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/*
* 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);
}
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