1141 lines
27 KiB
ArmAsm
1141 lines
27 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Low-level exception handling code
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*
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* Copyright (C) 2012 ARM Ltd.
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* Authors: Catalin Marinas <catalin.marinas@arm.com>
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* Will Deacon <will.deacon@arm.com>
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*/
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#include <linux/arm-smccc.h>
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#include <linux/init.h>
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#include <linux/linkage.h>
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#include <asm/alternative.h>
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#include <asm/assembler.h>
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#include <asm/asm-offsets.h>
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#include <asm/asm_pointer_auth.h>
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#include <asm/bug.h>
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#include <asm/cpufeature.h>
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#include <asm/errno.h>
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#include <asm/esr.h>
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#include <asm/irq.h>
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#include <asm/memory.h>
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#include <asm/mmu.h>
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#include <asm/processor.h>
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#include <asm/ptrace.h>
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#include <asm/scs.h>
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#include <asm/thread_info.h>
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#include <asm/asm-uaccess.h>
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#include <asm/unistd.h>
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/*
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* Context tracking subsystem. Used to instrument transitions
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* between user and kernel mode.
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*/
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.macro ct_user_exit_irqoff
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#ifdef CONFIG_CONTEXT_TRACKING
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bl enter_from_user_mode
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#endif
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.endm
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.macro ct_user_enter
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#ifdef CONFIG_CONTEXT_TRACKING
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bl context_tracking_user_enter
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#endif
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.endm
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.macro clear_gp_regs
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.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
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mov x\n, xzr
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.endr
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.endm
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/*
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* Bad Abort numbers
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*-----------------
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*/
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#define BAD_SYNC 0
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#define BAD_IRQ 1
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#define BAD_FIQ 2
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#define BAD_ERROR 3
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.macro kernel_ventry, el, label, regsize = 64
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.align 7
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#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
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.if \el == 0
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alternative_if ARM64_UNMAP_KERNEL_AT_EL0
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.if \regsize == 64
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mrs x30, tpidrro_el0
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msr tpidrro_el0, xzr
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.else
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mov x30, xzr
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.endif
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alternative_else_nop_endif
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.endif
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#endif
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sub sp, sp, #S_FRAME_SIZE
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#ifdef CONFIG_VMAP_STACK
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/*
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* Test whether the SP has overflowed, without corrupting a GPR.
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* Task and IRQ stacks are aligned so that SP & (1 << THREAD_SHIFT)
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* should always be zero.
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*/
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add sp, sp, x0 // sp' = sp + x0
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sub x0, sp, x0 // x0' = sp' - x0 = (sp + x0) - x0 = sp
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tbnz x0, #THREAD_SHIFT, 0f
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sub x0, sp, x0 // x0'' = sp' - x0' = (sp + x0) - sp = x0
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sub sp, sp, x0 // sp'' = sp' - x0 = (sp + x0) - x0 = sp
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b el\()\el\()_\label
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0:
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/*
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* Either we've just detected an overflow, or we've taken an exception
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* while on the overflow stack. Either way, we won't return to
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* userspace, and can clobber EL0 registers to free up GPRs.
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*/
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/* Stash the original SP (minus S_FRAME_SIZE) in tpidr_el0. */
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msr tpidr_el0, x0
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/* Recover the original x0 value and stash it in tpidrro_el0 */
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sub x0, sp, x0
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msr tpidrro_el0, x0
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/* Switch to the overflow stack */
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adr_this_cpu sp, overflow_stack + OVERFLOW_STACK_SIZE, x0
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/*
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* Check whether we were already on the overflow stack. This may happen
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* after panic() re-enables interrupts.
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*/
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mrs x0, tpidr_el0 // sp of interrupted context
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sub x0, sp, x0 // delta with top of overflow stack
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tst x0, #~(OVERFLOW_STACK_SIZE - 1) // within range?
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b.ne __bad_stack // no? -> bad stack pointer
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/* We were already on the overflow stack. Restore sp/x0 and carry on. */
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sub sp, sp, x0
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mrs x0, tpidrro_el0
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#endif
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b el\()\el\()_\label
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.endm
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.macro tramp_alias, dst, sym
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mov_q \dst, TRAMP_VALIAS
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add \dst, \dst, #(\sym - .entry.tramp.text)
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.endm
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/*
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* This macro corrupts x0-x3. It is the caller's duty to save/restore
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* them if required.
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*/
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.macro apply_ssbd, state, tmp1, tmp2
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#ifdef CONFIG_ARM64_SSBD
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alternative_cb arm64_enable_wa2_handling
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b .L__asm_ssbd_skip\@
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alternative_cb_end
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ldr_this_cpu \tmp2, arm64_ssbd_callback_required, \tmp1
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cbz \tmp2, .L__asm_ssbd_skip\@
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ldr \tmp2, [tsk, #TSK_TI_FLAGS]
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tbnz \tmp2, #TIF_SSBD, .L__asm_ssbd_skip\@
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mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2
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mov w1, #\state
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alternative_cb arm64_update_smccc_conduit
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nop // Patched to SMC/HVC #0
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alternative_cb_end
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.L__asm_ssbd_skip\@:
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#endif
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.endm
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.macro kernel_entry, el, regsize = 64
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.if \regsize == 32
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mov w0, w0 // zero upper 32 bits of x0
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.endif
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stp x0, x1, [sp, #16 * 0]
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stp x2, x3, [sp, #16 * 1]
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stp x4, x5, [sp, #16 * 2]
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stp x6, x7, [sp, #16 * 3]
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stp x8, x9, [sp, #16 * 4]
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stp x10, x11, [sp, #16 * 5]
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stp x12, x13, [sp, #16 * 6]
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stp x14, x15, [sp, #16 * 7]
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stp x16, x17, [sp, #16 * 8]
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stp x18, x19, [sp, #16 * 9]
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stp x20, x21, [sp, #16 * 10]
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stp x22, x23, [sp, #16 * 11]
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stp x24, x25, [sp, #16 * 12]
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stp x26, x27, [sp, #16 * 13]
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stp x28, x29, [sp, #16 * 14]
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.if \el == 0
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.if \regsize == 32
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/*
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* If we're returning from a 32-bit task on a system affected by
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* 1418040 then re-enable userspace access to the virtual counter.
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*/
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#ifdef CONFIG_ARM64_ERRATUM_1418040
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alternative_if ARM64_WORKAROUND_1418040
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mrs x0, cntkctl_el1
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orr x0, x0, #2 // ARCH_TIMER_USR_VCT_ACCESS_EN
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msr cntkctl_el1, x0
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alternative_else_nop_endif
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#endif
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.endif
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clear_gp_regs
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mrs x21, sp_el0
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ldr_this_cpu tsk, __entry_task, x20
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msr sp_el0, tsk
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/*
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* Ensure MDSCR_EL1.SS is clear, since we can unmask debug exceptions
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* when scheduling.
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*/
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ldr x19, [tsk, #TSK_TI_FLAGS]
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disable_step_tsk x19, x20
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apply_ssbd 1, x22, x23
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ptrauth_keys_install_kernel tsk, x20, x22, x23
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scs_load tsk, x20
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.else
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add x21, sp, #S_FRAME_SIZE
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get_current_task tsk
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/* Save the task's original addr_limit and set USER_DS */
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ldr x20, [tsk, #TSK_TI_ADDR_LIMIT]
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str x20, [sp, #S_ORIG_ADDR_LIMIT]
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mov x20, #USER_DS
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str x20, [tsk, #TSK_TI_ADDR_LIMIT]
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/* No need to reset PSTATE.UAO, hardware's already set it to 0 for us */
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.endif /* \el == 0 */
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mrs x22, elr_el1
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mrs x23, spsr_el1
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stp lr, x21, [sp, #S_LR]
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/*
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* In order to be able to dump the contents of struct pt_regs at the
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* time the exception was taken (in case we attempt to walk the call
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* stack later), chain it together with the stack frames.
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*/
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.if \el == 0
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stp xzr, xzr, [sp, #S_STACKFRAME]
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.else
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stp x29, x22, [sp, #S_STACKFRAME]
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.endif
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add x29, sp, #S_STACKFRAME
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#ifdef CONFIG_ARM64_SW_TTBR0_PAN
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alternative_if_not ARM64_HAS_PAN
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bl __swpan_entry_el\el
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alternative_else_nop_endif
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#endif
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stp x22, x23, [sp, #S_PC]
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/* Not in a syscall by default (el0_svc overwrites for real syscall) */
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.if \el == 0
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mov w21, #NO_SYSCALL
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str w21, [sp, #S_SYSCALLNO]
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.endif
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/* Save pmr */
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alternative_if ARM64_HAS_IRQ_PRIO_MASKING
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mrs_s x20, SYS_ICC_PMR_EL1
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str x20, [sp, #S_PMR_SAVE]
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alternative_else_nop_endif
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/*
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* Registers that may be useful after this macro is invoked:
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*
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* x20 - ICC_PMR_EL1
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* x21 - aborted SP
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* x22 - aborted PC
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* x23 - aborted PSTATE
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*/
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.endm
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.macro kernel_exit, el
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.if \el != 0
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disable_daif
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/* Restore the task's original addr_limit. */
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ldr x20, [sp, #S_ORIG_ADDR_LIMIT]
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str x20, [tsk, #TSK_TI_ADDR_LIMIT]
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/* No need to restore UAO, it will be restored from SPSR_EL1 */
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.endif
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/* Restore pmr */
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alternative_if ARM64_HAS_IRQ_PRIO_MASKING
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ldr x20, [sp, #S_PMR_SAVE]
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msr_s SYS_ICC_PMR_EL1, x20
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mrs_s x21, SYS_ICC_CTLR_EL1
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tbz x21, #6, .L__skip_pmr_sync\@ // Check for ICC_CTLR_EL1.PMHE
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dsb sy // Ensure priority change is seen by redistributor
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.L__skip_pmr_sync\@:
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alternative_else_nop_endif
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ldp x21, x22, [sp, #S_PC] // load ELR, SPSR
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.if \el == 0
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ct_user_enter
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.endif
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#ifdef CONFIG_ARM64_SW_TTBR0_PAN
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alternative_if_not ARM64_HAS_PAN
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bl __swpan_exit_el\el
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alternative_else_nop_endif
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#endif
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.if \el == 0
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ldr x23, [sp, #S_SP] // load return stack pointer
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msr sp_el0, x23
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tst x22, #PSR_MODE32_BIT // native task?
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b.eq 3f
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#ifdef CONFIG_ARM64_ERRATUM_1418040
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alternative_if ARM64_WORKAROUND_1418040
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mrs x0, cntkctl_el1
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bic x0, x0, #2 // ARCH_TIMER_USR_VCT_ACCESS_EN
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msr cntkctl_el1, x0
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alternative_else_nop_endif
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#endif
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#ifdef CONFIG_ARM64_ERRATUM_845719
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alternative_if ARM64_WORKAROUND_845719
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#ifdef CONFIG_PID_IN_CONTEXTIDR
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mrs x29, contextidr_el1
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msr contextidr_el1, x29
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#else
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msr contextidr_el1, xzr
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#endif
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alternative_else_nop_endif
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#endif
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3:
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scs_save tsk, x0
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/* No kernel C function calls after this as user keys are set. */
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ptrauth_keys_install_user tsk, x0, x1, x2
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apply_ssbd 0, x0, x1
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.endif
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msr elr_el1, x21 // set up the return data
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msr spsr_el1, x22
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ldp x0, x1, [sp, #16 * 0]
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ldp x2, x3, [sp, #16 * 1]
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ldp x4, x5, [sp, #16 * 2]
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ldp x6, x7, [sp, #16 * 3]
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ldp x8, x9, [sp, #16 * 4]
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ldp x10, x11, [sp, #16 * 5]
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ldp x12, x13, [sp, #16 * 6]
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ldp x14, x15, [sp, #16 * 7]
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ldp x16, x17, [sp, #16 * 8]
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ldp x18, x19, [sp, #16 * 9]
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ldp x20, x21, [sp, #16 * 10]
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ldp x22, x23, [sp, #16 * 11]
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ldp x24, x25, [sp, #16 * 12]
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ldp x26, x27, [sp, #16 * 13]
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ldp x28, x29, [sp, #16 * 14]
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ldr lr, [sp, #S_LR]
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add sp, sp, #S_FRAME_SIZE // restore sp
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.if \el == 0
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alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0
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#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
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bne 4f
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msr far_el1, x30
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tramp_alias x30, tramp_exit_native
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br x30
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4:
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tramp_alias x30, tramp_exit_compat
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br x30
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#endif
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.else
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eret
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.endif
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sb
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.endm
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#ifdef CONFIG_ARM64_SW_TTBR0_PAN
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/*
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* Set the TTBR0 PAN bit in SPSR. When the exception is taken from
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* EL0, there is no need to check the state of TTBR0_EL1 since
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* accesses are always enabled.
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* Note that the meaning of this bit differs from the ARMv8.1 PAN
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* feature as all TTBR0_EL1 accesses are disabled, not just those to
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* user mappings.
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*/
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SYM_CODE_START_LOCAL(__swpan_entry_el1)
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mrs x21, ttbr0_el1
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tst x21, #TTBR_ASID_MASK // Check for the reserved ASID
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orr x23, x23, #PSR_PAN_BIT // Set the emulated PAN in the saved SPSR
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b.eq 1f // TTBR0 access already disabled
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and x23, x23, #~PSR_PAN_BIT // Clear the emulated PAN in the saved SPSR
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SYM_INNER_LABEL(__swpan_entry_el0, SYM_L_LOCAL)
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__uaccess_ttbr0_disable x21
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1: ret
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SYM_CODE_END(__swpan_entry_el1)
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/*
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* Restore access to TTBR0_EL1. If returning to EL0, no need for SPSR
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* PAN bit checking.
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*/
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SYM_CODE_START_LOCAL(__swpan_exit_el1)
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tbnz x22, #22, 1f // Skip re-enabling TTBR0 access if the PSR_PAN_BIT is set
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__uaccess_ttbr0_enable x0, x1
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1: and x22, x22, #~PSR_PAN_BIT // ARMv8.0 CPUs do not understand this bit
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ret
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SYM_CODE_END(__swpan_exit_el1)
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SYM_CODE_START_LOCAL(__swpan_exit_el0)
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__uaccess_ttbr0_enable x0, x1
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/*
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* Enable errata workarounds only if returning to user. The only
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* workaround currently required for TTBR0_EL1 changes are for the
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* Cavium erratum 27456 (broadcast TLBI instructions may cause I-cache
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* corruption).
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*/
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b post_ttbr_update_workaround
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SYM_CODE_END(__swpan_exit_el0)
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#endif
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.macro irq_stack_entry
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mov x19, sp // preserve the original sp
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#ifdef CONFIG_SHADOW_CALL_STACK
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mov x24, scs_sp // preserve the original shadow stack
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#endif
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/*
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* Compare sp with the base of the task stack.
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* If the top ~(THREAD_SIZE - 1) bits match, we are on a task stack,
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* and should switch to the irq stack.
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*/
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ldr x25, [tsk, TSK_STACK]
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eor x25, x25, x19
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and x25, x25, #~(THREAD_SIZE - 1)
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cbnz x25, 9998f
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ldr_this_cpu x25, irq_stack_ptr, x26
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mov x26, #IRQ_STACK_SIZE
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add x26, x25, x26
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/* switch to the irq stack */
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mov sp, x26
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#ifdef CONFIG_SHADOW_CALL_STACK
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/* also switch to the irq shadow stack */
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adr_this_cpu scs_sp, irq_shadow_call_stack, x26
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#endif
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9998:
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.endm
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/*
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* The callee-saved regs (x19-x29) should be preserved between
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* irq_stack_entry and irq_stack_exit, but note that kernel_entry
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* uses x20-x23 to store data for later use.
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*/
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.macro irq_stack_exit
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mov sp, x19
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#ifdef CONFIG_SHADOW_CALL_STACK
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mov scs_sp, x24
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#endif
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.endm
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/* GPRs used by entry code */
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tsk .req x28 // current thread_info
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/*
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* Interrupt handling.
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*/
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.macro irq_handler
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ldr_l x1, handle_arch_irq
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mov x0, sp
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irq_stack_entry
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blr x1
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irq_stack_exit
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.endm
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#ifdef CONFIG_ARM64_PSEUDO_NMI
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/*
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* Set res to 0 if irqs were unmasked in interrupted context.
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* Otherwise set res to non-0 value.
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*/
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.macro test_irqs_unmasked res:req, pmr:req
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alternative_if ARM64_HAS_IRQ_PRIO_MASKING
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sub \res, \pmr, #GIC_PRIO_IRQON
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alternative_else
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mov \res, xzr
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alternative_endif
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.endm
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#endif
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.macro gic_prio_kentry_setup, tmp:req
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#ifdef CONFIG_ARM64_PSEUDO_NMI
|
|
alternative_if ARM64_HAS_IRQ_PRIO_MASKING
|
|
mov \tmp, #(GIC_PRIO_PSR_I_SET | GIC_PRIO_IRQON)
|
|
msr_s SYS_ICC_PMR_EL1, \tmp
|
|
alternative_else_nop_endif
|
|
#endif
|
|
.endm
|
|
|
|
.macro gic_prio_irq_setup, pmr:req, tmp:req
|
|
#ifdef CONFIG_ARM64_PSEUDO_NMI
|
|
alternative_if ARM64_HAS_IRQ_PRIO_MASKING
|
|
orr \tmp, \pmr, #GIC_PRIO_PSR_I_SET
|
|
msr_s SYS_ICC_PMR_EL1, \tmp
|
|
alternative_else_nop_endif
|
|
#endif
|
|
.endm
|
|
|
|
.text
|
|
|
|
/*
|
|
* Exception vectors.
|
|
*/
|
|
.pushsection ".entry.text", "ax"
|
|
|
|
.align 11
|
|
SYM_CODE_START(vectors)
|
|
kernel_ventry 1, sync_invalid // Synchronous EL1t
|
|
kernel_ventry 1, irq_invalid // IRQ EL1t
|
|
kernel_ventry 1, fiq_invalid // FIQ EL1t
|
|
kernel_ventry 1, error_invalid // Error EL1t
|
|
|
|
kernel_ventry 1, sync // Synchronous EL1h
|
|
kernel_ventry 1, irq // IRQ EL1h
|
|
kernel_ventry 1, fiq_invalid // FIQ EL1h
|
|
kernel_ventry 1, error // Error EL1h
|
|
|
|
kernel_ventry 0, sync // Synchronous 64-bit EL0
|
|
kernel_ventry 0, irq // IRQ 64-bit EL0
|
|
kernel_ventry 0, fiq_invalid // FIQ 64-bit EL0
|
|
kernel_ventry 0, error // Error 64-bit EL0
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
kernel_ventry 0, sync_compat, 32 // Synchronous 32-bit EL0
|
|
kernel_ventry 0, irq_compat, 32 // IRQ 32-bit EL0
|
|
kernel_ventry 0, fiq_invalid_compat, 32 // FIQ 32-bit EL0
|
|
kernel_ventry 0, error_compat, 32 // Error 32-bit EL0
|
|
#else
|
|
kernel_ventry 0, sync_invalid, 32 // Synchronous 32-bit EL0
|
|
kernel_ventry 0, irq_invalid, 32 // IRQ 32-bit EL0
|
|
kernel_ventry 0, fiq_invalid, 32 // FIQ 32-bit EL0
|
|
kernel_ventry 0, error_invalid, 32 // Error 32-bit EL0
|
|
#endif
|
|
SYM_CODE_END(vectors)
|
|
|
|
#ifdef CONFIG_VMAP_STACK
|
|
/*
|
|
* We detected an overflow in kernel_ventry, which switched to the
|
|
* overflow stack. Stash the exception regs, and head to our overflow
|
|
* handler.
|
|
*/
|
|
__bad_stack:
|
|
/* Restore the original x0 value */
|
|
mrs x0, tpidrro_el0
|
|
|
|
/*
|
|
* Store the original GPRs to the new stack. The orginal SP (minus
|
|
* S_FRAME_SIZE) was stashed in tpidr_el0 by kernel_ventry.
|
|
*/
|
|
sub sp, sp, #S_FRAME_SIZE
|
|
kernel_entry 1
|
|
mrs x0, tpidr_el0
|
|
add x0, x0, #S_FRAME_SIZE
|
|
str x0, [sp, #S_SP]
|
|
|
|
/* Stash the regs for handle_bad_stack */
|
|
mov x0, sp
|
|
|
|
/* Time to die */
|
|
bl handle_bad_stack
|
|
ASM_BUG()
|
|
#endif /* CONFIG_VMAP_STACK */
|
|
|
|
/*
|
|
* Invalid mode handlers
|
|
*/
|
|
.macro inv_entry, el, reason, regsize = 64
|
|
kernel_entry \el, \regsize
|
|
mov x0, sp
|
|
mov x1, #\reason
|
|
mrs x2, esr_el1
|
|
bl bad_mode
|
|
ASM_BUG()
|
|
.endm
|
|
|
|
SYM_CODE_START_LOCAL(el0_sync_invalid)
|
|
inv_entry 0, BAD_SYNC
|
|
SYM_CODE_END(el0_sync_invalid)
|
|
|
|
SYM_CODE_START_LOCAL(el0_irq_invalid)
|
|
inv_entry 0, BAD_IRQ
|
|
SYM_CODE_END(el0_irq_invalid)
|
|
|
|
SYM_CODE_START_LOCAL(el0_fiq_invalid)
|
|
inv_entry 0, BAD_FIQ
|
|
SYM_CODE_END(el0_fiq_invalid)
|
|
|
|
SYM_CODE_START_LOCAL(el0_error_invalid)
|
|
inv_entry 0, BAD_ERROR
|
|
SYM_CODE_END(el0_error_invalid)
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
SYM_CODE_START_LOCAL(el0_fiq_invalid_compat)
|
|
inv_entry 0, BAD_FIQ, 32
|
|
SYM_CODE_END(el0_fiq_invalid_compat)
|
|
#endif
|
|
|
|
SYM_CODE_START_LOCAL(el1_sync_invalid)
|
|
inv_entry 1, BAD_SYNC
|
|
SYM_CODE_END(el1_sync_invalid)
|
|
|
|
SYM_CODE_START_LOCAL(el1_irq_invalid)
|
|
inv_entry 1, BAD_IRQ
|
|
SYM_CODE_END(el1_irq_invalid)
|
|
|
|
SYM_CODE_START_LOCAL(el1_fiq_invalid)
|
|
inv_entry 1, BAD_FIQ
|
|
SYM_CODE_END(el1_fiq_invalid)
|
|
|
|
SYM_CODE_START_LOCAL(el1_error_invalid)
|
|
inv_entry 1, BAD_ERROR
|
|
SYM_CODE_END(el1_error_invalid)
|
|
|
|
/*
|
|
* EL1 mode handlers.
|
|
*/
|
|
.align 6
|
|
SYM_CODE_START_LOCAL_NOALIGN(el1_sync)
|
|
kernel_entry 1
|
|
mov x0, sp
|
|
bl el1_sync_handler
|
|
kernel_exit 1
|
|
SYM_CODE_END(el1_sync)
|
|
|
|
.align 6
|
|
SYM_CODE_START_LOCAL_NOALIGN(el1_irq)
|
|
kernel_entry 1
|
|
gic_prio_irq_setup pmr=x20, tmp=x1
|
|
enable_da_f
|
|
|
|
#ifdef CONFIG_ARM64_PSEUDO_NMI
|
|
test_irqs_unmasked res=x0, pmr=x20
|
|
cbz x0, 1f
|
|
bl asm_nmi_enter
|
|
1:
|
|
#endif
|
|
|
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
|
bl trace_hardirqs_off
|
|
#endif
|
|
|
|
irq_handler
|
|
|
|
#ifdef CONFIG_PREEMPTION
|
|
ldr x24, [tsk, #TSK_TI_PREEMPT] // get preempt count
|
|
alternative_if ARM64_HAS_IRQ_PRIO_MASKING
|
|
/*
|
|
* DA_F were cleared at start of handling. If anything is set in DAIF,
|
|
* we come back from an NMI, so skip preemption
|
|
*/
|
|
mrs x0, daif
|
|
orr x24, x24, x0
|
|
alternative_else_nop_endif
|
|
cbnz x24, 1f // preempt count != 0 || NMI return path
|
|
bl arm64_preempt_schedule_irq // irq en/disable is done inside
|
|
1:
|
|
#endif
|
|
|
|
#ifdef CONFIG_ARM64_PSEUDO_NMI
|
|
/*
|
|
* When using IRQ priority masking, we can get spurious interrupts while
|
|
* PMR is set to GIC_PRIO_IRQOFF. An NMI might also have occurred in a
|
|
* section with interrupts disabled. Skip tracing in those cases.
|
|
*/
|
|
test_irqs_unmasked res=x0, pmr=x20
|
|
cbz x0, 1f
|
|
bl asm_nmi_exit
|
|
1:
|
|
#endif
|
|
|
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
|
#ifdef CONFIG_ARM64_PSEUDO_NMI
|
|
test_irqs_unmasked res=x0, pmr=x20
|
|
cbnz x0, 1f
|
|
#endif
|
|
bl trace_hardirqs_on
|
|
1:
|
|
#endif
|
|
|
|
kernel_exit 1
|
|
SYM_CODE_END(el1_irq)
|
|
|
|
/*
|
|
* EL0 mode handlers.
|
|
*/
|
|
.align 6
|
|
SYM_CODE_START_LOCAL_NOALIGN(el0_sync)
|
|
kernel_entry 0
|
|
mov x0, sp
|
|
bl el0_sync_handler
|
|
b ret_to_user
|
|
SYM_CODE_END(el0_sync)
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
.align 6
|
|
SYM_CODE_START_LOCAL_NOALIGN(el0_sync_compat)
|
|
kernel_entry 0, 32
|
|
mov x0, sp
|
|
bl el0_sync_compat_handler
|
|
b ret_to_user
|
|
SYM_CODE_END(el0_sync_compat)
|
|
|
|
.align 6
|
|
SYM_CODE_START_LOCAL_NOALIGN(el0_irq_compat)
|
|
kernel_entry 0, 32
|
|
b el0_irq_naked
|
|
SYM_CODE_END(el0_irq_compat)
|
|
|
|
SYM_CODE_START_LOCAL_NOALIGN(el0_error_compat)
|
|
kernel_entry 0, 32
|
|
b el0_error_naked
|
|
SYM_CODE_END(el0_error_compat)
|
|
#endif
|
|
|
|
.align 6
|
|
SYM_CODE_START_LOCAL_NOALIGN(el0_irq)
|
|
kernel_entry 0
|
|
el0_irq_naked:
|
|
gic_prio_irq_setup pmr=x20, tmp=x0
|
|
ct_user_exit_irqoff
|
|
enable_da_f
|
|
|
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
|
bl trace_hardirqs_off
|
|
#endif
|
|
|
|
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
|
|
tbz x22, #55, 1f
|
|
bl do_el0_irq_bp_hardening
|
|
1:
|
|
#endif
|
|
irq_handler
|
|
|
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
|
bl trace_hardirqs_on
|
|
#endif
|
|
b ret_to_user
|
|
SYM_CODE_END(el0_irq)
|
|
|
|
SYM_CODE_START_LOCAL(el1_error)
|
|
kernel_entry 1
|
|
mrs x1, esr_el1
|
|
gic_prio_kentry_setup tmp=x2
|
|
enable_dbg
|
|
mov x0, sp
|
|
bl do_serror
|
|
kernel_exit 1
|
|
SYM_CODE_END(el1_error)
|
|
|
|
SYM_CODE_START_LOCAL(el0_error)
|
|
kernel_entry 0
|
|
el0_error_naked:
|
|
mrs x25, esr_el1
|
|
gic_prio_kentry_setup tmp=x2
|
|
ct_user_exit_irqoff
|
|
enable_dbg
|
|
mov x0, sp
|
|
mov x1, x25
|
|
bl do_serror
|
|
enable_da_f
|
|
b ret_to_user
|
|
SYM_CODE_END(el0_error)
|
|
|
|
/*
|
|
* "slow" syscall return path.
|
|
*/
|
|
SYM_CODE_START_LOCAL(ret_to_user)
|
|
disable_daif
|
|
gic_prio_kentry_setup tmp=x3
|
|
ldr x1, [tsk, #TSK_TI_FLAGS]
|
|
and x2, x1, #_TIF_WORK_MASK
|
|
cbnz x2, work_pending
|
|
finish_ret_to_user:
|
|
enable_step_tsk x1, x2
|
|
#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
|
|
bl stackleak_erase
|
|
#endif
|
|
kernel_exit 0
|
|
|
|
/*
|
|
* Ok, we need to do extra processing, enter the slow path.
|
|
*/
|
|
work_pending:
|
|
mov x0, sp // 'regs'
|
|
bl do_notify_resume
|
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
|
bl trace_hardirqs_on // enabled while in userspace
|
|
#endif
|
|
ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for single-step
|
|
b finish_ret_to_user
|
|
SYM_CODE_END(ret_to_user)
|
|
|
|
.popsection // .entry.text
|
|
|
|
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
|
|
/*
|
|
* Exception vectors trampoline.
|
|
*/
|
|
.pushsection ".entry.tramp.text", "ax"
|
|
|
|
.macro tramp_map_kernel, tmp
|
|
mrs \tmp, ttbr1_el1
|
|
add \tmp, \tmp, #(PAGE_SIZE + RESERVED_TTBR0_SIZE)
|
|
bic \tmp, \tmp, #USER_ASID_FLAG
|
|
msr ttbr1_el1, \tmp
|
|
#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1003
|
|
alternative_if ARM64_WORKAROUND_QCOM_FALKOR_E1003
|
|
/* ASID already in \tmp[63:48] */
|
|
movk \tmp, #:abs_g2_nc:(TRAMP_VALIAS >> 12)
|
|
movk \tmp, #:abs_g1_nc:(TRAMP_VALIAS >> 12)
|
|
/* 2MB boundary containing the vectors, so we nobble the walk cache */
|
|
movk \tmp, #:abs_g0_nc:((TRAMP_VALIAS & ~(SZ_2M - 1)) >> 12)
|
|
isb
|
|
tlbi vae1, \tmp
|
|
dsb nsh
|
|
alternative_else_nop_endif
|
|
#endif /* CONFIG_QCOM_FALKOR_ERRATUM_1003 */
|
|
.endm
|
|
|
|
.macro tramp_unmap_kernel, tmp
|
|
mrs \tmp, ttbr1_el1
|
|
sub \tmp, \tmp, #(PAGE_SIZE + RESERVED_TTBR0_SIZE)
|
|
orr \tmp, \tmp, #USER_ASID_FLAG
|
|
msr ttbr1_el1, \tmp
|
|
/*
|
|
* We avoid running the post_ttbr_update_workaround here because
|
|
* it's only needed by Cavium ThunderX, which requires KPTI to be
|
|
* disabled.
|
|
*/
|
|
.endm
|
|
|
|
.macro tramp_ventry, regsize = 64
|
|
.align 7
|
|
1:
|
|
.if \regsize == 64
|
|
msr tpidrro_el0, x30 // Restored in kernel_ventry
|
|
.endif
|
|
/*
|
|
* Defend against branch aliasing attacks by pushing a dummy
|
|
* entry onto the return stack and using a RET instruction to
|
|
* enter the full-fat kernel vectors.
|
|
*/
|
|
bl 2f
|
|
b .
|
|
2:
|
|
tramp_map_kernel x30
|
|
#ifdef CONFIG_RANDOMIZE_BASE
|
|
adr x30, tramp_vectors + PAGE_SIZE
|
|
alternative_insn isb, nop, ARM64_WORKAROUND_QCOM_FALKOR_E1003
|
|
ldr x30, [x30]
|
|
#else
|
|
ldr x30, =vectors
|
|
#endif
|
|
alternative_if_not ARM64_WORKAROUND_CAVIUM_TX2_219_PRFM
|
|
prfm plil1strm, [x30, #(1b - tramp_vectors)]
|
|
alternative_else_nop_endif
|
|
msr vbar_el1, x30
|
|
add x30, x30, #(1b - tramp_vectors)
|
|
isb
|
|
ret
|
|
.endm
|
|
|
|
.macro tramp_exit, regsize = 64
|
|
adr x30, tramp_vectors
|
|
msr vbar_el1, x30
|
|
tramp_unmap_kernel x30
|
|
.if \regsize == 64
|
|
mrs x30, far_el1
|
|
.endif
|
|
eret
|
|
sb
|
|
.endm
|
|
|
|
.align 11
|
|
SYM_CODE_START_NOALIGN(tramp_vectors)
|
|
.space 0x400
|
|
|
|
tramp_ventry
|
|
tramp_ventry
|
|
tramp_ventry
|
|
tramp_ventry
|
|
|
|
tramp_ventry 32
|
|
tramp_ventry 32
|
|
tramp_ventry 32
|
|
tramp_ventry 32
|
|
SYM_CODE_END(tramp_vectors)
|
|
|
|
SYM_CODE_START(tramp_exit_native)
|
|
tramp_exit
|
|
SYM_CODE_END(tramp_exit_native)
|
|
|
|
SYM_CODE_START(tramp_exit_compat)
|
|
tramp_exit 32
|
|
SYM_CODE_END(tramp_exit_compat)
|
|
|
|
.ltorg
|
|
.popsection // .entry.tramp.text
|
|
#ifdef CONFIG_RANDOMIZE_BASE
|
|
.pushsection ".rodata", "a"
|
|
.align PAGE_SHIFT
|
|
SYM_DATA_START(__entry_tramp_data_start)
|
|
.quad vectors
|
|
SYM_DATA_END(__entry_tramp_data_start)
|
|
.popsection // .rodata
|
|
#endif /* CONFIG_RANDOMIZE_BASE */
|
|
#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
|
|
|
|
/*
|
|
* Register switch for AArch64. The callee-saved registers need to be saved
|
|
* and restored. On entry:
|
|
* x0 = previous task_struct (must be preserved across the switch)
|
|
* x1 = next task_struct
|
|
* Previous and next are guaranteed not to be the same.
|
|
*
|
|
*/
|
|
SYM_FUNC_START(cpu_switch_to)
|
|
mov x10, #THREAD_CPU_CONTEXT
|
|
add x8, x0, x10
|
|
mov x9, sp
|
|
stp x19, x20, [x8], #16 // store callee-saved registers
|
|
stp x21, x22, [x8], #16
|
|
stp x23, x24, [x8], #16
|
|
stp x25, x26, [x8], #16
|
|
stp x27, x28, [x8], #16
|
|
stp x29, x9, [x8], #16
|
|
str lr, [x8]
|
|
add x8, x1, x10
|
|
ldp x19, x20, [x8], #16 // restore callee-saved registers
|
|
ldp x21, x22, [x8], #16
|
|
ldp x23, x24, [x8], #16
|
|
ldp x25, x26, [x8], #16
|
|
ldp x27, x28, [x8], #16
|
|
ldp x29, x9, [x8], #16
|
|
ldr lr, [x8]
|
|
mov sp, x9
|
|
msr sp_el0, x1
|
|
ptrauth_keys_install_kernel x1, x8, x9, x10
|
|
scs_save x0, x8
|
|
scs_load x1, x8
|
|
ret
|
|
SYM_FUNC_END(cpu_switch_to)
|
|
NOKPROBE(cpu_switch_to)
|
|
|
|
/*
|
|
* This is how we return from a fork.
|
|
*/
|
|
SYM_CODE_START(ret_from_fork)
|
|
bl schedule_tail
|
|
cbz x19, 1f // not a kernel thread
|
|
mov x0, x20
|
|
blr x19
|
|
1: get_current_task tsk
|
|
b ret_to_user
|
|
SYM_CODE_END(ret_from_fork)
|
|
NOKPROBE(ret_from_fork)
|
|
|
|
#ifdef CONFIG_ARM_SDE_INTERFACE
|
|
|
|
#include <asm/sdei.h>
|
|
#include <uapi/linux/arm_sdei.h>
|
|
|
|
.macro sdei_handler_exit exit_mode
|
|
/* On success, this call never returns... */
|
|
cmp \exit_mode, #SDEI_EXIT_SMC
|
|
b.ne 99f
|
|
smc #0
|
|
b .
|
|
99: hvc #0
|
|
b .
|
|
.endm
|
|
|
|
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
|
|
/*
|
|
* The regular SDEI entry point may have been unmapped along with the rest of
|
|
* the kernel. This trampoline restores the kernel mapping to make the x1 memory
|
|
* argument accessible.
|
|
*
|
|
* This clobbers x4, __sdei_handler() will restore this from firmware's
|
|
* copy.
|
|
*/
|
|
.ltorg
|
|
.pushsection ".entry.tramp.text", "ax"
|
|
SYM_CODE_START(__sdei_asm_entry_trampoline)
|
|
mrs x4, ttbr1_el1
|
|
tbz x4, #USER_ASID_BIT, 1f
|
|
|
|
tramp_map_kernel tmp=x4
|
|
isb
|
|
mov x4, xzr
|
|
|
|
/*
|
|
* Use reg->interrupted_regs.addr_limit to remember whether to unmap
|
|
* the kernel on exit.
|
|
*/
|
|
1: str x4, [x1, #(SDEI_EVENT_INTREGS + S_ORIG_ADDR_LIMIT)]
|
|
|
|
#ifdef CONFIG_RANDOMIZE_BASE
|
|
adr x4, tramp_vectors + PAGE_SIZE
|
|
add x4, x4, #:lo12:__sdei_asm_trampoline_next_handler
|
|
ldr x4, [x4]
|
|
#else
|
|
ldr x4, =__sdei_asm_handler
|
|
#endif
|
|
br x4
|
|
SYM_CODE_END(__sdei_asm_entry_trampoline)
|
|
NOKPROBE(__sdei_asm_entry_trampoline)
|
|
|
|
/*
|
|
* Make the exit call and restore the original ttbr1_el1
|
|
*
|
|
* x0 & x1: setup for the exit API call
|
|
* x2: exit_mode
|
|
* x4: struct sdei_registered_event argument from registration time.
|
|
*/
|
|
SYM_CODE_START(__sdei_asm_exit_trampoline)
|
|
ldr x4, [x4, #(SDEI_EVENT_INTREGS + S_ORIG_ADDR_LIMIT)]
|
|
cbnz x4, 1f
|
|
|
|
tramp_unmap_kernel tmp=x4
|
|
|
|
1: sdei_handler_exit exit_mode=x2
|
|
SYM_CODE_END(__sdei_asm_exit_trampoline)
|
|
NOKPROBE(__sdei_asm_exit_trampoline)
|
|
.ltorg
|
|
.popsection // .entry.tramp.text
|
|
#ifdef CONFIG_RANDOMIZE_BASE
|
|
.pushsection ".rodata", "a"
|
|
SYM_DATA_START(__sdei_asm_trampoline_next_handler)
|
|
.quad __sdei_asm_handler
|
|
SYM_DATA_END(__sdei_asm_trampoline_next_handler)
|
|
.popsection // .rodata
|
|
#endif /* CONFIG_RANDOMIZE_BASE */
|
|
#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
|
|
|
|
/*
|
|
* Software Delegated Exception entry point.
|
|
*
|
|
* x0: Event number
|
|
* x1: struct sdei_registered_event argument from registration time.
|
|
* x2: interrupted PC
|
|
* x3: interrupted PSTATE
|
|
* x4: maybe clobbered by the trampoline
|
|
*
|
|
* Firmware has preserved x0->x17 for us, we must save/restore the rest to
|
|
* follow SMC-CC. We save (or retrieve) all the registers as the handler may
|
|
* want them.
|
|
*/
|
|
SYM_CODE_START(__sdei_asm_handler)
|
|
stp x2, x3, [x1, #SDEI_EVENT_INTREGS + S_PC]
|
|
stp x4, x5, [x1, #SDEI_EVENT_INTREGS + 16 * 2]
|
|
stp x6, x7, [x1, #SDEI_EVENT_INTREGS + 16 * 3]
|
|
stp x8, x9, [x1, #SDEI_EVENT_INTREGS + 16 * 4]
|
|
stp x10, x11, [x1, #SDEI_EVENT_INTREGS + 16 * 5]
|
|
stp x12, x13, [x1, #SDEI_EVENT_INTREGS + 16 * 6]
|
|
stp x14, x15, [x1, #SDEI_EVENT_INTREGS + 16 * 7]
|
|
stp x16, x17, [x1, #SDEI_EVENT_INTREGS + 16 * 8]
|
|
stp x18, x19, [x1, #SDEI_EVENT_INTREGS + 16 * 9]
|
|
stp x20, x21, [x1, #SDEI_EVENT_INTREGS + 16 * 10]
|
|
stp x22, x23, [x1, #SDEI_EVENT_INTREGS + 16 * 11]
|
|
stp x24, x25, [x1, #SDEI_EVENT_INTREGS + 16 * 12]
|
|
stp x26, x27, [x1, #SDEI_EVENT_INTREGS + 16 * 13]
|
|
stp x28, x29, [x1, #SDEI_EVENT_INTREGS + 16 * 14]
|
|
mov x4, sp
|
|
stp lr, x4, [x1, #SDEI_EVENT_INTREGS + S_LR]
|
|
|
|
mov x19, x1
|
|
|
|
#if defined(CONFIG_VMAP_STACK) || defined(CONFIG_SHADOW_CALL_STACK)
|
|
ldrb w4, [x19, #SDEI_EVENT_PRIORITY]
|
|
#endif
|
|
|
|
#ifdef CONFIG_VMAP_STACK
|
|
/*
|
|
* entry.S may have been using sp as a scratch register, find whether
|
|
* this is a normal or critical event and switch to the appropriate
|
|
* stack for this CPU.
|
|
*/
|
|
cbnz w4, 1f
|
|
ldr_this_cpu dst=x5, sym=sdei_stack_normal_ptr, tmp=x6
|
|
b 2f
|
|
1: ldr_this_cpu dst=x5, sym=sdei_stack_critical_ptr, tmp=x6
|
|
2: mov x6, #SDEI_STACK_SIZE
|
|
add x5, x5, x6
|
|
mov sp, x5
|
|
#endif
|
|
|
|
#ifdef CONFIG_SHADOW_CALL_STACK
|
|
/* Use a separate shadow call stack for normal and critical events */
|
|
cbnz w4, 3f
|
|
adr_this_cpu dst=scs_sp, sym=sdei_shadow_call_stack_normal, tmp=x6
|
|
b 4f
|
|
3: adr_this_cpu dst=scs_sp, sym=sdei_shadow_call_stack_critical, tmp=x6
|
|
4:
|
|
#endif
|
|
|
|
/*
|
|
* We may have interrupted userspace, or a guest, or exit-from or
|
|
* return-to either of these. We can't trust sp_el0, restore it.
|
|
*/
|
|
mrs x28, sp_el0
|
|
ldr_this_cpu dst=x0, sym=__entry_task, tmp=x1
|
|
msr sp_el0, x0
|
|
|
|
/* If we interrupted the kernel point to the previous stack/frame. */
|
|
and x0, x3, #0xc
|
|
mrs x1, CurrentEL
|
|
cmp x0, x1
|
|
csel x29, x29, xzr, eq // fp, or zero
|
|
csel x4, x2, xzr, eq // elr, or zero
|
|
|
|
stp x29, x4, [sp, #-16]!
|
|
mov x29, sp
|
|
|
|
add x0, x19, #SDEI_EVENT_INTREGS
|
|
mov x1, x19
|
|
bl __sdei_handler
|
|
|
|
msr sp_el0, x28
|
|
/* restore regs >x17 that we clobbered */
|
|
mov x4, x19 // keep x4 for __sdei_asm_exit_trampoline
|
|
ldp x28, x29, [x4, #SDEI_EVENT_INTREGS + 16 * 14]
|
|
ldp x18, x19, [x4, #SDEI_EVENT_INTREGS + 16 * 9]
|
|
ldp lr, x1, [x4, #SDEI_EVENT_INTREGS + S_LR]
|
|
mov sp, x1
|
|
|
|
mov x1, x0 // address to complete_and_resume
|
|
/* x0 = (x0 <= 1) ? EVENT_COMPLETE:EVENT_COMPLETE_AND_RESUME */
|
|
cmp x0, #1
|
|
mov_q x2, SDEI_1_0_FN_SDEI_EVENT_COMPLETE
|
|
mov_q x3, SDEI_1_0_FN_SDEI_EVENT_COMPLETE_AND_RESUME
|
|
csel x0, x2, x3, ls
|
|
|
|
ldr_l x2, sdei_exit_mode
|
|
|
|
alternative_if_not ARM64_UNMAP_KERNEL_AT_EL0
|
|
sdei_handler_exit exit_mode=x2
|
|
alternative_else_nop_endif
|
|
|
|
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
|
|
tramp_alias dst=x5, sym=__sdei_asm_exit_trampoline
|
|
br x5
|
|
#endif
|
|
SYM_CODE_END(__sdei_asm_handler)
|
|
NOKPROBE(__sdei_asm_handler)
|
|
#endif /* CONFIG_ARM_SDE_INTERFACE */
|