blob: 1b9ce0fdd81de87595a15e0440c1e05095ae4fa9 [file] [log] [blame]
Andre Przywarae116a372014-11-14 15:54:09 +00001/*
2 * Contains CPU specific errata definitions
3 *
4 * Copyright (C) 2014 ARM Ltd.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 */
18
Arnd Bergmann94a5d872018-06-05 13:50:07 +020019#include <linux/arm-smccc.h>
20#include <linux/psci.h>
Andre Przywarae116a372014-11-14 15:54:09 +000021#include <linux/types.h>
Josh Poimboeufa111b7c2019-04-12 15:39:32 -050022#include <linux/cpu.h>
Andre Przywarae116a372014-11-14 15:54:09 +000023#include <asm/cpu.h>
24#include <asm/cputype.h>
25#include <asm/cpufeature.h>
26
Andre Przywara301bcfa2014-11-14 15:54:10 +000027static bool __maybe_unused
Suzuki K Poulose92406f02016-04-22 12:25:31 +010028is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
Andre Przywara301bcfa2014-11-14 15:54:10 +000029{
Ard Biesheuvele8002e02018-03-06 17:15:34 +000030 const struct arm64_midr_revidr *fix;
31 u32 midr = read_cpuid_id(), revidr;
32
Suzuki K Poulose92406f02016-04-22 12:25:31 +010033 WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
Suzuki K Poulose1df31052018-03-26 15:12:44 +010034 if (!is_midr_in_range(midr, &entry->midr_range))
Ard Biesheuvele8002e02018-03-06 17:15:34 +000035 return false;
36
37 midr &= MIDR_REVISION_MASK | MIDR_VARIANT_MASK;
38 revidr = read_cpuid(REVIDR_EL1);
39 for (fix = entry->fixed_revs; fix && fix->revidr_mask; fix++)
40 if (midr == fix->midr_rv && (revidr & fix->revidr_mask))
41 return false;
42
43 return true;
Andre Przywara301bcfa2014-11-14 15:54:10 +000044}
45
Stephen Boydbb487112017-12-13 14:19:37 -080046static bool __maybe_unused
Suzuki K Poulosebe5b2992018-03-26 15:12:45 +010047is_affected_midr_range_list(const struct arm64_cpu_capabilities *entry,
48 int scope)
49{
50 WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
51 return is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list);
Andre Przywara301bcfa2014-11-14 15:54:10 +000052}
53
Stephen Boydbb487112017-12-13 14:19:37 -080054static bool __maybe_unused
55is_kryo_midr(const struct arm64_cpu_capabilities *entry, int scope)
56{
57 u32 model;
58
59 WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
60
61 model = read_cpuid_id();
62 model &= MIDR_IMPLEMENTOR_MASK | (0xf00 << MIDR_PARTNUM_SHIFT) |
63 MIDR_ARCHITECTURE_MASK;
64
Suzuki K Poulose1df31052018-03-26 15:12:44 +010065 return model == entry->midr_range.model;
Stephen Boydbb487112017-12-13 14:19:37 -080066}
67
Suzuki K Poulose116c81f2016-09-09 14:07:16 +010068static bool
Suzuki K Poulose314d53d2018-07-04 23:07:46 +010069has_mismatched_cache_type(const struct arm64_cpu_capabilities *entry,
70 int scope)
Suzuki K Poulose116c81f2016-09-09 14:07:16 +010071{
Suzuki K Poulose1602df02018-10-09 14:47:06 +010072 u64 mask = arm64_ftr_reg_ctrel0.strict_mask;
73 u64 sys = arm64_ftr_reg_ctrel0.sys_val & mask;
74 u64 ctr_raw, ctr_real;
Suzuki K Poulose314d53d2018-07-04 23:07:46 +010075
Suzuki K Poulose116c81f2016-09-09 14:07:16 +010076 WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
Suzuki K Poulose1602df02018-10-09 14:47:06 +010077
78 /*
79 * We want to make sure that all the CPUs in the system expose
80 * a consistent CTR_EL0 to make sure that applications behaves
81 * correctly with migration.
82 *
83 * If a CPU has CTR_EL0.IDC but does not advertise it via CTR_EL0 :
84 *
85 * 1) It is safe if the system doesn't support IDC, as CPU anyway
86 * reports IDC = 0, consistent with the rest.
87 *
88 * 2) If the system has IDC, it is still safe as we trap CTR_EL0
89 * access on this CPU via the ARM64_HAS_CACHE_IDC capability.
90 *
91 * So, we need to make sure either the raw CTR_EL0 or the effective
92 * CTR_EL0 matches the system's copy to allow a secondary CPU to boot.
93 */
94 ctr_raw = read_cpuid_cachetype() & mask;
95 ctr_real = read_cpuid_effective_cachetype() & mask;
96
97 return (ctr_real != sys) && (ctr_raw != sys);
Suzuki K Poulose116c81f2016-09-09 14:07:16 +010098}
99
Dave Martinc0cda3b2018-03-26 15:12:28 +0100100static void
101cpu_enable_trap_ctr_access(const struct arm64_cpu_capabilities *__unused)
Suzuki K Poulose116c81f2016-09-09 14:07:16 +0100102{
Suzuki K Poulose4afe8e72018-10-09 14:47:07 +0100103 u64 mask = arm64_ftr_reg_ctrel0.strict_mask;
104
105 /* Trap CTR_EL0 access on this CPU, only if it has a mismatch */
106 if ((read_cpuid_cachetype() & mask) !=
107 (arm64_ftr_reg_ctrel0.sys_val & mask))
108 sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0);
Suzuki K Poulose116c81f2016-09-09 14:07:16 +0100109}
110
Marc Zyngier4205a892018-03-13 12:40:39 +0000111atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1);
112
Will Deacon0f15adb2018-01-03 11:17:58 +0000113#include <asm/mmu_context.h>
114#include <asm/cacheflush.h>
115
116DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
117
Marc Zyngiere8b22d0f2018-04-10 11:36:45 +0100118#ifdef CONFIG_KVM_INDIRECT_VECTORS
Marc Zyngierb0922012018-02-06 17:56:20 +0000119extern char __smccc_workaround_1_smc_start[];
120extern char __smccc_workaround_1_smc_end[];
Will Deaconaa6acde2018-01-03 12:46:21 +0000121
Will Deacon0f15adb2018-01-03 11:17:58 +0000122static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start,
123 const char *hyp_vecs_end)
124{
125 void *dst = lm_alias(__bp_harden_hyp_vecs_start + slot * SZ_2K);
126 int i;
127
128 for (i = 0; i < SZ_2K; i += 0x80)
129 memcpy(dst + i, hyp_vecs_start, hyp_vecs_end - hyp_vecs_start);
130
Will Deacon3b8c9f12018-06-11 14:22:09 +0100131 __flush_icache_range((uintptr_t)dst, (uintptr_t)dst + SZ_2K);
Will Deacon0f15adb2018-01-03 11:17:58 +0000132}
133
Marc Zyngier73f38162019-04-15 16:21:23 -0500134static void install_bp_hardening_cb(bp_hardening_cb_t fn,
135 const char *hyp_vecs_start,
136 const char *hyp_vecs_end)
Will Deacon0f15adb2018-01-03 11:17:58 +0000137{
James Morsed8797b12018-11-27 15:35:21 +0000138 static DEFINE_RAW_SPINLOCK(bp_lock);
Will Deacon0f15adb2018-01-03 11:17:58 +0000139 int cpu, slot = -1;
140
James Morse4debef52018-09-21 21:49:19 +0100141 /*
142 * enable_smccc_arch_workaround_1() passes NULL for the hyp_vecs
143 * start/end if we're a guest. Skip the hyp-vectors work.
144 */
145 if (!hyp_vecs_start) {
146 __this_cpu_write(bp_hardening_data.fn, fn);
147 return;
148 }
149
James Morsed8797b12018-11-27 15:35:21 +0000150 raw_spin_lock(&bp_lock);
Will Deacon0f15adb2018-01-03 11:17:58 +0000151 for_each_possible_cpu(cpu) {
152 if (per_cpu(bp_hardening_data.fn, cpu) == fn) {
153 slot = per_cpu(bp_hardening_data.hyp_vectors_slot, cpu);
154 break;
155 }
156 }
157
158 if (slot == -1) {
Marc Zyngier4205a892018-03-13 12:40:39 +0000159 slot = atomic_inc_return(&arm64_el2_vector_last_slot);
160 BUG_ON(slot >= BP_HARDEN_EL2_SLOTS);
Will Deacon0f15adb2018-01-03 11:17:58 +0000161 __copy_hyp_vect_bpi(slot, hyp_vecs_start, hyp_vecs_end);
162 }
163
164 __this_cpu_write(bp_hardening_data.hyp_vectors_slot, slot);
165 __this_cpu_write(bp_hardening_data.fn, fn);
James Morsed8797b12018-11-27 15:35:21 +0000166 raw_spin_unlock(&bp_lock);
Will Deacon0f15adb2018-01-03 11:17:58 +0000167}
168#else
Marc Zyngierb0922012018-02-06 17:56:20 +0000169#define __smccc_workaround_1_smc_start NULL
170#define __smccc_workaround_1_smc_end NULL
Will Deaconaa6acde2018-01-03 12:46:21 +0000171
Marc Zyngier73f38162019-04-15 16:21:23 -0500172static void install_bp_hardening_cb(bp_hardening_cb_t fn,
Will Deacon0f15adb2018-01-03 11:17:58 +0000173 const char *hyp_vecs_start,
174 const char *hyp_vecs_end)
175{
176 __this_cpu_write(bp_hardening_data.fn, fn);
177}
Marc Zyngiere8b22d0f2018-04-10 11:36:45 +0100178#endif /* CONFIG_KVM_INDIRECT_VECTORS */
Will Deacon0f15adb2018-01-03 11:17:58 +0000179
Marc Zyngierb0922012018-02-06 17:56:20 +0000180#include <uapi/linux/psci.h>
181#include <linux/arm-smccc.h>
Will Deaconaa6acde2018-01-03 12:46:21 +0000182#include <linux/psci.h>
183
Marc Zyngierb0922012018-02-06 17:56:20 +0000184static void call_smc_arch_workaround_1(void)
185{
186 arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
187}
188
189static void call_hvc_arch_workaround_1(void)
190{
191 arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
192}
193
Shanker Donthineni4bc352f2018-04-10 11:36:42 +0100194static void qcom_link_stack_sanitization(void)
195{
196 u64 tmp;
197
198 asm volatile("mov %0, x30 \n"
199 ".rept 16 \n"
200 "bl . + 4 \n"
201 ".endr \n"
202 "mov x30, %0 \n"
203 : "=&r" (tmp));
204}
205
Jeremy Lintone5ce5e72019-04-15 16:21:20 -0500206static bool __nospectre_v2;
207static int __init parse_nospectre_v2(char *str)
208{
209 __nospectre_v2 = true;
210 return 0;
211}
212early_param("nospectre_v2", parse_nospectre_v2);
213
Marc Zyngier73f38162019-04-15 16:21:23 -0500214/*
215 * -1: No workaround
216 * 0: No workaround required
217 * 1: Workaround installed
218 */
219static int detect_harden_bp_fw(void)
Marc Zyngierb0922012018-02-06 17:56:20 +0000220{
221 bp_hardening_cb_t cb;
222 void *smccc_start, *smccc_end;
223 struct arm_smccc_res res;
Shanker Donthineni4bc352f2018-04-10 11:36:42 +0100224 u32 midr = read_cpuid_id();
Marc Zyngierb0922012018-02-06 17:56:20 +0000225
Marc Zyngierb0922012018-02-06 17:56:20 +0000226 if (psci_ops.smccc_version == SMCCC_VERSION_1_0)
Marc Zyngier73f38162019-04-15 16:21:23 -0500227 return -1;
Marc Zyngierb0922012018-02-06 17:56:20 +0000228
229 switch (psci_ops.conduit) {
230 case PSCI_CONDUIT_HVC:
231 arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
232 ARM_SMCCC_ARCH_WORKAROUND_1, &res);
Marc Zyngier517953c2019-04-15 16:21:24 -0500233 switch ((int)res.a0) {
234 case 1:
235 /* Firmware says we're just fine */
236 return 0;
237 case 0:
238 cb = call_hvc_arch_workaround_1;
239 /* This is a guest, no need to patch KVM vectors */
240 smccc_start = NULL;
241 smccc_end = NULL;
242 break;
243 default:
Marc Zyngier73f38162019-04-15 16:21:23 -0500244 return -1;
Marc Zyngier517953c2019-04-15 16:21:24 -0500245 }
Marc Zyngierb0922012018-02-06 17:56:20 +0000246 break;
247
248 case PSCI_CONDUIT_SMC:
249 arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
250 ARM_SMCCC_ARCH_WORKAROUND_1, &res);
Marc Zyngier517953c2019-04-15 16:21:24 -0500251 switch ((int)res.a0) {
252 case 1:
253 /* Firmware says we're just fine */
254 return 0;
255 case 0:
256 cb = call_smc_arch_workaround_1;
257 smccc_start = __smccc_workaround_1_smc_start;
258 smccc_end = __smccc_workaround_1_smc_end;
259 break;
260 default:
Marc Zyngier73f38162019-04-15 16:21:23 -0500261 return -1;
Marc Zyngier517953c2019-04-15 16:21:24 -0500262 }
Marc Zyngierb0922012018-02-06 17:56:20 +0000263 break;
264
265 default:
Marc Zyngier73f38162019-04-15 16:21:23 -0500266 return -1;
Marc Zyngierb0922012018-02-06 17:56:20 +0000267 }
268
Shanker Donthineni4bc352f2018-04-10 11:36:42 +0100269 if (((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR) ||
270 ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1))
271 cb = qcom_link_stack_sanitization;
272
Jeremy Linton8c1e3d22019-04-15 16:21:25 -0500273 if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR))
274 install_bp_hardening_cb(cb, smccc_start, smccc_end);
Marc Zyngierb0922012018-02-06 17:56:20 +0000275
Marc Zyngier73f38162019-04-15 16:21:23 -0500276 return 1;
Will Deaconaa6acde2018-01-03 12:46:21 +0000277}
Will Deacon0f15adb2018-01-03 11:17:58 +0000278
Marc Zyngier5cf9ce62018-05-29 13:11:07 +0100279DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
280
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100281int ssbd_state __read_mostly = ARM64_SSBD_KERNEL;
Jeremy Linton526e0652019-04-15 16:21:28 -0500282static bool __ssb_safe = true;
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100283
284static const struct ssbd_options {
285 const char *str;
286 int state;
287} ssbd_options[] = {
288 { "force-on", ARM64_SSBD_FORCE_ENABLE, },
289 { "force-off", ARM64_SSBD_FORCE_DISABLE, },
290 { "kernel", ARM64_SSBD_KERNEL, },
291};
292
293static int __init ssbd_cfg(char *buf)
294{
295 int i;
296
297 if (!buf || !buf[0])
298 return -EINVAL;
299
300 for (i = 0; i < ARRAY_SIZE(ssbd_options); i++) {
301 int len = strlen(ssbd_options[i].str);
302
303 if (strncmp(buf, ssbd_options[i].str, len))
304 continue;
305
306 ssbd_state = ssbd_options[i].state;
307 return 0;
308 }
309
310 return -EINVAL;
311}
312early_param("ssbd", ssbd_cfg);
313
Marc Zyngier8e290622018-05-29 13:11:06 +0100314void __init arm64_update_smccc_conduit(struct alt_instr *alt,
315 __le32 *origptr, __le32 *updptr,
316 int nr_inst)
317{
318 u32 insn;
319
320 BUG_ON(nr_inst != 1);
321
322 switch (psci_ops.conduit) {
323 case PSCI_CONDUIT_HVC:
324 insn = aarch64_insn_get_hvc_value();
325 break;
326 case PSCI_CONDUIT_SMC:
327 insn = aarch64_insn_get_smc_value();
328 break;
329 default:
330 return;
331 }
332
333 *updptr = cpu_to_le32(insn);
334}
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100335
Marc Zyngier986372c2018-05-29 13:11:11 +0100336void __init arm64_enable_wa2_handling(struct alt_instr *alt,
337 __le32 *origptr, __le32 *updptr,
338 int nr_inst)
339{
340 BUG_ON(nr_inst != 1);
341 /*
342 * Only allow mitigation on EL1 entry/exit and guest
343 * ARCH_WORKAROUND_2 handling if the SSBD state allows it to
344 * be flipped.
345 */
346 if (arm64_get_ssbd_state() == ARM64_SSBD_KERNEL)
347 *updptr = cpu_to_le32(aarch64_insn_gen_nop());
348}
349
Marc Zyngier647d0512018-05-29 13:11:12 +0100350void arm64_set_ssbd_mitigation(bool state)
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100351{
Jeremy Lintond42281b2019-04-15 16:21:27 -0500352 if (!IS_ENABLED(CONFIG_ARM64_SSBD)) {
353 pr_info_once("SSBD disabled by kernel configuration\n");
354 return;
355 }
356
Will Deacon8f04e8e2018-08-07 13:47:06 +0100357 if (this_cpu_has_cap(ARM64_SSBS)) {
358 if (state)
359 asm volatile(SET_PSTATE_SSBS(0));
360 else
361 asm volatile(SET_PSTATE_SSBS(1));
362 return;
363 }
364
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100365 switch (psci_ops.conduit) {
366 case PSCI_CONDUIT_HVC:
367 arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_2, state, NULL);
368 break;
369
370 case PSCI_CONDUIT_SMC:
371 arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, state, NULL);
372 break;
373
374 default:
375 WARN_ON_ONCE(1);
376 break;
377 }
378}
379
380static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
381 int scope)
382{
383 struct arm_smccc_res res;
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100384 bool required = true;
385 s32 val;
Jeremy Linton526e0652019-04-15 16:21:28 -0500386 bool this_cpu_safe = false;
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100387
388 WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
389
Josh Poimboeufa111b7c2019-04-12 15:39:32 -0500390 if (cpu_mitigations_off())
391 ssbd_state = ARM64_SSBD_FORCE_DISABLE;
392
Jeremy Linton526e0652019-04-15 16:21:28 -0500393 /* delay setting __ssb_safe until we get a firmware response */
394 if (is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list))
395 this_cpu_safe = true;
396
Will Deaconeb337cd2019-04-30 16:58:56 +0100397 if (this_cpu_has_cap(ARM64_SSBS)) {
398 if (!this_cpu_safe)
399 __ssb_safe = false;
400 required = false;
401 goto out_printmsg;
402 }
403
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100404 if (psci_ops.smccc_version == SMCCC_VERSION_1_0) {
405 ssbd_state = ARM64_SSBD_UNKNOWN;
Jeremy Linton526e0652019-04-15 16:21:28 -0500406 if (!this_cpu_safe)
407 __ssb_safe = false;
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100408 return false;
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100409 }
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100410
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100411 switch (psci_ops.conduit) {
412 case PSCI_CONDUIT_HVC:
413 arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
414 ARM_SMCCC_ARCH_WORKAROUND_2, &res);
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100415 break;
416
417 case PSCI_CONDUIT_SMC:
418 arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
419 ARM_SMCCC_ARCH_WORKAROUND_2, &res);
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100420 break;
421
422 default:
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100423 ssbd_state = ARM64_SSBD_UNKNOWN;
Jeremy Linton526e0652019-04-15 16:21:28 -0500424 if (!this_cpu_safe)
425 __ssb_safe = false;
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100426 return false;
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100427 }
428
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100429 val = (s32)res.a0;
430
431 switch (val) {
432 case SMCCC_RET_NOT_SUPPORTED:
433 ssbd_state = ARM64_SSBD_UNKNOWN;
Jeremy Linton526e0652019-04-15 16:21:28 -0500434 if (!this_cpu_safe)
435 __ssb_safe = false;
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100436 return false;
437
Jeremy Linton526e0652019-04-15 16:21:28 -0500438 /* machines with mixed mitigation requirements must not return this */
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100439 case SMCCC_RET_NOT_REQUIRED:
440 pr_info_once("%s mitigation not required\n", entry->desc);
441 ssbd_state = ARM64_SSBD_MITIGATED;
442 return false;
443
444 case SMCCC_RET_SUCCESS:
Jeremy Linton526e0652019-04-15 16:21:28 -0500445 __ssb_safe = false;
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100446 required = true;
447 break;
448
449 case 1: /* Mitigation not required on this CPU */
450 required = false;
451 break;
452
453 default:
454 WARN_ON(1);
Jeremy Linton526e0652019-04-15 16:21:28 -0500455 if (!this_cpu_safe)
456 __ssb_safe = false;
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100457 return false;
458 }
459
460 switch (ssbd_state) {
461 case ARM64_SSBD_FORCE_DISABLE:
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100462 arm64_set_ssbd_mitigation(false);
463 required = false;
464 break;
465
466 case ARM64_SSBD_KERNEL:
467 if (required) {
468 __this_cpu_write(arm64_ssbd_callback_required, 1);
469 arm64_set_ssbd_mitigation(true);
470 }
471 break;
472
473 case ARM64_SSBD_FORCE_ENABLE:
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100474 arm64_set_ssbd_mitigation(true);
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100475 required = true;
476 break;
477
478 default:
479 WARN_ON(1);
480 break;
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100481 }
482
Will Deacon8f04e8e2018-08-07 13:47:06 +0100483out_printmsg:
484 switch (ssbd_state) {
485 case ARM64_SSBD_FORCE_DISABLE:
486 pr_info_once("%s disabled from command-line\n", entry->desc);
487 break;
488
489 case ARM64_SSBD_FORCE_ENABLE:
490 pr_info_once("%s forced from command-line\n", entry->desc);
491 break;
492 }
493
Marc Zyngiera43ae4d2018-05-29 13:11:09 +0100494 return required;
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100495}
Marc Zyngier8e290622018-05-29 13:11:06 +0100496
Jeremy Linton526e0652019-04-15 16:21:28 -0500497/* known invulnerable cores */
498static const struct midr_range arm64_ssb_cpus[] = {
499 MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
500 MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
501 MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
502 {},
503};
504
Will Deaconb8925ee2018-08-07 13:53:41 +0100505static void __maybe_unused
506cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused)
507{
508 sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCI, 0);
509}
510
Suzuki K Poulose5e7951c2018-03-26 15:12:43 +0100511#define CAP_MIDR_RANGE(model, v_min, r_min, v_max, r_max) \
512 .matches = is_affected_midr_range, \
Suzuki K Poulose1df31052018-03-26 15:12:44 +0100513 .midr_range = MIDR_RANGE(model, v_min, r_min, v_max, r_max)
Andre Przywara301bcfa2014-11-14 15:54:10 +0000514
Suzuki K Poulose5e7951c2018-03-26 15:12:43 +0100515#define CAP_MIDR_ALL_VERSIONS(model) \
516 .matches = is_affected_midr_range, \
Suzuki K Poulose1df31052018-03-26 15:12:44 +0100517 .midr_range = MIDR_ALL_VERSIONS(model)
Marc Zyngier06f14942017-02-01 14:38:46 +0000518
Ard Biesheuvele8002e02018-03-06 17:15:34 +0000519#define MIDR_FIXED(rev, revidr_mask) \
520 .fixed_revs = (struct arm64_midr_revidr[]){{ (rev), (revidr_mask) }, {}}
521
Suzuki K Poulose5e7951c2018-03-26 15:12:43 +0100522#define ERRATA_MIDR_RANGE(model, v_min, r_min, v_max, r_max) \
523 .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \
524 CAP_MIDR_RANGE(model, v_min, r_min, v_max, r_max)
525
Suzuki K Poulosebe5b2992018-03-26 15:12:45 +0100526#define CAP_MIDR_RANGE_LIST(list) \
527 .matches = is_affected_midr_range_list, \
528 .midr_range_list = list
529
Suzuki K Poulose5e7951c2018-03-26 15:12:43 +0100530/* Errata affecting a range of revisions of given model variant */
531#define ERRATA_MIDR_REV_RANGE(m, var, r_min, r_max) \
532 ERRATA_MIDR_RANGE(m, var, r_min, var, r_max)
533
534/* Errata affecting a single variant/revision of a model */
535#define ERRATA_MIDR_REV(model, var, rev) \
536 ERRATA_MIDR_RANGE(model, var, rev, var, rev)
537
538/* Errata affecting all variants/revisions of a given a model */
539#define ERRATA_MIDR_ALL_VERSIONS(model) \
540 .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \
541 CAP_MIDR_ALL_VERSIONS(model)
542
Suzuki K Poulosebe5b2992018-03-26 15:12:45 +0100543/* Errata affecting a list of midr ranges, with same work around */
544#define ERRATA_MIDR_RANGE_LIST(midr_list) \
545 .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \
546 CAP_MIDR_RANGE_LIST(midr_list)
547
Jeremy Lintond2532e22019-04-15 16:21:26 -0500548/* Track overall mitigation state. We are only mitigated if all cores are ok */
549static bool __hardenbp_enab = true;
550static bool __spectrev2_safe = true;
551
Suzuki K Poulosebe5b2992018-03-26 15:12:45 +0100552/*
Marc Zyngier73f38162019-04-15 16:21:23 -0500553 * List of CPUs that do not need any Spectre-v2 mitigation at all.
Suzuki K Poulosebe5b2992018-03-26 15:12:45 +0100554 */
Marc Zyngier73f38162019-04-15 16:21:23 -0500555static const struct midr_range spectre_v2_safe_list[] = {
556 MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
557 MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
558 MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
559 { /* sentinel */ }
Suzuki K Poulosebe5b2992018-03-26 15:12:45 +0100560};
561
Jeremy Lintond2532e22019-04-15 16:21:26 -0500562/*
563 * Track overall bp hardening for all heterogeneous cores in the machine.
564 * We are only considered "safe" if all booted cores are known safe.
565 */
Marc Zyngier73f38162019-04-15 16:21:23 -0500566static bool __maybe_unused
567check_branch_predictor(const struct arm64_cpu_capabilities *entry, int scope)
568{
569 int need_wa;
570
571 WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
572
573 /* If the CPU has CSV2 set, we're safe */
574 if (cpuid_feature_extract_unsigned_field(read_cpuid(ID_AA64PFR0_EL1),
575 ID_AA64PFR0_CSV2_SHIFT))
576 return false;
577
578 /* Alternatively, we have a list of unaffected CPUs */
579 if (is_midr_in_range_list(read_cpuid_id(), spectre_v2_safe_list))
580 return false;
581
582 /* Fallback to firmware detection */
583 need_wa = detect_harden_bp_fw();
584 if (!need_wa)
585 return false;
586
Jeremy Lintond2532e22019-04-15 16:21:26 -0500587 __spectrev2_safe = false;
588
Jeremy Linton8c1e3d22019-04-15 16:21:25 -0500589 if (!IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR)) {
590 pr_warn_once("spectrev2 mitigation disabled by kernel configuration\n");
591 __hardenbp_enab = false;
592 return false;
593 }
594
Marc Zyngier73f38162019-04-15 16:21:23 -0500595 /* forced off */
Josh Poimboeufa111b7c2019-04-12 15:39:32 -0500596 if (__nospectre_v2 || cpu_mitigations_off()) {
Marc Zyngier73f38162019-04-15 16:21:23 -0500597 pr_info_once("spectrev2 mitigation disabled by command line option\n");
Jeremy Lintond2532e22019-04-15 16:21:26 -0500598 __hardenbp_enab = false;
Marc Zyngier73f38162019-04-15 16:21:23 -0500599 return false;
600 }
601
Jeremy Lintond2532e22019-04-15 16:21:26 -0500602 if (need_wa < 0) {
Marc Zyngier73f38162019-04-15 16:21:23 -0500603 pr_warn_once("ARM_SMCCC_ARCH_WORKAROUND_1 missing from firmware\n");
Jeremy Lintond2532e22019-04-15 16:21:26 -0500604 __hardenbp_enab = false;
605 }
Marc Zyngier73f38162019-04-15 16:21:23 -0500606
607 return (need_wa > 0);
608}
Andre Przywara301bcfa2014-11-14 15:54:10 +0000609
Marc Zyngier8892b712018-04-10 11:36:43 +0100610#ifdef CONFIG_HARDEN_EL2_VECTORS
611
612static const struct midr_range arm64_harden_el2_vectors[] = {
613 MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
614 MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
615 {},
616};
617
Marc Zyngierdc6ed612018-03-28 12:46:07 +0100618#endif
619
Catalin Marinasce8c80c2018-11-19 11:27:28 +0000620#ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI
621
622static const struct midr_range arm64_repeat_tlbi_cpus[] = {
623#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1009
624 MIDR_RANGE(MIDR_QCOM_FALKOR_V1, 0, 0, 0, 0),
625#endif
626#ifdef CONFIG_ARM64_ERRATUM_1286807
627 MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 3, 0),
628#endif
629 {},
630};
631
632#endif
633
Suzuki K Poulosef58cdf72018-11-30 17:18:01 +0000634#ifdef CONFIG_CAVIUM_ERRATUM_27456
Will Deaconb89d82e2019-01-08 16:19:01 +0000635const struct midr_range cavium_erratum_27456_cpus[] = {
Suzuki K Poulosef58cdf72018-11-30 17:18:01 +0000636 /* Cavium ThunderX, T88 pass 1.x - 2.1 */
637 MIDR_RANGE(MIDR_THUNDERX, 0, 0, 1, 1),
638 /* Cavium ThunderX, T81 pass 1.0 */
639 MIDR_REV(MIDR_THUNDERX_81XX, 0, 0),
640 {},
641};
642#endif
643
644#ifdef CONFIG_CAVIUM_ERRATUM_30115
645static const struct midr_range cavium_erratum_30115_cpus[] = {
646 /* Cavium ThunderX, T88 pass 1.x - 2.2 */
647 MIDR_RANGE(MIDR_THUNDERX, 0, 0, 1, 2),
648 /* Cavium ThunderX, T81 pass 1.0 - 1.2 */
649 MIDR_REV_RANGE(MIDR_THUNDERX_81XX, 0, 0, 2),
650 /* Cavium ThunderX, T83 pass 1.0 */
651 MIDR_REV(MIDR_THUNDERX_83XX, 0, 0),
652 {},
653};
654#endif
655
Suzuki K Poulosea3dcea2c2018-11-30 17:18:02 +0000656#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1003
657static const struct arm64_cpu_capabilities qcom_erratum_1003_list[] = {
658 {
659 ERRATA_MIDR_REV(MIDR_QCOM_FALKOR_V1, 0, 0),
660 },
661 {
662 .midr_range.model = MIDR_QCOM_KRYO,
663 .matches = is_kryo_midr,
664 },
665 {},
666};
667#endif
668
Suzuki K Poulosec9460dc2018-11-30 17:18:00 +0000669#ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE
670static const struct midr_range workaround_clean_cache[] = {
Andre Przywarae116a372014-11-14 15:54:09 +0000671#if defined(CONFIG_ARM64_ERRATUM_826319) || \
672 defined(CONFIG_ARM64_ERRATUM_827319) || \
673 defined(CONFIG_ARM64_ERRATUM_824069)
Suzuki K Poulosec9460dc2018-11-30 17:18:00 +0000674 /* Cortex-A53 r0p[012]: ARM errata 826319, 827319, 824069 */
675 MIDR_REV_RANGE(MIDR_CORTEX_A53, 0, 0, 2),
Andre Przywarac0a01b82014-11-14 15:54:12 +0000676#endif
Suzuki K Poulosec9460dc2018-11-30 17:18:00 +0000677#ifdef CONFIG_ARM64_ERRATUM_819472
678 /* Cortex-A53 r0p[01] : ARM errata 819472 */
679 MIDR_REV_RANGE(MIDR_CORTEX_A53, 0, 0, 1),
680#endif
681 {},
682};
683#endif
684
685const struct arm64_cpu_capabilities arm64_errata[] = {
686#ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE
Andre Przywarac0a01b82014-11-14 15:54:12 +0000687 {
Suzuki K Poulosec9460dc2018-11-30 17:18:00 +0000688 .desc = "ARM errata 826319, 827319, 824069, 819472",
Andre Przywarac0a01b82014-11-14 15:54:12 +0000689 .capability = ARM64_WORKAROUND_CLEAN_CACHE,
Suzuki K Poulosec9460dc2018-11-30 17:18:00 +0000690 ERRATA_MIDR_RANGE_LIST(workaround_clean_cache),
Dave Martinc0cda3b2018-03-26 15:12:28 +0100691 .cpu_enable = cpu_enable_cache_maint_trap,
Andre Przywarac0a01b82014-11-14 15:54:12 +0000692 },
693#endif
694#ifdef CONFIG_ARM64_ERRATUM_832075
Andre Przywara301bcfa2014-11-14 15:54:10 +0000695 {
Andre Przywara5afaa1f2014-11-14 15:54:11 +0000696 /* Cortex-A57 r0p0 - r1p2 */
697 .desc = "ARM erratum 832075",
698 .capability = ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE,
Suzuki K Poulose5e7951c2018-03-26 15:12:43 +0100699 ERRATA_MIDR_RANGE(MIDR_CORTEX_A57,
700 0, 0,
701 1, 2),
Andre Przywara5afaa1f2014-11-14 15:54:11 +0000702 },
Andre Przywarac0a01b82014-11-14 15:54:12 +0000703#endif
Marc Zyngier498cd5c2015-11-16 10:28:18 +0000704#ifdef CONFIG_ARM64_ERRATUM_834220
705 {
706 /* Cortex-A57 r0p0 - r1p2 */
707 .desc = "ARM erratum 834220",
708 .capability = ARM64_WORKAROUND_834220,
Suzuki K Poulose5e7951c2018-03-26 15:12:43 +0100709 ERRATA_MIDR_RANGE(MIDR_CORTEX_A57,
710 0, 0,
711 1, 2),
Marc Zyngier498cd5c2015-11-16 10:28:18 +0000712 },
713#endif
Ard Biesheuvelca79acc2018-03-06 17:15:35 +0000714#ifdef CONFIG_ARM64_ERRATUM_843419
715 {
716 /* Cortex-A53 r0p[01234] */
717 .desc = "ARM erratum 843419",
718 .capability = ARM64_WORKAROUND_843419,
Suzuki K Poulose5e7951c2018-03-26 15:12:43 +0100719 ERRATA_MIDR_REV_RANGE(MIDR_CORTEX_A53, 0, 0, 4),
Ard Biesheuvelca79acc2018-03-06 17:15:35 +0000720 MIDR_FIXED(0x4, BIT(8)),
Will Deacon905e8c52015-03-23 19:07:02 +0000721 },
Robert Richter6d4e11c2015-09-21 22:58:35 +0200722#endif
723#ifdef CONFIG_ARM64_ERRATUM_845719
724 {
725 /* Cortex-A53 r0p[01234] */
726 .desc = "ARM erratum 845719",
727 .capability = ARM64_WORKAROUND_845719,
Suzuki K Poulose5e7951c2018-03-26 15:12:43 +0100728 ERRATA_MIDR_REV_RANGE(MIDR_CORTEX_A53, 0, 0, 4),
Marc Zyngier359b7062015-03-27 13:09:23 +0000729 },
Andre Przywarae116a372014-11-14 15:54:09 +0000730#endif
Robert Richter6d4e11c2015-09-21 22:58:35 +0200731#ifdef CONFIG_CAVIUM_ERRATUM_23154
732 {
733 /* Cavium ThunderX, pass 1.x */
734 .desc = "Cavium erratum 23154",
735 .capability = ARM64_WORKAROUND_CAVIUM_23154,
Suzuki K Poulose5e7951c2018-03-26 15:12:43 +0100736 ERRATA_MIDR_REV_RANGE(MIDR_THUNDERX, 0, 0, 1),
Robert Richter6d4e11c2015-09-21 22:58:35 +0200737 },
738#endif
Andrew Pinski104a0c02016-02-24 17:44:57 -0800739#ifdef CONFIG_CAVIUM_ERRATUM_27456
740 {
Andrew Pinski104a0c02016-02-24 17:44:57 -0800741 .desc = "Cavium erratum 27456",
742 .capability = ARM64_WORKAROUND_CAVIUM_27456,
Suzuki K Poulosef58cdf72018-11-30 17:18:01 +0000743 ERRATA_MIDR_RANGE_LIST(cavium_erratum_27456_cpus),
Ganapatrao Kulkarni47c459b2016-07-07 10:18:17 +0530744 },
Andrew Pinski104a0c02016-02-24 17:44:57 -0800745#endif
David Daney690a3412017-06-09 12:49:48 +0100746#ifdef CONFIG_CAVIUM_ERRATUM_30115
747 {
David Daney690a3412017-06-09 12:49:48 +0100748 .desc = "Cavium erratum 30115",
749 .capability = ARM64_WORKAROUND_CAVIUM_30115,
Suzuki K Poulosef58cdf72018-11-30 17:18:01 +0000750 ERRATA_MIDR_RANGE_LIST(cavium_erratum_30115_cpus),
David Daney690a3412017-06-09 12:49:48 +0100751 },
752#endif
Andre Przywarae116a372014-11-14 15:54:09 +0000753 {
Will Deacon880f7cc2018-09-19 11:41:21 +0100754 .desc = "Mismatched cache type (CTR_EL0)",
Suzuki K Poulose314d53d2018-07-04 23:07:46 +0100755 .capability = ARM64_MISMATCHED_CACHE_TYPE,
756 .matches = has_mismatched_cache_type,
Suzuki K Poulose5b4747c2018-03-26 15:12:32 +0100757 .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
Dave Martinc0cda3b2018-03-26 15:12:28 +0100758 .cpu_enable = cpu_enable_trap_ctr_access,
Suzuki K Poulose116c81f2016-09-09 14:07:16 +0100759 },
Christopher Covington38fd94b2017-02-08 15:08:37 -0500760#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1003
761 {
Suzuki K Poulosea3dcea2c2018-11-30 17:18:02 +0000762 .desc = "Qualcomm Technologies Falkor/Kryo erratum 1003",
Christopher Covington38fd94b2017-02-08 15:08:37 -0500763 .capability = ARM64_WORKAROUND_QCOM_FALKOR_E1003,
Will Deacon1e013d02018-12-12 15:53:54 +0000764 .matches = cpucap_multi_entry_cap_matches,
Suzuki K Poulosea3dcea2c2018-11-30 17:18:02 +0000765 .match_list = qcom_erratum_1003_list,
Stephen Boydbb487112017-12-13 14:19:37 -0800766 },
Christopher Covington38fd94b2017-02-08 15:08:37 -0500767#endif
Catalin Marinasce8c80c2018-11-19 11:27:28 +0000768#ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI
Christopher Covingtond9ff80f2017-01-31 12:50:19 -0500769 {
Catalin Marinasce8c80c2018-11-19 11:27:28 +0000770 .desc = "Qualcomm erratum 1009, ARM erratum 1286807",
Christopher Covingtond9ff80f2017-01-31 12:50:19 -0500771 .capability = ARM64_WORKAROUND_REPEAT_TLBI,
Catalin Marinasce8c80c2018-11-19 11:27:28 +0000772 ERRATA_MIDR_RANGE_LIST(arm64_repeat_tlbi_cpus),
Christopher Covingtond9ff80f2017-01-31 12:50:19 -0500773 },
774#endif
Marc Zyngiereeb1efb2017-03-20 17:18:06 +0000775#ifdef CONFIG_ARM64_ERRATUM_858921
776 {
777 /* Cortex-A73 all versions */
778 .desc = "ARM erratum 858921",
779 .capability = ARM64_WORKAROUND_858921,
Suzuki K Poulose5e7951c2018-03-26 15:12:43 +0100780 ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
Marc Zyngiereeb1efb2017-03-20 17:18:06 +0000781 },
782#endif
Will Deaconaa6acde2018-01-03 12:46:21 +0000783 {
784 .capability = ARM64_HARDEN_BRANCH_PREDICTOR,
Marc Zyngier73f38162019-04-15 16:21:23 -0500785 .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
786 .matches = check_branch_predictor,
Jayachandran Cf3d795d2018-01-19 04:22:47 -0800787 },
Marc Zyngier4b472ff2018-02-15 11:49:20 +0000788#ifdef CONFIG_HARDEN_EL2_VECTORS
789 {
Marc Zyngier8892b712018-04-10 11:36:43 +0100790 .desc = "EL2 vector hardening",
Marc Zyngier4b472ff2018-02-15 11:49:20 +0000791 .capability = ARM64_HARDEN_EL2_VECTORS,
Marc Zyngier8892b712018-04-10 11:36:43 +0100792 ERRATA_MIDR_RANGE_LIST(arm64_harden_el2_vectors),
Marc Zyngier4b472ff2018-02-15 11:49:20 +0000793 },
794#endif
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100795 {
796 .desc = "Speculative Store Bypass Disable",
797 .capability = ARM64_SSBD,
798 .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
799 .matches = has_ssbd_mitigation,
Jeremy Linton526e0652019-04-15 16:21:28 -0500800 .midr_range_list = arm64_ssb_cpus,
Marc Zyngiera725e3d2018-05-29 13:11:08 +0100801 },
Marc Zyngier95b861a42018-09-27 17:15:34 +0100802#ifdef CONFIG_ARM64_ERRATUM_1188873
803 {
804 /* Cortex-A76 r0p0 to r2p0 */
805 .desc = "ARM erratum 1188873",
806 .capability = ARM64_WORKAROUND_1188873,
807 ERRATA_MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 2, 0),
808 },
809#endif
Marc Zyngier8b2cca92018-12-06 17:31:23 +0000810#ifdef CONFIG_ARM64_ERRATUM_1165522
811 {
812 /* Cortex-A76 r0p0 to r2p0 */
813 .desc = "ARM erratum 1165522",
814 .capability = ARM64_WORKAROUND_1165522,
815 ERRATA_MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 2, 0),
816 },
817#endif
Suzuki K Poulose116c81f2016-09-09 14:07:16 +0100818 {
Andre Przywarae116a372014-11-14 15:54:09 +0000819 }
820};
Mian Yousaf Kaukab3891ebc2019-04-15 16:21:21 -0500821
822ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr,
823 char *buf)
824{
825 return sprintf(buf, "Mitigation: __user pointer sanitization\n");
826}
Jeremy Lintond2532e22019-04-15 16:21:26 -0500827
828ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr,
829 char *buf)
830{
831 if (__spectrev2_safe)
832 return sprintf(buf, "Not affected\n");
833
834 if (__hardenbp_enab)
835 return sprintf(buf, "Mitigation: Branch predictor hardening\n");
836
837 return sprintf(buf, "Vulnerable\n");
838}
Jeremy Linton526e0652019-04-15 16:21:28 -0500839
840ssize_t cpu_show_spec_store_bypass(struct device *dev,
841 struct device_attribute *attr, char *buf)
842{
843 if (__ssb_safe)
844 return sprintf(buf, "Not affected\n");
845
846 switch (ssbd_state) {
847 case ARM64_SSBD_KERNEL:
848 case ARM64_SSBD_FORCE_ENABLE:
849 if (IS_ENABLED(CONFIG_ARM64_SSBD))
850 return sprintf(buf,
851 "Mitigation: Speculative Store Bypass disabled via prctl\n");
852 }
853
854 return sprintf(buf, "Vulnerable\n");
855}