diff options
Diffstat (limited to 'arch/ppc/mm/fault.c')
| -rw-r--r-- | arch/ppc/mm/fault.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/arch/ppc/mm/fault.c b/arch/ppc/mm/fault.c new file mode 100644 index 000000000..ff7e0b9a8 --- /dev/null +++ b/arch/ppc/mm/fault.c @@ -0,0 +1,264 @@ +/* + * ARCH/ppc/mm/fault.c + * + * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds + * Ported to PPC by Gary Thomas + */ + +#include <linux/config.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/head.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 <asm/page.h> +#include <asm/pgtable.h> + +extern void die_if_kernel(char *, struct pt_regs *, long); +extern void do_page_fault(struct pt_regs *, unsigned long, unsigned long); + +#undef SHOW_FAULTS +#undef NOISY_INSTRFAULT +#undef NOISY_DATAFAULT + +#define NEWMM 1 + +void +DataAccessException(struct pt_regs *regs) +{ + pgd_t *dir; + pmd_t *pmd; + pte_t *pte; + int tries, mode = 0; + +#ifdef NOISY_DATAFAULT + printk("Data fault on %x\n",regs->dar); +#endif + + if (user_mode(regs)) mode |= 0x04; + if (regs->dsisr & 0x02000000) mode |= 0x02; /* Load/store */ + if (regs->dsisr & 0x08000000) mode |= 0x01; /* Protection violation */ + if (mode & 0x01) + { +#ifdef NOISY_DATAFAULT + printk("Write Protect fault\n "); +#endif + do_page_fault(regs, regs->dar, mode); +#ifdef NOISY_DATAFAULT + printk("Write Protect fault handled\n"); +#endif + return; + } + + + for (tries = 0; tries < 1; tries++) + { + dir = pgd_offset(current->mm, regs->dar & PAGE_MASK); + if (dir) + { + pmd = pmd_offset(dir, regs->dar & PAGE_MASK); + if (pmd && pmd_present(*pmd)) + { + pte = pte_offset(pmd, regs->dar & PAGE_MASK); + if (pte && pte_present(*pte)) + { +#if NOISY_DATAFAULT + printk("Page mapped - PTE: %x[%x]\n", pte, *(long *)pte); +#endif + MMU_hash_page(¤t->tss, regs->dar & PAGE_MASK, pte); + /*MMU_hash_page2(current->mm, regs->dar & PAGE_MASK, pte);*/ + return; + } + } + } else + { +#if NOISY_DATAFAULT + printk("No PGD\n"); +#endif + } + do_page_fault(regs, regs->dar, mode); + } +} + +void +InstructionAccessException(struct pt_regs *regs) +{ + pgd_t *dir; + pmd_t *pmd; + pte_t *pte; + int tries, mode = 0; + +#if NOISY_INSTRFAULT + printk("Instr fault on %x\n",regs->dar); +#endif + +#ifdef NEWMM + if (!user_mode(regs)) + { + + panic("InstructionAcessException in kernel mode. PC %x addr %x", + regs->nip, regs->dar); + } +#endif + if (user_mode(regs)) mode |= 0x04; + if (regs->dsisr & 0x02000000) mode |= 0x02; /* Load/store */ + if (regs->dsisr & 0x08000000) mode |= 0x01; /* Protection violation */ + + if (mode & 0x01) + { + do_page_fault(regs, regs->dar, mode); + return; + } + for (tries = 0; tries < 1; tries++) + { + dir = pgd_offset(current->mm, regs->dar & PAGE_MASK); + if (dir) + { + pmd = pmd_offset(dir, regs->dar & PAGE_MASK); + if (pmd && pmd_present(*pmd)) + { + pte = pte_offset(pmd, regs->dar & PAGE_MASK); + if (pte && pte_present(*pte)) + { + + MMU_hash_page(¤t->tss, regs->dar & PAGE_MASK, pte); + /* MMU_hash_page2(current->mm, regs->dar & PAGE_MASK, pte);*/ + return; + } + } + } else + { + } + do_page_fault(regs, regs->dar, mode); + } +} + + +/* + * This routine handles page faults. It determines the address, + * and the problem, and then passes it off to one of the appropriate + * routines. + * + * The error_code parameter just the same as in the i386 version: + * + * 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 + */ +void do_page_fault(struct pt_regs *regs, unsigned long address, unsigned long error_code) +{ + struct vm_area_struct * vma; + unsigned long page; + + vma = find_vma(current, address); + if (!vma) + { + goto bad_area; + } + + if (vma->vm_start <= address){ + goto good_area; + } + if (!(vma->vm_flags & VM_GROWSDOWN)) + { + goto bad_area; + } + if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur) + { + goto bad_area; + } + vma->vm_offset -= vma->vm_start - (address & PAGE_MASK); + + vma->vm_start = (address & PAGE_MASK); + +good_area: + /* a write */ + if (error_code & 2) { + if (!(vma->vm_flags & VM_WRITE)) + { + goto bad_area; + } + /* a read */ + } else { + /* protection fault */ + if (error_code & 1) + { + goto bad_area; + } + if (!(vma->vm_flags & (VM_READ | VM_EXEC))) + { + goto bad_area; + } + } + handle_mm_fault(vma, address, error_code & 2); + flush_page(address); /* Flush & Invalidate cache - note: address is OK now */ + return; + +bad_area: + if (user_mode(regs)) + { +/* printk("Bad User Area: Addr %x PC %x Task %x pid %d %s\n", + address,regs->nip, current,current->pid,current->comm);*/ + send_sig(SIGSEGV, current, 1); + return; + } + panic("KERNEL access of bad area PC %x address %x vm_flags %x\n", + regs->nip,address,vma->vm_flags); +} + + +va_to_phys(unsigned long address) +{ + pgd_t *dir; + pmd_t *pmd; + pte_t *pte; + dir = pgd_offset(current->mm, address & PAGE_MASK); + if (dir) + { + pmd = pmd_offset(dir, address & PAGE_MASK); + if (pmd && pmd_present(*pmd)) + { + pte = pte_offset(pmd, address & PAGE_MASK); + if (pte && pte_present(*pte)) + { + return(pte_page(*pte) | (address & ~(PAGE_MASK-1))); + } + } else + { + return (0); + } + } else + { + return (0); + } + return (0); +} + + +/* + * See if an address should be valid in the current context. + */ +valid_addr(unsigned long addr) +{ + struct vm_area_struct * vma; + for (vma = current->mm->mmap ; ; vma = vma->vm_next) + { + if (!vma) + { + return (0); + } + if (vma->vm_end > addr) + break; + } + if (vma->vm_start <= addr) + { + return (1); + } + return (0); +} |