diff options
Diffstat (limited to 'old/xenolinux-2.4.16-sparse/arch/xeno/mm/fault.c')
-rw-r--r-- | old/xenolinux-2.4.16-sparse/arch/xeno/mm/fault.c | 401 |
1 files changed, 0 insertions, 401 deletions
diff --git a/old/xenolinux-2.4.16-sparse/arch/xeno/mm/fault.c b/old/xenolinux-2.4.16-sparse/arch/xeno/mm/fault.c deleted file mode 100644 index 41d966901a..0000000000 --- a/old/xenolinux-2.4.16-sparse/arch/xeno/mm/fault.c +++ /dev/null @@ -1,401 +0,0 @@ -/* - * linux/arch/i386/mm/fault.c - * - * Copyright (C) 1995 Linus Torvalds - */ - -#include <linux/signal.h> -#include <linux/sched.h> -#include <linux/kernel.h> -#include <linux/errno.h> -#include <linux/string.h> -#include <linux/types.h> -#include <linux/ptrace.h> -#include <linux/mman.h> -#include <linux/mm.h> -#include <linux/smp.h> -#include <linux/smp_lock.h> -#include <linux/interrupt.h> -#include <linux/init.h> -#include <linux/tty.h> -#include <linux/vt_kern.h> /* For unblank_screen() */ - -#include <asm/system.h> -#include <asm/uaccess.h> -#include <asm/pgalloc.h> -#include <asm/hardirq.h> - -extern void die(const char *,struct pt_regs *,long); - -extern int console_loglevel; - -pgd_t *cur_pgd; - -/* - * Ugly, ugly, but the goto's result in better assembly.. - */ -int __verify_write(const void * addr, unsigned long size) -{ - struct vm_area_struct * vma; - unsigned long start = (unsigned long) addr; - - if (!size) - return 1; - - vma = find_vma(current->mm, start); - if (!vma) - goto bad_area; - if (vma->vm_start > start) - goto check_stack; - -good_area: - if (!(vma->vm_flags & VM_WRITE)) - goto bad_area; - size--; - size += start & ~PAGE_MASK; - size >>= PAGE_SHIFT; - start &= PAGE_MASK; - - for (;;) { - survive: - { - int fault = handle_mm_fault(current->mm, vma, start, 1); - if (!fault) - goto bad_area; - if (fault < 0) - goto out_of_memory; - } - if (!size) - break; - size--; - start += PAGE_SIZE; - if (start < vma->vm_end) - continue; - vma = vma->vm_next; - if (!vma || vma->vm_start != start) - goto bad_area; - if (!(vma->vm_flags & VM_WRITE)) - goto bad_area;; - } - return 1; - -check_stack: - if (!(vma->vm_flags & VM_GROWSDOWN)) - goto bad_area; - if (expand_stack(vma, start) == 0) - goto good_area; - -bad_area: - return 0; - -out_of_memory: - if (current->pid == 1) { - current->policy |= SCHED_YIELD; - schedule(); - goto survive; - } - goto bad_area; -} - -extern spinlock_t timerlist_lock; - -/* - * Unlock any spinlocks which will prevent us from getting the - * message out (timerlist_lock is acquired through the - * console unblank code) - */ -void bust_spinlocks(int yes) -{ - spin_lock_init(&timerlist_lock); - if (yes) { - oops_in_progress = 1; - } else { - int loglevel_save = console_loglevel; -#ifdef CONFIG_VT - unblank_screen(); -#endif - oops_in_progress = 0; - /* - * OK, the message is on the console. Now we call printk() - * without oops_in_progress set so that printk will give klogd - * a poke. Hold onto your hats... - */ - console_loglevel = 15; /* NMI oopser may have shut the console up */ - printk(" "); - console_loglevel = loglevel_save; - } -} - -void do_BUG(const char *file, int line) -{ - bust_spinlocks(1); - printk("kernel BUG at %s:%d!\n", file, line); -} - -/* - * 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: - * bit 0 == 0 means no page found, 1 means protection fault - * bit 1 == 0 means read, 1 means write - * bit 2 == 0 means kernel, 1 means user-mode - */ -asmlinkage void do_page_fault(struct pt_regs *regs, - unsigned long error_code, - unsigned long address) -{ - struct task_struct *tsk = current; - struct mm_struct *mm; - struct vm_area_struct * vma; - unsigned long page; - unsigned long fixup; - int write; - siginfo_t info; - - /* Set the "privileged fault" bit to something sane. */ - error_code &= 3; - error_code |= (regs->xcs & 2) << 1; - -#if PT_UPDATE_DEBUG > 0 - if ( (error_code == 0) && (address >= TASK_SIZE) ) - { - unsigned long paddr = __pa(address); - int i; - for ( i = 0; i < pt_update_queue_idx; i++ ) - { - if ( update_debug_queue[i].ptr == paddr ) - { - printk("XXX now(EIP=%08lx:ptr=%08lx) " - "then(%s/%d:p/v=%08lx/%08lx)\n", - regs->eip, address, - update_debug_queue[i].file, - update_debug_queue[i].line, - update_debug_queue[i].ptr, - update_debug_queue[i].val); - } - } - } -#endif - - if ( flush_page_update_queue() != 0 ) return; - - /* - * 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. - * - * This verifies that the fault happens in kernel space - * (error_code & 4) == 0, and that the fault was not a - * protection error (error_code & 1) == 0. - */ - if (address >= TASK_SIZE && !(error_code & 5)) - goto vmalloc_fault; - - mm = tsk->mm; - 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; - - 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 (error_code & 4) { - /* - * accessing the stack below %esp is always a bug. - * The "+ 32" is there due to some instructions (like - * pusha) doing post-decrement on the stack and that - * doesn't show up until later.. - */ - if (address + 32 < regs->esp) - 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; - write = 0; - switch (error_code & 3) { - default: /* 3: write, present */ - /* fall through */ - case 2: /* write, not present */ - if (!(vma->vm_flags & VM_WRITE)) - goto bad_area; - write++; - break; - case 1: /* read, present */ - goto bad_area; - case 0: /* read, not present */ - 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); - - /* User mode accesses just cause a SIGSEGV */ - if (error_code & 4) { - tsk->thread.cr2 = address; - tsk->thread.error_code = error_code; - tsk->thread.trap_no = 14; - 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? */ - if ((fixup = search_exception_table(regs->eip)) != 0) { - regs->eip = fixup; - return; - } - -/* - * Oops. The kernel tried to access some bad page. We'll have to - * terminate things with extreme prejudice. - */ - - bust_spinlocks(1); - - 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(" printing eip:\n"); - printk("%08lx\n", regs->eip); - page = ((unsigned long *) cur_pgd)[address >> 22]; - printk(KERN_ALERT "*pde=%08lx(%08lx)\n", page, machine_to_phys(page)); - if (page & 1) { - page &= PAGE_MASK; - address &= 0x003ff000; - page = machine_to_phys(page); - page = ((unsigned long *) __va(page))[address >> PAGE_SHIFT]; - printk(KERN_ALERT "*pte=%08lx(%08lx)\n", page, - machine_to_phys(page)); - } - die("Oops", regs, error_code); - bust_spinlocks(0); - 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 (error_code & 4) - 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.cr2 = address; - tsk->thread.error_code = error_code; - tsk->thread.trap_no = 14; - 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 (!(error_code & 4)) - goto no_context; - 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; - pmd_t *pmd, *pmd_k; - pte_t *pte_k; - - pgd = offset + cur_pgd; - pgd_k = init_mm.pgd + offset; - - if (!pgd_present(*pgd_k)) - goto no_context; - set_pgd(pgd, *pgd_k); - - pmd = pmd_offset(pgd, address); - pmd_k = pmd_offset(pgd_k, address); - if (!pmd_present(*pmd_k)) - goto no_context; - set_pmd(pmd, *pmd_k); - XENO_flush_page_update_queue(); /* flush PMD update */ - - pte_k = pte_offset(pmd_k, address); - if (!pte_present(*pte_k)) - goto no_context; - return; - } -} |