Differential D2199 Diff 4804 head/sys/arm64/arm64/trap.c

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head/sys/arm64/arm64/trap.c

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				/*-
				* Copyright (c) 2014 Andrew Turner
				* All rights reserved.
				*
				* Redistribution and use in source and binary forms, with or without
				* modification, are permitted provided that the following conditions
				* are met:
				* 1. Redistributions of source code must retain the above copyright
				* notice, this list of conditions and the following disclaimer.
				* 2. Redistributions in binary form must reproduce the above copyright
				* notice, this list of conditions and the following disclaimer in the
				* documentation and/or other materials provided with the distribution.
				*
				* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
				* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
				* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
				* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
				* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
				* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
				* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
				* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
				* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
				* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
				* SUCH DAMAGE.
				*
				*/

				#include <sys/cdefs.h>
				__FBSDID("$FreeBSD$");

				#include <sys/param.h>
				#include <sys/systm.h>
				#include <sys/kernel.h>
				#include <sys/lock.h>
				#include <sys/mutex.h>
				#include <sys/pioctl.h>
				#include <sys/proc.h>
				#include <sys/ptrace.h>
				#include <sys/syscall.h>
				#include <sys/sysent.h>
				#ifdef KDB
				#include <sys/kdb.h>
				#endif

				#include <vm/vm.h>
				#include <vm/pmap.h>
				#include <vm/vm_kern.h>
				#include <vm/vm_map.h>
				#include <vm/vm_extern.h>

				#include <machine/frame.h>
				#include <machine/pcb.h>
				#include <machine/pcpu.h>
				#include <machine/vmparam.h>

				#ifdef VFP
				#include <machine/vfp.h>
				#endif

				#ifdef KDB
				#include <machine/db_machdep.h>
				#endif

				#ifdef DDB
				#include <ddb/db_output.h>
				#endif

				extern uintptr_t fsu_intr_fault;

				/* Called from exception.S */
				void do_el1h_sync(struct trapframe *);
				void do_el0_sync(struct trapframe *);
				void do_el0_error(struct trapframe *);

				static __inline void
				call_trapsignal(struct thread *td, int sig, u_long code)
				{
				ksiginfo_t ksi;

				ksiginfo_init_trap(&ksi);
				ksi.ksi_signo = sig;
				ksi.ksi_code = (int)code;
				trapsignal(td, &ksi);
				}

				int
				cpu_fetch_syscall_args(struct thread td, struct syscall_args sa)
				{
				struct proc *p;
				register_t *ap;
				int nap;

				nap = 8;
				p = td->td_proc;
				ap = td->td_frame->tf_x;

				sa->code = td->td_frame->tf_x[8];

				if (sa->code == SYS_syscall \|\| sa->code == SYS___syscall) {
				sa->code = *ap++;
				nap--;
				}

				if (p->p_sysent->sv_mask)
				sa->code &= p->p_sysent->sv_mask;
				if (sa->code >= p->p_sysent->sv_size)
				sa->callp = &p->p_sysent->sv_table[0];
				else
				sa->callp = &p->p_sysent->sv_table[sa->code];

				sa->narg = sa->callp->sy_narg;
				memcpy(sa->args, ap, nap * sizeof(register_t));
				if (sa->narg > nap)
				panic("TODO: Could we have more then 8 args?");

				td->td_retval[0] = 0;
				td->td_retval[1] = 0;

				return (0);
				}

				#include "../../kern/subr_syscall.c"

				static void
				svc_handler(struct trapframe *frame)
				{
				struct syscall_args sa;
				struct thread *td;
				int error;

				td = curthread;
				td->td_frame = frame;

				error = syscallenter(td, &sa);
				syscallret(td, error, &sa);
				}

				static void
				data_abort(struct trapframe *frame, uint64_t esr, int lower)
				{
				struct vm_map *map;
				struct thread *td;
				struct proc *p;
				struct pcb *pcb;
				vm_prot_t ftype;
				vm_offset_t va;
				uint64_t far;
				int error, sig;

				td = curthread;
				pcb = td->td_pcb;

				/*
				* Special case for fuswintr and suswintr. These can't sleep so
				* handle them early on in the trap handler.
				*/
				if (__predict_false(pcb->pcb_onfault == fsu_intr_fault)) {
				frame->tf_elr = pcb->pcb_onfault;
				return;
				}

				far = READ_SPECIALREG(far_el1);
				p = td->td_proc;

				if (lower)
				map = &td->td_proc->p_vmspace->vm_map;
				else {
				/* The top bit tells us which range to use */
				if ((far >> 63) == 1)
				map = kernel_map;
				else
				map = &td->td_proc->p_vmspace->vm_map;
				}

				va = trunc_page(far);
				ftype = ((esr >> 6) & 1) ? VM_PROT_READ \| VM_PROT_WRITE : VM_PROT_READ;

				if (map != kernel_map) {
				/*
				* Keep swapout from messing with us during this
				* critical time.
				*/
				PROC_LOCK(p);
				++p->p_lock;
				PROC_UNLOCK(p);

				/* Fault in the user page: */
				error = vm_fault(map, va, ftype, VM_FAULT_NORMAL);

				PROC_LOCK(p);
				--p->p_lock;
				PROC_UNLOCK(p);
				} else {
				/*
				* Don't have to worry about process locking or stacks in the
				* kernel.
				*/
				error = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
				}

				if (error != 0) {
				if (lower) {
				if (error == ENOMEM)
				sig = SIGKILL;
				else
				sig = SIGSEGV;
				call_trapsignal(td, sig, 0);
				} else {
				if (td->td_intr_nesting_level == 0 &&
				pcb->pcb_onfault != 0) {
				frame->tf_x[0] = error;
				frame->tf_elr = pcb->pcb_onfault;
				return;
				}
				panic("vm_fault failed: %lx", frame->tf_elr);
				}
				}

				if (lower)
				userret(td, frame);
				}

				void
				do_el1h_sync(struct trapframe *frame)
				{
				uint32_t exception;
				uint64_t esr;

				/* Read the esr register to get the exception details */
				esr = READ_SPECIALREG(esr_el1);
				exception = ESR_ELx_EXCEPTION(esr);

				/*
				* Sanity check we are in an exception er can handle. The IL bit
				* is used to indicate the instruction length, except in a few
				* exceptions described in the ARMv8 ARM.
				*
				* It is unclear in some cases if the bit is implementation defined.
				* The Foundation Model and QEMU disagree on if the IL bit should
				* be set when we are in a data fault from the same EL and the ISV
				* bit (bit 24) is also set.
				*/
				KASSERT((esr & ESR_ELx_IL) == ESR_ELx_IL \|\|
				(exception == EXCP_DATA_ABORT && ((esr & ISS_DATA_ISV) == 0)),
				("Invalid instruction length in exception"));

				switch(exception) {
				case EXCP_FP_SIMD:
				case EXCP_TRAP_FP:
				panic("VFP exception in the kernel");
				case EXCP_DATA_ABORT:
				data_abort(frame, esr, 0);
				break;
				case EXCP_BRK:
				case EXCP_WATCHPT_EL1:
				case EXCP_SOFTSTP_EL1:
				#ifdef KDB
				kdb_trap(exception, 0, frame);
				#else
				panic("No debugger in kernel.\n");
				#endif
				break;
				default:
				panic("Unknown kernel exception %x esr_el1 %lx\n", exception,
				esr);
				}
				}

				void
				do_el0_sync(struct trapframe *frame)
				{
				uint32_t exception;
				uint64_t esr;

				/* Check we have a sane environment when entering from userland */
				KASSERT((uintptr_t)get_pcpu() >= VM_MIN_KERNEL_ADDRESS,
				("Invalid pcpu address from userland: %p (tpidr %lx)",
				get_pcpu(), READ_SPECIALREG(tpidr_el1)));

				esr = READ_SPECIALREG(esr_el1);
				exception = ESR_ELx_EXCEPTION(esr);

				switch(exception) {
				case EXCP_FP_SIMD:
				case EXCP_TRAP_FP:
				#ifdef VFP
				vfp_restore_state();
				#else
				panic("VFP exception in userland");
				#endif
				break;
				case EXCP_SVC:
				svc_handler(frame);
				break;
				case EXCP_INSN_ABORT_L:
				case EXCP_DATA_ABORT_L:
				data_abort(frame, esr, 1);
				break;
				default:
				panic("Unknown userland exception %x esr_el1 %lx\n", exception,
				esr);
				}
				}

				void
				do_el0_error(struct trapframe *frame)
				{

				panic("do_el0_error");
				}