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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Exception handling code
4 *
5 * Copyright (C) 2019 ARM Ltd.
6 */
7
8#include <linux/context_tracking.h>
9#include <linux/ptrace.h>
10#include <linux/thread_info.h>
11
12#include <asm/cpufeature.h>
13#include <asm/daifflags.h>
14#include <asm/esr.h>
15#include <asm/exception.h>
16#include <asm/kprobes.h>
17#include <asm/mmu.h>
18#include <asm/sysreg.h>
19
20static void notrace el1_abort(struct pt_regs *regs, unsigned long esr)
21{
22 unsigned long far = read_sysreg(far_el1);
23
24 local_daif_inherit(regs);
25 far = untagged_addr(far);
26 do_mem_abort(far, esr, regs);
27}
28NOKPROBE_SYMBOL(el1_abort);
29
30static void notrace el1_pc(struct pt_regs *regs, unsigned long esr)
31{
32 unsigned long far = read_sysreg(far_el1);
33
34 local_daif_inherit(regs);
35 do_sp_pc_abort(far, esr, regs);
36}
37NOKPROBE_SYMBOL(el1_pc);
38
39static void notrace el1_undef(struct pt_regs *regs)
40{
41 local_daif_inherit(regs);
42 do_undefinstr(regs);
43}
44NOKPROBE_SYMBOL(el1_undef);
45
46static void notrace el1_inv(struct pt_regs *regs, unsigned long esr)
47{
48 local_daif_inherit(regs);
49 bad_mode(regs, 0, esr);
50}
51NOKPROBE_SYMBOL(el1_inv);
52
53static void notrace el1_dbg(struct pt_regs *regs, unsigned long esr)
54{
55 unsigned long far = read_sysreg(far_el1);
56
57 /*
58 * The CPU masked interrupts, and we are leaving them masked during
59 * do_debug_exception(). Update PMR as if we had called
60 * local_daif_mask().
61 */
62 if (system_uses_irq_prio_masking())
63 gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
64
65 do_debug_exception(far, esr, regs);
66}
67NOKPROBE_SYMBOL(el1_dbg);
68
69asmlinkage void notrace el1_sync_handler(struct pt_regs *regs)
70{
71 unsigned long esr = read_sysreg(esr_el1);
72
73 switch (ESR_ELx_EC(esr)) {
74 case ESR_ELx_EC_DABT_CUR:
75 case ESR_ELx_EC_IABT_CUR:
76 el1_abort(regs, esr);
77 break;
78 /*
79 * We don't handle ESR_ELx_EC_SP_ALIGN, since we will have hit a
80 * recursive exception when trying to push the initial pt_regs.
81 */
82 case ESR_ELx_EC_PC_ALIGN:
83 el1_pc(regs, esr);
84 break;
85 case ESR_ELx_EC_SYS64:
86 case ESR_ELx_EC_UNKNOWN:
87 el1_undef(regs);
88 break;
89 case ESR_ELx_EC_BREAKPT_CUR:
90 case ESR_ELx_EC_SOFTSTP_CUR:
91 case ESR_ELx_EC_WATCHPT_CUR:
92 case ESR_ELx_EC_BRK64:
93 el1_dbg(regs, esr);
94 break;
95 default:
96 el1_inv(regs, esr);
97 }
98}
99NOKPROBE_SYMBOL(el1_sync_handler);
100
101static void notrace el0_da(struct pt_regs *regs, unsigned long esr)
102{
103 unsigned long far = read_sysreg(far_el1);
104
105 user_exit_irqoff();
106 local_daif_restore(DAIF_PROCCTX);
107 far = untagged_addr(far);
108 do_mem_abort(far, esr, regs);
109}
110NOKPROBE_SYMBOL(el0_da);
111
112static void notrace el0_ia(struct pt_regs *regs, unsigned long esr)
113{
114 unsigned long far = read_sysreg(far_el1);
115
116 /*
117 * We've taken an instruction abort from userspace and not yet
118 * re-enabled IRQs. If the address is a kernel address, apply
119 * BP hardening prior to enabling IRQs and pre-emption.
120 */
121 if (!is_ttbr0_addr(far))
122 arm64_apply_bp_hardening();
123
124 user_exit_irqoff();
125 local_daif_restore(DAIF_PROCCTX);
126 do_mem_abort(far, esr, regs);
127}
128NOKPROBE_SYMBOL(el0_ia);
129
130static void notrace el0_fpsimd_acc(struct pt_regs *regs, unsigned long esr)
131{
132 user_exit_irqoff();
133 local_daif_restore(DAIF_PROCCTX);
134 do_fpsimd_acc(esr, regs);
135}
136NOKPROBE_SYMBOL(el0_fpsimd_acc);
137
138static void notrace el0_sve_acc(struct pt_regs *regs, unsigned long esr)
139{
140 user_exit_irqoff();
141 local_daif_restore(DAIF_PROCCTX);
142 do_sve_acc(esr, regs);
143}
144NOKPROBE_SYMBOL(el0_sve_acc);
145
146static void notrace el0_fpsimd_exc(struct pt_regs *regs, unsigned long esr)
147{
148 user_exit_irqoff();
149 local_daif_restore(DAIF_PROCCTX);
150 do_fpsimd_exc(esr, regs);
151}
152NOKPROBE_SYMBOL(el0_fpsimd_exc);
153
154static void notrace el0_sys(struct pt_regs *regs, unsigned long esr)
155{
156 user_exit_irqoff();
157 local_daif_restore(DAIF_PROCCTX);
158 do_sysinstr(esr, regs);
159}
160NOKPROBE_SYMBOL(el0_sys);
161
162static void notrace el0_pc(struct pt_regs *regs, unsigned long esr)
163{
164 unsigned long far = read_sysreg(far_el1);
165
166 if (!is_ttbr0_addr(instruction_pointer(regs)))
167 arm64_apply_bp_hardening();
168
169 user_exit_irqoff();
170 local_daif_restore(DAIF_PROCCTX);
171 do_sp_pc_abort(far, esr, regs);
172}
173NOKPROBE_SYMBOL(el0_pc);
174
175static void notrace el0_sp(struct pt_regs *regs, unsigned long esr)
176{
177 user_exit_irqoff();
178 local_daif_restore(DAIF_PROCCTX);
179 do_sp_pc_abort(regs->sp, esr, regs);
180}
181NOKPROBE_SYMBOL(el0_sp);
182
183static void notrace el0_undef(struct pt_regs *regs)
184{
185 user_exit_irqoff();
186 local_daif_restore(DAIF_PROCCTX);
187 do_undefinstr(regs);
188}
189NOKPROBE_SYMBOL(el0_undef);
190
191static void notrace el0_bti(struct pt_regs *regs)
192{
193 user_exit_irqoff();
194 local_daif_restore(DAIF_PROCCTX);
195 do_bti(regs);
196}
197NOKPROBE_SYMBOL(el0_bti);
198
199static void notrace el0_inv(struct pt_regs *regs, unsigned long esr)
200{
201 user_exit_irqoff();
202 local_daif_restore(DAIF_PROCCTX);
203 bad_el0_sync(regs, 0, esr);
204}
205NOKPROBE_SYMBOL(el0_inv);
206
207static void notrace el0_dbg(struct pt_regs *regs, unsigned long esr)
208{
209 /* Only watchpoints write FAR_EL1, otherwise its UNKNOWN */
210 unsigned long far = read_sysreg(far_el1);
211
212 if (system_uses_irq_prio_masking())
213 gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
214
215 user_exit_irqoff();
216 do_debug_exception(far, esr, regs);
217 local_daif_restore(DAIF_PROCCTX_NOIRQ);
218}
219NOKPROBE_SYMBOL(el0_dbg);
220
221static void notrace el0_svc(struct pt_regs *regs)
222{
223 if (system_uses_irq_prio_masking())
224 gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
225
226 do_el0_svc(regs);
227}
228NOKPROBE_SYMBOL(el0_svc);
229
230asmlinkage void notrace el0_sync_handler(struct pt_regs *regs)
231{
232 unsigned long esr = read_sysreg(esr_el1);
233
234 switch (ESR_ELx_EC(esr)) {
235 case ESR_ELx_EC_SVC64:
236 el0_svc(regs);
237 break;
238 case ESR_ELx_EC_DABT_LOW:
239 el0_da(regs, esr);
240 break;
241 case ESR_ELx_EC_IABT_LOW:
242 el0_ia(regs, esr);
243 break;
244 case ESR_ELx_EC_FP_ASIMD:
245 el0_fpsimd_acc(regs, esr);
246 break;
247 case ESR_ELx_EC_SVE:
248 el0_sve_acc(regs, esr);
249 break;
250 case ESR_ELx_EC_FP_EXC64:
251 el0_fpsimd_exc(regs, esr);
252 break;
253 case ESR_ELx_EC_SYS64:
254 case ESR_ELx_EC_WFx:
255 el0_sys(regs, esr);
256 break;
257 case ESR_ELx_EC_SP_ALIGN:
258 el0_sp(regs, esr);
259 break;
260 case ESR_ELx_EC_PC_ALIGN:
261 el0_pc(regs, esr);
262 break;
263 case ESR_ELx_EC_UNKNOWN:
264 el0_undef(regs);
265 break;
266 case ESR_ELx_EC_BTI:
267 el0_bti(regs);
268 break;
269 case ESR_ELx_EC_BREAKPT_LOW:
270 case ESR_ELx_EC_SOFTSTP_LOW:
271 case ESR_ELx_EC_WATCHPT_LOW:
272 case ESR_ELx_EC_BRK64:
273 el0_dbg(regs, esr);
274 break;
275 default:
276 el0_inv(regs, esr);
277 }
278}
279NOKPROBE_SYMBOL(el0_sync_handler);
280
281#ifdef CONFIG_COMPAT
282static void notrace el0_cp15(struct pt_regs *regs, unsigned long esr)
283{
284 user_exit_irqoff();
285 local_daif_restore(DAIF_PROCCTX);
286 do_cp15instr(esr, regs);
287}
288NOKPROBE_SYMBOL(el0_cp15);
289
290static void notrace el0_svc_compat(struct pt_regs *regs)
291{
292 if (system_uses_irq_prio_masking())
293 gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
294
295 do_el0_svc_compat(regs);
296}
297NOKPROBE_SYMBOL(el0_svc_compat);
298
299asmlinkage void notrace el0_sync_compat_handler(struct pt_regs *regs)
300{
301 unsigned long esr = read_sysreg(esr_el1);
302
303 switch (ESR_ELx_EC(esr)) {
304 case ESR_ELx_EC_SVC32:
305 el0_svc_compat(regs);
306 break;
307 case ESR_ELx_EC_DABT_LOW:
308 el0_da(regs, esr);
309 break;
310 case ESR_ELx_EC_IABT_LOW:
311 el0_ia(regs, esr);
312 break;
313 case ESR_ELx_EC_FP_ASIMD:
314 el0_fpsimd_acc(regs, esr);
315 break;
316 case ESR_ELx_EC_FP_EXC32:
317 el0_fpsimd_exc(regs, esr);
318 break;
319 case ESR_ELx_EC_PC_ALIGN:
320 el0_pc(regs, esr);
321 break;
322 case ESR_ELx_EC_UNKNOWN:
323 case ESR_ELx_EC_CP14_MR:
324 case ESR_ELx_EC_CP14_LS:
325 case ESR_ELx_EC_CP14_64:
326 el0_undef(regs);
327 break;
328 case ESR_ELx_EC_CP15_32:
329 case ESR_ELx_EC_CP15_64:
330 el0_cp15(regs, esr);
331 break;
332 case ESR_ELx_EC_BREAKPT_LOW:
333 case ESR_ELx_EC_SOFTSTP_LOW:
334 case ESR_ELx_EC_WATCHPT_LOW:
335 case ESR_ELx_EC_BKPT32:
336 el0_dbg(regs, esr);
337 break;
338 default:
339 el0_inv(regs, esr);
340 }
341}
342NOKPROBE_SYMBOL(el0_sync_compat_handler);
343#endif /* CONFIG_COMPAT */