1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * Low-level exception handling code 4 * 5 * Copyright (C) 2012 ARM Ltd. 6 * Authors: Catalin Marinas <catalin.marinas@arm.com> 7 * Will Deacon <will.deacon@arm.com> 8 */ 9 10#include <linux/arm-smccc.h> 11#include <linux/init.h> 12#include <linux/linkage.h> 13 14#include <asm/alternative.h> 15#include <asm/assembler.h> 16#include <asm/asm-offsets.h> 17#include <asm/cpufeature.h> 18#include <asm/errno.h> 19#include <asm/esr.h> 20#include <asm/irq.h> 21#include <asm/memory.h> 22#include <asm/mmu.h> 23#include <asm/processor.h> 24#include <asm/ptrace.h> 25#include <asm/thread_info.h> 26#include <asm/asm-uaccess.h> 27#include <asm/unistd.h> 28 29/* 30 * Context tracking subsystem. Used to instrument transitions 31 * between user and kernel mode. 32 */ 33 .macro ct_user_exit 34#ifdef CONFIG_CONTEXT_TRACKING 35 bl context_tracking_user_exit 36#endif 37 .endm 38 39 .macro ct_user_enter 40#ifdef CONFIG_CONTEXT_TRACKING 41 bl context_tracking_user_enter 42#endif 43 .endm 44 45 .macro clear_gp_regs 46 .irp n,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29 47 mov x\n, xzr 48 .endr 49 .endm 50 51/* 52 * Bad Abort numbers 53 *----------------- 54 */ 55#define BAD_SYNC 0 56#define BAD_IRQ 1 57#define BAD_FIQ 2 58#define BAD_ERROR 3 59 60 .macro kernel_ventry, el, label, regsize = 64 61 .align 7 62#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 63alternative_if ARM64_UNMAP_KERNEL_AT_EL0 64 .if \el == 0 65 .if \regsize == 64 66 mrs x30, tpidrro_el0 67 msr tpidrro_el0, xzr 68 .else 69 mov x30, xzr 70 .endif 71 .endif 72alternative_else_nop_endif 73#endif 74 75 sub sp, sp, #S_FRAME_SIZE 76#ifdef CONFIG_VMAP_STACK 77 /* 78 * Test whether the SP has overflowed, without corrupting a GPR. 79 * Task and IRQ stacks are aligned to (1 << THREAD_SHIFT). 80 */ 81 add sp, sp, x0 // sp' = sp + x0 82 sub x0, sp, x0 // x0' = sp' - x0 = (sp + x0) - x0 = sp 83 tbnz x0, #THREAD_SHIFT, 0f 84 sub x0, sp, x0 // x0'' = sp' - x0' = (sp + x0) - sp = x0 85 sub sp, sp, x0 // sp'' = sp' - x0 = (sp + x0) - x0 = sp 86 b el\()\el\()_\label 87 880: 89 /* 90 * Either we've just detected an overflow, or we've taken an exception 91 * while on the overflow stack. Either way, we won't return to 92 * userspace, and can clobber EL0 registers to free up GPRs. 93 */ 94 95 /* Stash the original SP (minus S_FRAME_SIZE) in tpidr_el0. */ 96 msr tpidr_el0, x0 97 98 /* Recover the original x0 value and stash it in tpidrro_el0 */ 99 sub x0, sp, x0 100 msr tpidrro_el0, x0 101 102 /* Switch to the overflow stack */ 103 adr_this_cpu sp, overflow_stack + OVERFLOW_STACK_SIZE, x0 104 105 /* 106 * Check whether we were already on the overflow stack. This may happen 107 * after panic() re-enables interrupts. 108 */ 109 mrs x0, tpidr_el0 // sp of interrupted context 110 sub x0, sp, x0 // delta with top of overflow stack 111 tst x0, #~(OVERFLOW_STACK_SIZE - 1) // within range? 112 b.ne __bad_stack // no? -> bad stack pointer 113 114 /* We were already on the overflow stack. Restore sp/x0 and carry on. */ 115 sub sp, sp, x0 116 mrs x0, tpidrro_el0 117#endif 118 b el\()\el\()_\label 119 .endm 120 121 .macro tramp_alias, dst, sym 122 mov_q \dst, TRAMP_VALIAS 123 add \dst, \dst, #(\sym - .entry.tramp.text) 124 .endm 125 126 // This macro corrupts x0-x3. It is the caller's duty 127 // to save/restore them if required. 128 .macro apply_ssbd, state, tmp1, tmp2 129#ifdef CONFIG_ARM64_SSBD 130alternative_cb arm64_enable_wa2_handling 131 b .L__asm_ssbd_skip\@ 132alternative_cb_end 133 ldr_this_cpu \tmp2, arm64_ssbd_callback_required, \tmp1 134 cbz \tmp2, .L__asm_ssbd_skip\@ 135 ldr \tmp2, [tsk, #TSK_TI_FLAGS] 136 tbnz \tmp2, #TIF_SSBD, .L__asm_ssbd_skip\@ 137 mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2 138 mov w1, #\state 139alternative_cb arm64_update_smccc_conduit 140 nop // Patched to SMC/HVC #0 141alternative_cb_end 142.L__asm_ssbd_skip\@: 143#endif 144 .endm 145 146 .macro kernel_entry, el, regsize = 64 147 .if \regsize == 32 148 mov w0, w0 // zero upper 32 bits of x0 149 .endif 150 stp x0, x1, [sp, #16 * 0] 151 stp x2, x3, [sp, #16 * 1] 152 stp x4, x5, [sp, #16 * 2] 153 stp x6, x7, [sp, #16 * 3] 154 stp x8, x9, [sp, #16 * 4] 155 stp x10, x11, [sp, #16 * 5] 156 stp x12, x13, [sp, #16 * 6] 157 stp x14, x15, [sp, #16 * 7] 158 stp x16, x17, [sp, #16 * 8] 159 stp x18, x19, [sp, #16 * 9] 160 stp x20, x21, [sp, #16 * 10] 161 stp x22, x23, [sp, #16 * 11] 162 stp x24, x25, [sp, #16 * 12] 163 stp x26, x27, [sp, #16 * 13] 164 stp x28, x29, [sp, #16 * 14] 165 166 .if \el == 0 167 clear_gp_regs 168 mrs x21, sp_el0 169 ldr_this_cpu tsk, __entry_task, x20 // Ensure MDSCR_EL1.SS is clear, 170 ldr x19, [tsk, #TSK_TI_FLAGS] // since we can unmask debug 171 disable_step_tsk x19, x20 // exceptions when scheduling. 172 173 apply_ssbd 1, x22, x23 174 175 .else 176 add x21, sp, #S_FRAME_SIZE 177 get_current_task tsk 178 /* Save the task's original addr_limit and set USER_DS */ 179 ldr x20, [tsk, #TSK_TI_ADDR_LIMIT] 180 str x20, [sp, #S_ORIG_ADDR_LIMIT] 181 mov x20, #USER_DS 182 str x20, [tsk, #TSK_TI_ADDR_LIMIT] 183 /* No need to reset PSTATE.UAO, hardware's already set it to 0 for us */ 184 .endif /* \el == 0 */ 185 mrs x22, elr_el1 186 mrs x23, spsr_el1 187 stp lr, x21, [sp, #S_LR] 188 189 /* 190 * In order to be able to dump the contents of struct pt_regs at the 191 * time the exception was taken (in case we attempt to walk the call 192 * stack later), chain it together with the stack frames. 193 */ 194 .if \el == 0 195 stp xzr, xzr, [sp, #S_STACKFRAME] 196 .else 197 stp x29, x22, [sp, #S_STACKFRAME] 198 .endif 199 add x29, sp, #S_STACKFRAME 200 201#ifdef CONFIG_ARM64_SW_TTBR0_PAN 202 /* 203 * Set the TTBR0 PAN bit in SPSR. When the exception is taken from 204 * EL0, there is no need to check the state of TTBR0_EL1 since 205 * accesses are always enabled. 206 * Note that the meaning of this bit differs from the ARMv8.1 PAN 207 * feature as all TTBR0_EL1 accesses are disabled, not just those to 208 * user mappings. 209 */ 210alternative_if ARM64_HAS_PAN 211 b 1f // skip TTBR0 PAN 212alternative_else_nop_endif 213 214 .if \el != 0 215 mrs x21, ttbr0_el1 216 tst x21, #TTBR_ASID_MASK // Check for the reserved ASID 217 orr x23, x23, #PSR_PAN_BIT // Set the emulated PAN in the saved SPSR 218 b.eq 1f // TTBR0 access already disabled 219 and x23, x23, #~PSR_PAN_BIT // Clear the emulated PAN in the saved SPSR 220 .endif 221 222 __uaccess_ttbr0_disable x21 2231: 224#endif 225 226 stp x22, x23, [sp, #S_PC] 227 228 /* Not in a syscall by default (el0_svc overwrites for real syscall) */ 229 .if \el == 0 230 mov w21, #NO_SYSCALL 231 str w21, [sp, #S_SYSCALLNO] 232 .endif 233 234 /* 235 * Set sp_el0 to current thread_info. 236 */ 237 .if \el == 0 238 msr sp_el0, tsk 239 .endif 240 241 /* Save pmr */ 242alternative_if ARM64_HAS_IRQ_PRIO_MASKING 243 mrs_s x20, SYS_ICC_PMR_EL1 244 str x20, [sp, #S_PMR_SAVE] 245alternative_else_nop_endif 246 247 /* 248 * Registers that may be useful after this macro is invoked: 249 * 250 * x20 - ICC_PMR_EL1 251 * x21 - aborted SP 252 * x22 - aborted PC 253 * x23 - aborted PSTATE 254 */ 255 .endm 256 257 .macro kernel_exit, el 258 .if \el != 0 259 disable_daif 260 261 /* Restore the task's original addr_limit. */ 262 ldr x20, [sp, #S_ORIG_ADDR_LIMIT] 263 str x20, [tsk, #TSK_TI_ADDR_LIMIT] 264 265 /* No need to restore UAO, it will be restored from SPSR_EL1 */ 266 .endif 267 268 /* Restore pmr */ 269alternative_if ARM64_HAS_IRQ_PRIO_MASKING 270 ldr x20, [sp, #S_PMR_SAVE] 271 msr_s SYS_ICC_PMR_EL1, x20 272 /* Ensure priority change is seen by redistributor */ 273 dsb sy 274alternative_else_nop_endif 275 276 ldp x21, x22, [sp, #S_PC] // load ELR, SPSR 277 .if \el == 0 278 ct_user_enter 279 .endif 280 281#ifdef CONFIG_ARM64_SW_TTBR0_PAN 282 /* 283 * Restore access to TTBR0_EL1. If returning to EL0, no need for SPSR 284 * PAN bit checking. 285 */ 286alternative_if ARM64_HAS_PAN 287 b 2f // skip TTBR0 PAN 288alternative_else_nop_endif 289 290 .if \el != 0 291 tbnz x22, #22, 1f // Skip re-enabling TTBR0 access if the PSR_PAN_BIT is set 292 .endif 293 294 __uaccess_ttbr0_enable x0, x1 295 296 .if \el == 0 297 /* 298 * Enable errata workarounds only if returning to user. The only 299 * workaround currently required for TTBR0_EL1 changes are for the 300 * Cavium erratum 27456 (broadcast TLBI instructions may cause I-cache 301 * corruption). 302 */ 303 bl post_ttbr_update_workaround 304 .endif 3051: 306 .if \el != 0 307 and x22, x22, #~PSR_PAN_BIT // ARMv8.0 CPUs do not understand this bit 308 .endif 3092: 310#endif 311 312 .if \el == 0 313 ldr x23, [sp, #S_SP] // load return stack pointer 314 msr sp_el0, x23 315 tst x22, #PSR_MODE32_BIT // native task? 316 b.eq 3f 317 318#ifdef CONFIG_ARM64_ERRATUM_845719 319alternative_if ARM64_WORKAROUND_845719 320#ifdef CONFIG_PID_IN_CONTEXTIDR 321 mrs x29, contextidr_el1 322 msr contextidr_el1, x29 323#else 324 msr contextidr_el1, xzr 325#endif 326alternative_else_nop_endif 327#endif 3283: 329#ifdef CONFIG_ARM64_ERRATUM_1418040 330alternative_if_not ARM64_WORKAROUND_1418040 331 b 4f 332alternative_else_nop_endif 333 /* 334 * if (x22.mode32 == cntkctl_el1.el0vcten) 335 * cntkctl_el1.el0vcten = ~cntkctl_el1.el0vcten 336 */ 337 mrs x1, cntkctl_el1 338 eon x0, x1, x22, lsr #3 339 tbz x0, #1, 4f 340 eor x1, x1, #2 // ARCH_TIMER_USR_VCT_ACCESS_EN 341 msr cntkctl_el1, x1 3424: 343#endif 344 apply_ssbd 0, x0, x1 345 .endif 346 347 msr elr_el1, x21 // set up the return data 348 msr spsr_el1, x22 349 ldp x0, x1, [sp, #16 * 0] 350 ldp x2, x3, [sp, #16 * 1] 351 ldp x4, x5, [sp, #16 * 2] 352 ldp x6, x7, [sp, #16 * 3] 353 ldp x8, x9, [sp, #16 * 4] 354 ldp x10, x11, [sp, #16 * 5] 355 ldp x12, x13, [sp, #16 * 6] 356 ldp x14, x15, [sp, #16 * 7] 357 ldp x16, x17, [sp, #16 * 8] 358 ldp x18, x19, [sp, #16 * 9] 359 ldp x20, x21, [sp, #16 * 10] 360 ldp x22, x23, [sp, #16 * 11] 361 ldp x24, x25, [sp, #16 * 12] 362 ldp x26, x27, [sp, #16 * 13] 363 ldp x28, x29, [sp, #16 * 14] 364 ldr lr, [sp, #S_LR] 365 add sp, sp, #S_FRAME_SIZE // restore sp 366 367 .if \el == 0 368alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0 369#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 370 bne 5f 371 msr far_el1, x30 372 tramp_alias x30, tramp_exit_native 373 br x30 3745: 375 tramp_alias x30, tramp_exit_compat 376 br x30 377#endif 378 .else 379 eret 380 .endif 381 sb 382 .endm 383 384 .macro irq_stack_entry 385 mov x19, sp // preserve the original sp 386 387 /* 388 * Compare sp with the base of the task stack. 389 * If the top ~(THREAD_SIZE - 1) bits match, we are on a task stack, 390 * and should switch to the irq stack. 391 */ 392 ldr x25, [tsk, TSK_STACK] 393 eor x25, x25, x19 394 and x25, x25, #~(THREAD_SIZE - 1) 395 cbnz x25, 9998f 396 397 ldr_this_cpu x25, irq_stack_ptr, x26 398 mov x26, #IRQ_STACK_SIZE 399 add x26, x25, x26 400 401 /* switch to the irq stack */ 402 mov sp, x26 4039998: 404 .endm 405 406 /* 407 * x19 should be preserved between irq_stack_entry and 408 * irq_stack_exit. 409 */ 410 .macro irq_stack_exit 411 mov sp, x19 412 .endm 413 414/* GPRs used by entry code */ 415tsk .req x28 // current thread_info 416 417/* 418 * Interrupt handling. 419 */ 420 .macro irq_handler 421 ldr_l x1, handle_arch_irq 422 mov x0, sp 423 irq_stack_entry 424 blr x1 425 irq_stack_exit 426 .endm 427 428#ifdef CONFIG_ARM64_PSEUDO_NMI 429 /* 430 * Set res to 0 if irqs were unmasked in interrupted context. 431 * Otherwise set res to non-0 value. 432 */ 433 .macro test_irqs_unmasked res:req, pmr:req 434alternative_if ARM64_HAS_IRQ_PRIO_MASKING 435 sub \res, \pmr, #GIC_PRIO_IRQON 436alternative_else 437 mov \res, xzr 438alternative_endif 439 .endm 440#endif 441 442 .macro gic_prio_kentry_setup, tmp:req 443#ifdef CONFIG_ARM64_PSEUDO_NMI 444 alternative_if ARM64_HAS_IRQ_PRIO_MASKING 445 mov \tmp, #(GIC_PRIO_PSR_I_SET | GIC_PRIO_IRQON) 446 msr_s SYS_ICC_PMR_EL1, \tmp 447 alternative_else_nop_endif 448#endif 449 .endm 450 451 .macro gic_prio_irq_setup, pmr:req, tmp:req 452#ifdef CONFIG_ARM64_PSEUDO_NMI 453 alternative_if ARM64_HAS_IRQ_PRIO_MASKING 454 orr \tmp, \pmr, #GIC_PRIO_PSR_I_SET 455 msr_s SYS_ICC_PMR_EL1, \tmp 456 alternative_else_nop_endif 457#endif 458 .endm 459 460 .text 461 462/* 463 * Exception vectors. 464 */ 465 .pushsection ".entry.text", "ax" 466 467 .align 11 468ENTRY(vectors) 469 kernel_ventry 1, sync_invalid // Synchronous EL1t 470 kernel_ventry 1, irq_invalid // IRQ EL1t 471 kernel_ventry 1, fiq_invalid // FIQ EL1t 472 kernel_ventry 1, error_invalid // Error EL1t 473 474 kernel_ventry 1, sync // Synchronous EL1h 475 kernel_ventry 1, irq // IRQ EL1h 476 kernel_ventry 1, fiq_invalid // FIQ EL1h 477 kernel_ventry 1, error // Error EL1h 478 479 kernel_ventry 0, sync // Synchronous 64-bit EL0 480 kernel_ventry 0, irq // IRQ 64-bit EL0 481 kernel_ventry 0, fiq_invalid // FIQ 64-bit EL0 482 kernel_ventry 0, error // Error 64-bit EL0 483 484#ifdef CONFIG_COMPAT 485 kernel_ventry 0, sync_compat, 32 // Synchronous 32-bit EL0 486 kernel_ventry 0, irq_compat, 32 // IRQ 32-bit EL0 487 kernel_ventry 0, fiq_invalid_compat, 32 // FIQ 32-bit EL0 488 kernel_ventry 0, error_compat, 32 // Error 32-bit EL0 489#else 490 kernel_ventry 0, sync_invalid, 32 // Synchronous 32-bit EL0 491 kernel_ventry 0, irq_invalid, 32 // IRQ 32-bit EL0 492 kernel_ventry 0, fiq_invalid, 32 // FIQ 32-bit EL0 493 kernel_ventry 0, error_invalid, 32 // Error 32-bit EL0 494#endif 495END(vectors) 496 497#ifdef CONFIG_VMAP_STACK 498 /* 499 * We detected an overflow in kernel_ventry, which switched to the 500 * overflow stack. Stash the exception regs, and head to our overflow 501 * handler. 502 */ 503__bad_stack: 504 /* Restore the original x0 value */ 505 mrs x0, tpidrro_el0 506 507 /* 508 * Store the original GPRs to the new stack. The orginal SP (minus 509 * S_FRAME_SIZE) was stashed in tpidr_el0 by kernel_ventry. 510 */ 511 sub sp, sp, #S_FRAME_SIZE 512 kernel_entry 1 513 mrs x0, tpidr_el0 514 add x0, x0, #S_FRAME_SIZE 515 str x0, [sp, #S_SP] 516 517 /* Stash the regs for handle_bad_stack */ 518 mov x0, sp 519 520 /* Time to die */ 521 bl handle_bad_stack 522 ASM_BUG() 523#endif /* CONFIG_VMAP_STACK */ 524 525/* 526 * Invalid mode handlers 527 */ 528 .macro inv_entry, el, reason, regsize = 64 529 kernel_entry \el, \regsize 530 mov x0, sp 531 mov x1, #\reason 532 mrs x2, esr_el1 533 bl bad_mode 534 ASM_BUG() 535 .endm 536 537el0_sync_invalid: 538 inv_entry 0, BAD_SYNC 539ENDPROC(el0_sync_invalid) 540 541el0_irq_invalid: 542 inv_entry 0, BAD_IRQ 543ENDPROC(el0_irq_invalid) 544 545el0_fiq_invalid: 546 inv_entry 0, BAD_FIQ 547ENDPROC(el0_fiq_invalid) 548 549el0_error_invalid: 550 inv_entry 0, BAD_ERROR 551ENDPROC(el0_error_invalid) 552 553#ifdef CONFIG_COMPAT 554el0_fiq_invalid_compat: 555 inv_entry 0, BAD_FIQ, 32 556ENDPROC(el0_fiq_invalid_compat) 557#endif 558 559el1_sync_invalid: 560 inv_entry 1, BAD_SYNC 561ENDPROC(el1_sync_invalid) 562 563el1_irq_invalid: 564 inv_entry 1, BAD_IRQ 565ENDPROC(el1_irq_invalid) 566 567el1_fiq_invalid: 568 inv_entry 1, BAD_FIQ 569ENDPROC(el1_fiq_invalid) 570 571el1_error_invalid: 572 inv_entry 1, BAD_ERROR 573ENDPROC(el1_error_invalid) 574 575/* 576 * EL1 mode handlers. 577 */ 578 .align 6 579el1_sync: 580 kernel_entry 1 581 mrs x1, esr_el1 // read the syndrome register 582 lsr x24, x1, #ESR_ELx_EC_SHIFT // exception class 583 cmp x24, #ESR_ELx_EC_DABT_CUR // data abort in EL1 584 b.eq el1_da 585 cmp x24, #ESR_ELx_EC_IABT_CUR // instruction abort in EL1 586 b.eq el1_ia 587 cmp x24, #ESR_ELx_EC_SYS64 // configurable trap 588 b.eq el1_undef 589 cmp x24, #ESR_ELx_EC_SP_ALIGN // stack alignment exception 590 b.eq el1_sp_pc 591 cmp x24, #ESR_ELx_EC_PC_ALIGN // pc alignment exception 592 b.eq el1_sp_pc 593 cmp x24, #ESR_ELx_EC_UNKNOWN // unknown exception in EL1 594 b.eq el1_undef 595 cmp x24, #ESR_ELx_EC_BREAKPT_CUR // debug exception in EL1 596 b.ge el1_dbg 597 b el1_inv 598 599el1_ia: 600 /* 601 * Fall through to the Data abort case 602 */ 603el1_da: 604 /* 605 * Data abort handling 606 */ 607 mrs x3, far_el1 608 inherit_daif pstate=x23, tmp=x2 609 clear_address_tag x0, x3 610 mov x2, sp // struct pt_regs 611 bl do_mem_abort 612 613 kernel_exit 1 614el1_sp_pc: 615 /* 616 * Stack or PC alignment exception handling 617 */ 618 mrs x0, far_el1 619 inherit_daif pstate=x23, tmp=x2 620 mov x2, sp 621 bl do_sp_pc_abort 622 ASM_BUG() 623el1_undef: 624 /* 625 * Undefined instruction 626 */ 627 inherit_daif pstate=x23, tmp=x2 628 mov x0, sp 629 bl do_undefinstr 630 kernel_exit 1 631el1_dbg: 632 /* 633 * Debug exception handling 634 */ 635 cmp x24, #ESR_ELx_EC_BRK64 // if BRK64 636 cinc x24, x24, eq // set bit '0' 637 tbz x24, #0, el1_inv // EL1 only 638 gic_prio_kentry_setup tmp=x3 639 mrs x0, far_el1 640 mov x2, sp // struct pt_regs 641 bl do_debug_exception 642 kernel_exit 1 643el1_inv: 644 // TODO: add support for undefined instructions in kernel mode 645 inherit_daif pstate=x23, tmp=x2 646 mov x0, sp 647 mov x2, x1 648 mov x1, #BAD_SYNC 649 bl bad_mode 650 ASM_BUG() 651ENDPROC(el1_sync) 652 653 .align 6 654el1_irq: 655 kernel_entry 1 656 gic_prio_irq_setup pmr=x20, tmp=x1 657 enable_da_f 658 659#ifdef CONFIG_ARM64_PSEUDO_NMI 660 test_irqs_unmasked res=x0, pmr=x20 661 cbz x0, 1f 662 bl asm_nmi_enter 6631: 664#endif 665 666#ifdef CONFIG_TRACE_IRQFLAGS 667 bl trace_hardirqs_off 668#endif 669 670 irq_handler 671 672#ifdef CONFIG_PREEMPT 673 ldr x24, [tsk, #TSK_TI_PREEMPT] // get preempt count 674alternative_if ARM64_HAS_IRQ_PRIO_MASKING 675 /* 676 * DA_F were cleared at start of handling. If anything is set in DAIF, 677 * we come back from an NMI, so skip preemption 678 */ 679 mrs x0, daif 680 orr x24, x24, x0 681alternative_else_nop_endif 682 cbnz x24, 1f // preempt count != 0 || NMI return path 683 bl preempt_schedule_irq // irq en/disable is done inside 6841: 685#endif 686 687#ifdef CONFIG_ARM64_PSEUDO_NMI 688 /* 689 * When using IRQ priority masking, we can get spurious interrupts while 690 * PMR is set to GIC_PRIO_IRQOFF. An NMI might also have occurred in a 691 * section with interrupts disabled. Skip tracing in those cases. 692 */ 693 test_irqs_unmasked res=x0, pmr=x20 694 cbz x0, 1f 695 bl asm_nmi_exit 6961: 697#endif 698 699#ifdef CONFIG_TRACE_IRQFLAGS 700#ifdef CONFIG_ARM64_PSEUDO_NMI 701 test_irqs_unmasked res=x0, pmr=x20 702 cbnz x0, 1f 703#endif 704 bl trace_hardirqs_on 7051: 706#endif 707 708 kernel_exit 1 709ENDPROC(el1_irq) 710 711/* 712 * EL0 mode handlers. 713 */ 714 .align 6 715el0_sync: 716 kernel_entry 0 717 mrs x25, esr_el1 // read the syndrome register 718 lsr x24, x25, #ESR_ELx_EC_SHIFT // exception class 719 cmp x24, #ESR_ELx_EC_SVC64 // SVC in 64-bit state 720 b.eq el0_svc 721 cmp x24, #ESR_ELx_EC_DABT_LOW // data abort in EL0 722 b.eq el0_da 723 cmp x24, #ESR_ELx_EC_IABT_LOW // instruction abort in EL0 724 b.eq el0_ia 725 cmp x24, #ESR_ELx_EC_FP_ASIMD // FP/ASIMD access 726 b.eq el0_fpsimd_acc 727 cmp x24, #ESR_ELx_EC_SVE // SVE access 728 b.eq el0_sve_acc 729 cmp x24, #ESR_ELx_EC_FP_EXC64 // FP/ASIMD exception 730 b.eq el0_fpsimd_exc 731 cmp x24, #ESR_ELx_EC_SYS64 // configurable trap 732 ccmp x24, #ESR_ELx_EC_WFx, #4, ne 733 b.eq el0_sys 734 cmp x24, #ESR_ELx_EC_SP_ALIGN // stack alignment exception 735 b.eq el0_sp_pc 736 cmp x24, #ESR_ELx_EC_PC_ALIGN // pc alignment exception 737 b.eq el0_sp_pc 738 cmp x24, #ESR_ELx_EC_UNKNOWN // unknown exception in EL0 739 b.eq el0_undef 740 cmp x24, #ESR_ELx_EC_BREAKPT_LOW // debug exception in EL0 741 b.ge el0_dbg 742 b el0_inv 743 744#ifdef CONFIG_COMPAT 745 .align 6 746el0_sync_compat: 747 kernel_entry 0, 32 748 mrs x25, esr_el1 // read the syndrome register 749 lsr x24, x25, #ESR_ELx_EC_SHIFT // exception class 750 cmp x24, #ESR_ELx_EC_SVC32 // SVC in 32-bit state 751 b.eq el0_svc_compat 752 cmp x24, #ESR_ELx_EC_DABT_LOW // data abort in EL0 753 b.eq el0_da 754 cmp x24, #ESR_ELx_EC_IABT_LOW // instruction abort in EL0 755 b.eq el0_ia 756 cmp x24, #ESR_ELx_EC_FP_ASIMD // FP/ASIMD access 757 b.eq el0_fpsimd_acc 758 cmp x24, #ESR_ELx_EC_FP_EXC32 // FP/ASIMD exception 759 b.eq el0_fpsimd_exc 760 cmp x24, #ESR_ELx_EC_PC_ALIGN // pc alignment exception 761 b.eq el0_sp_pc 762 cmp x24, #ESR_ELx_EC_UNKNOWN // unknown exception in EL0 763 b.eq el0_undef 764 cmp x24, #ESR_ELx_EC_CP15_32 // CP15 MRC/MCR trap 765 b.eq el0_cp15 766 cmp x24, #ESR_ELx_EC_CP15_64 // CP15 MRRC/MCRR trap 767 b.eq el0_cp15 768 cmp x24, #ESR_ELx_EC_CP14_MR // CP14 MRC/MCR trap 769 b.eq el0_undef 770 cmp x24, #ESR_ELx_EC_CP14_LS // CP14 LDC/STC trap 771 b.eq el0_undef 772 cmp x24, #ESR_ELx_EC_CP14_64 // CP14 MRRC/MCRR trap 773 b.eq el0_undef 774 cmp x24, #ESR_ELx_EC_BREAKPT_LOW // debug exception in EL0 775 b.ge el0_dbg 776 b el0_inv 777el0_svc_compat: 778 mov x0, sp 779 bl el0_svc_compat_handler 780 b ret_to_user 781 782 .align 6 783el0_irq_compat: 784 kernel_entry 0, 32 785 b el0_irq_naked 786 787el0_error_compat: 788 kernel_entry 0, 32 789 b el0_error_naked 790 791el0_cp15: 792 /* 793 * Trapped CP15 (MRC, MCR, MRRC, MCRR) instructions 794 */ 795 enable_daif 796 ct_user_exit 797 mov x0, x25 798 mov x1, sp 799 bl do_cp15instr 800 b ret_to_user 801#endif 802 803el0_da: 804 /* 805 * Data abort handling 806 */ 807 mrs x26, far_el1 808 enable_daif 809 ct_user_exit 810 clear_address_tag x0, x26 811 mov x1, x25 812 mov x2, sp 813 bl do_mem_abort 814 b ret_to_user 815el0_ia: 816 /* 817 * Instruction abort handling 818 */ 819 mrs x26, far_el1 820 gic_prio_kentry_setup tmp=x0 821 enable_da_f 822#ifdef CONFIG_TRACE_IRQFLAGS 823 bl trace_hardirqs_off 824#endif 825 ct_user_exit 826 mov x0, x26 827 mov x1, x25 828 mov x2, sp 829 bl do_el0_ia_bp_hardening 830 b ret_to_user 831el0_fpsimd_acc: 832 /* 833 * Floating Point or Advanced SIMD access 834 */ 835 enable_daif 836 ct_user_exit 837 mov x0, x25 838 mov x1, sp 839 bl do_fpsimd_acc 840 b ret_to_user 841el0_sve_acc: 842 /* 843 * Scalable Vector Extension access 844 */ 845 enable_daif 846 ct_user_exit 847 mov x0, x25 848 mov x1, sp 849 bl do_sve_acc 850 b ret_to_user 851el0_fpsimd_exc: 852 /* 853 * Floating Point, Advanced SIMD or SVE exception 854 */ 855 enable_daif 856 ct_user_exit 857 mov x0, x25 858 mov x1, sp 859 bl do_fpsimd_exc 860 b ret_to_user 861el0_sp_pc: 862 /* 863 * Stack or PC alignment exception handling 864 */ 865 mrs x26, far_el1 866 gic_prio_kentry_setup tmp=x0 867 enable_da_f 868#ifdef CONFIG_TRACE_IRQFLAGS 869 bl trace_hardirqs_off 870#endif 871 ct_user_exit 872 mov x0, x26 873 mov x1, x25 874 mov x2, sp 875 bl do_sp_pc_abort 876 b ret_to_user 877el0_undef: 878 /* 879 * Undefined instruction 880 */ 881 enable_daif 882 ct_user_exit 883 mov x0, sp 884 bl do_undefinstr 885 b ret_to_user 886el0_sys: 887 /* 888 * System instructions, for trapped cache maintenance instructions 889 */ 890 enable_daif 891 ct_user_exit 892 mov x0, x25 893 mov x1, sp 894 bl do_sysinstr 895 b ret_to_user 896el0_dbg: 897 /* 898 * Debug exception handling 899 */ 900 tbnz x24, #0, el0_inv // EL0 only 901 gic_prio_kentry_setup tmp=x3 902 mrs x0, far_el1 903 mov x1, x25 904 mov x2, sp 905 bl do_debug_exception 906 enable_da_f 907 ct_user_exit 908 b ret_to_user 909el0_inv: 910 enable_daif 911 ct_user_exit 912 mov x0, sp 913 mov x1, #BAD_SYNC 914 mov x2, x25 915 bl bad_el0_sync 916 b ret_to_user 917ENDPROC(el0_sync) 918 919 .align 6 920el0_irq: 921 kernel_entry 0 922el0_irq_naked: 923 gic_prio_irq_setup pmr=x20, tmp=x0 924 enable_da_f 925 926#ifdef CONFIG_TRACE_IRQFLAGS 927 bl trace_hardirqs_off 928#endif 929 930 ct_user_exit 931#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR 932 tbz x22, #55, 1f 933 bl do_el0_irq_bp_hardening 9341: 935#endif 936 irq_handler 937 938#ifdef CONFIG_TRACE_IRQFLAGS 939 bl trace_hardirqs_on 940#endif 941 b ret_to_user 942ENDPROC(el0_irq) 943 944el1_error: 945 kernel_entry 1 946 mrs x1, esr_el1 947 gic_prio_kentry_setup tmp=x2 948 enable_dbg 949 mov x0, sp 950 bl do_serror 951 kernel_exit 1 952ENDPROC(el1_error) 953 954el0_error: 955 kernel_entry 0 956el0_error_naked: 957 mrs x1, esr_el1 958 gic_prio_kentry_setup tmp=x2 959 enable_dbg 960 mov x0, sp 961 bl do_serror 962 enable_da_f 963 ct_user_exit 964 b ret_to_user 965ENDPROC(el0_error) 966 967/* 968 * Ok, we need to do extra processing, enter the slow path. 969 */ 970work_pending: 971 mov x0, sp // 'regs' 972 bl do_notify_resume 973#ifdef CONFIG_TRACE_IRQFLAGS 974 bl trace_hardirqs_on // enabled while in userspace 975#endif 976 ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for single-step 977 b finish_ret_to_user 978/* 979 * "slow" syscall return path. 980 */ 981ret_to_user: 982 disable_daif 983 gic_prio_kentry_setup tmp=x3 984 ldr x1, [tsk, #TSK_TI_FLAGS] 985 and x2, x1, #_TIF_WORK_MASK 986 cbnz x2, work_pending 987finish_ret_to_user: 988 enable_step_tsk x1, x2 989#ifdef CONFIG_GCC_PLUGIN_STACKLEAK 990 bl stackleak_erase 991#endif 992 kernel_exit 0 993ENDPROC(ret_to_user) 994 995/* 996 * SVC handler. 997 */ 998 .align 6 999el0_svc: 1000 gic_prio_kentry_setup tmp=x1 1001 mov x0, sp 1002 bl el0_svc_handler 1003 b ret_to_user 1004ENDPROC(el0_svc) 1005 1006 .popsection // .entry.text 1007 1008#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 1009/* 1010 * Exception vectors trampoline. 1011 */ 1012 .pushsection ".entry.tramp.text", "ax" 1013 1014 .macro tramp_map_kernel, tmp 1015 mrs \tmp, ttbr1_el1 1016 add \tmp, \tmp, #(PAGE_SIZE + RESERVED_TTBR0_SIZE) 1017 bic \tmp, \tmp, #USER_ASID_FLAG 1018 msr ttbr1_el1, \tmp 1019#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1003 1020alternative_if ARM64_WORKAROUND_QCOM_FALKOR_E1003 1021 /* ASID already in \tmp[63:48] */ 1022 movk \tmp, #:abs_g2_nc:(TRAMP_VALIAS >> 12) 1023 movk \tmp, #:abs_g1_nc:(TRAMP_VALIAS >> 12) 1024 /* 2MB boundary containing the vectors, so we nobble the walk cache */ 1025 movk \tmp, #:abs_g0_nc:((TRAMP_VALIAS & ~(SZ_2M - 1)) >> 12) 1026 isb 1027 tlbi vae1, \tmp 1028 dsb nsh 1029alternative_else_nop_endif 1030#endif /* CONFIG_QCOM_FALKOR_ERRATUM_1003 */ 1031 .endm 1032 1033 .macro tramp_unmap_kernel, tmp 1034 mrs \tmp, ttbr1_el1 1035 sub \tmp, \tmp, #(PAGE_SIZE + RESERVED_TTBR0_SIZE) 1036 orr \tmp, \tmp, #USER_ASID_FLAG 1037 msr ttbr1_el1, \tmp 1038 /* 1039 * We avoid running the post_ttbr_update_workaround here because 1040 * it's only needed by Cavium ThunderX, which requires KPTI to be 1041 * disabled. 1042 */ 1043 .endm 1044 1045 .macro tramp_ventry, regsize = 64 1046 .align 7 10471: 1048 .if \regsize == 64 1049 msr tpidrro_el0, x30 // Restored in kernel_ventry 1050 .endif 1051 /* 1052 * Defend against branch aliasing attacks by pushing a dummy 1053 * entry onto the return stack and using a RET instruction to 1054 * enter the full-fat kernel vectors. 1055 */ 1056 bl 2f 1057 b . 10582: 1059 tramp_map_kernel x30 1060#ifdef CONFIG_RANDOMIZE_BASE 1061 adr x30, tramp_vectors + PAGE_SIZE 1062alternative_insn isb, nop, ARM64_WORKAROUND_QCOM_FALKOR_E1003 1063 ldr x30, [x30] 1064#else 1065 ldr x30, =vectors 1066#endif 1067 prfm plil1strm, [x30, #(1b - tramp_vectors)] 1068 msr vbar_el1, x30 1069 add x30, x30, #(1b - tramp_vectors) 1070 isb 1071 ret 1072 .endm 1073 1074 .macro tramp_exit, regsize = 64 1075 adr x30, tramp_vectors 1076 msr vbar_el1, x30 1077 tramp_unmap_kernel x30 1078 .if \regsize == 64 1079 mrs x30, far_el1 1080 .endif 1081 eret 1082 sb 1083 .endm 1084 1085 .align 11 1086ENTRY(tramp_vectors) 1087 .space 0x400 1088 1089 tramp_ventry 1090 tramp_ventry 1091 tramp_ventry 1092 tramp_ventry 1093 1094 tramp_ventry 32 1095 tramp_ventry 32 1096 tramp_ventry 32 1097 tramp_ventry 32 1098END(tramp_vectors) 1099 1100ENTRY(tramp_exit_native) 1101 tramp_exit 1102END(tramp_exit_native) 1103 1104ENTRY(tramp_exit_compat) 1105 tramp_exit 32 1106END(tramp_exit_compat) 1107 1108 .ltorg 1109 .popsection // .entry.tramp.text 1110#ifdef CONFIG_RANDOMIZE_BASE 1111 .pushsection ".rodata", "a" 1112 .align PAGE_SHIFT 1113 .globl __entry_tramp_data_start 1114__entry_tramp_data_start: 1115 .quad vectors 1116 .popsection // .rodata 1117#endif /* CONFIG_RANDOMIZE_BASE */ 1118#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ 1119 1120/* 1121 * Register switch for AArch64. The callee-saved registers need to be saved 1122 * and restored. On entry: 1123 * x0 = previous task_struct (must be preserved across the switch) 1124 * x1 = next task_struct 1125 * Previous and next are guaranteed not to be the same. 1126 * 1127 */ 1128ENTRY(cpu_switch_to) 1129 mov x10, #THREAD_CPU_CONTEXT 1130 add x8, x0, x10 1131 mov x9, sp 1132 stp x19, x20, [x8], #16 // store callee-saved registers 1133 stp x21, x22, [x8], #16 1134 stp x23, x24, [x8], #16 1135 stp x25, x26, [x8], #16 1136 stp x27, x28, [x8], #16 1137 stp x29, x9, [x8], #16 1138 str lr, [x8] 1139 add x8, x1, x10 1140 ldp x19, x20, [x8], #16 // restore callee-saved registers 1141 ldp x21, x22, [x8], #16 1142 ldp x23, x24, [x8], #16 1143 ldp x25, x26, [x8], #16 1144 ldp x27, x28, [x8], #16 1145 ldp x29, x9, [x8], #16 1146 ldr lr, [x8] 1147 mov sp, x9 1148 msr sp_el0, x1 1149 ret 1150ENDPROC(cpu_switch_to) 1151NOKPROBE(cpu_switch_to) 1152 1153/* 1154 * This is how we return from a fork. 1155 */ 1156ENTRY(ret_from_fork) 1157 bl schedule_tail 1158 cbz x19, 1f // not a kernel thread 1159 mov x0, x20 1160 blr x19 11611: get_current_task tsk 1162 b ret_to_user 1163ENDPROC(ret_from_fork) 1164NOKPROBE(ret_from_fork) 1165 1166#ifdef CONFIG_ARM_SDE_INTERFACE 1167 1168#include <asm/sdei.h> 1169#include <uapi/linux/arm_sdei.h> 1170 1171.macro sdei_handler_exit exit_mode 1172 /* On success, this call never returns... */ 1173 cmp \exit_mode, #SDEI_EXIT_SMC 1174 b.ne 99f 1175 smc #0 1176 b . 117799: hvc #0 1178 b . 1179.endm 1180 1181#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 1182/* 1183 * The regular SDEI entry point may have been unmapped along with the rest of 1184 * the kernel. This trampoline restores the kernel mapping to make the x1 memory 1185 * argument accessible. 1186 * 1187 * This clobbers x4, __sdei_handler() will restore this from firmware's 1188 * copy. 1189 */ 1190.ltorg 1191.pushsection ".entry.tramp.text", "ax" 1192ENTRY(__sdei_asm_entry_trampoline) 1193 mrs x4, ttbr1_el1 1194 tbz x4, #USER_ASID_BIT, 1f 1195 1196 tramp_map_kernel tmp=x4 1197 isb 1198 mov x4, xzr 1199 1200 /* 1201 * Use reg->interrupted_regs.addr_limit to remember whether to unmap 1202 * the kernel on exit. 1203 */ 12041: str x4, [x1, #(SDEI_EVENT_INTREGS + S_ORIG_ADDR_LIMIT)] 1205 1206#ifdef CONFIG_RANDOMIZE_BASE 1207 adr x4, tramp_vectors + PAGE_SIZE 1208 add x4, x4, #:lo12:__sdei_asm_trampoline_next_handler 1209 ldr x4, [x4] 1210#else 1211 ldr x4, =__sdei_asm_handler 1212#endif 1213 br x4 1214ENDPROC(__sdei_asm_entry_trampoline) 1215NOKPROBE(__sdei_asm_entry_trampoline) 1216 1217/* 1218 * Make the exit call and restore the original ttbr1_el1 1219 * 1220 * x0 & x1: setup for the exit API call 1221 * x2: exit_mode 1222 * x4: struct sdei_registered_event argument from registration time. 1223 */ 1224ENTRY(__sdei_asm_exit_trampoline) 1225 ldr x4, [x4, #(SDEI_EVENT_INTREGS + S_ORIG_ADDR_LIMIT)] 1226 cbnz x4, 1f 1227 1228 tramp_unmap_kernel tmp=x4 1229 12301: sdei_handler_exit exit_mode=x2 1231ENDPROC(__sdei_asm_exit_trampoline) 1232NOKPROBE(__sdei_asm_exit_trampoline) 1233 .ltorg 1234.popsection // .entry.tramp.text 1235#ifdef CONFIG_RANDOMIZE_BASE 1236.pushsection ".rodata", "a" 1237__sdei_asm_trampoline_next_handler: 1238 .quad __sdei_asm_handler 1239.popsection // .rodata 1240#endif /* CONFIG_RANDOMIZE_BASE */ 1241#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ 1242 1243/* 1244 * Software Delegated Exception entry point. 1245 * 1246 * x0: Event number 1247 * x1: struct sdei_registered_event argument from registration time. 1248 * x2: interrupted PC 1249 * x3: interrupted PSTATE 1250 * x4: maybe clobbered by the trampoline 1251 * 1252 * Firmware has preserved x0->x17 for us, we must save/restore the rest to 1253 * follow SMC-CC. We save (or retrieve) all the registers as the handler may 1254 * want them. 1255 */ 1256ENTRY(__sdei_asm_handler) 1257 stp x2, x3, [x1, #SDEI_EVENT_INTREGS + S_PC] 1258 stp x4, x5, [x1, #SDEI_EVENT_INTREGS + 16 * 2] 1259 stp x6, x7, [x1, #SDEI_EVENT_INTREGS + 16 * 3] 1260 stp x8, x9, [x1, #SDEI_EVENT_INTREGS + 16 * 4] 1261 stp x10, x11, [x1, #SDEI_EVENT_INTREGS + 16 * 5] 1262 stp x12, x13, [x1, #SDEI_EVENT_INTREGS + 16 * 6] 1263 stp x14, x15, [x1, #SDEI_EVENT_INTREGS + 16 * 7] 1264 stp x16, x17, [x1, #SDEI_EVENT_INTREGS + 16 * 8] 1265 stp x18, x19, [x1, #SDEI_EVENT_INTREGS + 16 * 9] 1266 stp x20, x21, [x1, #SDEI_EVENT_INTREGS + 16 * 10] 1267 stp x22, x23, [x1, #SDEI_EVENT_INTREGS + 16 * 11] 1268 stp x24, x25, [x1, #SDEI_EVENT_INTREGS + 16 * 12] 1269 stp x26, x27, [x1, #SDEI_EVENT_INTREGS + 16 * 13] 1270 stp x28, x29, [x1, #SDEI_EVENT_INTREGS + 16 * 14] 1271 mov x4, sp 1272 stp lr, x4, [x1, #SDEI_EVENT_INTREGS + S_LR] 1273 1274 mov x19, x1 1275 1276#ifdef CONFIG_VMAP_STACK 1277 /* 1278 * entry.S may have been using sp as a scratch register, find whether 1279 * this is a normal or critical event and switch to the appropriate 1280 * stack for this CPU. 1281 */ 1282 ldrb w4, [x19, #SDEI_EVENT_PRIORITY] 1283 cbnz w4, 1f 1284 ldr_this_cpu dst=x5, sym=sdei_stack_normal_ptr, tmp=x6 1285 b 2f 12861: ldr_this_cpu dst=x5, sym=sdei_stack_critical_ptr, tmp=x6 12872: mov x6, #SDEI_STACK_SIZE 1288 add x5, x5, x6 1289 mov sp, x5 1290#endif 1291 1292 /* 1293 * We may have interrupted userspace, or a guest, or exit-from or 1294 * return-to either of these. We can't trust sp_el0, restore it. 1295 */ 1296 mrs x28, sp_el0 1297 ldr_this_cpu dst=x0, sym=__entry_task, tmp=x1 1298 msr sp_el0, x0 1299 1300 /* If we interrupted the kernel point to the previous stack/frame. */ 1301 and x0, x3, #0xc 1302 mrs x1, CurrentEL 1303 cmp x0, x1 1304 csel x29, x29, xzr, eq // fp, or zero 1305 csel x4, x2, xzr, eq // elr, or zero 1306 1307 stp x29, x4, [sp, #-16]! 1308 mov x29, sp 1309 1310 add x0, x19, #SDEI_EVENT_INTREGS 1311 mov x1, x19 1312 bl __sdei_handler 1313 1314 msr sp_el0, x28 1315 /* restore regs >x17 that we clobbered */ 1316 mov x4, x19 // keep x4 for __sdei_asm_exit_trampoline 1317 ldp x28, x29, [x4, #SDEI_EVENT_INTREGS + 16 * 14] 1318 ldp x18, x19, [x4, #SDEI_EVENT_INTREGS + 16 * 9] 1319 ldp lr, x1, [x4, #SDEI_EVENT_INTREGS + S_LR] 1320 mov sp, x1 1321 1322 mov x1, x0 // address to complete_and_resume 1323 /* x0 = (x0 <= 1) ? EVENT_COMPLETE:EVENT_COMPLETE_AND_RESUME */ 1324 cmp x0, #1 1325 mov_q x2, SDEI_1_0_FN_SDEI_EVENT_COMPLETE 1326 mov_q x3, SDEI_1_0_FN_SDEI_EVENT_COMPLETE_AND_RESUME 1327 csel x0, x2, x3, ls 1328 1329 ldr_l x2, sdei_exit_mode 1330 1331alternative_if_not ARM64_UNMAP_KERNEL_AT_EL0 1332 sdei_handler_exit exit_mode=x2 1333alternative_else_nop_endif 1334 1335#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 1336 tramp_alias dst=x5, sym=__sdei_asm_exit_trampoline 1337 br x5 1338#endif 1339ENDPROC(__sdei_asm_handler) 1340NOKPROBE(__sdei_asm_handler) 1341#endif /* CONFIG_ARM_SDE_INTERFACE */ 1342