sp_p = get_v7m_sp_ptr(env, true, threadmode, spsel); | |
1802 | frameptr = *frame_sp_p; | |
1803 | ||
1804 | /* | |
1805 | * These loads may throw an exception (for MPU faults). We want to | |
1806 | * do them as secure, so work out what MMU index that is. | |
1807 | */ | |
1808 | mmu_idx = arm_v7m_mmu_idx_for_secstate(env, true); | |
1809 | oi = make_memop_idx(MO_LE, arm_to_core_mmu_idx(mmu_idx)); | |
1810 | newpc = helper_le_ldul_mmu(env, frameptr, oi, 0); | |
1811 | newpsr = helper_le_ldul_mmu(env, frameptr + 4, oi, 0); | |
1812 | ||
1813 | /* Consistency checks on new IPSR */ | |
1814 | newpsr_exc = newpsr & XPSR_EXCP; | |
1815 | if (!((env->v7m.exception == 0 && newpsr_exc == 0) || | |
1816 | (env->v7m.exception == 1 && newpsr_exc != 0))) { | |
1817 | /* Pend the fault and tell our caller to take it */ | |
1818 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK; | |
1819 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, | |
1820 | env->v7m.secure); | |
1821 | qemu_log_mask(CPU_LOG_INT, | |
1822 | "...taking INVPC UsageFault: " | |
1823 | "IPSR consistency check failed\n"); | |
1824 | return false; | |
1825 | } | |
1826 | ||
1827 | *frame_sp_p = frameptr + 8; | |
1828 | } | |
1829 | ||
1830 | /* This invalidates frame_sp_p */ | |
1831 | switch_v7m_security_state(env, true); | |
1832 | env->v7m.exception = newpsr_exc; | |
1833 | env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK; | |
1834 | if (newpsr & XPSR_SFPA) { | |
1835 | env->v7m.control[M_REG_S] |= R_V7M_CONTROL_SFPA_MASK; | |
1836 | } | |
1837 | xpsr_write(env, 0, XPSR_IT); | |
1838 | env->thumb = newpc & 1; | |
1839 | env->regs[15] = newpc & ~1; | |
1840 | ||
1841 | qemu_log_mask(CPU_LOG_INT, "...function return successful\n"); | |
1842 | return true; | |
1843 | } | |
1844 | ||
1845 | static bool v7m_read_half_insn(ARMCPU *cpu, ARMMMUIdx mmu_idx, | |
1846 | uint32_t addr, uint16_t *insn) | |
1847 | { | |
1848 | /* | |
1849 | * Load a 16-bit portion of a v7M instruction, returning true on success, | |
1850 | * or false on failure (in which case we will have pended the appropriate | |
1851 | * exception). | |
1852 | * We need to do the instruction fetch's MPU and SAU checks | |
1853 | * like this because there is no MMU index that would allow | |
1854 | * doing the load with a single function call. Instead we must | |
1855 | * first check that the security attributes permit the load | |
1856 | * and that they don't mismatch on the two halves of the instruction, | |
1857 | * and then we do the load as a secure load (ie using the security | |
1858 | * attributes of the address, not the CPU, as architecturally required). | |
1859 | */ | |
1860 | CPUState *cs = CPU(cpu); | |
1861 | CPUARMState *env = &cpu->env; | |
1862 | V8M_SAttributes sattrs = {}; | |
1863 | MemTxAttrs attrs = {}; | |
1864 | ARMMMUFaultInfo fi = {}; | |
1865 | MemTxResult txres; | |
1866 | target_ulong page_size; | |
1867 | hwaddr physaddr; | |
1868 | int prot; | |
1869 | ||
1870 | v8m_security_lookup(env, addr, MMU_INST_FETCH, mmu_idx, &sattrs); | |
1871 | if (!sattrs.nsc || sattrs.ns) { | |
1872 | /* | |
1873 | * This must be the second half of the insn, and it straddles a | |
1874 | * region boundary with the second half not being S&NSC. | |
1875 | */ | |
1876 | env->v7m.sfsr |= R_V7M_SFSR_INVEP_MASK; | |
1877 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); | |
1878 | qemu_log_mask(CPU_LOG_INT, | |
1879 | "...really SecureFault with SFSR.INVEP\n"); | |
1880 | return false; | |
1881 | } | |
1882 | if (get_phys_addr(env, addr, MMU_INST_FETCH, mmu_idx, | |
1883 | &physaddr, &attrs, &prot, &page_size, &fi, NULL)) { | |
1884 | /* the MPU lookup failed */ | |
1885 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_IACCVIOL_MASK; | |
1886 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_MEM, env->v7m.secure); | |
1887 | qemu_log_mask(CPU_LOG_INT, "...really MemManage with CFSR.IACCVIOL\n"); | |
1888 | return false; | |
1889 | } | |
1890 | *insn = address_space_lduw_le(arm_addressspace(cs, attrs), physaddr, | |
1891 | attrs, &txres); | |
1892 | if (txres != MEMTX_OK) { | |
1893 | env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_IBUSERR_MASK; | |
1894 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_BUS, false); | |
1895 | qemu_log_mask(CPU_LOG_INT, "...really BusFault with CFSR.IBUSERR\n"); | |
1896 | return false; | |
1897 | } | |
1898 | return true; | |
1899 | } | |
1900 | ||
1901 | static bool v7m_handle_execute_nsc(ARMCPU *cpu) | |
1902 | { | |
1903 | /* | |
1904 | * Check whether this attempt to execute code in a Secure & NS-Callable | |
1905 | * memory region is for an SG instruction; if so, then emulate the | |
1906 | * effect of the SG instruction and return true. Otherwise pend | |
1907 | * the correct kind of exception and return false. | |
1908 | */ | |
1909 | CPUARMState *env = &cpu->env; | |
1910 | ARMMMUIdx mmu_idx; | |
1911 | uint16_t insn; | |
1912 | ||
1913 | /* | |
1914 | * We should never get here unless get_phys_addr_pmsav8() caused | |
1915 | * an exception for NS executing in S&NSC memory. | |
1916 | */ | |
1917 | assert(!env->v7m.secure); | |
1918 | assert(arm_feature(env, ARM_FEATURE_M_SECURITY)); | |
1919 | ||
1920 | /* We want to do the MPU lookup as secure; work out what mmu_idx that is */ | |
1921 | mmu_idx = arm_v7m_mmu_idx_for_secstate(env, true); | |
1922 | ||
1923 | if (!v7m_read_half_insn(cpu, mmu_idx, env->regs[15], &insn)) { | |
1924 | return false; | |
1925 | } | |
1926 | ||
1927 | if (!env->thumb) { | |
1928 | goto gen_invep; | |
1929 | } | |
1930 | ||
1931 | if (insn != 0xe97f) { | |
1932 | /* | |
1933 | * Not an SG instruction first half (we choose the IMPDEF | |
1934 | * early-SG-check option). | |
1935 | */ | |
1936 | goto gen_invep; | |
1937 | } | |
1938 | ||
1939 | if (!v7m_read_half_insn(cpu, mmu_idx, env->regs[15] + 2, &insn)) { | |
1940 | return false; | |
1941 | } | |
1942 | ||
1943 | if (insn != 0xe97f) { | |
1944 | /* | |
1945 | * Not an SG instruction second half (yes, both halves of the SG | |
1946 | * insn have the same hex value) | |
1947 | */ | |
1948 | goto gen_invep; | |
1949 | } | |
1950 | ||
1951 | /* | |
1952 | * OK, we have confirmed that we really have an SG instruction. | |
1953 | * We know we're NS in S memory so don't need to repeat those checks. | |
1954 | */ | |
1955 | qemu_log_mask(CPU_LOG_INT, "...really an SG instruction at 0x%08" PRIx32 | |
1956 | ", executing it\n", env->regs[15]); | |
1957 | env->regs[14] &= ~1; | |
1958 | env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK; | |
1959 | switch_v7m_security_state(env, true); | |
1960 | xpsr_write(env, 0, XPSR_IT); | |
1961 | env->regs[15] += 4; | |
1962 | return true; | |
1963 | ||
1964 | gen_invep: | |
1965 | env->v7m.sfsr |= R_V7M_SFSR_INVEP_MASK; | |
1966 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); | |
1967 | qemu_log_mask(CPU_LOG_INT, | |
1968 | "...really SecureFault with SFSR.INVEP\n"); | |
1969 | return false; | |
1970 | } | |
1971 | ||
1972 | void arm_v7m_cpu_do_interrupt(CPUState *cs) | |
1973 | { | |
1974 | ARMCPU *cpu = ARM_CPU(cs); | |
1975 | CPUARMState *env = &cpu->env; | |
1976 | uint32_t lr; | |
1977 | bool ignore_stackfaults; | |
1978 | ||
1979 | arm_log_exception(cs->exception_index); | |
1980 | ||
1981 | /* | |
1982 | * For exceptions we just mark as pending on the NVIC, and let that | |
1983 | * handle it. | |
1984 | */ | |
1985 | switch (cs->exception_index) { | |
1986 | case EXCP_UDEF: | |
1987 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); | |
1988 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_UNDEFINSTR_MASK; | |
1989 | break; | |
1990 | case EXCP_NOCP: | |
1991 | { | |
1992 | /* | |
1993 | * NOCP might be directed to something other than the current | |
1994 | * security state if this fault is because of NSACR; we indicate | |
1995 | * the target security state using exception.target_el. | |
1996 | */ | |
1997 | int target_secstate; | |
1998 | ||
1999 | if (env->exception.target_el == 3) { | |
2000 | target_secstate = M_REG_S; | |
2001 | } else { | |
2002 | target_secstate = env->v7m.secure; | |
2003 | } | |
2004 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, target_secstate); | |
2005 | env->v7m.cfsr[target_secstate] |= R_V7M_CFSR_NOCP_MASK; | |
2006 | break; | |
2007 | } | |
2008 | case EXCP_INVSTATE: | |
2009 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); | |
2010 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVSTATE_MASK; | |
2011 | break; | |
2012 | case EXCP_STKOF: | |
2013 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); | |
2014 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_STKOF_MASK; | |
2015 | break; | |
2016 | case EXCP_LSERR: | |
2017 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); | |
2018 | env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK; | |
2019 | break; | |
2020 | case EXCP_UNALIGNED: | |
2021 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); | |
2022 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_UNALIGNED_MASK; | |
2023 | break; | |
2024 | case EXCP_SWI: | |
2025 | /* The PC already points to the next instruction. */ | |
2026 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SVC, env->v7m.secure); | |
2027 | break; | |
2028 | case EXCP_PREFETCH_ABORT: | |
2029 | case EXCP_DATA_ABORT: | |
2030 | /* | |
2031 | * Note that for M profile we don't have a guest facing FSR, but | |
2032 | * the env->exception.fsr will be populated by the code that | |
2033 | * raises the fault, in the A profile short-descriptor format. | |
2034 | */ | |
2035 | switch (env->exception.fsr & 0xf) { | |
2036 | case M_FAKE_FSR_NSC_EXEC: | |
2037 | /* | |
2038 | * Exception generated when we try to execute code at an address | |
2039 | * which is marked as Secure & Non-Secure Callable and the CPU | |
2040 | * is in the Non-Secure state. The only instruction which can | |
2041 | * be executed like this is SG (and that only if both halves of | |
2042 | * the SG instruction have the same security attributes.) | |
2043 | * Everything else must generate an INVEP SecureFault, so we | |
2044 | * emulate the SG instruction here. | |
2045 | */ | |
2046 | if (v7m_handle_execute_nsc(cpu)) { | |
2047 | return; | |
2048 | } | |
2049 | break; | |
2050 | case M_FAKE_FSR_SFAULT: | |
2051 | /* | |
2052 | * Various flavours of SecureFault for attempts to execute or | |
2053 | * access data in the wrong security state. | |
2054 | */ | |
2055 | switch (cs->exception_index) { | |
2056 | case EXCP_PREFETCH_ABORT: | |
2057 | if (env->v7m.secure) { | |
2058 | env->v7m.sfsr |= R_V7M_SFSR_INVTRAN_MASK; | |
2059 | qemu_log_mask(CPU_LOG_INT, | |
2060 | "...really SecureFault with SFSR.INVTRAN\n"); | |
2061 | } else { | |
2062 | env->v7m.sfsr |= R_V7M_SFSR_INVEP_MASK; | |
2063 | qemu_log_mask(CPU_LOG_INT, | |
2064 | "...really SecureFault with SFSR.INVEP\n"); | |
2065 | } | |
2066 | break; | |
2067 | case EXCP_DATA_ABORT: | |
2068 | /* This must be an NS access to S memory */ | |
2069 | env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK; | |
2070 | qemu_log_mask(CPU_LOG_INT, | |
2071 | "...really SecureFault with SFSR.AUVIOL\n"); | |
2072 | break; | |
2073 | } | |
2074 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); | |
2075 | break; | |
2076 | case 0x8: /* External Abort */ | |
2077 | switch (cs->exception_index) { | |
2078 | case EXCP_PREFETCH_ABORT: | |
2079 | env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_IBUSERR_MASK; | |
2080 | qemu_log_mask(CPU_LOG_INT, "...with CFSR.IBUSERR\n"); | |
2081 | break; | |
2082 | case EXCP_DATA_ABORT: | |
2083 | env->v7m.cfsr[M_REG_NS] |= | |
2084 | (R_V7M_CFSR_PRECISERR_MASK | R_V7M_CFSR_BFARVALID_MASK); | |
2085 | env->v7m.bfar = env->exception.vaddress; | |
2086 | qemu_log_mask(CPU_LOG_INT, | |
2087 | "...with CFSR.PRECISERR and BFAR 0x%x\n", | |
2088 | env->v7m.bfar); | |
2089 | break; | |
2090 | } | |
2091 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_BUS, false); | |
2092 | break; | |
2093 | default: | |
2094 | /* | |
2095 | * All other FSR values are either MPU faults or "can't happen | |
2096 | * for M profile" cases. | |
2097 | */ | |
2098 | switch (cs->exception_index) { | |
2099 | case EXCP_PREFETCH_ABORT: | |
2100 | env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_IACCVIOL_MASK; | |
2101 | qemu_log_mask(CPU_LOG_INT, "...with CFSR.IACCVIOL\n"); | |
2102 | break; | |
2103 | case EXCP_DATA_ABORT: | |
2104 | env->v7m.cfsr[env->v7m.secure] |= | |
2105 | (R_V7M_CFSR_DACCVIOL_MASK | R_V7M_CFSR_MMARVALID_MASK); | |
2106 | env->v7m.mmfar[env->v7m.secure] = env->exception.vaddress; | |
2107 | qemu_log_mask(CPU_LOG_INT, | |
2108 | "...with CFSR.DACCVIOL and MMFAR 0x%x\n", | |
2109 | env->v7m.mmfar[env->v7m.secure]); | |
2110 | break; | |
2111 | } | |
2112 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_MEM, | |
2113 | env->v7m.secure); | |
2114 | break; | |
2115 | } | |
2116 | break; | |
2117 | case EXCP_BKPT: | |
2118 | if (semihosting_enabled()) { | |
2119 | int nr; | |
2120 | nr = arm_lduw_code(env, env->regs[15], arm_sctlr_b(env)) & 0xff; | |
2121 | if (nr == 0xab) { | |
2122 | env->regs[15] += 2; | |
2123 | qemu_log_mask(CPU_LOG_INT, | |
2124 | "...handling as semihosting call 0x%x\n", | |
2125 | env->regs[0]); | |
2126 | env->regs[0] = do_arm_semihosting(env); | |
2127 | return; | |
2128 | } | |
2129 | } | |
2130 | armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_DEBUG, false); | |
2131 | break; | |
2132 | case EXCP_IRQ: | |
2133 | break; | |
2134 | case EXCP_EXCEPTION_EXIT: | |
2135 | if (env->regs[15] < EXC_RETURN_MIN_MAGIC) { | |
2136 | /* Must be v8M security extension function return */ | |
2137 | assert(env->regs[15] >= FNC_RETURN_MIN_MAGIC); | |
2138 | assert(arm_feature(env, ARM_FEATURE_M_SECURITY)); | |
2139 | if (do_v7m_function_return(cpu)) { | |
2140 | return; | |
2141 | } | |
2142 | } else { | |
2143 | do_v7m_exception_exit(cpu); | |
2144 | return; | |
2145 | } | |
2146 | break; | |
2147 | case EXCP_LAZYFP: | |
2148 | /* | |
2149 | * We already pended the specific exception in the NVIC in the | |
2150 | * v7m_preserve_fp_state() helper function. | |
2151 | */ | |
2152 | break; | |
2153 | default: | |
2154 | cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index); | |
2155 | return; /* Never happens. Keep compiler happy. */ | |
2156 | } | |
2157 | ||
2158 | if (arm_feature(env, ARM_FEATURE_V8)) { | |
2159 | lr = R_V7M_EXCRET_RES1_MASK | | |
2160 | R_V7M_EXCRET_DCRS_MASK; | |
2161 | /* | |
2162 | * The S bit indicates whether we should return to Secure | |
2163 | * or NonSecure (ie our current state). | |
2164 | * The ES bit indicates whether we're taking this exception | |
2165 | * to Secure or NonSecure (ie our target state). We set it | |
2166 | * later, in v7m_exception_taken(). | |
2167 | * The SPSEL bit is also set in v7m_exception_taken() for v8M. | |
2168 | * This corresponds to the ARM ARM pseudocode for v8M setting | |
2169 | * some LR bits in PushStack() and some in ExceptionTaken(); | |
2170 | * the distinction matters for the tailchain cases where we | |
2171 | * can take an exception without pushing the stack. | |
2172 | */ | |
2173 | if (env->v7m.secure) { | |
2174 | lr |= R_V7M_EXCRET_S_MASK; | |
2175 | } | |
2176 | if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK)) { | |
2177 | lr |= R_V7M_EXCRET_FTYPE_MASK; | |
2178 | } | |
2179 | } else { | |
2180 | lr = R_V7M_EXCRET_RES1_MASK | | |
2181 | R_V7M_EXCRET_S_MASK | | |
2182 | R_V7M_EXCRET_DCRS_MASK | | |
2183 | R_V7M_EXCRET_FTYPE_MASK | | |
2184 | R_V7M_EXCRET_ES_MASK; | |
2185 | if (env->v7m.control[M_REG_NS] & R_V7M_CONTROL_SPSEL_MASK) { | |
2186 | lr |= R_V7M_EXCRET_SPSEL_MASK; | |
2187 | } | |
2188 | } | |
2189 | if (!arm_v7m_is_handler_mode(env)) { | |
2190 | lr |= R_V7M_EXCRET_MODE_MASK; | |
2191 | } | |
2192 | ||
2193 | ignore_stackfaults = v7m_push_stack(cpu); | |
2194 | v7m_exception_taken(cpu, lr, false, ignore_stackfaults); | |
2195 | } | |
2196 | ||
2197 | uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg) | |
2198 | { | |
2199 | uint32_t mask; | |
2200 | unsigned el = arm_current_el(env); | |
2201 | ||
2202 | /* First handle registers which unprivileged can read */ | |
2203 | ||
2204 | switch (reg) { | |
2205 | case 0 ... 7: /* xPSR sub-fields */ | |
2206 | mask = 0; | |
2207 | if ((reg & 1) && el) { | |
2208 | mask |= XPSR_EXCP; /* IPSR (unpriv. reads as zero) */ | |
2209 | } | |
2210 | if (!(reg & 4)) { | |
2211 | mask |= XPSR_NZCV | XPSR_Q; /* APSR */ | |
2212 | if (arm_feature(env, ARM_FEATURE_THUMB_DSP)) { | |
2213 | mask |= XPSR_GE; | |
2214 | } | |
2215 | } | |
2216 | /* EPSR reads as zero */ | |
2217 | return xpsr_read(env) & mask; | |
2218 | break; | |
2219 | case 20: /* CONTROL */ | |
2220 | { | |
2221 | uint32_t value = env->v7m.control[env->v7m.secure]; | |
2222 | if (!env->v7m.secure) { | |
2223 | /* SFPA is RAZ/WI from NS; FPCA is stored in the M_REG_S bank */ | |
2224 | value |= env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK; | |
2225 | } | |
2226 | return value; | |
2227 | } | |
2228 | case 0x94: /* CONTROL_NS */ | |
2229 | /* | |
2230 | * We have to handle this here because unprivileged Secure code | |
2231 | * can read the NS CONTROL register. | |
2232 | */ | |
2233 | if (!env->v7m.secure) { | |
2234 | return 0; | |
2235 | } | |
2236 | return env->v7m.control[M_REG_NS] | | |
2237 | (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK); | |
2238 | } | |
2239 | ||
2240 | if (el == 0) { | |
2241 | return 0; /* unprivileged reads others as zero */ | |
2242 | } | |
2243 | ||
2244 | if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { | |
2245 | switch (reg) { | |
2246 | case 0x88: /* MSP_NS */ | |
2247 | if (!env->v7m.secure) { | |
2248 | return 0; | |
2249 | } | |
2250 | return env->v7m.other_ss_msp; | |
2251 | case 0x89: /* PSP_NS */ | |
2252 | if (!env->v7m.secure) { | |
2253 | return 0; | |
2254 | } | |
2255 | return env->v7m.other_ss_psp; | |
2256 | case 0x8a: /* MSPLIM_NS */ | |
2257 | if (!env->v7m.secure) { | |
2258 | return 0; | |
2259 | } | |
2260 | return env->v7m.msplim[M_REG_NS]; | |
2261 | case 0x8b: /* PSPLIM_NS */ | |
2262 | if (!env->v7m.secure) { | |
2263 | return 0; | |
2264 | } | |
2265 | return env->v7m.psplim[M_REG_NS]; | |
2266 | case 0x90: /* PRIMASK_NS */ | |
2267 | if (!env->v7m.secure) { | |
2268 | return 0; | |
2269 | } | |
2270 | return env->v7m.primask[M_REG_NS]; | |
2271 | case 0x91: /* BASEPRI_NS */ | |
2272 | if (!env->v7m.secure) { | |
2273 | return 0; | |
2274 | } | |
2275 | return env->v7m.basepri[M_REG_NS]; | |
2276 | case 0x93: /* FAULTMASK_NS */ | |
2277 | if (!env->v7m.secure) { | |
2278 | return 0; | |
2279 | } | |
2280 | return env->v7m.faultmask[M_REG_NS]; | |
2281 | case 0x98: /* SP_NS */ | |
2282 | { | |
2283 | /* | |
2284 | * This gives the non-secure SP selected based on whether we're | |
2285 | * currently in handler mode or not, using the NS CONTROL.SPSEL. | |
2286 | */ | |
2287 | bool spsel = env->v7m.control[M_REG_NS] & R_V7M_CONTROL_SPSEL_MASK; | |
2288 | ||
2289 | if (!env->v7m.secure) { | |
2290 | return 0; | |
2291 | } | |
2292 | if (!arm_v7m_is_handler_mode(env) && spsel) { | |
2293 | return env->v7m.other_ss_psp; | |
2294 | } else { | |
2295 | return env->v7m.other_ss_msp; | |
2296 | } | |
2297 | } | |
2298 | default: | |
2299 | break; | |
2300 | } | |
2301 | } | |
2302 | ||
2303 | switch (reg) { | |
2304 | case 8: /* MSP */ | |
2305 | return v7m_using_psp(env) ? env->v7m.other_sp : env->regs[13]; | |
2306 | case 9: /* PSP */ | |
2307 | return v7m_using_psp(env) ? env->regs[13] : env->v7m.other_sp; | |
2308 | case 10: /* MSPLIM */ | |
2309 | if (!arm_feature(env, ARM_FEATURE_V8)) { | |
2310 | goto bad_reg; | |
2311 | } | |
2312 | return env->v7m.msplim[env->v7m.secure]; | |
2313 | case 11: /* PSPLIM */ | |
2314 | if (!arm_feature(env, ARM_FEATURE_V8)) { | |
2315 | goto bad_reg; | |
2316 | } | |
2317 | return env->v7m.psplim[env->v7m.secure]; | |
2318 | case 16: /* PRIMASK */ | |
2319 | return env->v7m.primask[env->v7m.secure]; | |
2320 | case 17: /* BASEPRI */ | |
2321 | case 18: /* BASEPRI_MAX */ | |
2322 | return env->v7m.basepri[env->v7m.secure]; | |
2323 | case 19: /* FAULTMASK */ | |
2324 | return env->v7m.faultmask[env->v7m.secure]; | |
2325 | default: | |
2326 | bad_reg: | |
2327 | qemu_log_mask(LOG_GUEST_ERROR, "Attempt to read unknown special" | |
2328 | " register %d\n", reg); | |
2329 | return 0; | |
2330 | } | |
2331 | } | |
2332 | ||
2333 | void HELPER(v7m_msr)(CPUARMState *env, uint32_t maskreg, uint32_t val) | |
2334 | { | |
2335 | /* | |
2336 | * We're passed bits [11..0] of the instruction; extract | |
2337 | * SYSm and the mask bits. | |
2338 | * Invalid combinations of SYSm and mask are UNPREDICTABLE; | |
2339 | * we choose to treat them as if the mask bits were valid. | |
2340 | * NB that the pseudocode 'mask' variable is bits [11..10], | |
2341 | * whereas ours is [11..8]. | |
2342 | */ | |
2343 | uint32_t mask = extract32(maskreg, 8, 4); | |
2344 | uint32_t reg = extract32(maskreg, 0, 8); | |
2345 | int cur_el = arm_current_el(env); | |
2346 | ||
2347 | if (cur_el == 0 && reg > 7 && reg != 20) { | |
2348 | /* | |
2349 | * only xPSR sub-fields and CONTROL.SFPA may be written by | |
2350 | * unprivileged code | |
2351 | */ | |
2352 | return; | |
2353 | } | |
2354 | ||
2355 | if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { | |
2356 | switch (reg) { | |
2357 | case 0x88: /* MSP_NS */ | |
2358 | if (!env->v7m.secure) { | |
2359 | return; | |
2360 | } | |
2361 | env->v7m.other_ss_msp = val; | |
2362 | return; | |
2363 | case 0x89: /* PSP_NS */ | |
2364 | if (!env->v7m.secure) { | |
2365 | return; | |
2366 | } | |
2367 | env->v7m.other_ss_psp = val; | |
2368 | return; | |
2369 | case 0x8a: /* MSPLIM_NS */ | |
2370 | if (!env->v7m.secure) { | |
2371 | return; | |
2372 | } | |
2373 | env->v7m.msplim[M_REG_NS] = val & ~7; | |
2374 | return; | |
2375 | case 0x8b: /* PSPLIM_NS */ | |
2376 | if (!env->v7m.secure) { | |
2377 | return; | |
2378 | } | |
2379 | env->v7m.psplim[M_REG_NS] = val & ~7; | |
2380 | return; | |
2381 | case 0x90: /* PRIMASK_NS */ | |
2382 | if (!env->v7m.secure) { | |
2383 | return; | |
2384 | } | |
2385 | env->v7m.primask[M_REG_NS] = val & 1; | |
2386 | return; | |
2387 | case 0x91: /* BASEPRI_NS */ | |
2388 | if (!env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_MAIN)) { | |
2389 | return; | |
2390 | } | |
2391 | env->v7m.basepri[M_REG_NS] = val & 0xff; | |
2392 | return; | |
2393 | case 0x93: /* FAULTMASK_NS */ | |
2394 | if (!env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_MAIN)) { | |
2395 | return; | |
2396 | } | |
2397 | env->v7m.faultmask[M_REG_NS] = val & 1; | |
2398 | return; | |
2399 | case 0x94: /* CONTROL_NS */ | |
2400 | if (!env->v7m.secure) { | |
2401 | return; | |
2402 | } | |
2403 | write_v7m_control_spsel_for_secstate(env, | |
2404 | val & R_V7M_CONTROL_SPSEL_MASK, | |
2405 | M_REG_NS); | |
2406 | if (arm_feature(env, ARM_FEATURE_M_MAIN)) { | |
2407 | env->v7m.control[M_REG_NS] &= ~R_V7M_CONTROL_NPRIV_MASK; | |
2408 | env->v7m.control[M_REG_NS] |= val & R_V7M_CONTROL_NPRIV_MASK; | |
2409 | } | |
2410 | /* | |
2411 | * SFPA is RAZ/WI from NS. FPCA is RO if NSACR.CP10 == 0, | |
2412 | * RES0 if the FPU is not present, and is stored in the S bank | |
2413 | */ | |
2414 | if (arm_feature(env, ARM_FEATURE_VFP) && | |
2415 | extract32(env->v7m.nsacr, 10, 1)) { | |
2416 | env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK; | |
2417 | env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_FPCA_MASK; | |
2418 | } | |
2419 | return; | |
2420 | case 0x98: /* SP_NS */ | |
2421 | { | |
2422 | /* | |
2423 | * This gives the non-secure SP selected based on whether we're | |
2424 | * currently in handler mode or not, using the NS CONTROL.SPSEL. | |
2425 | */ | |
2426 | bool spsel = env->v7m.control[M_REG_NS] & R_V7M_CONTROL_SPSEL_MASK; | |
2427 | bool is_psp = !arm_v7m_is_handler_mode(env) && spsel; | |
2428 | uint32_t limit; | |
2429 | ||
2430 | if (!env->v7m.secure) { | |
2431 | return; | |
2432 | } | |
2433 | ||
2434 | limit = is_psp ? env->v7m.psplim[false] : env->v7m.msplim[false]; | |
2435 | ||
2436 | if (val < limit) { | |
2437 | CPUState *cs = env_cpu(env); | |
2438 | ||
2439 | cpu_restore_state(cs, GETPC(), true); | |
2440 | raise_exception(env, EXCP_STKOF, 0, 1); | |
2441 | } | |
2442 | ||
2443 | if (is_psp) { | |
2444 | env->v7m.other_ss_psp = val; | |
2445 | } else { | |
2446 | env->v7m.other_ss_msp = val; | |
2447 | } | |
2448 | return; | |
2449 | } | |
2450 | default: | |
2451 | break; | |
2452 | } | |
2453 | } | |
2454 | ||
2455 | switch (reg) { | |
2456 | case 0 ... 7: /* xPSR sub-fields */ | |
2457 | /* only APSR is actually writable */ | |
2458 | if (!(reg & 4)) { | |
2459 | uint32_t apsrmask = 0; | |
2460 | ||
2461 | if (mask & 8) { | |
2462 | apsrmask |= XPSR_NZCV | XPSR_Q; | |
2463 | } | |
2464 | if ((mask & 4) && arm_feature(env, ARM_FEATURE_THUMB_DSP)) { | |
2465 | apsrmask |= XPSR_GE; | |
2466 | } | |
2467 | xpsr_write(env, val, apsrmask); | |
2468 | } | |
2469 | break; | |
2470 | case 8: /* MSP */ | |
2471 | if (v7m_using_psp(env)) { | |
2472 | env->v7m.other_sp = val; | |
2473 | } else { | |
2474 | env->regs[13] = val; | |
2475 | } | |
2476 | break; | |
2477 | case 9: /* PSP */ | |
2478 | if (v7m_using_psp(env)) { | |
2479 | env->regs[13] = val; | |
2480 | } else { | |
2481 | env->v7m.other_sp = val; | |
2482 | } | |
2483 | break; | |
2484 | case 10: /* MSPLIM */ | |
2485 | if (!arm_feature(env, ARM_FEATURE_V8)) { | |
2486 | goto bad_reg; | |
2487 | } | |
2488 | env->v7m.msplim[env->v7m.secure] = val & ~7; | |
2489 | break; | |
2490 | case 11: /* PSPLIM */ | |
2491 | if (!arm_feature(env, ARM_FEATURE_V8)) { | |
2492 | goto bad_reg; | |
2493 | } | |
2494 | env->v7m.psplim[env->v7m.secure] = val & ~7; | |
2495 | break; | |
2496 | case 16: /* PRIMASK */ | |
2497 | env->v7m.primask[env->v7m.secure] = val & 1; | |
2498 | break; | |
2499 | case 17: /* BASEPRI */ | |
2500 | if (!arm_feature(env, ARM_FEATURE_M_MAIN)) { | |
2501 | goto bad_reg; | |
2502 | } | |
2503 | env->v7m.basepri[env->v7m.secure] = val & 0xff; | |
2504 | break; | |
2505 | case 18: /* BASEPRI_MAX */ | |
2506 | if (!arm_feature(env, ARM_FEATURE_M_MAIN)) { | |
2507 | goto bad_reg; | |
2508 | } | |
2509 | val &= 0xff; | |
2510 | if (val != 0 && (val < env->v7m.basepri[env->v7m.secure] | |
2511 | || env->v7m.basepri[env->v7m.secure] == 0)) { | |
2512 | env->v7m.basepri[env->v7m.secure] = val; | |
2513 | } | |
2514 | break; | |
2515 | case 19: /* FAULTMASK */ | |
2516 | if (!arm_feature(env, ARM_FEATURE_M_MAIN)) { | |
2517 | goto bad_reg; | |
2518 | } | |
2519 | env->v7m.faultmask[env->v7m.secure] = val & 1; | |
2520 | break; | |
2521 | case 20: /* CONTROL */ | |
2522 | /* | |
2523 | * Writing to the SPSEL bit only has an effect if we are in | |
2524 | * thread mode; other bits can be updated by any privileged code. | |
2525 | * write_v7m_control_spsel() deals with updating the SPSEL bit in | |
2526 | * env->v7m.control, so we only need update the others. | |
2527 | * For v7M, we must just ignore explicit writes to SPSEL in handler | |
2528 | * mode; for v8M the write is permitted but will have no effect. | |
2529 | * All these bits are writes-ignored from non-privileged code, | |
2530 | * except for SFPA. | |
2531 | */ | |
2532 | if (cur_el > 0 && (arm_feature(env, ARM_FEATURE_V8) || | |
2533 | !arm_v7m_is_handler_mode(env))) { | |
2534 | write_v7m_control_spsel(env, (val & R_V7M_CONTROL_SPSEL_MASK) != 0); | |
2535 | } | |
2536 | if (cur_el > 0 && arm_feature(env, ARM_FEATURE_M_MAIN)) { | |
2537 | env->v7m.control[env->v7m.secure] &= ~R_V7M_CONTROL_NPRIV_MASK; | |
2538 | env->v7m.control[env->v7m.secure] |= val & R_V7M_CONTROL_NPRIV_MASK; | |
2539 | } | |
2540 | if (arm_feature(env, ARM_FEATURE_VFP)) { | |
2541 | /* | |
2542 | * SFPA is RAZ/WI from NS or if no FPU. | |
2543 | * FPCA is RO if NSACR.CP10 == 0, RES0 if the FPU is not present. | |
2544 | * Both are stored in the S bank. | |
2545 | */ | |
2546 | if (env->v7m.secure) { | |
2547 | env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK; | |
2548 | env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_SFPA_MASK; | |
2549 | } | |
2550 | if (cur_el > 0 && | |
2551 | (env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_SECURITY) || | |
2552 | extract32(env->v7m.nsacr, 10, 1))) { | |
2553 | env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK; | |
2554 | env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_FPCA_MASK; | |
2555 | } | |
2556 | } | |
2557 | break; | |
2558 | default: | |
2559 | bad_reg: | |
2560 | qemu_log_mask(LOG_GUEST_ERROR, "Attempt to write unknown special" | |
2561 | " register %d\n", reg); | |
2562 | return; | |
2563 | } | |
2564 | } | |
2565 | ||
2566 | uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op) | |
2567 | { | |
2568 | /* Implement the TT instruction. op is bits [7:6] of the insn. */ | |
2569 | bool forceunpriv = op & 1; | |
2570 | bool alt = op & 2; | |
2571 | V8M_SAttributes sattrs = {}; | |
2572 | uint32_t tt_resp; | |
2573 | bool r, rw, nsr, nsrw, mrvalid; | |
2574 | int prot; | |
2575 | ARMMMUFaultInfo fi = {}; | |
2576 | MemTxAttrs attrs = {}; | |
2577 | hwaddr phys_addr; | |
2578 | ARMMMUIdx mmu_idx; | |
2579 | uint32_t mregion; | |
2580 | bool targetpriv; | |
2581 | bool targetsec = env->v7m.secure; | |
2582 | bool is_subpage; | |
2583 | ||
2584 | /* | |
2585 | * Work out what the security state and privilege level we're | |
2586 | * interested in is... | |
2587 | */ | |
2588 | if (alt) { | |
2589 | targetsec = !targetsec; | |
2590 | } | |
2591 | ||
2592 | if (forceunpriv) { | |
2593 | targetpriv = false; | |
2594 | } else { | |
2595 | targetpriv = arm_v7m_is_handler_mode(env) || | |
2596 | !(env->v7m.control[targetsec] & R_V7M_CONTROL_NPRIV_MASK); | |
2597 | } | |
2598 | ||
2599 | /* ...and then figure out which MMU index this is */ | |
2600 | mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, targetsec, targetpriv); | |
2601 | ||
2602 | /* | |
2603 | * We know that the MPU and SAU don't care about the access type | |
2604 | * for our purposes beyond that we don't want to claim to be | |
2605 | * an insn fetch, so we arbitrarily call this a read. | |
2606 | */ | |
2607 | ||
2608 | /* | |
2609 | * MPU region info only available for privileged or if | |
2610 | * inspecting the other MPU state. | |
2611 | */ | |
2612 | if (arm_current_el(env) != 0 || alt) { | |
2613 | /* We can ignore the return value as prot is always set */ | |
2614 | pmsav8_mpu_lookup(env, addr, MMU_DATA_LOAD, mmu_idx, | |
2615 | &phys_addr, &attrs, &prot, &is_subpage, | |
2616 | &fi, &mregion); | |
2617 | if (mregion == -1) { | |
2618 | mrvalid = false; | |
2619 | mregion = 0; | |
2620 | } else { | |
2621 | mrvalid = true; | |
2622 | } | |
2623 | r = prot & PAGE_READ; | |
2624 | rw = prot & PAGE_WRITE; | |
2625 | } else { | |
2626 | r = false; | |
2627 | rw = false; | |
2628 | mrvalid = false; | |
2629 | mregion = 0; | |
2630 | } | |
2631 | ||
2632 | if (env->v7m.secure) { | |
2633 | v8m_security_lookup(env, addr, MMU_DATA_LOAD, mmu_idx, &sattrs); | |
2634 | nsr = sattrs.ns && r; | |
2635 | nsrw = sattrs.ns && rw; | |
2636 | } else { | |
2637 | sattrs.ns = true; | |
2638 | nsr = false; | |
2639 | nsrw = false; | |
2640 | } | |
2641 | ||
2642 | tt_resp = (sattrs.iregion << 24) | | |
2643 | (sattrs.irvalid << 23) | | |
2644 | ((!sattrs.ns) << 22) | | |
2645 | (nsrw << 21) | | |
2646 | (nsr << 20) | | |
2647 | (rw << 19) | | |
2648 | (r << 18) | | |
2649 | (sattrs.srvalid << 17) | | |
2650 | (mrvalid << 16) | | |
2651 | (sattrs.sregion << 8) | | |
2652 | mregion; | |
2653 | ||
2654 | return tt_resp; | |
2655 | } | |
2656 | ||
2657 | #endif /* !CONFIG_USER_ONLY */ | |
2658 | ||
2659 | ARMMMUIdx arm_v7m_mmu_idx_all(CPUARMState *env, | |
2660 | bool secstate, bool priv, bool negpri) | |
2661 | { | |
2662 | ARMMMUIdx mmu_idx = ARM_MMU_IDX_M; | |
2663 | ||
2664 | if (priv) { | |
2665 | mmu_idx |= ARM_MMU_IDX_M_PRIV; | |
2666 | } | |
2667 | ||
2668 | if (negpri) { | |
2669 | mmu_idx |= ARM_MMU_IDX_M_NEGPRI; | |
2670 | } | |
2671 | ||
2672 | if (secstate) { | |
2673 | mmu_idx |= ARM_MMU_IDX_M_S; | |
2674 | } | |
2675 | ||
2676 | return mmu_idx; | |
2677 | } | |
2678 | ||
2679 | ARMMMUIdx arm_v7m_mmu_idx_for_secstate_and_priv(CPUARMState *env, | |
2680 | bool secstate, bool priv) | |
2681 | { | |
2682 | bool negpri = armv7m_nvic_neg_prio_requested(env->nvic, secstate); | |
2683 | ||
2684 | return arm_v7m_mmu_idx_all(env, secstate, priv, negpri); | |
2685 | } | |
2686 | ||
2687 | /* Return the MMU index for a v7M CPU in the specified security state */ | |
2688 | ARMMMUIdx arm_v7m_mmu_idx_for_secstate(CPUARMState *env, bool secstate) | |
2689 | { | |
2690 | bool priv = arm_current_el(env) != 0; | |
2691 | ||
2692 | return arm_v7m_mmu_idx_for_secstate_and_priv(env, secstate, priv); | |
2693 | } |