patch-2.2.8 linux/arch/arm/mm/fault-armo.c

• Lines: 235
• Date: Sat May 8 11:06:56 1999
• Orig file: v2.2.7/linux/arch/arm/mm/fault-armo.c
• Orig date: Tue Dec 22 14:16:53 1998

diff -u --recursive --new-file v2.2.7/linux/arch/arm/mm/fault-armo.c linux/arch/arm/mm/fault-armo.c
@@ -1,11 +1,10 @@
 /*
- *  linux/arch/arm/mm/fault.c
+ *  linux/arch/arm/mm/fault-armo.c
  *
  *  Copyright (C) 1995  Linus Torvalds
- *  Modifications for ARM processor (c) 1995, 1996 Russell King
+ *  Modifications for ARM processor (c) 1995-1999 Russell King
  */
 
-#include <linux/config.h>
 #include <linux/signal.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
@@ -15,8 +14,7 @@
 #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 <asm/system.h>
 #include <asm/uaccess.h>
@@ -27,35 +25,32 @@
 #define FAULT_CODE_WRITE	0x02
 #define FAULT_CODE_USER		0x01
 
-struct pgtable_cache_struct quicklists;
+#define DO_COW(m)		((m) & (FAULT_CODE_WRITE|FAULT_CODE_FORCECOW))
+#define READ_FAULT(m)		(!((m) & FAULT_CODE_WRITE))
 
-void __bad_pmd(pmd_t *pmd)
+#include "fault-common.c"
+
+static void *alloc_table(int size, int prio)
 {
-	printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd));
-#ifdef CONFIG_DEBUG_ERRORS
-	__backtrace();
-#endif
-	set_pmd(pmd, mk_pmd(BAD_PAGETABLE));
+	if (size != 128)
+		printk("invalid table size\n");
+	return (void *)get_page_8k(prio);
 }
 
-void __bad_pmd_kernel(pmd_t *pmd)
+void free_table(void *table)
 {
-	printk("Bad pmd in pte_alloc_kernel: %08lx\n", pmd_val(*pmd));
-#ifdef CONFIG_DEBUG_ERRORS
-	__backtrace();
-#endif
-	set_pmd(pmd, mk_pmd(BAD_PAGETABLE));
+	free_page_8k((unsigned long)table);
 }
 
 pgd_t *get_pgd_slow(void)
 {
-	pgd_t *pgd = (pgd_t *) kmalloc(PTRS_PER_PGD * BYTES_PER_PTR, GFP_KERNEL);
+	pgd_t *pgd = (pgd_t *)alloc_table(PTRS_PER_PGD * BYTES_PER_PTR, GFP_KERNEL);
 	pgd_t *init;
-	
+
 	if (pgd) {
 		init = pgd_offset(&init_mm, 0);
-		memzero (pgd, USER_PTRS_PER_PGD * BYTES_PER_PTR);
-		memcpy (pgd + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
+		memzero(pgd, USER_PTRS_PER_PGD * BYTES_PER_PTR);
+		memcpy(pgd + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
 			(PTRS_PER_PGD - USER_PTRS_PER_PGD) * BYTES_PER_PTR);
 	}
 	return pgd;
@@ -65,17 +60,17 @@
 {
 	pte_t *pte;
 
-	pte = (pte_t *) kmalloc (PTRS_PER_PTE * BYTES_PER_PTR, GFP_KERNEL);
+	pte = (pte_t *)alloc_table(PTRS_PER_PTE * BYTES_PER_PTR, GFP_KERNEL);
 	if (pmd_none(*pmd)) {
 		if (pte) {
-			memzero (pte, PTRS_PER_PTE * BYTES_PER_PTR);
+			memzero(pte, PTRS_PER_PTE * BYTES_PER_PTR);
 			set_pmd(pmd, mk_pmd(pte));
 			return pte + offset;
 		}
 		set_pmd(pmd, mk_pmd(BAD_PAGETABLE));
 		return NULL;
 	}
-	kfree (pte);
+	free_table((void *)pte);
 	if (pmd_bad(*pmd)) {
 		__bad_pmd(pmd);
 		return NULL;
@@ -83,126 +78,22 @@
 	return (pte_t *) pmd_page(*pmd) + offset;
 }
 
-extern void die_if_kernel(char *msg, struct pt_regs *regs, unsigned int err, unsigned int ret);
-
-static void kernel_page_fault (unsigned long addr, int mode, struct pt_regs *regs,
-			       struct task_struct *tsk, struct mm_struct *mm)
-{
-	/*
-	 * Oops. The kernel tried to access some bad page. We'll have to
-	 * terminate things with extreme prejudice.
-	 */
-	pgd_t *pgd;
-	if (addr < 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", addr);
-	printk (KERN_ALERT "current->tss.memmap = %08lX\n", tsk->tss.memmap);
-	pgd = pgd_offset (mm, addr);
-	printk (KERN_ALERT "*pgd = %08lx", pgd_val (*pgd));
-	if (!pgd_none (*pgd)) {
-		pmd_t *pmd;
-		pmd = pmd_offset (pgd, addr);
-		printk (", *pmd = %08lx", pmd_val (*pmd));
-		if (!pmd_none (*pmd))
-			printk (", *pte = %08lx", pte_val (*pte_offset (pmd, addr)));
-	}
-	printk ("\n");
-	die_if_kernel ("Oops", regs, mode, SIGKILL);
-	do_exit (SIGKILL);
-}
-
-static void
-handle_dataabort (unsigned long addr, int mode, struct pt_regs *regs)
-{
-	struct task_struct *tsk;
-	struct mm_struct *mm;
-	struct vm_area_struct *vma;
-	unsigned long fixup;
-
-	lock_kernel();
-	tsk = current;
-	mm = tsk->mm;
-
-	down(&mm->mmap_sem);
-	vma = find_vma (mm, addr);
-	if (!vma)
-		goto bad_area;
-	if (addr >= vma->vm_start)
-		goto good_area;
-	if (!(vma->vm_flags & VM_GROWSDOWN) || expand_stack (vma, addr))
-		goto bad_area;
-
-	/*
-	 * Ok, we have a good vm_area for this memory access, so
-	 * we can handle it..
-	 */
-good_area:
-	if (!(mode & FAULT_CODE_WRITE)) { /* write? */
-		if (!(vma->vm_flags & (VM_READ|VM_EXEC)))
-			goto bad_area;
-	} else {
-		if (!(vma->vm_flags & VM_WRITE))
-			goto bad_area;
-	}
-	handle_mm_fault (tsk, vma, addr, mode & (FAULT_CODE_WRITE|FAULT_CODE_FORCECOW));
-	up(&mm->mmap_sem);
-	goto out;
-
-	/*
-	 * 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(&mm->mmap_sem);
-	if (mode & FAULT_CODE_USER) {
-//extern int console_loglevel;
-//cli();
-		tsk->tss.error_code = mode;
-		tsk->tss.trap_no = 14;
-//console_loglevel = 9;
-		printk ("%s: memory violation at pc=0x%08lx, lr=0x%08lx (bad address=0x%08lx, code %d)\n",
-			tsk->comm, regs->ARM_pc, regs->ARM_lr, addr, mode);
-//#ifdef DEBUG
-		show_regs (regs);
-		c_backtrace (regs->ARM_fp, 0);
-//#endif
-		force_sig(SIGSEGV, tsk);
-//while (1);
-		goto out;
-	}
-
-	/* Are we prepared to handle this kernel fault?  */
-	if ((fixup = search_exception_table(instruction_pointer(regs))) != 0) {
-		printk(KERN_DEBUG "%s: Exception at [<%lx>] addr=%lx (fixup: %lx)\n",
-			tsk->comm, regs->ARM_pc, addr, fixup);
-		regs->ARM_pc = fixup;
-		goto out;
-	}
-
-
-	kernel_page_fault (addr, mode, regs, tsk, mm);
-out:
-	unlock_kernel();
-}
-
 /*
  * 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
+ * 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_DataAbort(unsigned long min_addr, unsigned long max_addr, int mode, struct pt_regs *regs)
 {
-	handle_dataabort (min_addr, mode, regs);
+	do_page_fault(min_addr, mode, regs);
 
 	if ((min_addr ^ max_addr) >> PAGE_SHIFT)
-		handle_dataabort (max_addr, mode | FAULT_CODE_FORCECOW, regs);
+		do_page_fault(max_addr, mode | FAULT_CODE_FORCECOW, regs);
 }
 
 asmlinkage int
-do_PrefetchAbort (unsigned long addr, int mode, struct pt_regs *regs)
+do_PrefetchAbort(unsigned long addr, struct pt_regs *regs)
 {
 #if 0
 	if (the memc mapping for this page exists - can check now...) {
@@ -210,6 +101,6 @@
 		return 0;
 	}
 #endif
-	handle_dataabort (addr, mode, regs);
+	do_page_fault(addr, FAULT_CODE_USER|FAULT_CODE_PREFETCH, regs);
 	return 1;
 }