*
* Copyright (C) 2000, 2001 Paolo Alberelli
* Copyright (C) 2003 Richard Curnow (/proc/tlb, bug fixes)
- * Copyright (C) 2003 - 2009 Paul Mundt
+ * Copyright (C) 2003 - 2012 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
#include <asm/pgalloc.h>
#include <asm/mmu_context.h>
-extern void die(const char *,struct pt_regs *,long);
-
-#define PFLAG(val,flag) (( (val) & (flag) ) ? #flag : "" )
-#define PPROT(flag) PFLAG(pgprot_val(prot),flag)
-
-static inline void print_prots(pgprot_t prot)
-{
- printk("prot is 0x%016llx\n",pgprot_val(prot));
-
- printk("%s %s %s %s %s\n",PPROT(_PAGE_SHARED),PPROT(_PAGE_READ),
- PPROT(_PAGE_EXECUTE),PPROT(_PAGE_WRITE),PPROT(_PAGE_USER));
-}
-
-static inline void print_vma(struct vm_area_struct *vma)
-{
- printk("vma start 0x%08lx\n", vma->vm_start);
- printk("vma end 0x%08lx\n", vma->vm_end);
-
- print_prots(vma->vm_page_prot);
- printk("vm_flags 0x%08lx\n", vma->vm_flags);
-}
-
-static inline void print_task(struct task_struct *tsk)
-{
- printk("Task pid %d\n", task_pid_nr(tsk));
-}
-
-static pte_t *lookup_pte(struct mm_struct *mm, unsigned long address)
-{
- pgd_t *dir;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
- pte_t entry;
-
- dir = pgd_offset(mm, address);
- if (pgd_none(*dir))
- return NULL;
-
- pud = pud_offset(dir, address);
- if (pud_none(*pud))
- return NULL;
-
- pmd = pmd_offset(pud, address);
- if (pmd_none(*pmd))
- return NULL;
-
- pte = pte_offset_kernel(pmd, address);
- entry = *pte;
- if (pte_none(entry) || !pte_present(entry))
- return NULL;
-
- return pte;
-}
-
-/*
- * 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 writeaccess,
- unsigned long textaccess, unsigned long address)
-{
- struct task_struct *tsk;
- struct mm_struct *mm;
- struct vm_area_struct * vma;
- const struct exception_table_entry *fixup;
- pte_t *pte;
- int fault;
-
- /* SIM
- * Note this is now called with interrupts still disabled
- * This is to cope with being called for a missing IO port
- * address with interrupts disabled. This should be fixed as
- * soon as we have a better 'fast path' miss handler.
- *
- * Plus take care how you try and debug this stuff.
- * For example, writing debug data to a port which you
- * have just faulted on is not going to work.
- */
-
- tsk = current;
- mm = tsk->mm;
-
- /* Not an IO address, so reenable interrupts */
- local_irq_enable();
-
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
-
- /*
- * If we're in an interrupt or have no user
- * context, we must not take the fault..
- */
- if (in_atomic() || !mm)
- goto no_context;
-
- /* TLB misses upon some cache flushes get done under cli() */
- down_read(&mm->mmap_sem);
-
- vma = find_vma(mm, address);
-
- if (!vma) {
-#ifdef DEBUG_FAULT
- print_task(tsk);
- printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
- __func__, __LINE__,
- address,regs->pc,textaccess,writeaccess);
- show_regs(regs);
-#endif
- goto bad_area;
- }
- if (vma->vm_start <= address) {
- goto good_area;
- }
-
- if (!(vma->vm_flags & VM_GROWSDOWN)) {
-#ifdef DEBUG_FAULT
- print_task(tsk);
- printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
- __func__, __LINE__,
- address,regs->pc,textaccess,writeaccess);
- show_regs(regs);
-
- print_vma(vma);
-#endif
- goto bad_area;
- }
- if (expand_stack(vma, address)) {
-#ifdef DEBUG_FAULT
- print_task(tsk);
- printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
- __func__, __LINE__,
- address,regs->pc,textaccess,writeaccess);
- show_regs(regs);
-#endif
- goto bad_area;
- }
-/*
- * Ok, we have a good vm_area for this memory access, so
- * we can handle it..
- */
-good_area:
- if (textaccess) {
- if (!(vma->vm_flags & VM_EXEC))
- goto bad_area;
- } else {
- if (writeaccess) {
- if (!(vma->vm_flags & VM_WRITE))
- goto bad_area;
- } else {
- if (!(vma->vm_flags & VM_READ))
- 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(mm, vma, address, writeaccess ? 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;
- BUG();
- }
-
- if (fault & VM_FAULT_MAJOR) {
- tsk->maj_flt++;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
- regs, address);
- } else {
- tsk->min_flt++;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
- regs, address);
- }
-
- /* If we get here, the page fault has been handled. Do the TLB refill
- now from the newly-setup PTE, to avoid having to fault again right
- away on the same instruction. */
- pte = lookup_pte (mm, address);
- if (!pte) {
- /* From empirical evidence, we can get here, due to
- !pte_present(pte). (e.g. if a swap-in occurs, and the page
- is swapped back out again before the process that wanted it
- gets rescheduled?) */
- goto no_pte;
- }
-
- __do_tlb_refill(address, textaccess, pte);
-
-no_pte:
-
- 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:
-#ifdef DEBUG_FAULT
- printk("fault:bad area\n");
-#endif
- up_read(&mm->mmap_sem);
-
- if (user_mode(regs)) {
- static int count=0;
- siginfo_t info;
- if (count < 4) {
- /* This is really to help debug faults when starting
- * usermode, so only need a few */
- count++;
- printk("user mode bad_area address=%08lx pid=%d (%s) pc=%08lx\n",
- address, task_pid_nr(current), current->comm,
- (unsigned long) regs->pc);
-#if 0
- show_regs(regs);
-#endif
- }
- if (is_global_init(tsk)) {
- panic("INIT had user mode bad_area\n");
- }
- tsk->thread.address = address;
- tsk->thread.error_code = writeaccess;
- info.si_signo = SIGSEGV;
- info.si_errno = 0;
- info.si_addr = (void *) address;
- force_sig_info(SIGSEGV, &info, tsk);
- return;
- }
-
-no_context:
-#ifdef DEBUG_FAULT
- printk("fault:No context\n");
-#endif
- /* Are we prepared to handle this kernel fault? */
- fixup = search_exception_tables(regs->pc);
- if (fixup) {
- regs->pc = fixup->fixup;
- return;
- }
-
-/*
- * Oops. The kernel tried to access some bad page. We'll have to
- * terminate things with extreme prejudice.
- *
- */
- if (address < PAGE_SIZE)
- printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
- else
- printk(KERN_ALERT "Unable to handle kernel paging request");
- printk(" at virtual address %08lx\n", address);
- printk(KERN_ALERT "pc = %08Lx%08Lx\n", regs->pc >> 32, regs->pc & 0xffffffff);
- die("Oops", regs, writeaccess);
- 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 (!user_mode(regs))
- goto no_context;
- pagefault_out_of_memory();
- return;
-
-do_sigbus:
- printk("fault:Do sigbus\n");
- up_read(&mm->mmap_sem);
-
- /*
- * Send a sigbus, regardless of whether we were in kernel
- * or user mode.
- */
- tsk->thread.address = address;
- tsk->thread.error_code = writeaccess;
- tsk->thread.trap_no = 14;
- force_sig(SIGBUS, tsk);
-
- /* Kernel mode? Handle exceptions or die */
- if (!user_mode(regs))
- goto no_context;
-}
-
void local_flush_tlb_one(unsigned long asid, unsigned long page)
{
unsigned long long match, pteh=0, lpage;
{
flush_tlb_all();
}
-
-void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
-{
-}
projects / firefly-linux-kernel-4.4.55.git / blobdiff