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target/arm: Implement the GMI instruction
[qemu.git] / target / arm / pauth_helper.c
blobb909630317ecede831df7d0dd3d8c5a7646d6b70
1 /*
2 * ARM v8.3-PAuth Operations
3 *
4 * Copyright (c) 2019 Linaro, Ltd.
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include "qemu/osdep.h"
21 #include "cpu.h"
22 #include "internals.h"
23 #include "exec/exec-all.h"
24 #include "exec/cpu_ldst.h"
25 #include "exec/helper-proto.h"
26 #include "tcg/tcg-gvec-desc.h"
27
28
29 static uint64_t pac_cell_shuffle(uint64_t i)
30 {
31 uint64_t o = 0;
32
33 o |= extract64(i, 52, 4);
34 o |= extract64(i, 24, 4) << 4;
35 o |= extract64(i, 44, 4) << 8;
36 o |= extract64(i, 0, 4) << 12;
37
38 o |= extract64(i, 28, 4) << 16;
39 o |= extract64(i, 48, 4) << 20;
40 o |= extract64(i, 4, 4) << 24;
41 o |= extract64(i, 40, 4) << 28;
42
43 o |= extract64(i, 32, 4) << 32;
44 o |= extract64(i, 12, 4) << 36;
45 o |= extract64(i, 56, 4) << 40;
46 o |= extract64(i, 20, 4) << 44;
47
48 o |= extract64(i, 8, 4) << 48;
49 o |= extract64(i, 36, 4) << 52;
50 o |= extract64(i, 16, 4) << 56;
51 o |= extract64(i, 60, 4) << 60;
52
53 return o;
54 }
55
56 static uint64_t pac_cell_inv_shuffle(uint64_t i)
57 {
58 uint64_t o = 0;
59
60 o |= extract64(i, 12, 4);
61 o |= extract64(i, 24, 4) << 4;
62 o |= extract64(i, 48, 4) << 8;
63 o |= extract64(i, 36, 4) << 12;
64
65 o |= extract64(i, 56, 4) << 16;
66 o |= extract64(i, 44, 4) << 20;
67 o |= extract64(i, 4, 4) << 24;
68 o |= extract64(i, 16, 4) << 28;
69
70 o |= i & MAKE_64BIT_MASK(32, 4);
71 o |= extract64(i, 52, 4) << 36;
72 o |= extract64(i, 28, 4) << 40;
73 o |= extract64(i, 8, 4) << 44;
74
75 o |= extract64(i, 20, 4) << 48;
76 o |= extract64(i, 0, 4) << 52;
77 o |= extract64(i, 40, 4) << 56;
78 o |= i & MAKE_64BIT_MASK(60, 4);
79
80 return o;
81 }
82
83 static uint64_t pac_sub(uint64_t i)
84 {
85 static const uint8_t sub[16] = {
86 0xb, 0x6, 0x8, 0xf, 0xc, 0x0, 0x9, 0xe,
87 0x3, 0x7, 0x4, 0x5, 0xd, 0x2, 0x1, 0xa,
88 };
89 uint64_t o = 0;
90 int b;
91
92 for (b = 0; b < 64; b += 4) {
93 o |= (uint64_t)sub[(i >> b) & 0xf] << b;
94 }
95 return o;
96 }
97
98 static uint64_t pac_inv_sub(uint64_t i)
99 {
100 static const uint8_t inv_sub[16] = {
101 0x5, 0xe, 0xd, 0x8, 0xa, 0xb, 0x1, 0x9,
102 0x2, 0x6, 0xf, 0x0, 0x4, 0xc, 0x7, 0x3,
103 };
104 uint64_t o = 0;
105 int b;
106
107 for (b = 0; b < 64; b += 4) {
108 o |= (uint64_t)inv_sub[(i >> b) & 0xf] << b;
109 }
110 return o;
111 }
112
113 static int rot_cell(int cell, int n)
114 {
115 /* 4-bit rotate left by n. */
116 cell |= cell << 4;
117 return extract32(cell, 4 - n, 4);
118 }
119
120 static uint64_t pac_mult(uint64_t i)
121 {
122 uint64_t o = 0;
123 int b;
124
125 for (b = 0; b < 4 * 4; b += 4) {
126 int i0, i4, i8, ic, t0, t1, t2, t3;
127
128 i0 = extract64(i, b, 4);
129 i4 = extract64(i, b + 4 * 4, 4);
130 i8 = extract64(i, b + 8 * 4, 4);
131 ic = extract64(i, b + 12 * 4, 4);
132
133 t0 = rot_cell(i8, 1) ^ rot_cell(i4, 2) ^ rot_cell(i0, 1);
134 t1 = rot_cell(ic, 1) ^ rot_cell(i4, 1) ^ rot_cell(i0, 2);
135 t2 = rot_cell(ic, 2) ^ rot_cell(i8, 1) ^ rot_cell(i0, 1);
136 t3 = rot_cell(ic, 1) ^ rot_cell(i8, 2) ^ rot_cell(i4, 1);
137
138 o |= (uint64_t)t3 << b;
139 o |= (uint64_t)t2 << (b + 4 * 4);
140 o |= (uint64_t)t1 << (b + 8 * 4);
141 o |= (uint64_t)t0 << (b + 12 * 4);
142 }
143 return o;
144 }
145
146 static uint64_t tweak_cell_rot(uint64_t cell)
147 {
148 return (cell >> 1) | (((cell ^ (cell >> 1)) & 1) << 3);
149 }
150
151 static uint64_t tweak_shuffle(uint64_t i)
152 {
153 uint64_t o = 0;
154
155 o |= extract64(i, 16, 4) << 0;
156 o |= extract64(i, 20, 4) << 4;
157 o |= tweak_cell_rot(extract64(i, 24, 4)) << 8;
158 o |= extract64(i, 28, 4) << 12;
159
160 o |= tweak_cell_rot(extract64(i, 44, 4)) << 16;
161 o |= extract64(i, 8, 4) << 20;
162 o |= extract64(i, 12, 4) << 24;
163 o |= tweak_cell_rot(extract64(i, 32, 4)) << 28;
164
165 o |= extract64(i, 48, 4) << 32;
166 o |= extract64(i, 52, 4) << 36;
167 o |= extract64(i, 56, 4) << 40;
168 o |= tweak_cell_rot(extract64(i, 60, 4)) << 44;
169
170 o |= tweak_cell_rot(extract64(i, 0, 4)) << 48;
171 o |= extract64(i, 4, 4) << 52;
172 o |= tweak_cell_rot(extract64(i, 40, 4)) << 56;
173 o |= tweak_cell_rot(extract64(i, 36, 4)) << 60;
174
175 return o;
176 }
177
178 static uint64_t tweak_cell_inv_rot(uint64_t cell)
179 {
180 return ((cell << 1) & 0xf) | ((cell & 1) ^ (cell >> 3));
181 }
182
183 static uint64_t tweak_inv_shuffle(uint64_t i)
184 {
185 uint64_t o = 0;
186
187 o |= tweak_cell_inv_rot(extract64(i, 48, 4));
188 o |= extract64(i, 52, 4) << 4;
189 o |= extract64(i, 20, 4) << 8;
190 o |= extract64(i, 24, 4) << 12;
191
192 o |= extract64(i, 0, 4) << 16;
193 o |= extract64(i, 4, 4) << 20;
194 o |= tweak_cell_inv_rot(extract64(i, 8, 4)) << 24;
195 o |= extract64(i, 12, 4) << 28;
196
197 o |= tweak_cell_inv_rot(extract64(i, 28, 4)) << 32;
198 o |= tweak_cell_inv_rot(extract64(i, 60, 4)) << 36;
199 o |= tweak_cell_inv_rot(extract64(i, 56, 4)) << 40;
200 o |= tweak_cell_inv_rot(extract64(i, 16, 4)) << 44;
201
202 o |= extract64(i, 32, 4) << 48;
203 o |= extract64(i, 36, 4) << 52;
204 o |= extract64(i, 40, 4) << 56;
205 o |= tweak_cell_inv_rot(extract64(i, 44, 4)) << 60;
206
207 return o;
208 }
209
210 static uint64_t pauth_computepac(uint64_t data, uint64_t modifier,
211 ARMPACKey key)
212 {
213 static const uint64_t RC[5] = {
214 0x0000000000000000ull,
215 0x13198A2E03707344ull,
216 0xA4093822299F31D0ull,
217 0x082EFA98EC4E6C89ull,
218 0x452821E638D01377ull,
219 };
220 const uint64_t alpha = 0xC0AC29B7C97C50DDull;
221 /*
222 * Note that in the ARM pseudocode, key0 contains bits <127:64>
223 * and key1 contains bits <63:0> of the 128-bit key.
224 */
225 uint64_t key0 = key.hi, key1 = key.lo;
226 uint64_t workingval, runningmod, roundkey, modk0;
227 int i;
228
229 modk0 = (key0 << 63) | ((key0 >> 1) ^ (key0 >> 63));
230 runningmod = modifier;
231 workingval = data ^ key0;
232
233 for (i = 0; i <= 4; ++i) {
234 roundkey = key1 ^ runningmod;
235 workingval ^= roundkey;
236 workingval ^= RC[i];
237 if (i > 0) {
238 workingval = pac_cell_shuffle(workingval);
239 workingval = pac_mult(workingval);
240 }
241 workingval = pac_sub(workingval);
242 runningmod = tweak_shuffle(runningmod);
243 }
244 roundkey = modk0 ^ runningmod;
245 workingval ^= roundkey;
246 workingval = pac_cell_shuffle(workingval);
247 workingval = pac_mult(workingval);
248 workingval = pac_sub(workingval);
249 workingval = pac_cell_shuffle(workingval);
250 workingval = pac_mult(workingval);
251 workingval ^= key1;
252 workingval = pac_cell_inv_shuffle(workingval);
253 workingval = pac_inv_sub(workingval);
254 workingval = pac_mult(workingval);
255 workingval = pac_cell_inv_shuffle(workingval);
256 workingval ^= key0;
257 workingval ^= runningmod;
258 for (i = 0; i <= 4; ++i) {
259 workingval = pac_inv_sub(workingval);
260 if (i < 4) {
261 workingval = pac_mult(workingval);
262 workingval = pac_cell_inv_shuffle(workingval);
263 }
264 runningmod = tweak_inv_shuffle(runningmod);
265 roundkey = key1 ^ runningmod;
266 workingval ^= RC[4 - i];
267 workingval ^= roundkey;
268 workingval ^= alpha;
269 }
270 workingval ^= modk0;
271
272 return workingval;
273 }
274
275 static uint64_t pauth_addpac(CPUARMState *env, uint64_t ptr, uint64_t modifier,
276 ARMPACKey *key, bool data)
277 {
278 ARMMMUIdx mmu_idx = arm_stage1_mmu_idx(env);
279 ARMVAParameters param = aa64_va_parameters(env, ptr, mmu_idx, data);
280 uint64_t pac, ext_ptr, ext, test;
281 int bot_bit, top_bit;
282
283 /* If tagged pointers are in use, use ptr<55>, otherwise ptr<63>. */
284 if (param.tbi) {
285 ext = sextract64(ptr, 55, 1);
286 } else {
287 ext = sextract64(ptr, 63, 1);
288 }
289
290 /* Build a pointer with known good extension bits. */
291 top_bit = 64 - 8 * param.tbi;
292 bot_bit = 64 - param.tsz;
293 ext_ptr = deposit64(ptr, bot_bit, top_bit - bot_bit, ext);
294
295 pac = pauth_computepac(ext_ptr, modifier, *key);
296
297 /*
298 * Check if the ptr has good extension bits and corrupt the
299 * pointer authentication code if not.
300 */
301 test = sextract64(ptr, bot_bit, top_bit - bot_bit);
302 if (test != 0 && test != -1) {
303 pac ^= MAKE_64BIT_MASK(top_bit - 1, 1);
304 }
305
306 /*
307 * Preserve the determination between upper and lower at bit 55,
308 * and insert pointer authentication code.
309 */
310 if (param.tbi) {
311 ptr &= ~MAKE_64BIT_MASK(bot_bit, 55 - bot_bit + 1);
312 pac &= MAKE_64BIT_MASK(bot_bit, 54 - bot_bit + 1);
313 } else {
314 ptr &= MAKE_64BIT_MASK(0, bot_bit);
315 pac &= ~(MAKE_64BIT_MASK(55, 1) | MAKE_64BIT_MASK(0, bot_bit));
316 }
317 ext &= MAKE_64BIT_MASK(55, 1);
318 return pac | ext | ptr;
319 }
320
321 static uint64_t pauth_original_ptr(uint64_t ptr, ARMVAParameters param)
322 {
323 /* Note that bit 55 is used whether or not the regime has 2 ranges. */
324 uint64_t extfield = sextract64(ptr, 55, 1);
325 int bot_pac_bit = 64 - param.tsz;
326 int top_pac_bit = 64 - 8 * param.tbi;
327
328 return deposit64(ptr, bot_pac_bit, top_pac_bit - bot_pac_bit, extfield);
329 }
330
331 static uint64_t pauth_auth(CPUARMState *env, uint64_t ptr, uint64_t modifier,
332 ARMPACKey *key, bool data, int keynumber)
333 {
334 ARMMMUIdx mmu_idx = arm_stage1_mmu_idx(env);
335 ARMVAParameters param = aa64_va_parameters(env, ptr, mmu_idx, data);
336 int bot_bit, top_bit;
337 uint64_t pac, orig_ptr, test;
338
339 orig_ptr = pauth_original_ptr(ptr, param);
340 pac = pauth_computepac(orig_ptr, modifier, *key);
341 bot_bit = 64 - param.tsz;
342 top_bit = 64 - 8 * param.tbi;
343
344 test = (pac ^ ptr) & ~MAKE_64BIT_MASK(55, 1);
345 if (unlikely(extract64(test, bot_bit, top_bit - bot_bit))) {
346 int error_code = (keynumber << 1) | (keynumber ^ 1);
347 if (param.tbi) {
348 return deposit64(orig_ptr, 53, 2, error_code);
349 } else {
350 return deposit64(orig_ptr, 61, 2, error_code);
351 }
352 }
353 return orig_ptr;
354 }
355
356 static uint64_t pauth_strip(CPUARMState *env, uint64_t ptr, bool data)
357 {
358 ARMMMUIdx mmu_idx = arm_stage1_mmu_idx(env);
359 ARMVAParameters param = aa64_va_parameters(env, ptr, mmu_idx, data);
360
361 return pauth_original_ptr(ptr, param);
362 }
363
364 static void QEMU_NORETURN pauth_trap(CPUARMState *env, int target_el,
365 uintptr_t ra)
366 {
367 raise_exception_ra(env, EXCP_UDEF, syn_pactrap(), target_el, ra);
368 }
369
370 static void pauth_check_trap(CPUARMState *env, int el, uintptr_t ra)
371 {
372 if (el < 2 && arm_feature(env, ARM_FEATURE_EL2)) {
373 uint64_t hcr = arm_hcr_el2_eff(env);
374 bool trap = !(hcr & HCR_API);
375 if (el == 0) {
376 /* Trap only applies to EL1&0 regime. */
377 trap &= (hcr & (HCR_E2H | HCR_TGE)) != (HCR_E2H | HCR_TGE);
378 }
379 /* FIXME: ARMv8.3-NV: HCR_NV trap takes precedence for ERETA[AB]. */
380 if (trap) {
381 pauth_trap(env, 2, ra);
382 }
383 }
384 if (el < 3 && arm_feature(env, ARM_FEATURE_EL3)) {
385 if (!(env->cp15.scr_el3 & SCR_API)) {
386 pauth_trap(env, 3, ra);
387 }
388 }
389 }
390
391 static bool pauth_key_enabled(CPUARMState *env, int el, uint32_t bit)
392 {
393 return (arm_sctlr(env, el) & bit) != 0;
394 }
395
396 uint64_t HELPER(pacia)(CPUARMState *env, uint64_t x, uint64_t y)
397 {
398 int el = arm_current_el(env);
399 if (!pauth_key_enabled(env, el, SCTLR_EnIA)) {
400 return x;
401 }
402 pauth_check_trap(env, el, GETPC());
403 return pauth_addpac(env, x, y, &env->keys.apia, false);
404 }
405
406 uint64_t HELPER(pacib)(CPUARMState *env, uint64_t x, uint64_t y)
407 {
408 int el = arm_current_el(env);
409 if (!pauth_key_enabled(env, el, SCTLR_EnIB)) {
410 return x;
411 }
412 pauth_check_trap(env, el, GETPC());
413 return pauth_addpac(env, x, y, &env->keys.apib, false);
414 }
415
416 uint64_t HELPER(pacda)(CPUARMState *env, uint64_t x, uint64_t y)
417 {
418 int el = arm_current_el(env);
419 if (!pauth_key_enabled(env, el, SCTLR_EnDA)) {
420 return x;
421 }
422 pauth_check_trap(env, el, GETPC());
423 return pauth_addpac(env, x, y, &env->keys.apda, true);
424 }
425
426 uint64_t HELPER(pacdb)(CPUARMState *env, uint64_t x, uint64_t y)
427 {
428 int el = arm_current_el(env);
429 if (!pauth_key_enabled(env, el, SCTLR_EnDB)) {
430 return x;
431 }
432 pauth_check_trap(env, el, GETPC());
433 return pauth_addpac(env, x, y, &env->keys.apdb, true);
434 }
435
436 uint64_t HELPER(pacga)(CPUARMState *env, uint64_t x, uint64_t y)
437 {
438 uint64_t pac;
439
440 pauth_check_trap(env, arm_current_el(env), GETPC());
441 pac = pauth_computepac(x, y, env->keys.apga);
442
443 return pac & 0xffffffff00000000ull;
444 }
445
446 uint64_t HELPER(autia)(CPUARMState *env, uint64_t x, uint64_t y)
447 {
448 int el = arm_current_el(env);
449 if (!pauth_key_enabled(env, el, SCTLR_EnIA)) {
450 return x;
451 }
452 pauth_check_trap(env, el, GETPC());
453 return pauth_auth(env, x, y, &env->keys.apia, false, 0);
454 }
455
456 uint64_t HELPER(autib)(CPUARMState *env, uint64_t x, uint64_t y)
457 {
458 int el = arm_current_el(env);
459 if (!pauth_key_enabled(env, el, SCTLR_EnIB)) {
460 return x;
461 }
462 pauth_check_trap(env, el, GETPC());
463 return pauth_auth(env, x, y, &env->keys.apib, false, 1);
464 }
465
466 uint64_t HELPER(autda)(CPUARMState *env, uint64_t x, uint64_t y)
467 {
468 int el = arm_current_el(env);
469 if (!pauth_key_enabled(env, el, SCTLR_EnDA)) {
470 return x;
471 }
472 pauth_check_trap(env, el, GETPC());
473 return pauth_auth(env, x, y, &env->keys.apda, true, 0);
474 }
475
476 uint64_t HELPER(autdb)(CPUARMState *env, uint64_t x, uint64_t y)
477 {
478 int el = arm_current_el(env);
479 if (!pauth_key_enabled(env, el, SCTLR_EnDB)) {
480 return x;
481 }
482 pauth_check_trap(env, el, GETPC());
483 return pauth_auth(env, x, y, &env->keys.apdb, true, 1);
484 }
485
486 uint64_t HELPER(xpaci)(CPUARMState *env, uint64_t a)
487 {
488 return pauth_strip(env, a, false);
489 }
490
491 uint64_t HELPER(xpacd)(CPUARMState *env, uint64_t a)
492 {
493 return pauth_strip(env, a, true);
494 }
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