void __init page_table_range_init(unsigned long start, unsigned long end,
pgd_t *pgd_base)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;
int i, j, k;
unsigned long vaddr;
vaddr = start;
i = __pgd_offset(vaddr);
j = __pud_offset(vaddr);
k = __pmd_offset(vaddr);
pgd = pgd_base + i;
for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
pud = (pud_t *)pgd;
for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
pmd = one_md_table_init(pud);
#ifndef __PAGETABLE_PMD_FOLDED
pmd += k;
#endif
for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
pte = page_table_kmap_check(one_page_table_init(pmd),
pmd, vaddr, pte);
vaddr += PMD_SIZE;
}
k = 0;
}
j = 0;
}
}
static int __do_vmalloc_fault(unsigned long addr, struct mm_struct *mm)
{
/* Synchronise this task's top level page-table
* with the 'reference' page table.
*/
int offset = __pgd_offset(addr);
pgd_t *pgd, *pgd_k;
pmd_t *pmd, *pmd_k;
pgd_k = init_mm.pgd + offset;
if (!pgd_present(*pgd_k))
goto bad_area;
pgd = mm->pgd + offset;
#if 0 /* note that we are two-level */
if (!pgd_present(*pgd))
set_pgd(pgd, *pgd_k);
#endif
pmd_k = pmd_offset(pgd_k, addr);
if (pmd_none(*pmd_k))
goto bad_area;
pmd = pmd_offset(pgd, addr);
if (!pmd_none(*pmd))
goto bad_area;
set_pmd(pmd, *pmd_k);
return 1;
bad_area:
return -2;
}
/*
* fault_is_priv()
* Return true if the fault is a privilege violation.
*/
STATIC int fault_is_priv(struct pt_regs *regs,
unsigned long missqw0,
unsigned long missqw1)
{
pgd_t *pgd;
pmd_t *pmd;
pte_t *ptep;
unsigned long address;
/*
* Check if this is user or kernel in pt_regs/CSR.
*/
pgd = (pgd_t *)(MMU_MISSQW0_PGD_GET(missqw0) << MMU_MISSQW0_PGD_SHIFT);
address = (unsigned long)(MMU_MISSQW1_VPN_GET(missqw1) << MMU_VPN_SHIFT);
pmd = (pmd_t *)__pgd_offset(pgd, address);
if (unlikely(pmd_none(*pmd)) || (unlikely(pmd_bad(*pmd)))) {
return 0;
}
ptep = pte_offset_map(pmd, address);
if (unlikely(pte_none(*ptep)) || (unlikely(pte_bad(*ptep)))) {
return 0;
}
/*
* If the PTE is a supervisory PTE and we are in user_mode()
* declare this as a privilege violation.
*/
if (user_mode(regs) && ((pte_val(*ptep) & L_PTE_USER) == 0)) {
return 1;
}
return 0;
}
/*
* fault_is_resolved()
* Return true if the fault appears to be resolved.
*/
STATIC int fault_is_resolved(struct pt_regs *regs,
unsigned long missqw0,
unsigned long missqw1)
{
pgd_t *pgd;
pmd_t *pmd;
pte_t *ptep;
unsigned long address;
unsigned long src = MMU_MISSQW1_SRC_GET(missqw1);
unsigned long op = MMU_MISSQW0_OP_GET(missqw0);
/*
* Potential hardware bug, check if this is an ifetch with a write op.
* If so, we will be in an infinite loop. check here because this
* is under debug.
*/
if ((src == 0) && (op == 1)) {
printk(KERN_CRIT "iftech/write: missqw0=%lx, missqw1=%lx\n",
missqw0, missqw1);
return 0;
}
/*
* See if we now have a valid pte?
*/
pgd = (pgd_t *)(MMU_MISSQW0_PGD_GET(missqw0) << MMU_MISSQW0_PGD_SHIFT);
address = (unsigned long)(MMU_MISSQW1_VPN_GET(missqw1) << MMU_VPN_SHIFT);
pmd = (pmd_t *)__pgd_offset(pgd, address);
if (unlikely(pmd_none(*pmd)) || (unlikely(pmd_bad(*pmd)))) {
printk(KERN_CRIT "address[0x%lx] pgd[%p] pmd[%p] is empty\n",
address, pgd, pmd);
return 0;
}
ptep = pte_offset_map(pmd, address);
if (unlikely(pte_none(*ptep)) || (unlikely(pte_bad(*ptep)))) {
printk(KERN_CRIT "address[0x%lx] pgd[%p] pmd[%p] pte[%p] is empty\n",
address, pgd, pmd, ptep);
return 0;
}
if (unlikely(!pte_present(*ptep))) {
printk(KERN_CRIT "address[0x%lx] pgd[%p] pmd[%p] pte[%p] is invalid: 0x%lx\n",
address, pgd, pmd, ptep, pte_val(*ptep));
return 0;
}
if (MMU_MISSQW0_OP_GET(missqw0) && !pte_write(*ptep)) {
printk(KERN_CRIT "address[0x%lx] pgd[%p] pmd[%p] pte[%p] write requested but not given: 0x%lx\n",
address, pgd, pmd, ptep, pte_val(*ptep));
/* Fall through, not as critical */
}
fault_printk(FAULT_DBG_TRACE, "FAULT[%d]: ti[%p], missqw0=%08lx, missqw1=%08lx, resolved!\n",
raw_smp_processor_id(), (void *)current_thread_info(), missqw0, missqw1);
return 1;
}
/*
* fault_pte()
* Obtain the pte corresponding to the fault.
*/
STATIC pte_t *fault_pte(pgd_t *pgd, unsigned long address)
{
pmd_t *pmd = (pmd_t *)__pgd_offset(pgd, address);
if (unlikely(pmd_none(*pmd)) ||
(unlikely(pmd_bad(*pmd))) ||
(unlikely(pmd_present(*pmd) == 0))) {
return 0;
}
return pte_offset_map(pmd, address);
}
/*
* First Level Translation Fault Handler
*
* We enter here because the first level page table doesn't contain
* a valid entry for the address.
*
* If the address is in kernel space (>= TASK_SIZE), then we are
* probably faulting in the vmalloc() area.
*
* If the init_task's first level page tables contains the relevant
* entry, we copy the it to this task. If not, we send the process
* a signal, fixup the exception, or oops the kernel.
*
* 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.
*/
int do_translation_fault(unsigned long addr, unsigned int fsr,
struct pt_regs *regs)
{
struct task_struct *tsk;
int offset;
pgd_t *pgd, *pgd_k;
pmd_t *pmd, *pmd_k;
if (addr < TASK_SIZE)
return do_page_fault(addr, fsr, regs);
offset = __pgd_offset(addr);
/*
* FIXME: CP15 C1 is write only on ARMv3 architectures.
* You really need to read the value in the page table
* register, not a copy.
*/
pgd = cpu_get_pgd() + offset;
pgd_k = init_mm.pgd + offset;
if (pgd_none(*pgd_k))
goto bad_area;
#if 0 /* note that we are two-level */
if (!pgd_present(*pgd))
set_pgd(pgd, *pgd_k);
#endif
pmd_k = pmd_offset(pgd_k, addr);
pmd = pmd_offset(pgd, addr);
if (pmd_none(*pmd_k))
goto bad_area;
set_pmd(pmd, *pmd_k);
return 0;
bad_area:
tsk = current;
do_bad_area(tsk, tsk->active_mm, addr, fsr, regs);
return 0;
}
/*
* First Level Translation Fault Handler
*
* We enter here because the first level page table doesn't contain
* a valid entry for the address.
*
* If the address is in kernel space (>= TASK_SIZE), then we are
* probably faulting in the vmalloc() area.
*
* If the init_task's first level page tables contains the relevant
* entry, we copy the it to this task. If not, we send the process
* a signal, fixup the exception, or oops the kernel.
*
* 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.
*/
int do_translation_fault(unsigned long addr, int error_code, struct pt_regs *regs)
{
struct task_struct *tsk;
struct mm_struct *mm;
int offset;
pgd_t *pgd, *pgd_k;
pmd_t *pmd, *pmd_k;
if (addr < TASK_SIZE)
return do_page_fault(addr, error_code, regs);
offset = __pgd_offset(addr);
/*
* FIXME: CP15 C1 is write only on ARMv3 architectures.
*/
pgd = cpu_get_pgd() + offset;
pgd_k = init_mm.pgd + offset;
if (pgd_none(*pgd_k))
goto bad_area;
#if 0 /* note that we are two-level */
if (!pgd_present(*pgd))
set_pgd(pgd, *pgd_k);
#endif
pmd_k = pmd_offset(pgd_k, addr);
pmd = pmd_offset(pgd, addr);
if (pmd_none(*pmd_k))
goto bad_area;
set_pmd(pmd, *pmd_k);
return 0;
bad_area:
tsk = current;
mm = tsk->active_mm;
do_bad_area(tsk, mm, addr, error_code, regs);
return 0;
}
void __init pagetable_init(void)
{
unsigned long vaddr;
pgd_t *pgd_base;
#ifdef CONFIG_HIGHMEM
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
#endif
/* Initialize the entire pgd. */
pgd_init((unsigned long)swapper_pg_dir);
pgd_init((unsigned long)swapper_pg_dir
+ sizeof(pgd_t) * USER_PTRS_PER_PGD);
pgd_base = swapper_pg_dir;
/*
* Fixed mappings:
*/
#ifdef CONFIG_BCM53000_HIGHMEM
vaddr = __fix_to_virt(VALIAS_IDX(__end_of_fixed_addresses - 1)) & PMD_MASK;
#else
vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
#endif
fixrange_init(vaddr, 0, pgd_base);
#ifdef CONFIG_HIGHMEM
/*
* Permanent kmaps:
*/
vaddr = PKMAP_BASE;
fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
pgd = swapper_pg_dir + __pgd_offset(vaddr);
pud = pud_offset(pgd, vaddr);
pmd = pmd_offset(pud, vaddr);
pte = pte_offset_kernel(pmd, vaddr);
pkmap_page_table = pte;
#endif
}
/*
* 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 = NULL;
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
const int field = sizeof(unsigned long) * 2;
siginfo_t info;
#if 0
printk("Cpu%d[%s:%d:%0*lx:%ld:%0*lx]\n", smp_processor_id(),
current->comm, current->pid, field, address, write,
field, regs->cp0_epc);
#endif
info.si_code = SEGV_MAPERR;
/*
* 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 (unlikely(address >= VMALLOC_START && address <= VMALLOC_END))
goto vmalloc_fault;
/*
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
if (in_atomic() || !mm)
goto bad_area_nosemaphore;
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:
info.si_code = SEGV_ACCERR;
if (write) {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
} else {
if (!(vma->vm_flags & (VM_READ | VM_WRITE | 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 VM_FAULT_MINOR:
tsk->min_flt++;
break;
case VM_FAULT_MAJOR:
tsk->maj_flt++;
break;
case VM_FAULT_SIGBUS:
goto do_sigbus;
case VM_FAULT_OOM:
goto out_of_memory;
default:
BUG();
}
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 "
"invalid %s\n%0*lx (epc == %0*lx, ra == %0*lx)\n",
tsk->comm,
write ? "write access to" : "read access from",
field, address,
field, (unsigned long) regs->cp0_epc,
field, (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 __user *) address;
force_sig_info(SIGSEGV, &info, tsk);
return;
}
no_context:
/* Are we prepared to handle this kernel fault? */
if (fixup_exception(regs)) {
current->thread.cp0_baduaddr = address;
return;
}
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
bust_spinlocks(1);
printk(KERN_ALERT "CPU %d Unable to handle kernel paging request at "
"virtual address %0*lx, epc == %0*lx, ra == %0*lx\n",
smp_processor_id(), field, address, field, regs->cp0_epc,
field, regs->regs[31]);
die("Oops", regs);
/*
* 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 (is_init(tsk)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
}
printk("VM: killing process %s\n", tsk->comm);
if (user_mode(regs))
do_exit(SIGKILL);
goto no_context;
do_sigbus:
up_read(&mm->mmap_sem);
/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs))
goto no_context;
else
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
#if 0
printk("do_page_fault() #3: sending SIGBUS to %s for "
"invalid %s\n%0*lx (epc == %0*lx, ra == %0*lx)\n",
tsk->comm,
write ? "write access to" : "read access from",
field, address,
field, (unsigned long) regs->cp0_epc,
field, (unsigned long) regs->regs[31]);
#endif
tsk->thread.cp0_badvaddr = address;
info.si_signo = SIGBUS;
info.si_errno = 0;
info.si_code = BUS_ADRERR;
info.si_addr = (void __user *) address;
force_sig_info(SIGBUS, &info, tsk);
return;
vmalloc_fault:
{
/*
* Synchronize this task's top level page-table
* with the 'reference' page table.
*
* Do _not_ use "tsk" here. We might be inside
* an interrupt in the middle of a task switch..
*/
int offset = __pgd_offset(address);
pgd_t *pgd, *pgd_k;
pud_t *pud, *pud_k;
pmd_t *pmd, *pmd_k;
pte_t *pte_k;
pgd = (pgd_t *) pgd_current[smp_processor_id()] + offset;
pgd_k = init_mm.pgd + offset;
if (!pgd_present(*pgd_k))
goto no_context;
set_pgd(pgd, *pgd_k);
pud = pud_offset(pgd, address);
pud_k = pud_offset(pgd_k, address);
if (!pud_present(*pud_k))
goto no_context;
pmd = pmd_offset(pud, address);
pmd_k = pmd_offset(pud_k, address);
if (!pmd_present(*pmd_k))
goto no_context;
set_pmd(pmd, *pmd_k);
pte_k = pte_offset_kernel(pmd_k, address);
if (!pte_present(*pte_k))
goto no_context;
return;
}
}
/*
* 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 mmu_meh)
{
struct vm_area_struct *vma = NULL;
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
int si_code;
int fault;
unsigned long address = mmu_meh & PAGE_MASK;
si_code = SEGV_MAPERR;
#ifndef CONFIG_CPU_HAS_TLBI
/*
* 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 (unlikely(address >= VMALLOC_START) &&
unlikely(address <= VMALLOC_END)) {
/*
* Synchronize this task's top level page-table
* with the 'reference' page table.
*
* Do _not_ use "tsk" here. We might be inside
* an interrupt in the middle of a task switch..
*/
int offset = __pgd_offset(address);
pgd_t *pgd, *pgd_k;
pud_t *pud, *pud_k;
pmd_t *pmd, *pmd_k;
pte_t *pte_k;
unsigned long pgd_base;
pgd_base = tlb_get_pgd();
pgd = (pgd_t *)pgd_base + offset;
pgd_k = init_mm.pgd + offset;
if (!pgd_present(*pgd_k))
goto no_context;
set_pgd(pgd, *pgd_k);
pud = (pud_t *)pgd;
pud_k = (pud_t *)pgd_k;
if (!pud_present(*pud_k))
goto no_context;
pmd = pmd_offset(pud, address);
pmd_k = pmd_offset(pud_k, address);
if (!pmd_present(*pmd_k))
goto no_context;
set_pmd(pmd, *pmd_k);
pte_k = pte_offset_kernel(pmd_k, address);
if (!pte_present(*pte_k))
goto no_context;
return;
}
#endif
/*
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
if (in_atomic() || !mm)
goto bad_area_nosemaphore;
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 (write) {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
} else {
if (!(vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)))
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.
*/
fault = handle_mm_fault(vma, address, write ? FAULT_FLAG_WRITE : 0);
if (unlikely(fault & VM_FAULT_ERROR)) {
if (fault & VM_FAULT_OOM)
goto out_of_memory;
else if (fault & VM_FAULT_SIGBUS)
goto do_sigbus;
else if (fault & VM_FAULT_SIGSEGV)
goto bad_area;
BUG();
}
if (fault & VM_FAULT_MAJOR)
tsk->maj_flt++;
else
tsk->min_flt++;
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)) {
force_sig_fault(SIGSEGV, si_code, (void __user *)address, current);
return;
}
no_context:
/* Are we prepared to handle this kernel fault? */
if (fixup_exception(regs))
return;
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
bust_spinlocks(1);
pr_alert("Unable to handle kernel paging request at virtual "
"address 0x%08lx, pc: 0x%08lx\n", address, regs->pc);
die_if_kernel("Oops", regs, write);
out_of_memory:
/*
* We ran out of memory, call the OOM killer, and return the userspace
* (which will retry the fault, or kill us if we got oom-killed).
*/
pagefault_out_of_memory();
return;
do_sigbus:
up_read(&mm->mmap_sem);
/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs))
goto no_context;
force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address, current);
}
