diff options
Diffstat (limited to 'arch/arm26/mm/fault.c')
| -rw-r--r-- | arch/arm26/mm/fault.c | 312 |
1 files changed, 0 insertions, 312 deletions
diff --git a/arch/arm26/mm/fault.c b/arch/arm26/mm/fault.c deleted file mode 100644 index dec638a0c8d..00000000000 --- a/arch/arm26/mm/fault.c +++ /dev/null @@ -1,312 +0,0 @@ -/* - * linux/arch/arm26/mm/fault.c - * - * Copyright (C) 1995 Linus Torvalds - * Modifications for ARM processor (c) 1995-2001 Russell King - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ -#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/interrupt.h> -#include <linux/proc_fs.h> -#include <linux/init.h> - -#include <asm/system.h> -#include <asm/pgtable.h> -#include <asm/uaccess.h> //FIXME this header may be bogusly included - -#include "fault.h" - -#define FAULT_CODE_LDRSTRPOST 0x80 -#define FAULT_CODE_LDRSTRPRE 0x40 -#define FAULT_CODE_LDRSTRREG 0x20 -#define FAULT_CODE_LDMSTM 0x10 -#define FAULT_CODE_LDCSTC 0x08 -#define FAULT_CODE_PREFETCH 0x04 -#define FAULT_CODE_WRITE 0x02 -#define FAULT_CODE_FORCECOW 0x01 - -#define DO_COW(m) ((m) & (FAULT_CODE_WRITE|FAULT_CODE_FORCECOW)) -#define READ_FAULT(m) (!((m) & FAULT_CODE_WRITE)) -#define DEBUG -/* - * This is useful to dump out the page tables associated with - * 'addr' in mm 'mm'. - */ -void show_pte(struct mm_struct *mm, unsigned long addr) -{ - pgd_t *pgd; - - if (!mm) - mm = &init_mm; - - printk(KERN_ALERT "pgd = %p\n", mm->pgd); - pgd = pgd_offset(mm, addr); - printk(KERN_ALERT "[%08lx] *pgd=%08lx", addr, pgd_val(*pgd)); - - do { - pmd_t *pmd; - pte_t *pte; - - pmd = pmd_offset(pgd, addr); - - if (pmd_none(*pmd)) - break; - - if (pmd_bad(*pmd)) { - printk("(bad)"); - break; - } - - /* We must not map this if we have highmem enabled */ - /* FIXME */ - pte = pte_offset_map(pmd, addr); - printk(", *pte=%08lx", pte_val(*pte)); - pte_unmap(pte); - } while(0); - - printk("\n"); -} - -/* - * 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) -{ - /* - * Are we prepared to handle this kernel fault? - */ - if (fixup_exception(regs)) - return; - - /* - * No handler, we'll have to terminate things with extreme prejudice. - */ - bust_spinlocks(1); - 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); - bust_spinlocks(0); - do_exit(SIGKILL); -} - -/* - * Something tried to access memory that isn't in our memory map.. - * User mode accesses just cause a SIGSEGV - */ -static void -__do_user_fault(struct task_struct *tsk, unsigned long addr, - unsigned int fsr, int code, struct pt_regs *regs) -{ - struct siginfo si; - -#ifdef CONFIG_DEBUG_USER - printk("%s: unhandled page fault at 0x%08lx, code 0x%03x\n", - tsk->comm, addr, fsr); - show_pte(tsk->mm, addr); - show_regs(regs); - //dump_backtrace(regs, tsk); // FIXME ARM32 dropped this - why? - while(1); //FIXME - hack to stop debug going nutso -#endif - - tsk->thread.address = addr; - tsk->thread.error_code = fsr; - tsk->thread.trap_no = 14; - si.si_signo = SIGSEGV; - si.si_errno = 0; - si.si_code = code; - si.si_addr = (void *)addr; - force_sig_info(SIGSEGV, &si, tsk); -} - -static int -__do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, - struct task_struct *tsk) -{ - struct vm_area_struct *vma; - int fault, mask; - - vma = find_vma(mm, addr); - fault = -2; /* bad map area */ - if (!vma) - goto out; - if (vma->vm_start > addr) - goto check_stack; - - /* - * Ok, we have a good vm_area for this - * memory access, so we can handle it. - */ -good_area: - if (READ_FAULT(fsr)) /* read? */ - mask = VM_READ|VM_EXEC|VM_WRITE; - else - mask = VM_WRITE; - - fault = -1; /* bad access type */ - if (!(vma->vm_flags & mask)) - goto out; - - /* - * If for any reason at all we couldn't handle - * the fault, make sure we exit gracefully rather - * than endlessly redo the fault. - */ -survive: - fault = handle_mm_fault(mm, vma, addr & PAGE_MASK, DO_COW(fsr)); - if (unlikely(fault & VM_FAULT_ERROR)) { - if (fault & VM_FAULT_OOM) - goto out_of_memory; - else if (fault & VM_FAULT_SIGBUS) - return fault; - BUG(); - } - if (fault & VM_FAULT_MAJOR) - tsk->maj_flt++; - else - tsk->min_flt++; - return fault; - -out_of_memory: - fault = -3; /* out of memory */ - if (!is_init(tsk)) - goto out; - - /* - * If we are out of memory for pid1, - * sleep for a while and retry - */ - yield(); - goto survive; - -check_stack: - if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) - goto good_area; -out: - return fault; -} - -int do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) -{ - struct task_struct *tsk; - struct mm_struct *mm; - int fault; - - tsk = current; - mm = tsk->mm; - - /* - * If we're in an interrupt or have no user - * context, we must not take the fault.. - */ - if (in_atomic() || !mm) - goto no_context; - - down_read(&mm->mmap_sem); - fault = __do_page_fault(mm, addr, fsr, tsk); - up_read(&mm->mmap_sem); - - /* - * Handle the "normal" case first - */ - if (likely(!(fault & VM_FAULT_ERROR))) - return 0; - if (fault & VM_FAULT_SIGBUS) - goto do_sigbus; - /* else VM_FAULT_OOM */ - - /* - * If we are in kernel mode at this point, we - * have no context to handle this fault with. - * FIXME - is this test right? - */ - 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{ - __do_user_fault(tsk, addr, fsr, fault == -1 ? SEGV_ACCERR : SEGV_MAPERR, regs); - } - - 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; //FIXME - need other bits setting? - tsk->thread.error_code = fsr; - tsk->thread.trap_no = 14; - force_sig(SIGBUS, tsk); -#ifdef CONFIG_DEBUG_USER - printk(KERN_DEBUG "%s: sigbus at 0x%08lx, pc=0x%08lx\n", - current->comm, addr, instruction_pointer(regs)); -#endif - - /* Kernel mode? Handle exceptions or die */ - if (user_mode(regs)) - return 0; - -no_context: - __do_kernel_fault(mm, addr, fsr, regs); - return 0; -} - -/* - * Handle a data abort. Note that we have to handle a range of addresses - * on ARM2/3 for ldm. If both pages are zero-mapped, then we have to force - * a copy-on-write. However, on the second page, we always force COW. - */ -asmlinkage void -do_DataAbort(unsigned long min_addr, unsigned long max_addr, int mode, struct pt_regs *regs) -{ - do_page_fault(min_addr, mode, regs); - - if ((min_addr ^ max_addr) >> PAGE_SHIFT){ - do_page_fault(max_addr, mode | FAULT_CODE_FORCECOW, regs); - } -} - -asmlinkage int -do_PrefetchAbort(unsigned long addr, struct pt_regs *regs) -{ -#if 0 - if (the memc mapping for this page exists) { - printk ("Page in, but got abort (undefined instruction?)\n"); - return 0; - } -#endif - do_page_fault(addr, FAULT_CODE_PREFETCH, regs); - return 1; -} - |