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NetBSD/sys/arch/arm/arm32/fault.c

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/* $NetBSD: fault.c,v 1.62 2006/07/23 22:06:04 ad Exp $ */
/*
* Copyright 2003 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Steve C. Woodford for Wasabi Systems, Inc.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
* 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.
*/
/*
* Copyright (c) 1994-1997 Mark Brinicombe.
* Copyright (c) 1994 Brini.
* All rights reserved.
*
* This code is derived from software written for Brini by Mark Brinicombe
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Brini.
* 4. The name of the company nor the name of the author may be used to
* endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY BRINI ``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 BRINI 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.
*
* RiscBSD kernel project
*
* fault.c
*
* Fault handlers
*
* Created : 28/11/94
*/
#include "opt_ddb.h"
#include "opt_kgdb.h"
#include <sys/types.h>
__KERNEL_RCSID(0, "$NetBSD: fault.c,v 1.62 2006/07/23 22:06:04 ad Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/savar.h>
#include <sys/user.h>
#include <sys/kernel.h>
#include <sys/kauth.h>
#include <uvm/uvm_extern.h>
#include <uvm/uvm_stat.h>
#ifdef UVMHIST
#include <uvm/uvm.h>
#endif
#include <arm/cpuconf.h>
#include <machine/frame.h>
#include <arm/arm32/katelib.h>
#include <machine/cpu.h>
#include <machine/intr.h>
#if defined(DDB) || defined(KGDB)
#include <machine/db_machdep.h>
#ifdef KGDB
#include <sys/kgdb.h>
#endif
#if !defined(DDB)
#define kdb_trap kgdb_trap
#endif
#endif
#include <arch/arm/arm/disassem.h>
#include <arm/arm32/machdep.h>
extern char fusubailout[];
#ifdef DEBUG
int last_fault_code; /* For the benefit of pmap_fault_fixup() */
#endif
#if defined(CPU_ARM3) || defined(CPU_ARM6) || \
defined(CPU_ARM7) || defined(CPU_ARM7TDMI)
/* These CPUs may need data/prefetch abort fixups */
#define CPU_ABORT_FIXUP_REQUIRED
#endif
struct data_abort {
int (*func)(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *);
const char *desc;
};
static int dab_fatal(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *);
static int dab_align(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *);
static int dab_buserr(trapframe_t *, u_int, u_int, struct lwp *, ksiginfo_t *);
static const struct data_abort data_aborts[] = {
{dab_fatal, "Vector Exception"},
{dab_align, "Alignment Fault 1"},
{dab_fatal, "Terminal Exception"},
{dab_align, "Alignment Fault 3"},
{dab_buserr, "External Linefetch Abort (S)"},
{NULL, "Translation Fault (S)"},
{dab_buserr, "External Linefetch Abort (P)"},
{NULL, "Translation Fault (P)"},
{dab_buserr, "External Non-Linefetch Abort (S)"},
{NULL, "Domain Fault (S)"},
{dab_buserr, "External Non-Linefetch Abort (P)"},
{NULL, "Domain Fault (P)"},
{dab_buserr, "External Translation Abort (L1)"},
{NULL, "Permission Fault (S)"},
{dab_buserr, "External Translation Abort (L2)"},
{NULL, "Permission Fault (P)"}
};
/* Determine if a fault came from user mode */
#define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE)
/* Determine if 'x' is a permission fault */
#define IS_PERMISSION_FAULT(x) \
(((1 << ((x) & FAULT_TYPE_MASK)) & \
((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0)
#if 0
/* maybe one day we'll do emulations */
#define TRAPSIGNAL(l,k) (*(l)->l_proc->p_emul->e_trapsignal)((l), (k))
#else
#define TRAPSIGNAL(l,k) trapsignal((l), (k))
#endif
static inline void
call_trapsignal(struct lwp *l, ksiginfo_t *ksi)
{
KERNEL_PROC_LOCK(l);
TRAPSIGNAL(l, ksi);
KERNEL_PROC_UNLOCK(l);
}
static inline int
data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l)
{
#ifdef CPU_ABORT_FIXUP_REQUIRED
int error;
/* Call the CPU specific data abort fixup routine */
error = cpu_dataabt_fixup(tf);
if (__predict_true(error != ABORT_FIXUP_FAILED))
return (error);
/*
* Oops, couldn't fix up the instruction
*/
printf("data_abort_fixup: fixup for %s mode data abort failed.\n",
TRAP_USERMODE(tf) ? "user" : "kernel");
#ifdef THUMB_CODE
if (tf->tf_spsr & PSR_T_bit) {
printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ",
tf->tf_pc, *((u_int16 *)(tf->tf_pc & ~1),
*((u_int16 *)((tf->tf_pc + 2) & ~1));
}
else
#endif
{
printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc,
*((u_int *)tf->tf_pc));
}
disassemble(tf->tf_pc);
/* Die now if this happened in kernel mode */
if (!TRAP_USERMODE(tf))
dab_fatal(tf, fsr, far, l, NULL);
return (error);
#else
return (ABORT_FIXUP_OK);
#endif /* CPU_ABORT_FIXUP_REQUIRED */
}
void
data_abort_handler(trapframe_t *tf)
{
struct vm_map *map;
struct pcb *pcb;
struct lwp *l;
u_int user, far, fsr;
vm_prot_t ftype;
void *onfault;
vaddr_t va;
int error;
ksiginfo_t ksi;
UVMHIST_FUNC("data_abort_handler");
/* Grab FAR/FSR before enabling interrupts */
far = cpu_faultaddress();
fsr = cpu_faultstatus();
UVMHIST_CALLED(maphist);
/* Update vmmeter statistics */
uvmexp.traps++;
/* Re-enable interrupts if they were enabled previously */
if (__predict_true((tf->tf_spsr & I32_bit) == 0))
enable_interrupts(I32_bit);
/* Get the current lwp structure or lwp0 if there is none */
l = (curlwp != NULL) ? curlwp : &lwp0;
UVMHIST_LOG(maphist, " (pc=0x%x, l=0x%x, far=0x%x, fsr=0x%x)",
tf->tf_pc, l, far, fsr);
/* Data abort came from user mode? */
if ((user = TRAP_USERMODE(tf)) != 0)
LWP_CACHE_CREDS(l, l->l_proc);
/* Grab the current pcb */
pcb = &l->l_addr->u_pcb;
/* Invoke the appropriate handler, if necessary */
if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) {
if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far,
l, &ksi))
goto do_trapsignal;
goto out;
}
/*
* At this point, we're dealing with one of the following data aborts:
*
* FAULT_TRANS_S - Translation -- Section
* FAULT_TRANS_P - Translation -- Page
* FAULT_DOMAIN_S - Domain -- Section
* FAULT_DOMAIN_P - Domain -- Page
* FAULT_PERM_S - Permission -- Section
* FAULT_PERM_P - Permission -- Page
*
* These are the main virtual memory-related faults signalled by
* the MMU.
*/
/* fusubailout is used by [fs]uswintr to avoid page faulting */
if (__predict_false(pcb->pcb_onfault == fusubailout)) {
tf->tf_r0 = EFAULT;
tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
return;
}
if (user)
l->l_addr->u_pcb.pcb_tf = tf;
/*
* Make sure the Program Counter is sane. We could fall foul of
* someone executing Thumb code, in which case the PC might not
* be word-aligned. This would cause a kernel alignment fault
* further down if we have to decode the current instruction.
*/
#ifdef THUMB_CODE
/*
* XXX: It would be nice to be able to support Thumb in the kernel
* at some point.
*/
if (__predict_false(!user && (tf->tf_pc & 3) != 0)) {
printf("\ndata_abort_fault: Misaligned Kernel-mode "
"Program Counter\n");
dab_fatal(tf, fsr, far, l, NULL);
}
#else
if (__predict_false((tf->tf_pc & 3) != 0)) {
if (user) {
/*
* Give the user an illegal instruction signal.
*/
/* Deliver a SIGILL to the process */
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGILL;
ksi.ksi_code = ILL_ILLOPC;
ksi.ksi_addr = (u_int32_t *)(intptr_t) far;
ksi.ksi_trap = fsr;
goto do_trapsignal;
}
/*
* The kernel never executes Thumb code.
*/
printf("\ndata_abort_fault: Misaligned Kernel-mode "
"Program Counter\n");
dab_fatal(tf, fsr, far, l, NULL);
}
#endif
/* See if the CPU state needs to be fixed up */
switch (data_abort_fixup(tf, fsr, far, l)) {
case ABORT_FIXUP_RETURN:
return;
case ABORT_FIXUP_FAILED:
/* Deliver a SIGILL to the process */
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGILL;
ksi.ksi_code = ILL_ILLOPC;
ksi.ksi_addr = (u_int32_t *)(intptr_t) far;
ksi.ksi_trap = fsr;
goto do_trapsignal;
default:
break;
}
va = trunc_page((vaddr_t)far);
/*
* It is only a kernel address space fault iff:
* 1. user == 0 and
* 2. pcb_onfault not set or
* 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction.
*/
if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS ||
(va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) &&
__predict_true((pcb->pcb_onfault == NULL ||
(ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) {
map = kernel_map;
/* Was the fault due to the FPE/IPKDB ? */
if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) {
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGSEGV;
ksi.ksi_code = SEGV_ACCERR;
ksi.ksi_addr = (u_int32_t *)(intptr_t) far;
ksi.ksi_trap = fsr;
/*
* Force exit via userret()
* This is necessary as the FPE is an extension to
* userland that actually runs in a priveledged mode
* but uses USR mode permissions for its accesses.
*/
user = 1;
goto do_trapsignal;
}
} else {
map = &l->l_proc->p_vmspace->vm_map;
if (l->l_flag & L_SA) {
l->l_savp->savp_faultaddr = (vaddr_t)far;
l->l_flag |= L_SA_PAGEFAULT;
}
}
/*
* We need to know whether the page should be mapped
* as R or R/W. The MMU does not give us the info as
* to whether the fault was caused by a read or a write.
*
* However, we know that a permission fault can only be
* the result of a write to a read-only location, so
* we can deal with those quickly.
*
* Otherwise we need to disassemble the instruction
* responsible to determine if it was a write.
*/
if (IS_PERMISSION_FAULT(fsr))
ftype = VM_PROT_WRITE;
else {
#ifdef THUMB_CODE
/* Fast track the ARM case. */
if (__predict_false(tf->tf_spsr & PSR_T_bit)) {
u_int insn = fusword((void *)(tf->tf_pc & ~1));
u_int insn_f8 = insn & 0xf800;
u_int insn_fe = insn & 0xfe00;
if (insn_f8 == 0x6000 || /* STR(1) */
insn_f8 == 0x7000 || /* STRB(1) */
insn_f8 == 0x8000 || /* STRH(1) */
insn_f8 == 0x9000 || /* STR(3) */
insn_f8 == 0xc000 || /* STM */
insn_fe == 0x5000 || /* STR(2) */
insn_fe == 0x5200 || /* STRH(2) */
insn_fe == 0x5400) /* STRB(2) */
ftype = VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
}
else
#endif
{
u_int insn = ReadWord(tf->tf_pc);
if (((insn & 0x0c100000) == 0x04000000) || /* STR[B] */
((insn & 0x0e1000b0) == 0x000000b0) || /* STR[HD]*/
((insn & 0x0a100000) == 0x08000000)) /* STM/CDT*/
ftype = VM_PROT_WRITE;
else if ((insn & 0x0fb00ff0) == 0x01000090)/* SWP */
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
}
}
/*
* See if the fault is as a result of ref/mod emulation,
* or domain mismatch.
*/
#ifdef DEBUG
last_fault_code = fsr;
#endif
if (pmap_fault_fixup(map->pmap, va, ftype, user)) {
if (map != kernel_map)
l->l_flag &= ~L_SA_PAGEFAULT;
UVMHIST_LOG(maphist, " <- ref/mod emul", 0, 0, 0, 0);
goto out;
}
if (__predict_false(current_intr_depth > 0)) {
if (pcb->pcb_onfault) {
tf->tf_r0 = EINVAL;
tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
return;
}
printf("\nNon-emulated page fault with intr_depth > 0\n");
dab_fatal(tf, fsr, far, l, NULL);
}
onfault = pcb->pcb_onfault;
pcb->pcb_onfault = NULL;
error = uvm_fault(map, va, ftype);
pcb->pcb_onfault = onfault;
if (map != kernel_map)
l->l_flag &= ~L_SA_PAGEFAULT;
if (__predict_true(error == 0)) {
if (user)
uvm_grow(l->l_proc, va); /* Record any stack growth */
UVMHIST_LOG(maphist, " <- uvm", 0, 0, 0, 0);
goto out;
}
if (user == 0) {
if (pcb->pcb_onfault) {
tf->tf_r0 = error;
tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
return;
}
printf("\nuvm_fault(%p, %lx, %x) -> %x\n", map, va, ftype,
error);
dab_fatal(tf, fsr, far, l, NULL);
}
KSI_INIT_TRAP(&ksi);
if (error == ENOMEM) {
printf("UVM: pid %d (%s), uid %d killed: "
"out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm,
l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1);
ksi.ksi_signo = SIGKILL;
} else
ksi.ksi_signo = SIGSEGV;
ksi.ksi_code = (error == EACCES) ? SEGV_ACCERR : SEGV_MAPERR;
ksi.ksi_addr = (u_int32_t *)(intptr_t) far;
ksi.ksi_trap = fsr;
UVMHIST_LOG(maphist, " <- erorr (%d)", error, 0, 0, 0);
do_trapsignal:
call_trapsignal(l, &ksi);
out:
/* If returning to user mode, make sure to invoke userret() */
if (user)
userret(l);
}
/*
* dab_fatal() handles the following data aborts:
*
* FAULT_WRTBUF_0 - Vector Exception
* FAULT_WRTBUF_1 - Terminal Exception
*
* We should never see these on a properly functioning system.
*
* This function is also called by the other handlers if they
* detect a fatal problem.
*
* Note: If 'l' is NULL, we assume we're dealing with a prefetch abort.
*/
static int
dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi)
{
const char *mode;
mode = TRAP_USERMODE(tf) ? "user" : "kernel";
if (l != NULL) {
printf("Fatal %s mode data abort: '%s'\n", mode,
data_aborts[fsr & FAULT_TYPE_MASK].desc);
printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr);
if ((fsr & FAULT_IMPRECISE) == 0)
printf("%08x, ", far);
else
printf("Invalid, ");
printf("spsr=%08x\n", tf->tf_spsr);
} else {
printf("Fatal %s mode prefetch abort at 0x%08x\n",
mode, tf->tf_pc);
printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr);
}
printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n",
tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3);
printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n",
tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7);
printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n",
tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11);
printf("r12=%08x, ", tf->tf_r12);
if (TRAP_USERMODE(tf))
printf("usp=%08x, ulr=%08x",
tf->tf_usr_sp, tf->tf_usr_lr);
else
printf("ssp=%08x, slr=%08x",
tf->tf_svc_sp, tf->tf_svc_lr);
printf(", pc =%08x\n\n", tf->tf_pc);
#if defined(DDB) || defined(KGDB)
kdb_trap(T_FAULT, tf);
#endif
panic("Fatal abort");
/*NOTREACHED*/
}
/*
* dab_align() handles the following data aborts:
*
* FAULT_ALIGN_0 - Alignment fault
* FAULT_ALIGN_0 - Alignment fault
*
* These faults are fatal if they happen in kernel mode. Otherwise, we
* deliver a bus error to the process.
*/
static int
dab_align(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi)
{
/* Alignment faults are always fatal if they occur in kernel mode */
if (!TRAP_USERMODE(tf))
dab_fatal(tf, fsr, far, l, NULL);
/* pcb_onfault *must* be NULL at this point */
KDASSERT(l->l_addr->u_pcb.pcb_onfault == NULL);
/* See if the CPU state needs to be fixed up */
(void) data_abort_fixup(tf, fsr, far, l);
/* Deliver a bus error signal to the process */
KSI_INIT_TRAP(ksi);
ksi->ksi_signo = SIGBUS;
ksi->ksi_code = BUS_ADRALN;
ksi->ksi_addr = (u_int32_t *)(intptr_t)far;
ksi->ksi_trap = fsr;
l->l_addr->u_pcb.pcb_tf = tf;
return (1);
}
/*
* dab_buserr() handles the following data aborts:
*
* FAULT_BUSERR_0 - External Abort on Linefetch -- Section
* FAULT_BUSERR_1 - External Abort on Linefetch -- Page
* FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section
* FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page
* FAULT_BUSTRNL1 - External abort on Translation -- Level 1
* FAULT_BUSTRNL2 - External abort on Translation -- Level 2
*
* If pcb_onfault is set, flag the fault and return to the handler.
* If the fault occurred in user mode, give the process a SIGBUS.
*
* Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2
* can be flagged as imprecise in the FSR. This causes a real headache
* since some of the machine state is lost. In this case, tf->tf_pc
* may not actually point to the offending instruction. In fact, if
* we've taken a double abort fault, it generally points somewhere near
* the top of "data_abort_entry" in exception.S.
*
* In all other cases, these data aborts are considered fatal.
*/
static int
dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l,
ksiginfo_t *ksi)
{
struct pcb *pcb = &l->l_addr->u_pcb;
#ifdef __XSCALE__
if ((fsr & FAULT_IMPRECISE) != 0 &&
(tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) {
/*
* Oops, an imprecise, double abort fault. We've lost the
* r14_abt/spsr_abt values corresponding to the original
* abort, and the spsr saved in the trapframe indicates
* ABT mode.
*/
tf->tf_spsr &= ~PSR_MODE;
/*
* We use a simple heuristic to determine if the double abort
* happened as a result of a kernel or user mode access.
* If the current trapframe is at the top of the kernel stack,
* the fault _must_ have come from user mode.
*/
if (tf != ((trapframe_t *)pcb->pcb_un.un_32.pcb32_sp) - 1) {
/*
* Kernel mode. We're either about to die a
* spectacular death, or pcb_onfault will come
* to our rescue. Either way, the current value
* of tf->tf_pc is irrelevant.
*/
tf->tf_spsr |= PSR_SVC32_MODE;
if (pcb->pcb_onfault == NULL)
printf("\nKernel mode double abort!\n");
} else {
/*
* User mode. We've lost the program counter at the
* time of the fault (not that it was accurate anyway;
* it's not called an imprecise fault for nothing).
* About all we can do is copy r14_usr to tf_pc and
* hope for the best. The process is about to get a
* SIGBUS, so it's probably history anyway.
*/
tf->tf_spsr |= PSR_USR32_MODE;
tf->tf_pc = tf->tf_usr_lr;
#ifdef THUMB_CODE
tf->tf_spsr &= ~PSR_T_bit;
if (tf->tf_usr_lr & 1)
tf->tf_spsr |= PSR_T_bit;
#endif
}
}
/* FAR is invalid for imprecise exceptions */
if ((fsr & FAULT_IMPRECISE) != 0)
far = 0;
#endif /* __XSCALE__ */
if (pcb->pcb_onfault) {
KDASSERT(TRAP_USERMODE(tf) == 0);
tf->tf_r0 = EFAULT;
tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
return (0);
}
/* See if the CPU state needs to be fixed up */
(void) data_abort_fixup(tf, fsr, far, l);
/*
* At this point, if the fault happened in kernel mode, we're toast
*/
if (!TRAP_USERMODE(tf))
dab_fatal(tf, fsr, far, l, NULL);
/* Deliver a bus error signal to the process */
KSI_INIT_TRAP(ksi);
ksi->ksi_signo = SIGBUS;
ksi->ksi_code = BUS_ADRERR;
ksi->ksi_addr = (u_int32_t *)(intptr_t)far;
ksi->ksi_trap = fsr;
l->l_addr->u_pcb.pcb_tf = tf;
return (1);
}
static inline int
prefetch_abort_fixup(trapframe_t *tf)
{
#ifdef CPU_ABORT_FIXUP_REQUIRED
int error;
/* Call the CPU specific prefetch abort fixup routine */
error = cpu_prefetchabt_fixup(tf);
if (__predict_true(error != ABORT_FIXUP_FAILED))
return (error);
/*
* Oops, couldn't fix up the instruction
*/
printf(
"prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n",
TRAP_USERMODE(tf) ? "user" : "kernel");
#ifdef THUMB_CODE
if (tf->tf_spsr & PSR_T_bit) {
printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ",
tf->tf_pc, *((u_int16 *)(tf->tf_pc & ~1),
*((u_int16 *)((tf->tf_pc + 2) & ~1));
}
else
#endif
{
printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc,
*((u_int *)tf->tf_pc));
}
disassemble(tf->tf_pc);
/* Die now if this happened in kernel mode */
if (!TRAP_USERMODE(tf))
dab_fatal(tf, 0, tf->tf_pc, NULL, NULL);
return (error);
#else
return (ABORT_FIXUP_OK);
#endif /* CPU_ABORT_FIXUP_REQUIRED */
}
/*
* void prefetch_abort_handler(trapframe_t *tf)
*
* Abort handler called when instruction execution occurs at
* a non existent or restricted (access permissions) memory page.
* If the address is invalid and we were in SVC mode then panic as
* the kernel should never prefetch abort.
* If the address is invalid and the page is mapped then the user process
* does no have read permission so send it a signal.
* Otherwise fault the page in and try again.
*/
void
prefetch_abort_handler(trapframe_t *tf)
{
struct lwp *l;
struct vm_map *map;
vaddr_t fault_pc, va;
ksiginfo_t ksi;
int error, user;
UVMHIST_FUNC("prefetch_abort_handler"); UVMHIST_CALLED(maphist);
/* Update vmmeter statistics */
uvmexp.traps++;
l = curlwp;
if ((user = TRAP_USERMODE(tf)) != 0)
LWP_CACHE_CREDS(l, l->l_proc);
/*
* Enable IRQ's (disabled by the abort) This always comes
* from user mode so we know interrupts were not disabled.
* But we check anyway.
*/
if (__predict_true((tf->tf_spsr & I32_bit) == 0))
enable_interrupts(I32_bit);
/* See if the CPU state needs to be fixed up */
switch (prefetch_abort_fixup(tf)) {
case ABORT_FIXUP_RETURN:
return;
case ABORT_FIXUP_FAILED:
/* Deliver a SIGILL to the process */
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGILL;
ksi.ksi_code = ILL_ILLOPC;
ksi.ksi_addr = (u_int32_t *)(intptr_t) tf->tf_pc;
l->l_addr->u_pcb.pcb_tf = tf;
goto do_trapsignal;
default:
break;
}
/* Prefetch aborts cannot happen in kernel mode */
if (__predict_false(!user))
dab_fatal(tf, 0, tf->tf_pc, NULL, NULL);
/* Get fault address */
fault_pc = tf->tf_pc;
l = curlwp;
l->l_addr->u_pcb.pcb_tf = tf;
UVMHIST_LOG(maphist, " (pc=0x%x, l=0x%x, tf=0x%x)", fault_pc, l, tf,
0);
/* Ok validate the address, can only execute in USER space */
if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS ||
(fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) {
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGSEGV;
ksi.ksi_code = SEGV_ACCERR;
ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
ksi.ksi_trap = fault_pc;
goto do_trapsignal;
}
map = &l->l_proc->p_vmspace->vm_map;
va = trunc_page(fault_pc);
/*
* See if the pmap can handle this fault on its own...
*/
#ifdef DEBUG
last_fault_code = -1;
#endif
if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) {
UVMHIST_LOG (maphist, " <- emulated", 0, 0, 0, 0);
goto out;
}
#ifdef DIAGNOSTIC
if (__predict_false(current_intr_depth > 0)) {
printf("\nNon-emulated prefetch abort with intr_depth > 0\n");
dab_fatal(tf, 0, tf->tf_pc, NULL, NULL);
}
#endif
if (map != kernel_map && l->l_flag & L_SA) {
l->l_savp->savp_faultaddr = fault_pc;
l->l_flag |= L_SA_PAGEFAULT;
}
error = uvm_fault(map, va, VM_PROT_READ);
if (map != kernel_map)
l->l_flag &= ~L_SA_PAGEFAULT;
if (__predict_true(error == 0)) {
UVMHIST_LOG (maphist, " <- uvm", 0, 0, 0, 0);
goto out;
}
KSI_INIT_TRAP(&ksi);
UVMHIST_LOG (maphist, " <- fatal (%d)", error, 0, 0, 0);
if (error == ENOMEM) {
printf("UVM: pid %d (%s), uid %d killed: "
"out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm,
l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1);
ksi.ksi_signo = SIGKILL;
} else
ksi.ksi_signo = SIGSEGV;
ksi.ksi_code = SEGV_MAPERR;
ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
ksi.ksi_trap = fault_pc;
do_trapsignal:
call_trapsignal(l, &ksi);
out:
userret(l);
}
/*
* Tentatively read an 8, 16, or 32-bit value from 'addr'.
* If the read succeeds, the value is written to 'rptr' and zero is returned.
* Else, return EFAULT.
*/
int
badaddr_read(void *addr, size_t size, void *rptr)
{
extern int badaddr_read_1(const uint8_t *, uint8_t *);
extern int badaddr_read_2(const uint16_t *, uint16_t *);
extern int badaddr_read_4(const uint32_t *, uint32_t *);
union {
uint8_t v1;
uint16_t v2;
uint32_t v4;
} u;
struct pcb *curpcb_save;
int rv, s;
cpu_drain_writebuf();
/*
* We might be called at interrupt time, so arrange to steal
* lwp0's PCB temporarily, if required, so that pcb_onfault
* handling works correctly.
*/
s = splhigh();
if ((curpcb_save = curpcb) == NULL)
curpcb = &lwp0.l_addr->u_pcb;
/* Read from the test address. */
switch (size) {
case sizeof(uint8_t):
rv = badaddr_read_1(addr, &u.v1);
if (rv == 0 && rptr)
*(uint8_t *) rptr = u.v1;
break;
case sizeof(uint16_t):
rv = badaddr_read_2(addr, &u.v2);
if (rv == 0 && rptr)
*(uint16_t *) rptr = u.v2;
break;
case sizeof(uint32_t):
rv = badaddr_read_4(addr, &u.v4);
if (rv == 0 && rptr)
*(uint32_t *) rptr = u.v4;
break;
default:
curpcb = curpcb_save;
panic("badaddr: invalid size (%lu)", (u_long) size);
}
/* Restore curpcb */
curpcb = curpcb_save;
splx(s);
/* Return EFAULT if the address was invalid, else zero */
return (rv);
}
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