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60ffc30d CM |
1 | /* |
2 | * Low-level exception handling code | |
3 | * | |
4 | * Copyright (C) 2012 ARM Ltd. | |
5 | * Authors: Catalin Marinas <catalin.marinas@arm.com> | |
6 | * Will Deacon <will.deacon@arm.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
19 | */ | |
20 | ||
21 | #include <linux/init.h> | |
22 | #include <linux/linkage.h> | |
23 | ||
8d883b23 | 24 | #include <asm/alternative.h> |
60ffc30d CM |
25 | #include <asm/assembler.h> |
26 | #include <asm/asm-offsets.h> | |
905e8c5d | 27 | #include <asm/cpufeature.h> |
60ffc30d | 28 | #include <asm/errno.h> |
5c1ce6f7 | 29 | #include <asm/esr.h> |
8e23dacd | 30 | #include <asm/irq.h> |
d57a98a9 WD |
31 | #include <asm/memory.h> |
32 | #include <asm/mmu.h> | |
eef94a3d | 33 | #include <asm/processor.h> |
39bc88e5 | 34 | #include <asm/ptrace.h> |
60ffc30d | 35 | #include <asm/thread_info.h> |
b4b8664d | 36 | #include <asm/asm-uaccess.h> |
60ffc30d CM |
37 | #include <asm/unistd.h> |
38 | ||
6c81fe79 LB |
39 | /* |
40 | * Context tracking subsystem. Used to instrument transitions | |
41 | * between user and kernel mode. | |
42 | */ | |
43 | .macro ct_user_exit, syscall = 0 | |
44 | #ifdef CONFIG_CONTEXT_TRACKING | |
45 | bl context_tracking_user_exit | |
46 | .if \syscall == 1 | |
47 | /* | |
48 | * Save/restore needed during syscalls. Restore syscall arguments from | |
49 | * the values already saved on stack during kernel_entry. | |
50 | */ | |
51 | ldp x0, x1, [sp] | |
52 | ldp x2, x3, [sp, #S_X2] | |
53 | ldp x4, x5, [sp, #S_X4] | |
54 | ldp x6, x7, [sp, #S_X6] | |
55 | .endif | |
56 | #endif | |
57 | .endm | |
58 | ||
59 | .macro ct_user_enter | |
60 | #ifdef CONFIG_CONTEXT_TRACKING | |
61 | bl context_tracking_user_enter | |
62 | #endif | |
63 | .endm | |
64 | ||
60ffc30d CM |
65 | /* |
66 | * Bad Abort numbers | |
67 | *----------------- | |
68 | */ | |
69 | #define BAD_SYNC 0 | |
70 | #define BAD_IRQ 1 | |
71 | #define BAD_FIQ 2 | |
72 | #define BAD_ERROR 3 | |
73 | ||
ca58e0a9 | 74 | .macro kernel_ventry, el, label, regsize = 64 |
b11e5759 | 75 | .align 7 |
8448fb20 | 76 | #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 |
9db1dc71 | 77 | alternative_if ARM64_UNMAP_KERNEL_AT_EL0 |
8448fb20 WD |
78 | .if \el == 0 |
79 | .if \regsize == 64 | |
80 | mrs x30, tpidrro_el0 | |
81 | msr tpidrro_el0, xzr | |
82 | .else | |
83 | mov x30, xzr | |
84 | .endif | |
85 | .endif | |
9db1dc71 | 86 | alternative_else_nop_endif |
8448fb20 WD |
87 | #endif |
88 | ||
63648dd2 | 89 | sub sp, sp, #S_FRAME_SIZE |
872d8327 MR |
90 | #ifdef CONFIG_VMAP_STACK |
91 | /* | |
92 | * Test whether the SP has overflowed, without corrupting a GPR. | |
93 | * Task and IRQ stacks are aligned to (1 << THREAD_SHIFT). | |
94 | */ | |
95 | add sp, sp, x0 // sp' = sp + x0 | |
96 | sub x0, sp, x0 // x0' = sp' - x0 = (sp + x0) - x0 = sp | |
97 | tbnz x0, #THREAD_SHIFT, 0f | |
98 | sub x0, sp, x0 // x0'' = sp' - x0' = (sp + x0) - sp = x0 | |
99 | sub sp, sp, x0 // sp'' = sp' - x0 = (sp + x0) - x0 = sp | |
ca58e0a9 | 100 | b el\()\el\()_\label |
872d8327 MR |
101 | |
102 | 0: | |
103 | /* | |
104 | * Either we've just detected an overflow, or we've taken an exception | |
105 | * while on the overflow stack. Either way, we won't return to | |
106 | * userspace, and can clobber EL0 registers to free up GPRs. | |
107 | */ | |
108 | ||
109 | /* Stash the original SP (minus S_FRAME_SIZE) in tpidr_el0. */ | |
110 | msr tpidr_el0, x0 | |
111 | ||
112 | /* Recover the original x0 value and stash it in tpidrro_el0 */ | |
113 | sub x0, sp, x0 | |
114 | msr tpidrro_el0, x0 | |
115 | ||
116 | /* Switch to the overflow stack */ | |
117 | adr_this_cpu sp, overflow_stack + OVERFLOW_STACK_SIZE, x0 | |
118 | ||
119 | /* | |
120 | * Check whether we were already on the overflow stack. This may happen | |
121 | * after panic() re-enables interrupts. | |
122 | */ | |
123 | mrs x0, tpidr_el0 // sp of interrupted context | |
124 | sub x0, sp, x0 // delta with top of overflow stack | |
125 | tst x0, #~(OVERFLOW_STACK_SIZE - 1) // within range? | |
126 | b.ne __bad_stack // no? -> bad stack pointer | |
127 | ||
128 | /* We were already on the overflow stack. Restore sp/x0 and carry on. */ | |
129 | sub sp, sp, x0 | |
130 | mrs x0, tpidrro_el0 | |
131 | #endif | |
ca58e0a9 | 132 | b el\()\el\()_\label |
b11e5759 MR |
133 | .endm |
134 | ||
8448fb20 WD |
135 | .macro tramp_alias, dst, sym |
136 | mov_q \dst, TRAMP_VALIAS | |
137 | add \dst, \dst, #(\sym - .entry.tramp.text) | |
138 | .endm | |
139 | ||
b11e5759 | 140 | .macro kernel_entry, el, regsize = 64 |
60ffc30d CM |
141 | .if \regsize == 32 |
142 | mov w0, w0 // zero upper 32 bits of x0 | |
143 | .endif | |
63648dd2 WD |
144 | stp x0, x1, [sp, #16 * 0] |
145 | stp x2, x3, [sp, #16 * 1] | |
146 | stp x4, x5, [sp, #16 * 2] | |
147 | stp x6, x7, [sp, #16 * 3] | |
148 | stp x8, x9, [sp, #16 * 4] | |
149 | stp x10, x11, [sp, #16 * 5] | |
150 | stp x12, x13, [sp, #16 * 6] | |
151 | stp x14, x15, [sp, #16 * 7] | |
152 | stp x16, x17, [sp, #16 * 8] | |
153 | stp x18, x19, [sp, #16 * 9] | |
154 | stp x20, x21, [sp, #16 * 10] | |
155 | stp x22, x23, [sp, #16 * 11] | |
156 | stp x24, x25, [sp, #16 * 12] | |
157 | stp x26, x27, [sp, #16 * 13] | |
158 | stp x28, x29, [sp, #16 * 14] | |
159 | ||
60ffc30d CM |
160 | .if \el == 0 |
161 | mrs x21, sp_el0 | |
c02433dd MR |
162 | ldr_this_cpu tsk, __entry_task, x20 // Ensure MDSCR_EL1.SS is clear, |
163 | ldr x19, [tsk, #TSK_TI_FLAGS] // since we can unmask debug | |
2a283070 | 164 | disable_step_tsk x19, x20 // exceptions when scheduling. |
49003a8d JM |
165 | |
166 | mov x29, xzr // fp pointed to user-space | |
60ffc30d CM |
167 | .else |
168 | add x21, sp, #S_FRAME_SIZE | |
e19a6ee2 | 169 | get_thread_info tsk |
43ab11c8 | 170 | /* Save the task's original addr_limit and set USER_DS */ |
c02433dd | 171 | ldr x20, [tsk, #TSK_TI_ADDR_LIMIT] |
e19a6ee2 | 172 | str x20, [sp, #S_ORIG_ADDR_LIMIT] |
43ab11c8 | 173 | mov x20, #USER_DS |
c02433dd | 174 | str x20, [tsk, #TSK_TI_ADDR_LIMIT] |
563cada0 | 175 | /* No need to reset PSTATE.UAO, hardware's already set it to 0 for us */ |
e19a6ee2 | 176 | .endif /* \el == 0 */ |
60ffc30d CM |
177 | mrs x22, elr_el1 |
178 | mrs x23, spsr_el1 | |
179 | stp lr, x21, [sp, #S_LR] | |
39bc88e5 | 180 | |
73267498 AB |
181 | /* |
182 | * In order to be able to dump the contents of struct pt_regs at the | |
183 | * time the exception was taken (in case we attempt to walk the call | |
184 | * stack later), chain it together with the stack frames. | |
185 | */ | |
186 | .if \el == 0 | |
187 | stp xzr, xzr, [sp, #S_STACKFRAME] | |
188 | .else | |
189 | stp x29, x22, [sp, #S_STACKFRAME] | |
190 | .endif | |
191 | add x29, sp, #S_STACKFRAME | |
192 | ||
39bc88e5 CM |
193 | #ifdef CONFIG_ARM64_SW_TTBR0_PAN |
194 | /* | |
195 | * Set the TTBR0 PAN bit in SPSR. When the exception is taken from | |
196 | * EL0, there is no need to check the state of TTBR0_EL1 since | |
197 | * accesses are always enabled. | |
198 | * Note that the meaning of this bit differs from the ARMv8.1 PAN | |
199 | * feature as all TTBR0_EL1 accesses are disabled, not just those to | |
200 | * user mappings. | |
201 | */ | |
202 | alternative_if ARM64_HAS_PAN | |
203 | b 1f // skip TTBR0 PAN | |
204 | alternative_else_nop_endif | |
205 | ||
206 | .if \el != 0 | |
6884bbc7 | 207 | mrs x21, ttbr0_el1 |
c164f9b2 | 208 | tst x21, #TTBR_ASID_MASK // Check for the reserved ASID |
39bc88e5 CM |
209 | orr x23, x23, #PSR_PAN_BIT // Set the emulated PAN in the saved SPSR |
210 | b.eq 1f // TTBR0 access already disabled | |
211 | and x23, x23, #~PSR_PAN_BIT // Clear the emulated PAN in the saved SPSR | |
212 | .endif | |
213 | ||
214 | __uaccess_ttbr0_disable x21 | |
215 | 1: | |
216 | #endif | |
217 | ||
60ffc30d CM |
218 | stp x22, x23, [sp, #S_PC] |
219 | ||
17c28958 | 220 | /* Not in a syscall by default (el0_svc overwrites for real syscall) */ |
60ffc30d | 221 | .if \el == 0 |
17c28958 | 222 | mov w21, #NO_SYSCALL |
35d0e6fb | 223 | str w21, [sp, #S_SYSCALLNO] |
60ffc30d CM |
224 | .endif |
225 | ||
6cdf9c7c JL |
226 | /* |
227 | * Set sp_el0 to current thread_info. | |
228 | */ | |
229 | .if \el == 0 | |
230 | msr sp_el0, tsk | |
231 | .endif | |
232 | ||
60ffc30d CM |
233 | /* |
234 | * Registers that may be useful after this macro is invoked: | |
235 | * | |
236 | * x21 - aborted SP | |
237 | * x22 - aborted PC | |
238 | * x23 - aborted PSTATE | |
239 | */ | |
240 | .endm | |
241 | ||
412fcb6c | 242 | .macro kernel_exit, el |
e19a6ee2 | 243 | .if \el != 0 |
8d66772e JM |
244 | disable_daif |
245 | ||
e19a6ee2 JM |
246 | /* Restore the task's original addr_limit. */ |
247 | ldr x20, [sp, #S_ORIG_ADDR_LIMIT] | |
c02433dd | 248 | str x20, [tsk, #TSK_TI_ADDR_LIMIT] |
e19a6ee2 JM |
249 | |
250 | /* No need to restore UAO, it will be restored from SPSR_EL1 */ | |
251 | .endif | |
252 | ||
60ffc30d CM |
253 | ldp x21, x22, [sp, #S_PC] // load ELR, SPSR |
254 | .if \el == 0 | |
6c81fe79 | 255 | ct_user_enter |
39bc88e5 CM |
256 | .endif |
257 | ||
258 | #ifdef CONFIG_ARM64_SW_TTBR0_PAN | |
259 | /* | |
260 | * Restore access to TTBR0_EL1. If returning to EL0, no need for SPSR | |
261 | * PAN bit checking. | |
262 | */ | |
263 | alternative_if ARM64_HAS_PAN | |
264 | b 2f // skip TTBR0 PAN | |
265 | alternative_else_nop_endif | |
266 | ||
267 | .if \el != 0 | |
268 | tbnz x22, #22, 1f // Skip re-enabling TTBR0 access if the PSR_PAN_BIT is set | |
269 | .endif | |
270 | ||
7a7e2f4d | 271 | __uaccess_ttbr0_enable x0, x1 |
39bc88e5 CM |
272 | |
273 | .if \el == 0 | |
274 | /* | |
275 | * Enable errata workarounds only if returning to user. The only | |
276 | * workaround currently required for TTBR0_EL1 changes are for the | |
277 | * Cavium erratum 27456 (broadcast TLBI instructions may cause I-cache | |
278 | * corruption). | |
279 | */ | |
aafb2daf | 280 | bl post_ttbr_update_workaround |
39bc88e5 CM |
281 | .endif |
282 | 1: | |
283 | .if \el != 0 | |
284 | and x22, x22, #~PSR_PAN_BIT // ARMv8.0 CPUs do not understand this bit | |
285 | .endif | |
286 | 2: | |
287 | #endif | |
288 | ||
289 | .if \el == 0 | |
60ffc30d | 290 | ldr x23, [sp, #S_SP] // load return stack pointer |
63648dd2 | 291 | msr sp_el0, x23 |
8448fb20 WD |
292 | tst x22, #PSR_MODE32_BIT // native task? |
293 | b.eq 3f | |
294 | ||
905e8c5d | 295 | #ifdef CONFIG_ARM64_ERRATUM_845719 |
6ba3b554 | 296 | alternative_if ARM64_WORKAROUND_845719 |
e28cabf1 DT |
297 | #ifdef CONFIG_PID_IN_CONTEXTIDR |
298 | mrs x29, contextidr_el1 | |
299 | msr contextidr_el1, x29 | |
905e8c5d | 300 | #else |
e28cabf1 | 301 | msr contextidr_el1, xzr |
905e8c5d | 302 | #endif |
6ba3b554 | 303 | alternative_else_nop_endif |
905e8c5d | 304 | #endif |
8448fb20 | 305 | 3: |
60ffc30d | 306 | .endif |
39bc88e5 | 307 | |
63648dd2 WD |
308 | msr elr_el1, x21 // set up the return data |
309 | msr spsr_el1, x22 | |
63648dd2 | 310 | ldp x0, x1, [sp, #16 * 0] |
63648dd2 WD |
311 | ldp x2, x3, [sp, #16 * 1] |
312 | ldp x4, x5, [sp, #16 * 2] | |
313 | ldp x6, x7, [sp, #16 * 3] | |
314 | ldp x8, x9, [sp, #16 * 4] | |
315 | ldp x10, x11, [sp, #16 * 5] | |
316 | ldp x12, x13, [sp, #16 * 6] | |
317 | ldp x14, x15, [sp, #16 * 7] | |
318 | ldp x16, x17, [sp, #16 * 8] | |
319 | ldp x18, x19, [sp, #16 * 9] | |
320 | ldp x20, x21, [sp, #16 * 10] | |
321 | ldp x22, x23, [sp, #16 * 11] | |
322 | ldp x24, x25, [sp, #16 * 12] | |
323 | ldp x26, x27, [sp, #16 * 13] | |
324 | ldp x28, x29, [sp, #16 * 14] | |
325 | ldr lr, [sp, #S_LR] | |
326 | add sp, sp, #S_FRAME_SIZE // restore sp | |
8448fb20 | 327 | |
8448fb20 | 328 | .if \el == 0 |
9db1dc71 WD |
329 | alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0 |
330 | #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 | |
8448fb20 WD |
331 | bne 4f |
332 | msr far_el1, x30 | |
333 | tramp_alias x30, tramp_exit_native | |
334 | br x30 | |
335 | 4: | |
336 | tramp_alias x30, tramp_exit_compat | |
337 | br x30 | |
9db1dc71 | 338 | #endif |
8448fb20 WD |
339 | .else |
340 | eret | |
341 | .endif | |
60ffc30d CM |
342 | .endm |
343 | ||
971c67ce | 344 | .macro irq_stack_entry |
8e23dacd JM |
345 | mov x19, sp // preserve the original sp |
346 | ||
8e23dacd | 347 | /* |
c02433dd MR |
348 | * Compare sp with the base of the task stack. |
349 | * If the top ~(THREAD_SIZE - 1) bits match, we are on a task stack, | |
350 | * and should switch to the irq stack. | |
8e23dacd | 351 | */ |
c02433dd MR |
352 | ldr x25, [tsk, TSK_STACK] |
353 | eor x25, x25, x19 | |
354 | and x25, x25, #~(THREAD_SIZE - 1) | |
355 | cbnz x25, 9998f | |
8e23dacd | 356 | |
f60fe78f | 357 | ldr_this_cpu x25, irq_stack_ptr, x26 |
34be98f4 | 358 | mov x26, #IRQ_STACK_SIZE |
8e23dacd | 359 | add x26, x25, x26 |
d224a69e JM |
360 | |
361 | /* switch to the irq stack */ | |
8e23dacd | 362 | mov sp, x26 |
8e23dacd JM |
363 | 9998: |
364 | .endm | |
365 | ||
366 | /* | |
367 | * x19 should be preserved between irq_stack_entry and | |
368 | * irq_stack_exit. | |
369 | */ | |
370 | .macro irq_stack_exit | |
371 | mov sp, x19 | |
372 | .endm | |
373 | ||
60ffc30d CM |
374 | /* |
375 | * These are the registers used in the syscall handler, and allow us to | |
376 | * have in theory up to 7 arguments to a function - x0 to x6. | |
377 | * | |
378 | * x7 is reserved for the system call number in 32-bit mode. | |
379 | */ | |
35d0e6fb | 380 | wsc_nr .req w25 // number of system calls |
05ce179c | 381 | xsc_nr .req x25 // number of system calls (zero-extended) |
35d0e6fb DM |
382 | wscno .req w26 // syscall number |
383 | xscno .req x26 // syscall number (zero-extended) | |
60ffc30d CM |
384 | stbl .req x27 // syscall table pointer |
385 | tsk .req x28 // current thread_info | |
386 | ||
387 | /* | |
388 | * Interrupt handling. | |
389 | */ | |
390 | .macro irq_handler | |
8e23dacd | 391 | ldr_l x1, handle_arch_irq |
60ffc30d | 392 | mov x0, sp |
971c67ce | 393 | irq_stack_entry |
60ffc30d | 394 | blr x1 |
8e23dacd | 395 | irq_stack_exit |
60ffc30d CM |
396 | .endm |
397 | ||
398 | .text | |
399 | ||
400 | /* | |
401 | * Exception vectors. | |
402 | */ | |
888b3c87 | 403 | .pushsection ".entry.text", "ax" |
60ffc30d CM |
404 | |
405 | .align 11 | |
406 | ENTRY(vectors) | |
ca58e0a9 WD |
407 | kernel_ventry 1, sync_invalid // Synchronous EL1t |
408 | kernel_ventry 1, irq_invalid // IRQ EL1t | |
409 | kernel_ventry 1, fiq_invalid // FIQ EL1t | |
410 | kernel_ventry 1, error_invalid // Error EL1t | |
60ffc30d | 411 | |
ca58e0a9 WD |
412 | kernel_ventry 1, sync // Synchronous EL1h |
413 | kernel_ventry 1, irq // IRQ EL1h | |
414 | kernel_ventry 1, fiq_invalid // FIQ EL1h | |
415 | kernel_ventry 1, error // Error EL1h | |
60ffc30d | 416 | |
ca58e0a9 WD |
417 | kernel_ventry 0, sync // Synchronous 64-bit EL0 |
418 | kernel_ventry 0, irq // IRQ 64-bit EL0 | |
419 | kernel_ventry 0, fiq_invalid // FIQ 64-bit EL0 | |
420 | kernel_ventry 0, error // Error 64-bit EL0 | |
60ffc30d CM |
421 | |
422 | #ifdef CONFIG_COMPAT | |
ca58e0a9 WD |
423 | kernel_ventry 0, sync_compat, 32 // Synchronous 32-bit EL0 |
424 | kernel_ventry 0, irq_compat, 32 // IRQ 32-bit EL0 | |
425 | kernel_ventry 0, fiq_invalid_compat, 32 // FIQ 32-bit EL0 | |
426 | kernel_ventry 0, error_compat, 32 // Error 32-bit EL0 | |
60ffc30d | 427 | #else |
ca58e0a9 WD |
428 | kernel_ventry 0, sync_invalid, 32 // Synchronous 32-bit EL0 |
429 | kernel_ventry 0, irq_invalid, 32 // IRQ 32-bit EL0 | |
430 | kernel_ventry 0, fiq_invalid, 32 // FIQ 32-bit EL0 | |
431 | kernel_ventry 0, error_invalid, 32 // Error 32-bit EL0 | |
60ffc30d CM |
432 | #endif |
433 | END(vectors) | |
434 | ||
872d8327 MR |
435 | #ifdef CONFIG_VMAP_STACK |
436 | /* | |
437 | * We detected an overflow in kernel_ventry, which switched to the | |
438 | * overflow stack. Stash the exception regs, and head to our overflow | |
439 | * handler. | |
440 | */ | |
441 | __bad_stack: | |
442 | /* Restore the original x0 value */ | |
443 | mrs x0, tpidrro_el0 | |
444 | ||
445 | /* | |
446 | * Store the original GPRs to the new stack. The orginal SP (minus | |
447 | * S_FRAME_SIZE) was stashed in tpidr_el0 by kernel_ventry. | |
448 | */ | |
449 | sub sp, sp, #S_FRAME_SIZE | |
450 | kernel_entry 1 | |
451 | mrs x0, tpidr_el0 | |
452 | add x0, x0, #S_FRAME_SIZE | |
453 | str x0, [sp, #S_SP] | |
454 | ||
455 | /* Stash the regs for handle_bad_stack */ | |
456 | mov x0, sp | |
457 | ||
458 | /* Time to die */ | |
459 | bl handle_bad_stack | |
460 | ASM_BUG() | |
461 | #endif /* CONFIG_VMAP_STACK */ | |
462 | ||
60ffc30d CM |
463 | /* |
464 | * Invalid mode handlers | |
465 | */ | |
466 | .macro inv_entry, el, reason, regsize = 64 | |
b660950c | 467 | kernel_entry \el, \regsize |
60ffc30d CM |
468 | mov x0, sp |
469 | mov x1, #\reason | |
470 | mrs x2, esr_el1 | |
2d0e751a MR |
471 | bl bad_mode |
472 | ASM_BUG() | |
60ffc30d CM |
473 | .endm |
474 | ||
475 | el0_sync_invalid: | |
476 | inv_entry 0, BAD_SYNC | |
477 | ENDPROC(el0_sync_invalid) | |
478 | ||
479 | el0_irq_invalid: | |
480 | inv_entry 0, BAD_IRQ | |
481 | ENDPROC(el0_irq_invalid) | |
482 | ||
483 | el0_fiq_invalid: | |
484 | inv_entry 0, BAD_FIQ | |
485 | ENDPROC(el0_fiq_invalid) | |
486 | ||
487 | el0_error_invalid: | |
488 | inv_entry 0, BAD_ERROR | |
489 | ENDPROC(el0_error_invalid) | |
490 | ||
491 | #ifdef CONFIG_COMPAT | |
492 | el0_fiq_invalid_compat: | |
493 | inv_entry 0, BAD_FIQ, 32 | |
494 | ENDPROC(el0_fiq_invalid_compat) | |
60ffc30d CM |
495 | #endif |
496 | ||
497 | el1_sync_invalid: | |
498 | inv_entry 1, BAD_SYNC | |
499 | ENDPROC(el1_sync_invalid) | |
500 | ||
501 | el1_irq_invalid: | |
502 | inv_entry 1, BAD_IRQ | |
503 | ENDPROC(el1_irq_invalid) | |
504 | ||
505 | el1_fiq_invalid: | |
506 | inv_entry 1, BAD_FIQ | |
507 | ENDPROC(el1_fiq_invalid) | |
508 | ||
509 | el1_error_invalid: | |
510 | inv_entry 1, BAD_ERROR | |
511 | ENDPROC(el1_error_invalid) | |
512 | ||
513 | /* | |
514 | * EL1 mode handlers. | |
515 | */ | |
516 | .align 6 | |
517 | el1_sync: | |
518 | kernel_entry 1 | |
519 | mrs x1, esr_el1 // read the syndrome register | |
aed40e01 MR |
520 | lsr x24, x1, #ESR_ELx_EC_SHIFT // exception class |
521 | cmp x24, #ESR_ELx_EC_DABT_CUR // data abort in EL1 | |
60ffc30d | 522 | b.eq el1_da |
9adeb8e7 LA |
523 | cmp x24, #ESR_ELx_EC_IABT_CUR // instruction abort in EL1 |
524 | b.eq el1_ia | |
aed40e01 | 525 | cmp x24, #ESR_ELx_EC_SYS64 // configurable trap |
60ffc30d | 526 | b.eq el1_undef |
aed40e01 | 527 | cmp x24, #ESR_ELx_EC_SP_ALIGN // stack alignment exception |
60ffc30d | 528 | b.eq el1_sp_pc |
aed40e01 | 529 | cmp x24, #ESR_ELx_EC_PC_ALIGN // pc alignment exception |
60ffc30d | 530 | b.eq el1_sp_pc |
aed40e01 | 531 | cmp x24, #ESR_ELx_EC_UNKNOWN // unknown exception in EL1 |
60ffc30d | 532 | b.eq el1_undef |
aed40e01 | 533 | cmp x24, #ESR_ELx_EC_BREAKPT_CUR // debug exception in EL1 |
60ffc30d CM |
534 | b.ge el1_dbg |
535 | b el1_inv | |
9adeb8e7 LA |
536 | |
537 | el1_ia: | |
538 | /* | |
539 | * Fall through to the Data abort case | |
540 | */ | |
60ffc30d CM |
541 | el1_da: |
542 | /* | |
543 | * Data abort handling | |
544 | */ | |
276e9327 | 545 | mrs x3, far_el1 |
b55a5a1b | 546 | inherit_daif pstate=x23, tmp=x2 |
276e9327 | 547 | clear_address_tag x0, x3 |
60ffc30d CM |
548 | mov x2, sp // struct pt_regs |
549 | bl do_mem_abort | |
550 | ||
60ffc30d CM |
551 | kernel_exit 1 |
552 | el1_sp_pc: | |
553 | /* | |
554 | * Stack or PC alignment exception handling | |
555 | */ | |
556 | mrs x0, far_el1 | |
b55a5a1b | 557 | inherit_daif pstate=x23, tmp=x2 |
60ffc30d | 558 | mov x2, sp |
2d0e751a MR |
559 | bl do_sp_pc_abort |
560 | ASM_BUG() | |
60ffc30d CM |
561 | el1_undef: |
562 | /* | |
563 | * Undefined instruction | |
564 | */ | |
b55a5a1b | 565 | inherit_daif pstate=x23, tmp=x2 |
60ffc30d | 566 | mov x0, sp |
2d0e751a MR |
567 | bl do_undefinstr |
568 | ASM_BUG() | |
60ffc30d CM |
569 | el1_dbg: |
570 | /* | |
571 | * Debug exception handling | |
572 | */ | |
aed40e01 | 573 | cmp x24, #ESR_ELx_EC_BRK64 // if BRK64 |
ee6214ce | 574 | cinc x24, x24, eq // set bit '0' |
60ffc30d CM |
575 | tbz x24, #0, el1_inv // EL1 only |
576 | mrs x0, far_el1 | |
577 | mov x2, sp // struct pt_regs | |
578 | bl do_debug_exception | |
60ffc30d CM |
579 | kernel_exit 1 |
580 | el1_inv: | |
581 | // TODO: add support for undefined instructions in kernel mode | |
b55a5a1b | 582 | inherit_daif pstate=x23, tmp=x2 |
60ffc30d | 583 | mov x0, sp |
1b42804d | 584 | mov x2, x1 |
60ffc30d | 585 | mov x1, #BAD_SYNC |
2d0e751a MR |
586 | bl bad_mode |
587 | ASM_BUG() | |
60ffc30d CM |
588 | ENDPROC(el1_sync) |
589 | ||
590 | .align 6 | |
591 | el1_irq: | |
592 | kernel_entry 1 | |
b282e1ce | 593 | enable_da_f |
60ffc30d CM |
594 | #ifdef CONFIG_TRACE_IRQFLAGS |
595 | bl trace_hardirqs_off | |
596 | #endif | |
64681787 | 597 | |
60ffc30d | 598 | irq_handler |
64681787 | 599 | |
60ffc30d | 600 | #ifdef CONFIG_PREEMPT |
c02433dd | 601 | ldr w24, [tsk, #TSK_TI_PREEMPT] // get preempt count |
717321fc | 602 | cbnz w24, 1f // preempt count != 0 |
c02433dd | 603 | ldr x0, [tsk, #TSK_TI_FLAGS] // get flags |
60ffc30d CM |
604 | tbz x0, #TIF_NEED_RESCHED, 1f // needs rescheduling? |
605 | bl el1_preempt | |
606 | 1: | |
607 | #endif | |
608 | #ifdef CONFIG_TRACE_IRQFLAGS | |
609 | bl trace_hardirqs_on | |
610 | #endif | |
611 | kernel_exit 1 | |
612 | ENDPROC(el1_irq) | |
613 | ||
614 | #ifdef CONFIG_PREEMPT | |
615 | el1_preempt: | |
616 | mov x24, lr | |
2a283070 | 617 | 1: bl preempt_schedule_irq // irq en/disable is done inside |
c02433dd | 618 | ldr x0, [tsk, #TSK_TI_FLAGS] // get new tasks TI_FLAGS |
60ffc30d CM |
619 | tbnz x0, #TIF_NEED_RESCHED, 1b // needs rescheduling? |
620 | ret x24 | |
621 | #endif | |
622 | ||
623 | /* | |
624 | * EL0 mode handlers. | |
625 | */ | |
626 | .align 6 | |
627 | el0_sync: | |
628 | kernel_entry 0 | |
629 | mrs x25, esr_el1 // read the syndrome register | |
aed40e01 MR |
630 | lsr x24, x25, #ESR_ELx_EC_SHIFT // exception class |
631 | cmp x24, #ESR_ELx_EC_SVC64 // SVC in 64-bit state | |
60ffc30d | 632 | b.eq el0_svc |
aed40e01 | 633 | cmp x24, #ESR_ELx_EC_DABT_LOW // data abort in EL0 |
60ffc30d | 634 | b.eq el0_da |
aed40e01 | 635 | cmp x24, #ESR_ELx_EC_IABT_LOW // instruction abort in EL0 |
60ffc30d | 636 | b.eq el0_ia |
aed40e01 | 637 | cmp x24, #ESR_ELx_EC_FP_ASIMD // FP/ASIMD access |
60ffc30d | 638 | b.eq el0_fpsimd_acc |
bc0ee476 DM |
639 | cmp x24, #ESR_ELx_EC_SVE // SVE access |
640 | b.eq el0_sve_acc | |
aed40e01 | 641 | cmp x24, #ESR_ELx_EC_FP_EXC64 // FP/ASIMD exception |
60ffc30d | 642 | b.eq el0_fpsimd_exc |
aed40e01 | 643 | cmp x24, #ESR_ELx_EC_SYS64 // configurable trap |
7dd01aef | 644 | b.eq el0_sys |
aed40e01 | 645 | cmp x24, #ESR_ELx_EC_SP_ALIGN // stack alignment exception |
60ffc30d | 646 | b.eq el0_sp_pc |
aed40e01 | 647 | cmp x24, #ESR_ELx_EC_PC_ALIGN // pc alignment exception |
60ffc30d | 648 | b.eq el0_sp_pc |
aed40e01 | 649 | cmp x24, #ESR_ELx_EC_UNKNOWN // unknown exception in EL0 |
60ffc30d | 650 | b.eq el0_undef |
aed40e01 | 651 | cmp x24, #ESR_ELx_EC_BREAKPT_LOW // debug exception in EL0 |
60ffc30d CM |
652 | b.ge el0_dbg |
653 | b el0_inv | |
654 | ||
655 | #ifdef CONFIG_COMPAT | |
656 | .align 6 | |
657 | el0_sync_compat: | |
658 | kernel_entry 0, 32 | |
659 | mrs x25, esr_el1 // read the syndrome register | |
aed40e01 MR |
660 | lsr x24, x25, #ESR_ELx_EC_SHIFT // exception class |
661 | cmp x24, #ESR_ELx_EC_SVC32 // SVC in 32-bit state | |
60ffc30d | 662 | b.eq el0_svc_compat |
aed40e01 | 663 | cmp x24, #ESR_ELx_EC_DABT_LOW // data abort in EL0 |
60ffc30d | 664 | b.eq el0_da |
aed40e01 | 665 | cmp x24, #ESR_ELx_EC_IABT_LOW // instruction abort in EL0 |
60ffc30d | 666 | b.eq el0_ia |
aed40e01 | 667 | cmp x24, #ESR_ELx_EC_FP_ASIMD // FP/ASIMD access |
60ffc30d | 668 | b.eq el0_fpsimd_acc |
aed40e01 | 669 | cmp x24, #ESR_ELx_EC_FP_EXC32 // FP/ASIMD exception |
60ffc30d | 670 | b.eq el0_fpsimd_exc |
77f3228f MS |
671 | cmp x24, #ESR_ELx_EC_PC_ALIGN // pc alignment exception |
672 | b.eq el0_sp_pc | |
aed40e01 | 673 | cmp x24, #ESR_ELx_EC_UNKNOWN // unknown exception in EL0 |
60ffc30d | 674 | b.eq el0_undef |
aed40e01 | 675 | cmp x24, #ESR_ELx_EC_CP15_32 // CP15 MRC/MCR trap |
381cc2b9 | 676 | b.eq el0_undef |
aed40e01 | 677 | cmp x24, #ESR_ELx_EC_CP15_64 // CP15 MRRC/MCRR trap |
381cc2b9 | 678 | b.eq el0_undef |
aed40e01 | 679 | cmp x24, #ESR_ELx_EC_CP14_MR // CP14 MRC/MCR trap |
381cc2b9 | 680 | b.eq el0_undef |
aed40e01 | 681 | cmp x24, #ESR_ELx_EC_CP14_LS // CP14 LDC/STC trap |
381cc2b9 | 682 | b.eq el0_undef |
aed40e01 | 683 | cmp x24, #ESR_ELx_EC_CP14_64 // CP14 MRRC/MCRR trap |
381cc2b9 | 684 | b.eq el0_undef |
aed40e01 | 685 | cmp x24, #ESR_ELx_EC_BREAKPT_LOW // debug exception in EL0 |
60ffc30d CM |
686 | b.ge el0_dbg |
687 | b el0_inv | |
688 | el0_svc_compat: | |
689 | /* | |
690 | * AArch32 syscall handling | |
691 | */ | |
bc0ee476 | 692 | ldr x16, [tsk, #TSK_TI_FLAGS] // load thread flags |
0156411b | 693 | adrp stbl, compat_sys_call_table // load compat syscall table pointer |
35d0e6fb DM |
694 | mov wscno, w7 // syscall number in w7 (r7) |
695 | mov wsc_nr, #__NR_compat_syscalls | |
60ffc30d CM |
696 | b el0_svc_naked |
697 | ||
698 | .align 6 | |
699 | el0_irq_compat: | |
700 | kernel_entry 0, 32 | |
701 | b el0_irq_naked | |
a92d4d14 XX |
702 | |
703 | el0_error_compat: | |
704 | kernel_entry 0, 32 | |
705 | b el0_error_naked | |
60ffc30d CM |
706 | #endif |
707 | ||
708 | el0_da: | |
709 | /* | |
710 | * Data abort handling | |
711 | */ | |
6ab6463a | 712 | mrs x26, far_el1 |
746647c7 | 713 | enable_daif |
6c81fe79 | 714 | ct_user_exit |
276e9327 | 715 | clear_address_tag x0, x26 |
60ffc30d CM |
716 | mov x1, x25 |
717 | mov x2, sp | |
d54e81f9 WD |
718 | bl do_mem_abort |
719 | b ret_to_user | |
60ffc30d CM |
720 | el0_ia: |
721 | /* | |
722 | * Instruction abort handling | |
723 | */ | |
6ab6463a | 724 | mrs x26, far_el1 |
9a5fa750 WD |
725 | enable_da_f |
726 | #ifdef CONFIG_TRACE_IRQFLAGS | |
727 | bl trace_hardirqs_off | |
728 | #endif | |
6c81fe79 | 729 | ct_user_exit |
6ab6463a | 730 | mov x0, x26 |
541ec870 | 731 | mov x1, x25 |
60ffc30d | 732 | mov x2, sp |
9a5fa750 | 733 | bl do_el0_ia_bp_hardening |
d54e81f9 | 734 | b ret_to_user |
60ffc30d CM |
735 | el0_fpsimd_acc: |
736 | /* | |
737 | * Floating Point or Advanced SIMD access | |
738 | */ | |
746647c7 | 739 | enable_daif |
6c81fe79 | 740 | ct_user_exit |
60ffc30d CM |
741 | mov x0, x25 |
742 | mov x1, sp | |
d54e81f9 WD |
743 | bl do_fpsimd_acc |
744 | b ret_to_user | |
bc0ee476 DM |
745 | el0_sve_acc: |
746 | /* | |
747 | * Scalable Vector Extension access | |
748 | */ | |
749 | enable_daif | |
750 | ct_user_exit | |
751 | mov x0, x25 | |
752 | mov x1, sp | |
753 | bl do_sve_acc | |
754 | b ret_to_user | |
60ffc30d CM |
755 | el0_fpsimd_exc: |
756 | /* | |
bc0ee476 | 757 | * Floating Point, Advanced SIMD or SVE exception |
60ffc30d | 758 | */ |
746647c7 | 759 | enable_daif |
6c81fe79 | 760 | ct_user_exit |
60ffc30d CM |
761 | mov x0, x25 |
762 | mov x1, sp | |
d54e81f9 WD |
763 | bl do_fpsimd_exc |
764 | b ret_to_user | |
60ffc30d CM |
765 | el0_sp_pc: |
766 | /* | |
767 | * Stack or PC alignment exception handling | |
768 | */ | |
6ab6463a | 769 | mrs x26, far_el1 |
0505ec92 WD |
770 | enable_da_f |
771 | #ifdef CONFIG_TRACE_IRQFLAGS | |
772 | bl trace_hardirqs_off | |
773 | #endif | |
46b0567c | 774 | ct_user_exit |
6ab6463a | 775 | mov x0, x26 |
60ffc30d CM |
776 | mov x1, x25 |
777 | mov x2, sp | |
d54e81f9 WD |
778 | bl do_sp_pc_abort |
779 | b ret_to_user | |
60ffc30d CM |
780 | el0_undef: |
781 | /* | |
782 | * Undefined instruction | |
783 | */ | |
746647c7 | 784 | enable_daif |
6c81fe79 | 785 | ct_user_exit |
2a283070 | 786 | mov x0, sp |
d54e81f9 WD |
787 | bl do_undefinstr |
788 | b ret_to_user | |
7dd01aef AP |
789 | el0_sys: |
790 | /* | |
791 | * System instructions, for trapped cache maintenance instructions | |
792 | */ | |
746647c7 | 793 | enable_daif |
7dd01aef AP |
794 | ct_user_exit |
795 | mov x0, x25 | |
796 | mov x1, sp | |
797 | bl do_sysinstr | |
798 | b ret_to_user | |
60ffc30d CM |
799 | el0_dbg: |
800 | /* | |
801 | * Debug exception handling | |
802 | */ | |
803 | tbnz x24, #0, el0_inv // EL0 only | |
804 | mrs x0, far_el1 | |
60ffc30d CM |
805 | mov x1, x25 |
806 | mov x2, sp | |
2a283070 | 807 | bl do_debug_exception |
746647c7 | 808 | enable_daif |
6c81fe79 | 809 | ct_user_exit |
2a283070 | 810 | b ret_to_user |
60ffc30d | 811 | el0_inv: |
746647c7 | 812 | enable_daif |
6c81fe79 | 813 | ct_user_exit |
60ffc30d CM |
814 | mov x0, sp |
815 | mov x1, #BAD_SYNC | |
1b42804d | 816 | mov x2, x25 |
7d9e8f71 | 817 | bl bad_el0_sync |
d54e81f9 | 818 | b ret_to_user |
60ffc30d CM |
819 | ENDPROC(el0_sync) |
820 | ||
821 | .align 6 | |
822 | el0_irq: | |
823 | kernel_entry 0 | |
824 | el0_irq_naked: | |
b282e1ce | 825 | enable_da_f |
60ffc30d CM |
826 | #ifdef CONFIG_TRACE_IRQFLAGS |
827 | bl trace_hardirqs_off | |
828 | #endif | |
64681787 | 829 | |
6c81fe79 | 830 | ct_user_exit |
60ffc30d | 831 | irq_handler |
64681787 | 832 | |
60ffc30d CM |
833 | #ifdef CONFIG_TRACE_IRQFLAGS |
834 | bl trace_hardirqs_on | |
835 | #endif | |
836 | b ret_to_user | |
837 | ENDPROC(el0_irq) | |
838 | ||
a92d4d14 XX |
839 | el1_error: |
840 | kernel_entry 1 | |
841 | mrs x1, esr_el1 | |
842 | enable_dbg | |
843 | mov x0, sp | |
844 | bl do_serror | |
845 | kernel_exit 1 | |
846 | ENDPROC(el1_error) | |
847 | ||
848 | el0_error: | |
849 | kernel_entry 0 | |
850 | el0_error_naked: | |
851 | mrs x1, esr_el1 | |
852 | enable_dbg | |
853 | mov x0, sp | |
854 | bl do_serror | |
855 | enable_daif | |
856 | ct_user_exit | |
857 | b ret_to_user | |
858 | ENDPROC(el0_error) | |
859 | ||
860 | ||
60ffc30d CM |
861 | /* |
862 | * This is the fast syscall return path. We do as little as possible here, | |
863 | * and this includes saving x0 back into the kernel stack. | |
864 | */ | |
865 | ret_fast_syscall: | |
8d66772e | 866 | disable_daif |
412fcb6c | 867 | str x0, [sp, #S_X0] // returned x0 |
c02433dd | 868 | ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing |
04d7e098 JS |
869 | and x2, x1, #_TIF_SYSCALL_WORK |
870 | cbnz x2, ret_fast_syscall_trace | |
60ffc30d | 871 | and x2, x1, #_TIF_WORK_MASK |
412fcb6c | 872 | cbnz x2, work_pending |
2a283070 | 873 | enable_step_tsk x1, x2 |
412fcb6c | 874 | kernel_exit 0 |
04d7e098 | 875 | ret_fast_syscall_trace: |
8d66772e | 876 | enable_daif |
412fcb6c | 877 | b __sys_trace_return_skipped // we already saved x0 |
60ffc30d CM |
878 | |
879 | /* | |
880 | * Ok, we need to do extra processing, enter the slow path. | |
881 | */ | |
60ffc30d | 882 | work_pending: |
60ffc30d | 883 | mov x0, sp // 'regs' |
60ffc30d | 884 | bl do_notify_resume |
db3899a6 | 885 | #ifdef CONFIG_TRACE_IRQFLAGS |
421dd6fa | 886 | bl trace_hardirqs_on // enabled while in userspace |
db3899a6 | 887 | #endif |
c02433dd | 888 | ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for single-step |
421dd6fa | 889 | b finish_ret_to_user |
60ffc30d CM |
890 | /* |
891 | * "slow" syscall return path. | |
892 | */ | |
59dc67b0 | 893 | ret_to_user: |
8d66772e | 894 | disable_daif |
c02433dd | 895 | ldr x1, [tsk, #TSK_TI_FLAGS] |
60ffc30d CM |
896 | and x2, x1, #_TIF_WORK_MASK |
897 | cbnz x2, work_pending | |
421dd6fa | 898 | finish_ret_to_user: |
2a283070 | 899 | enable_step_tsk x1, x2 |
412fcb6c | 900 | kernel_exit 0 |
60ffc30d CM |
901 | ENDPROC(ret_to_user) |
902 | ||
60ffc30d CM |
903 | /* |
904 | * SVC handler. | |
905 | */ | |
906 | .align 6 | |
907 | el0_svc: | |
bc0ee476 | 908 | ldr x16, [tsk, #TSK_TI_FLAGS] // load thread flags |
60ffc30d | 909 | adrp stbl, sys_call_table // load syscall table pointer |
35d0e6fb DM |
910 | mov wscno, w8 // syscall number in w8 |
911 | mov wsc_nr, #__NR_syscalls | |
bc0ee476 | 912 | |
43994d82 DM |
913 | #ifdef CONFIG_ARM64_SVE |
914 | alternative_if_not ARM64_SVE | |
bc0ee476 | 915 | b el0_svc_naked |
43994d82 | 916 | alternative_else_nop_endif |
bc0ee476 DM |
917 | tbz x16, #TIF_SVE, el0_svc_naked // Skip unless TIF_SVE set: |
918 | bic x16, x16, #_TIF_SVE // discard SVE state | |
919 | str x16, [tsk, #TSK_TI_FLAGS] | |
920 | ||
921 | /* | |
922 | * task_fpsimd_load() won't be called to update CPACR_EL1 in | |
923 | * ret_to_user unless TIF_FOREIGN_FPSTATE is still set, which only | |
924 | * happens if a context switch or kernel_neon_begin() or context | |
925 | * modification (sigreturn, ptrace) intervenes. | |
926 | * So, ensure that CPACR_EL1 is already correct for the fast-path case: | |
927 | */ | |
928 | mrs x9, cpacr_el1 | |
929 | bic x9, x9, #CPACR_EL1_ZEN_EL0EN // disable SVE for el0 | |
930 | msr cpacr_el1, x9 // synchronised by eret to el0 | |
43994d82 | 931 | #endif |
bc0ee476 | 932 | |
60ffc30d | 933 | el0_svc_naked: // compat entry point |
35d0e6fb | 934 | stp x0, xscno, [sp, #S_ORIG_X0] // save the original x0 and syscall number |
746647c7 | 935 | enable_daif |
6c81fe79 | 936 | ct_user_exit 1 |
60ffc30d | 937 | |
bc0ee476 | 938 | tst x16, #_TIF_SYSCALL_WORK // check for syscall hooks |
449f81a4 | 939 | b.ne __sys_trace |
35d0e6fb | 940 | cmp wscno, wsc_nr // check upper syscall limit |
60ffc30d | 941 | b.hs ni_sys |
05ce179c | 942 | mask_nospec64 xscno, xsc_nr, x19 // enforce bounds for syscall number |
35d0e6fb | 943 | ldr x16, [stbl, xscno, lsl #3] // address in the syscall table |
d54e81f9 WD |
944 | blr x16 // call sys_* routine |
945 | b ret_fast_syscall | |
60ffc30d CM |
946 | ni_sys: |
947 | mov x0, sp | |
d54e81f9 WD |
948 | bl do_ni_syscall |
949 | b ret_fast_syscall | |
60ffc30d CM |
950 | ENDPROC(el0_svc) |
951 | ||
952 | /* | |
953 | * This is the really slow path. We're going to be doing context | |
954 | * switches, and waiting for our parent to respond. | |
955 | */ | |
956 | __sys_trace: | |
17c28958 | 957 | cmp wscno, #NO_SYSCALL // user-issued syscall(-1)? |
1014c81d | 958 | b.ne 1f |
35d0e6fb | 959 | mov x0, #-ENOSYS // set default errno if so |
1014c81d AT |
960 | str x0, [sp, #S_X0] |
961 | 1: mov x0, sp | |
3157858f | 962 | bl syscall_trace_enter |
17c28958 | 963 | cmp w0, #NO_SYSCALL // skip the syscall? |
1014c81d | 964 | b.eq __sys_trace_return_skipped |
35d0e6fb | 965 | mov wscno, w0 // syscall number (possibly new) |
60ffc30d | 966 | mov x1, sp // pointer to regs |
35d0e6fb | 967 | cmp wscno, wsc_nr // check upper syscall limit |
d54e81f9 | 968 | b.hs __ni_sys_trace |
60ffc30d CM |
969 | ldp x0, x1, [sp] // restore the syscall args |
970 | ldp x2, x3, [sp, #S_X2] | |
971 | ldp x4, x5, [sp, #S_X4] | |
972 | ldp x6, x7, [sp, #S_X6] | |
35d0e6fb | 973 | ldr x16, [stbl, xscno, lsl #3] // address in the syscall table |
d54e81f9 | 974 | blr x16 // call sys_* routine |
60ffc30d CM |
975 | |
976 | __sys_trace_return: | |
1014c81d AT |
977 | str x0, [sp, #S_X0] // save returned x0 |
978 | __sys_trace_return_skipped: | |
3157858f AT |
979 | mov x0, sp |
980 | bl syscall_trace_exit | |
60ffc30d CM |
981 | b ret_to_user |
982 | ||
d54e81f9 WD |
983 | __ni_sys_trace: |
984 | mov x0, sp | |
985 | bl do_ni_syscall | |
986 | b __sys_trace_return | |
987 | ||
888b3c87 PA |
988 | .popsection // .entry.text |
989 | ||
d57a98a9 WD |
990 | #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 |
991 | /* | |
992 | * Exception vectors trampoline. | |
993 | */ | |
994 | .pushsection ".entry.tramp.text", "ax" | |
995 | ||
996 | .macro tramp_map_kernel, tmp | |
997 | mrs \tmp, ttbr1_el1 | |
998 | sub \tmp, \tmp, #(SWAPPER_DIR_SIZE + RESERVED_TTBR0_SIZE) | |
999 | bic \tmp, \tmp, #USER_ASID_FLAG | |
1000 | msr ttbr1_el1, \tmp | |
715faa31 WD |
1001 | #ifdef CONFIG_QCOM_FALKOR_ERRATUM_1003 |
1002 | alternative_if ARM64_WORKAROUND_QCOM_FALKOR_E1003 | |
1003 | /* ASID already in \tmp[63:48] */ | |
1004 | movk \tmp, #:abs_g2_nc:(TRAMP_VALIAS >> 12) | |
1005 | movk \tmp, #:abs_g1_nc:(TRAMP_VALIAS >> 12) | |
1006 | /* 2MB boundary containing the vectors, so we nobble the walk cache */ | |
1007 | movk \tmp, #:abs_g0_nc:((TRAMP_VALIAS & ~(SZ_2M - 1)) >> 12) | |
1008 | isb | |
1009 | tlbi vae1, \tmp | |
1010 | dsb nsh | |
1011 | alternative_else_nop_endif | |
1012 | #endif /* CONFIG_QCOM_FALKOR_ERRATUM_1003 */ | |
d57a98a9 WD |
1013 | .endm |
1014 | ||
1015 | .macro tramp_unmap_kernel, tmp | |
1016 | mrs \tmp, ttbr1_el1 | |
1017 | add \tmp, \tmp, #(SWAPPER_DIR_SIZE + RESERVED_TTBR0_SIZE) | |
1018 | orr \tmp, \tmp, #USER_ASID_FLAG | |
1019 | msr ttbr1_el1, \tmp | |
1020 | /* | |
173d4e04 WD |
1021 | * We avoid running the post_ttbr_update_workaround here because |
1022 | * it's only needed by Cavium ThunderX, which requires KPTI to be | |
1023 | * disabled. | |
d57a98a9 WD |
1024 | */ |
1025 | .endm | |
1026 | ||
1027 | .macro tramp_ventry, regsize = 64 | |
1028 | .align 7 | |
1029 | 1: | |
1030 | .if \regsize == 64 | |
1031 | msr tpidrro_el0, x30 // Restored in kernel_ventry | |
1032 | .endif | |
9fd39c5f WD |
1033 | /* |
1034 | * Defend against branch aliasing attacks by pushing a dummy | |
1035 | * entry onto the return stack and using a RET instruction to | |
1036 | * enter the full-fat kernel vectors. | |
1037 | */ | |
1038 | bl 2f | |
1039 | b . | |
1040 | 2: | |
d57a98a9 | 1041 | tramp_map_kernel x30 |
4a159cc4 WD |
1042 | #ifdef CONFIG_RANDOMIZE_BASE |
1043 | adr x30, tramp_vectors + PAGE_SIZE | |
1044 | alternative_insn isb, nop, ARM64_WORKAROUND_QCOM_FALKOR_E1003 | |
1045 | ldr x30, [x30] | |
1046 | #else | |
d57a98a9 | 1047 | ldr x30, =vectors |
4a159cc4 | 1048 | #endif |
d57a98a9 WD |
1049 | prfm plil1strm, [x30, #(1b - tramp_vectors)] |
1050 | msr vbar_el1, x30 | |
1051 | add x30, x30, #(1b - tramp_vectors) | |
1052 | isb | |
9fd39c5f | 1053 | ret |
d57a98a9 WD |
1054 | .endm |
1055 | ||
1056 | .macro tramp_exit, regsize = 64 | |
1057 | adr x30, tramp_vectors | |
1058 | msr vbar_el1, x30 | |
1059 | tramp_unmap_kernel x30 | |
1060 | .if \regsize == 64 | |
1061 | mrs x30, far_el1 | |
1062 | .endif | |
1063 | eret | |
1064 | .endm | |
1065 | ||
1066 | .align 11 | |
1067 | ENTRY(tramp_vectors) | |
1068 | .space 0x400 | |
1069 | ||
1070 | tramp_ventry | |
1071 | tramp_ventry | |
1072 | tramp_ventry | |
1073 | tramp_ventry | |
1074 | ||
1075 | tramp_ventry 32 | |
1076 | tramp_ventry 32 | |
1077 | tramp_ventry 32 | |
1078 | tramp_ventry 32 | |
1079 | END(tramp_vectors) | |
1080 | ||
1081 | ENTRY(tramp_exit_native) | |
1082 | tramp_exit | |
1083 | END(tramp_exit_native) | |
1084 | ||
1085 | ENTRY(tramp_exit_compat) | |
1086 | tramp_exit 32 | |
1087 | END(tramp_exit_compat) | |
1088 | ||
1089 | .ltorg | |
1090 | .popsection // .entry.tramp.text | |
4a159cc4 WD |
1091 | #ifdef CONFIG_RANDOMIZE_BASE |
1092 | .pushsection ".rodata", "a" | |
1093 | .align PAGE_SHIFT | |
1094 | .globl __entry_tramp_data_start | |
1095 | __entry_tramp_data_start: | |
1096 | .quad vectors | |
1097 | .popsection // .rodata | |
1098 | #endif /* CONFIG_RANDOMIZE_BASE */ | |
d57a98a9 WD |
1099 | #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ |
1100 | ||
60ffc30d CM |
1101 | /* |
1102 | * Special system call wrappers. | |
1103 | */ | |
60ffc30d CM |
1104 | ENTRY(sys_rt_sigreturn_wrapper) |
1105 | mov x0, sp | |
1106 | b sys_rt_sigreturn | |
1107 | ENDPROC(sys_rt_sigreturn_wrapper) | |
ed84b4e9 MR |
1108 | |
1109 | /* | |
1110 | * Register switch for AArch64. The callee-saved registers need to be saved | |
1111 | * and restored. On entry: | |
1112 | * x0 = previous task_struct (must be preserved across the switch) | |
1113 | * x1 = next task_struct | |
1114 | * Previous and next are guaranteed not to be the same. | |
1115 | * | |
1116 | */ | |
1117 | ENTRY(cpu_switch_to) | |
1118 | mov x10, #THREAD_CPU_CONTEXT | |
1119 | add x8, x0, x10 | |
1120 | mov x9, sp | |
1121 | stp x19, x20, [x8], #16 // store callee-saved registers | |
1122 | stp x21, x22, [x8], #16 | |
1123 | stp x23, x24, [x8], #16 | |
1124 | stp x25, x26, [x8], #16 | |
1125 | stp x27, x28, [x8], #16 | |
1126 | stp x29, x9, [x8], #16 | |
1127 | str lr, [x8] | |
1128 | add x8, x1, x10 | |
1129 | ldp x19, x20, [x8], #16 // restore callee-saved registers | |
1130 | ldp x21, x22, [x8], #16 | |
1131 | ldp x23, x24, [x8], #16 | |
1132 | ldp x25, x26, [x8], #16 | |
1133 | ldp x27, x28, [x8], #16 | |
1134 | ldp x29, x9, [x8], #16 | |
1135 | ldr lr, [x8] | |
1136 | mov sp, x9 | |
1137 | msr sp_el0, x1 | |
1138 | ret | |
1139 | ENDPROC(cpu_switch_to) | |
1140 | NOKPROBE(cpu_switch_to) | |
1141 | ||
1142 | /* | |
1143 | * This is how we return from a fork. | |
1144 | */ | |
1145 | ENTRY(ret_from_fork) | |
1146 | bl schedule_tail | |
1147 | cbz x19, 1f // not a kernel thread | |
1148 | mov x0, x20 | |
1149 | blr x19 | |
1150 | 1: get_thread_info tsk | |
1151 | b ret_to_user | |
1152 | ENDPROC(ret_from_fork) | |
1153 | NOKPROBE(ret_from_fork) |