void MachineCheckException(struct pt_regs *regs)
{
unsigned long fixup, val;
if ((fixup = search_exception_table(regs->nip)) != 0) {
regs->nip = fixup;
val = mfspr(MCSR);
/* Clear MCSR */
mtspr(SPRN_MCSR, val);
return;
}
rt_kprintf("Machine Check Exception.\n");
rt_kprintf("Caused by (from msr): ");
rt_kprintf("regs %p ", regs);
val = get_esr();
if (val& ESR_IMCP) {
rt_kprintf("Instruction");
mtspr(ESR, val & ~ESR_IMCP);
} else {
rt_kprintf("Data");
}
rt_kprintf(" machine check.\n");
show_regs(regs);
print_backtrace((unsigned long *)regs->gpr[1]);
panic("machine check");
}
/*
* Oops. The kernel tried to access some page that wasn't present.
*/
static void
__do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
struct pt_regs *regs)
{
unsigned long fixup;
/*
* Are we prepared to handle this kernel fault?
*/
if ((fixup = search_exception_table(instruction_pointer(regs))) != 0) {
#ifdef DEBUG
printk(KERN_DEBUG "%s: Exception at [<%lx>] addr=%lx (fixup: %lx)\n",
current->comm, regs->ARM_pc, addr, fixup);
#endif
regs->ARM_pc = fixup;
return;
}
/*
* No handler, we'll have to terminate things with extreme prejudice.
*/
printk(KERN_ALERT
"Unable to handle kernel %s at virtual address %08lx\n",
(addr < PAGE_SIZE) ? "NULL pointer dereference" :
"paging request", addr);
show_pte(mm, addr);
die("Oops", regs, fsr);
do_exit(SIGKILL);
}
/*
* instruction or data access exception
*/
asmlinkage void memory_access_exception(unsigned long esr0,
unsigned long ear0,
unsigned long epcr0)
{
siginfo_t info;
#ifdef CONFIG_MMU
unsigned long fixup;
fixup = search_exception_table(__frame->pc);
if (fixup) {
__frame->pc = fixup;
return;
}
#endif
die_if_kernel("-- Memory Access Exception --\n"
"ESR0 : %08lx\n"
"EAR0 : %08lx\n"
"EPCR0 : %08lx\n",
esr0, ear0, epcr0);
info.si_signo = SIGSEGV;
info.si_code = SEGV_ACCERR;
info.si_errno = 0;
info.si_addr = NULL;
if ((esr0 & (ESRx_VALID | ESR0_EAV)) == (ESRx_VALID | ESR0_EAV))
info.si_addr = (void __user *) ear0;
force_sig_info(info.si_signo, &info, current);
} /* end memory_access_exception() */
int arch_fixup(unsigned long address, void *sc_ptr)
{
struct sigcontext *sc = sc_ptr;
unsigned long fixup;
fixup = search_exception_table(address);
if(fixup != 0) {
sc->eip = fixup;
return(1);
}
return(0);
}
int send_fault_sig(struct pt_regs *regs)
{
siginfo_t siginfo = { 0, 0, 0, };
siginfo.si_signo = current->thread.signo;
siginfo.si_code = current->thread.code;
siginfo.si_addr = (void *)current->thread.faddr;
#ifdef DEBUG
printk("send_fault_sig: %p,%d,%d\n", siginfo.si_addr, siginfo.si_signo, siginfo.si_code);
#endif
if (user_mode(regs)) {
force_sig_info(siginfo.si_signo,
&siginfo, current);
} else {
unsigned long fixup;
/* Are we prepared to handle this kernel fault? */
if ((fixup = search_exception_table(regs->pc))) {
struct pt_regs *tregs;
/* Create a new four word stack frame, discarding the old
one. */
regs->stkadj = frame_extra_sizes[regs->format];
tregs = (struct pt_regs *)((ulong)regs + regs->stkadj);
tregs->vector = regs->vector;
tregs->format = 0;
tregs->pc = fixup;
tregs->sr = regs->sr;
return -1;
}
//if (siginfo.si_signo == SIGBUS)
// force_sig_info(siginfo.si_signo,
// &siginfo, current);
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
if ((unsigned long)siginfo.si_addr < PAGE_SIZE)
printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
else
printk(KERN_ALERT "Unable to handle kernel access");
printk(" at virtual address %p\n", siginfo.si_addr);
die_if_kernel("Oops", regs, 0 /*error_code*/);
do_exit(SIGKILL);
}
return 1;
}
void
MachineCheckException(struct pt_regs *regs)
{
#ifdef CONFIG_ALL_PPC
unsigned long fixup;
#endif /* CONFIG_ALL_PPC */
if (user_mode(regs)) {
_exception(SIGSEGV, regs);
return;
}
#if defined(CONFIG_8xx) && defined(CONFIG_PCI)
/* the qspan pci read routines can cause machine checks -- Cort */
bad_page_fault(regs, regs->dar);
return;
#endif
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
if (debugger_fault_handler) {
debugger_fault_handler(regs);
return;
}
#endif
#ifdef CONFIG_ALL_PPC
/*
* I/O accesses can cause machine checks on powermacs.
* Check if the NIP corresponds to the address of a sync
* instruction for which there is an entry in the exception
* table.
*/
if (regs->msr & (0x80000 | 0x40000)
&& (fixup = search_exception_table(regs->nip)) != 0) {
/*
* Check that it's a sync instruction.
* As the address is in the exception table
* we should be able to read the instr there.
*/
if (*(unsigned int *)regs->nip == 0x7c0004ac) {
unsigned int lsi = ((unsigned int *)regs->nip)[-1];
int rb = (lsi >> 11) & 0x1f;
printk(KERN_DEBUG "%s bad port %lx at %lx\n",
(lsi & 0x100)? "OUT to": "IN from",
regs->gpr[rb] - _IO_BASE, regs->nip);
regs->nip = fixup;
return;
}
}
/*
* bad_page_fault is called when we have a bad access from the kernel.
* It is called from do_page_fault above and from some of the procedures
* in traps.c.
*/
void
bad_page_fault(struct pt_regs *regs, unsigned long address)
{
unsigned long fixup;
/* Are we prepared to handle this fault? */
if ((fixup = search_exception_table(regs->nip)) != 0) {
regs->nip = fixup;
return;
}
/* kernel has accessed a bad area */
show_regs(regs);
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
if (debugger_kernel_faults)
debugger(regs);
#endif
print_backtrace( (unsigned long *)regs->gpr[1] );
panic("kernel access of bad area pc %lx lr %lx address %lX tsk %s/%d",
regs->nip,regs->link,address,current->comm,current->pid);
}
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
* routines.
*
* error_code:
* ****0004 Protection -> Write-Protection (suprression)
* ****0010 Segment translation -> Not present (nullification)
* ****0011 Page translation -> Not present (nullification)
* ****003B Region third exception -> Not present (nullification)
*/
asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code)
{
struct task_struct *tsk;
struct mm_struct *mm;
struct vm_area_struct * vma;
unsigned long address;
unsigned long fixup;
int write;
int si_code = SEGV_MAPERR;
int kernel_address = 0;
tsk = current;
mm = tsk->mm;
/*
* Check for low-address protection. This needs to be treated
* as a special case because the translation exception code
* field is not guaranteed to contain valid data in this case.
*/
if ((error_code & 0xff) == 4 && !(S390_lowcore.trans_exc_code & 4)) {
/* Low-address protection hit in kernel mode means
NULL pointer write access in kernel mode. */
if (!(regs->psw.mask & PSW_PROBLEM_STATE)) {
address = 0;
kernel_address = 1;
goto no_context;
}
/* Low-address protection hit in user mode 'cannot happen'. */
die ("Low-address protection", regs, error_code);
do_exit(SIGKILL);
}
/*
* get the failing address
* more specific the segment and page table portion of
* the address
*/
address = S390_lowcore.trans_exc_code&-4096L;
/*
* Check which address space the address belongs to
*/
switch (S390_lowcore.trans_exc_code & 3)
{
case 0: /* Primary Segment Table Descriptor */
kernel_address = 1;
goto no_context;
case 1: /* STD determined via access register */
if (S390_lowcore.exc_access_id == 0)
{
kernel_address = 1;
goto no_context;
}
if (regs && S390_lowcore.exc_access_id < NUM_ACRS)
{
if (regs->acrs[S390_lowcore.exc_access_id] == 0)
{
kernel_address = 1;
goto no_context;
}
if (regs->acrs[S390_lowcore.exc_access_id] == 1)
{
/* user space address */
break;
}
}
die("page fault via unknown access register", regs, error_code);
do_exit(SIGKILL);
break;
case 2: /* Secondary Segment Table Descriptor */
case 3: /* Home Segment Table Descriptor */
/* user space address */
break;
}
/*
* Check whether we have a user MM in the first place.
*/
if (in_interrupt() || !mm || !(regs->psw.mask & _PSW_IO_MASK_BIT))
goto no_context;
/*
* When we get here, the fault happened in the current
* task's user address space, so we can switch on the
* interrupts again and then search the VMAs
*/
__sti();
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
if (vma->vm_start <= address)
goto good_area;
if (!(vma->vm_flags & VM_GROWSDOWN))
goto bad_area;
if (expand_stack(vma, address))
goto bad_area;
/*
* Ok, we have a good vm_area for this memory access, so
* we can handle it..
*/
good_area:
write = 0;
si_code = SEGV_ACCERR;
switch (error_code & 0xFF) {
case 0x04: /* write, present*/
write = 1;
break;
case 0x10: /* not present*/
case 0x11: /* not present*/
case 0x3B: /* not present*/
if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
goto bad_area;
break;
default:
printk("code should be 4, 10 or 11 (%lX) \n",error_code&0xFF);
goto bad_area;
}
survive:
/*
* If for any reason at all we couldn't handle the fault,
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
switch (handle_mm_fault(mm, vma, address, write)) {
case 1:
tsk->min_flt++;
break;
case 2:
tsk->maj_flt++;
break;
case 0:
goto do_sigbus;
default:
goto out_of_memory;
}
up_read(&mm->mmap_sem);
return;
/*
* Something tried to access memory that isn't in our memory map..
* Fix it, but check if it's kernel or user first..
*/
bad_area:
up_read(&mm->mmap_sem);
/* User mode accesses just cause a SIGSEGV */
if (regs->psw.mask & PSW_PROBLEM_STATE) {
tsk->thread.prot_addr = address;
tsk->thread.trap_no = error_code;
#ifndef CONFIG_SYSCTL
#ifdef CONFIG_PROCESS_DEBUG
printk("User process fault: interruption code 0x%lX\n",error_code);
printk("failing address: %lX\n",address);
show_regs(regs);
#endif
#else
if (sysctl_userprocess_debug) {
printk("User process fault: interruption code 0x%lX\n",
error_code);
printk("failing address: %lX\n", address);
show_regs(regs);
}
#endif
force_sigsegv(tsk, si_code, (void *)address);
return;
}
no_context:
/* Are we prepared to handle this kernel fault? */
if ((fixup = search_exception_table(regs->psw.addr)) != 0) {
regs->psw.addr = fixup;
return;
}
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
if (kernel_address)
printk(KERN_ALERT "Unable to handle kernel pointer dereference"
" at virtual kernel address %016lx\n", address);
else
printk(KERN_ALERT "Unable to handle kernel paging request"
" at virtual user address %016lx\n", address);
die("Oops", regs, error_code);
do_exit(SIGKILL);
/*
* We ran out of memory, or some other thing happened to us that made
* us unable to handle the page fault gracefully.
*/
out_of_memory:
up_read(&mm->mmap_sem);
if (tsk->pid == 1) {
tsk->policy |= SCHED_YIELD;
schedule();
down_read(&mm->mmap_sem);
goto survive;
}
printk("VM: killing process %s\n", tsk->comm);
if (regs->psw.mask & PSW_PROBLEM_STATE)
do_exit(SIGKILL);
goto no_context;
do_sigbus:
up_read(&mm->mmap_sem);
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
tsk->thread.prot_addr = address;
tsk->thread.trap_no = error_code;
force_sig(SIGBUS, tsk);
/* Kernel mode? Handle exceptions or die */
if (!(regs->psw.mask & PSW_PROBLEM_STATE))
goto no_context;
}
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
* routines.
*/
asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
unsigned long address)
{
struct vm_area_struct * vma;
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
unsigned long fixup;
siginfo_t info;
/*
* We fault-in kernel-space virtual memory on-demand. The
* 'reference' page table is init_mm.pgd.
*
* NOTE! We MUST NOT take any locks for this case. We may
* be in an interrupt or a critical region, and should
* only copy the information from the master page table,
* nothing more.
*/
if (address >= VMALLOC_START)
goto vmalloc_fault;
info.si_code = SEGV_MAPERR;
/*
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
if (in_interrupt() || !mm)
goto no_context;
#if 0
printk("[%s:%d:%08lx:%ld:%08lx]\n", current->comm, current->pid,
address, write, regs->cp0_epc);
#endif
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
if (vma->vm_start <= address)
goto good_area;
if (expand_stack(vma, address))
goto bad_area;
/*
* Ok, we have a good vm_area for this memory access, so
* we can handle it..
*/
good_area:
info.si_code = SEGV_ACCERR;
if (write) {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
} else {
if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
goto bad_area;
}
survive:
/*
* If for any reason at all we couldn't handle the fault,
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
switch (handle_mm_fault(mm, vma, address, write)) {
case 1:
tsk->min_flt++;
break;
case 2:
tsk->maj_flt++;
break;
case 0:
goto do_sigbus;
default:
goto out_of_memory;
}
up_read(&mm->mmap_sem);
return;
/*
* Something tried to access memory that isn't in our memory map..
* Fix it, but check if it's kernel or user first..
*/
bad_area:
up_read(&mm->mmap_sem);
bad_area_nosemaphore:
/* User mode accesses just cause a SIGSEGV */
if (user_mode(regs)) {
tsk->thread.cp0_badvaddr = address;
tsk->thread.error_code = write;
#if 0
printk("do_page_fault() #2: sending SIGSEGV to %s for illegal %s\n"
"%08lx (epc == %08lx, ra == %08lx)\n",
tsk->comm,
write ? "write access to" : "read access from",
address,
(unsigned long) regs->cp0_epc,
(unsigned long) regs->regs[31]);
#endif
info.si_signo = SIGSEGV;
info.si_errno = 0;
/* info.si_code has been set above */
info.si_addr = (void *) address;
force_sig_info(SIGSEGV, &info, tsk);
return;
}
no_context:
/* Are we prepared to handle this kernel fault? */
fixup = search_exception_table(exception_epc(regs));
if (fixup) {
long new_epc;
tsk->thread.cp0_baduaddr = address;
new_epc = fixup_exception(dpf_reg, fixup, regs->cp0_epc);
if (development_version)
printk(KERN_DEBUG "%s: Exception at [<%lx>] (%lx)\n",
tsk->comm, regs->cp0_epc, new_epc);
regs->cp0_epc = new_epc;
return;
}
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
printk(KERN_ALERT "Unable to handle kernel paging request at virtual "
"address %08lx, epc == %08lx, ra == %08lx\n",
address, regs->cp0_epc, regs->regs[31]);
die("Oops", regs);
/* Game over. */
/*
* We ran out of memory, or some other thing happened to us that made
* us unable to handle the page fault gracefully.
*/
out_of_memory:
if (tsk->pid == 1) {
yield();
goto survive;
}
up_read(&mm->mmap_sem);
printk(KERN_NOTICE "VM: killing process %s\n", tsk->comm);
if (user_mode(regs))
do_exit(SIGKILL);
goto no_context;
do_sigbus:
up_read(&mm->mmap_sem);
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
tsk->thread.cp0_badvaddr = address;
info.si_signo = SIGBUS;
info.si_errno = 0;
info.si_code = BUS_ADRERR;
info.si_addr = (void *) address;
force_sig_info(SIGBUS, &info, tsk);
/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs))
goto no_context;
return;
vmalloc_fault:
{
/*
* Synchronize this task's top level page-table
* with the 'reference' page table.
*/
int offset = pgd_index(address);
pgd_t *pgd, *pgd_k;
pmd_t *pmd, *pmd_k;
pgd = tsk->active_mm->pgd + offset;
pgd_k = init_mm.pgd + offset;
if (!pgd_present(*pgd)) {
if (!pgd_present(*pgd_k))
goto bad_area_nosemaphore;
set_pgd(pgd, *pgd_k);
return;
}
pmd = pmd_offset(pgd, address);
pmd_k = pmd_offset(pgd_k, address);
if (pmd_present(*pmd) || !pmd_present(*pmd_k))
goto bad_area_nosemaphore;
set_pmd(pmd, *pmd_k);
}
}
static int do_page_fault(unsigned long addr, int mode, struct pt_regs *regs)
{
struct task_struct *tsk;
struct mm_struct *mm;
unsigned long fixup;
int fault;
tsk = current;
mm = tsk->mm;
/*
* We fault-in kernel-space virtual memory on-demand. The
* 'reference' page table is init_mm.pgd.
*
* NOTE! We MUST NOT take any locks for this case. We may
* be in an interrupt or a critical region, and should
* only copy the information from the master page table,
* nothing more.
*/
if (addr >= TASK_SIZE)
goto vmalloc_fault;
/*
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
if (in_interrupt() || !mm)
goto no_context;
down(&mm->mmap_sem);
fault = __do_page_fault(mm, addr, mode, tsk);
up(&mm->mmap_sem);
ret:
/*
* Handle the "normal" case first
*/
if (fault > 0)
return 0;
/*
* We had some memory, but were unable to
* successfully fix up this page fault.
*/
if (fault == 0)
goto do_sigbus;
/*
* If we are in kernel mode at this point, we
* have no context to handle this fault with.
*/
if (!user_mode(regs))
goto no_context;
if (fault == -3) {
/*
* We ran out of memory, or some other thing happened to
* us that made us unable to handle the page fault gracefully.
*/
printk("VM: killing process %s\n", tsk->comm);
do_exit(SIGKILL);
} else {
/*
* Something tried to access memory that isn't in our memory map..
* User mode accesses just cause a SIGSEGV
*/
struct siginfo si;
#ifdef CONFIG_DEBUG_USER
printk(KERN_DEBUG "%s: unhandled page fault at pc=0x%08lx, "
"lr=0x%08lx (bad address=0x%08lx, code %d)\n",
tsk->comm, regs->ARM_pc, regs->ARM_lr, addr, mode);
#endif
tsk->thread.address = addr;
tsk->thread.error_code = mode;
tsk->thread.trap_no = 14;
si.si_signo = SIGSEGV;
si.si_errno = 0;
si.si_code = fault == -1 ? SEGV_ACCERR : SEGV_MAPERR;
si.si_addr = (void *)addr;
force_sig_info(SIGSEGV, &si, tsk);
}
return 0;
/*
* We ran out of memory, or some other thing happened to us that made
* us unable to handle the page fault gracefully.
*/
do_sigbus:
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
tsk->thread.address = addr;
tsk->thread.error_code = mode;
tsk->thread.trap_no = 14;
force_sig(SIGBUS, tsk);
/* Kernel mode? Handle exceptions or die */
if (user_mode(regs))
return 0;
no_context:
/* Are we prepared to handle this kernel fault? */
if ((fixup = search_exception_table(instruction_pointer(regs))) != 0) {
#ifdef DEBUG
printk(KERN_DEBUG "%s: Exception at [<%lx>] addr=%lx (fixup: %lx)\n",
tsk->comm, regs->ARM_pc, addr, fixup);
#endif
regs->ARM_pc = fixup;
return 0;
}
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
printk(KERN_ALERT "Unable to handle kernel %s at virtual address %08lx\n",
(addr < PAGE_SIZE) ? "NULL pointer dereference" : "paging request", addr);
show_pte(mm, addr);
die("Oops", regs, mode);
do_exit(SIGKILL);
return 0;
vmalloc_fault:
fault = __do_vmalloc_fault(addr, mm);
goto ret;
}
static inline void
emulate_load_store_insn(struct pt_regs *regs,
unsigned long addr,
unsigned long pc)
{
union mips_instruction insn;
unsigned long value, fixup;
regs->regs[0] = 0;
/*
* This load never faults.
*/
__get_user(insn.word, (unsigned int *)pc);
switch (insn.i_format.opcode) {
/*
* These are instructions that a compiler doesn't generate. We
* can assume therefore that the code is MIPS-aware and
* really buggy. Emulating these instructions would break the
* semantics anyway.
*/
case ll_op:
case lld_op:
case sc_op:
case scd_op:
/*
* For these instructions the only way to create an address
* error is an attempted access to kernel/supervisor address
* space.
*/
case ldl_op:
case ldr_op:
case lwl_op:
case lwr_op:
case sdl_op:
case sdr_op:
case swl_op:
case swr_op:
case lb_op:
case lbu_op:
case sb_op:
goto sigbus;
/*
* The remaining opcodes are the ones that are really of interest.
*/
case lh_op:
check_axs(pc, addr, 2);
__asm__(
".set\tnoat\n"
#ifdef __BIG_ENDIAN
"1:\tlb\t%0,0(%1)\n"
"2:\tlbu\t$1,1(%1)\n\t"
#endif
#ifdef __LITTLE_ENDIAN
"1:\tlb\t%0,1(%1)\n"
"2:\tlbu\t$1,0(%1)\n\t"
#endif
"sll\t%0,0x8\n\t"
"or\t%0,$1\n\t"
".set\tat\n\t"
".section\t__ex_table,\"a\"\n\t"
STR(PTR)"\t1b,%2\n\t"
STR(PTR)"\t2b,%2\n\t"
".previous"
:"=&r" (value)
:"r" (addr), "i" (&&fault)
:"$1");
regs->regs[insn.i_format.rt] = value;
return;
case lw_op:
check_axs(pc, addr, 4);
__asm__(
#ifdef __BIG_ENDIAN
"1:\tlwl\t%0,(%1)\n"
"2:\tlwr\t%0,3(%1)\n\t"
#endif
#ifdef __LITTLE_ENDIAN
"1:\tlwl\t%0,3(%1)\n"
"2:\tlwr\t%0,(%1)\n\t"
#endif
".section\t__ex_table,\"a\"\n\t"
STR(PTR)"\t1b,%2\n\t"
STR(PTR)"\t2b,%2\n\t"
".previous"
:"=&r" (value)
:"r" (addr), "i" (&&fault));
regs->regs[insn.i_format.rt] = value;
return;
case lhu_op:
check_axs(pc, addr, 2);
__asm__(
".set\tnoat\n"
#ifdef __BIG_ENDIAN
"1:\tlbu\t%0,0(%1)\n"
"2:\tlbu\t$1,1(%1)\n\t"
#endif
#ifdef __LITTLE_ENDIAN
"1:\tlbu\t%0,1(%1)\n"
"2:\tlbu\t$1,0(%1)\n\t"
#endif
"sll\t%0,0x8\n\t"
"or\t%0,$1\n\t"
".set\tat\n\t"
".section\t__ex_table,\"a\"\n\t"
STR(PTR)"\t1b,%2\n\t"
STR(PTR)"\t2b,%2\n\t"
".previous"
:"=&r" (value)
:"r" (addr), "i" (&&fault)
:"$1");
regs->regs[insn.i_format.rt] = value;
return;
case lwu_op:
check_axs(pc, addr, 4);
__asm__(
#ifdef __BIG_ENDIAN
"1:\tlwl\t%0,(%1)\n"
"2:\tlwr\t%0,3(%1)\n\t"
#endif
#ifdef __LITTLE_ENDIAN
"1:\tlwl\t%0,3(%1)\n"
"2:\tlwr\t%0,(%1)\n\t"
#endif
".section\t__ex_table,\"a\"\n\t"
STR(PTR)"\t1b,%2\n\t"
STR(PTR)"\t2b,%2\n\t"
".previous"
:"=&r" (value)
:"r" (addr), "i" (&&fault));
value &= 0xffffffff;
regs->regs[insn.i_format.rt] = value;
return;
case ld_op:
check_axs(pc, addr, 8);
__asm__(
".set\tmips3\n"
#ifdef __BIG_ENDIAN
"1:\tldl\t%0,(%1)\n"
"2:\tldr\t%0,7(%1)\n\t"
#endif
#ifdef __LITTLE_ENDIAN
"1:\tldl\t%0,7(%1)\n"
"2:\tldr\t%0,(%1)\n\t"
#endif
".set\tmips0\n\t"
".section\t__ex_table,\"a\"\n\t"
STR(PTR)"\t1b,%2\n\t"
STR(PTR)"\t2b,%2\n\t"
".previous"
:"=&r" (value)
:"r" (addr), "i" (&&fault));
regs->regs[insn.i_format.rt] = value;
return;
case sh_op:
check_axs(pc, addr, 2);
value = regs->regs[insn.i_format.rt];
__asm__(
#ifdef __BIG_ENDIAN
".set\tnoat\n"
"1:\tsb\t%0,1(%1)\n\t"
"srl\t$1,%0,0x8\n"
"2:\tsb\t$1,0(%1)\n\t"
".set\tat\n\t"
#endif
#ifdef __LITTLE_ENDIAN
".set\tnoat\n"
"1:\tsb\t%0,0(%1)\n\t"
"srl\t$1,%0,0x8\n"
"2:\tsb\t$1,1(%1)\n\t"
".set\tat\n\t"
#endif
".section\t__ex_table,\"a\"\n\t"
STR(PTR)"\t1b,%2\n\t"
STR(PTR)"\t2b,%2\n\t"
".previous"
: /* no outputs */
:"r" (value), "r" (addr), "i" (&&fault)
:"$1");
return;
case sw_op:
check_axs(pc, addr, 4);
value = regs->regs[insn.i_format.rt];
__asm__(
#ifdef __BIG_ENDIAN
"1:\tswl\t%0,(%1)\n"
"2:\tswr\t%0,3(%1)\n\t"
#endif
#ifdef __LITTLE_ENDIAN
"1:\tswl\t%0,3(%1)\n"
"2:\tswr\t%0,(%1)\n\t"
#endif
".section\t__ex_table,\"a\"\n\t"
STR(PTR)"\t1b,%2\n\t"
STR(PTR)"\t2b,%2\n\t"
".previous"
: /* no outputs */
:"r" (value), "r" (addr), "i" (&&fault));
return;
case sd_op:
check_axs(pc, addr, 8);
value = regs->regs[insn.i_format.rt];
__asm__(
".set\tmips3\n"
#ifdef __BIG_ENDIAN
"1:\tsdl\t%0,(%1)\n"
"2:\tsdr\t%0,7(%1)\n\t"
#endif
#ifdef __LITTLE_ENDIAN
"1:\tsdl\t%0,7(%1)\n"
"2:\tsdr\t%0,(%1)\n\t"
#endif
".set\tmips0\n\t"
".section\t__ex_table,\"a\"\n\t"
STR(PTR)"\t1b,%2\n\t"
STR(PTR)"\t2b,%2\n\t"
".previous"
: /* no outputs */
:"r" (value), "r" (addr), "i" (&&fault));
return;
case lwc1_op:
case ldc1_op:
case swc1_op:
case sdc1_op:
/*
* I herewith declare: this does not happen. So send SIGBUS.
*/
goto sigbus;
case lwc2_op:
case ldc2_op:
case swc2_op:
case sdc2_op:
/*
* These are the coprocessor 2 load/stores. The current
* implementations don't use cp2 and cp2 should always be
* disabled in c0_status. So send SIGILL.
* (No longer true: The Sony Praystation uses cp2 for
* 3D matrix operations. Dunno if that thingy has a MMU ...)
*/
default:
/*
* Pheeee... We encountered an yet unknown instruction or
* cache coherence problem. Die sucker, die ...
*/
goto sigill;
}
return;
fault:
/* Did we have an exception handler installed? */
fixup = search_exception_table(regs->cp0_epc);
if (fixup) {
long new_epc;
new_epc = fixup_exception(dpf_reg, fixup, regs->cp0_epc);
printk(KERN_DEBUG "%s: Forwarding exception at [<%lx>] (%lx)\n",
current->comm, regs->cp0_epc, new_epc);
regs->cp0_epc = new_epc;
return;
}
lock_kernel();
send_sig(SIGSEGV, current, 1);
unlock_kernel();
return;
sigbus:
lock_kernel();
send_sig(SIGBUS, current, 1);
unlock_kernel();
return;
sigill:
lock_kernel();
send_sig(SIGILL, current, 1);
unlock_kernel();
return;
}
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
* routines.
*
* error_code:
* 04 Protection -> Write-Protection (suprression)
* 10 Segment translation -> Not present (nullification)
* 11 Page translation -> Not present (nullification)
* 3b Region third trans. -> Not present (nullification)
*/
extern inline void do_exception(struct pt_regs *regs, unsigned long error_code)
{
struct task_struct *tsk;
struct mm_struct *mm;
struct vm_area_struct * vma;
unsigned long address;
int user_address;
unsigned long fixup;
int si_code = SEGV_MAPERR;
tsk = current;
mm = tsk->mm;
/*
* Check for low-address protection. This needs to be treated
* as a special case because the translation exception code
* field is not guaranteed to contain valid data in this case.
*/
if (error_code == 4 && !(S390_lowcore.trans_exc_code & 4)) {
/* Low-address protection hit in kernel mode means
NULL pointer write access in kernel mode. */
if (!(regs->psw.mask & PSW_PROBLEM_STATE)) {
address = 0;
user_address = 0;
goto no_context;
}
/* Low-address protection hit in user mode 'cannot happen'. */
die ("Low-address protection", regs, error_code);
do_exit(SIGKILL);
}
/*
* get the failing address
* more specific the segment and page table portion of
* the address
*/
address = S390_lowcore.trans_exc_code & -4096L;
user_address = check_user_space(regs, error_code);
/*
* Verify that the fault happened in user space, that
* we are not in an interrupt and that there is a
* user context.
*/
if (user_address == 0 || in_interrupt() || !mm)
goto no_context;
/*
* When we get here, the fault happened in the current
* task's user address space, so we can switch on the
* interrupts again and then search the VMAs
*/
__sti();
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
if (vma->vm_start <= address)
goto good_area;
if (!(vma->vm_flags & VM_GROWSDOWN))
goto bad_area;
if (expand_stack(vma, address))
goto bad_area;
/*
* Ok, we have a good vm_area for this memory access, so
* we can handle it..
*/
good_area:
si_code = SEGV_ACCERR;
if (error_code != 4) {
/* page not present, check vm flags */
if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
goto bad_area;
} else {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
}
survive:
/*
* If for any reason at all we couldn't handle the fault,
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
switch (handle_mm_fault(mm, vma, address, error_code == 4)) {
case 1:
tsk->min_flt++;
break;
case 2:
tsk->maj_flt++;
break;
case 0:
goto do_sigbus;
default:
goto out_of_memory;
}
up_read(&mm->mmap_sem);
return;
/*
* Something tried to access memory that isn't in our memory map..
* Fix it, but check if it's kernel or user first..
*/
bad_area:
up_read(&mm->mmap_sem);
/* User mode accesses just cause a SIGSEGV */
if (regs->psw.mask & PSW_PROBLEM_STATE) {
tsk->thread.prot_addr = address;
tsk->thread.trap_no = error_code;
force_sigsegv(regs, error_code, si_code, address);
return;
}
no_context:
/* Are we prepared to handle this kernel fault? */
if ((fixup = search_exception_table(regs->psw.addr)) != 0) {
regs->psw.addr = fixup;
return;
}
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
if (user_address == 0)
printk(KERN_ALERT "Unable to handle kernel pointer dereference"
" at virtual kernel address %016lx\n", address);
else
printk(KERN_ALERT "Unable to handle kernel paging request"
" at virtual user address %016lx\n", address);
die("Oops", regs, error_code);
do_exit(SIGKILL);
/*
* We ran out of memory, or some other thing happened to us that made
* us unable to handle the page fault gracefully.
*/
out_of_memory:
if (tsk->pid == 1) {
yield();
goto survive;
}
up_read(&mm->mmap_sem);
printk("VM: killing process %s\n", tsk->comm);
if (regs->psw.mask & PSW_PROBLEM_STATE)
do_exit(SIGKILL);
goto no_context;
do_sigbus:
up_read(&mm->mmap_sem);
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
tsk->thread.prot_addr = address;
tsk->thread.trap_no = error_code;
force_sig(SIGBUS, tsk);
/* Kernel mode? Handle exceptions or die */
if (!(regs->psw.mask & PSW_PROBLEM_STATE))
goto no_context;
}
void do_page_fault(struct pt_regs *regs, unsigned long code,
unsigned long address)
{
struct vm_area_struct * vma;
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
const struct exception_table_entry *fix;
unsigned long acc_type;
if (in_interrupt() || !mm)
goto no_context;
down_read(&mm->mmap_sem);
vma = pa_find_vma(mm, address);
if (!vma)
goto bad_area;
if (address < vma->vm_end)
goto good_area;
if (!(vma->vm_flags & VM_GROWSUP) || expand_stackup(vma, address))
goto bad_area;
/*
* Ok, we have a good vm_area for this memory access. We still need to
* check the access permissions.
*/
good_area:
acc_type = parisc_acctyp(code,regs->iir);
if ((vma->vm_flags & acc_type) != acc_type)
goto bad_area;
/*
* If for any reason at all we couldn't handle the fault, make
* sure we exit gracefully rather than endlessly redo the
* fault.
*/
switch (handle_mm_fault(mm, vma, address, (acc_type & VM_WRITE) != 0)) {
case 1:
++current->min_flt;
break;
case 2:
++current->maj_flt;
break;
case 0:
/*
* We ran out of memory, or some other thing happened
* to us that made us unable to handle the page fault
* gracefully.
*/
goto bad_area;
default:
goto out_of_memory;
}
up_read(&mm->mmap_sem);
return;
/*
* Something tried to access memory that isn't in our memory map..
*/
bad_area:
up_read(&mm->mmap_sem);
if (user_mode(regs)) {
struct siginfo si;
printk("\ndo_page_fault() pid=%d command='%s'\n",
tsk->pid, tsk->comm);
show_regs(regs);
/* FIXME: actually we need to get the signo and code correct */
si.si_signo = SIGSEGV;
si.si_errno = 0;
si.si_code = SEGV_MAPERR;
si.si_addr = (void *) address;
force_sig_info(SIGSEGV, &si, current);
return;
}
no_context:
if (!user_mode(regs)) {
fix = search_exception_table(regs->iaoq[0]);
if (fix) {
if (fix->skip & 1)
regs->gr[8] = -EFAULT;
if (fix->skip & 2)
regs->gr[9] = 0;
regs->iaoq[0] += ((fix->skip) & ~3);
/*
* NOTE: In some cases the faulting instruction
* may be in the delay slot of a branch. We
* don't want to take the branch, so we don't
* increment iaoq[1], instead we set it to be
* iaoq[0]+4, and clear the B bit in the PSW
*/
regs->iaoq[1] = regs->iaoq[0] + 4;
regs->gr[0] &= ~PSW_B; /* IPSW in gr[0] */
return;
}
}
parisc_terminate("Bad Address (null pointer deref?)",regs,code,address);
out_of_memory:
up_read(&mm->mmap_sem);
printk("VM: killing process %s\n", current->comm);
if (user_mode(regs))
do_exit(SIGKILL);
goto no_context;
}
