patch-2.3.10 linux/arch/i386/kernel/ptrace.c

• Lines: 239
• Date: Sun Jul 4 13:41:08 1999
• Orig file: v2.3.9/linux/arch/i386/kernel/ptrace.c
• Orig date: Mon Jun 7 11:15:33 1999

diff -u --recursive --new-file v2.3.9/linux/arch/i386/kernel/ptrace.c linux/arch/i386/kernel/ptrace.c
@@ -67,205 +67,6 @@
 	return 0;
 }
 
-/*
- * This routine gets a long from any process space by following the page
- * tables. NOTE! You should check that the long isn't on a page boundary,
- * and that it is in the task area before calling this: this routine does
- * no checking.
- */
-static unsigned long get_long(struct task_struct * tsk, 
-	struct vm_area_struct * vma, unsigned long addr)
-{
-	pgd_t * pgdir;
-	pmd_t * pgmiddle;
-	pte_t * pgtable;
-	unsigned long page;
-
-repeat:
-	pgdir = pgd_offset(vma->vm_mm, addr);
-	if (pgd_none(*pgdir)) {
-		handle_mm_fault(tsk, vma, addr, 0);
-		goto repeat;
-	}
-	if (pgd_bad(*pgdir)) {
-		printk("ptrace: bad page directory %08lx\n", pgd_val(*pgdir));
-		pgd_clear(pgdir);
-		return 0;
-	}
-	pgmiddle = pmd_offset(pgdir, addr);
-	if (pmd_none(*pgmiddle)) {
-		handle_mm_fault(tsk, vma, addr, 0);
-		goto repeat;
-	}
-	if (pmd_bad(*pgmiddle)) {
-		printk("ptrace: bad page middle %08lx\n", pmd_val(*pgmiddle));
-		pmd_clear(pgmiddle);
-		return 0;
-	}
-	pgtable = pte_offset(pgmiddle, addr);
-	if (!pte_present(*pgtable)) {
-		handle_mm_fault(tsk, vma, addr, 0);
-		goto repeat;
-	}
-	page = pte_page(*pgtable);
-/* this is a hack for non-kernel-mapped video buffers and similar */
-	if (MAP_NR(page) >= max_mapnr)
-		return 0;
-	page += addr & ~PAGE_MASK;
-	return *(unsigned long *) page;
-}
-
-/*
- * This routine puts a long into any process space by following the page
- * tables. NOTE! You should check that the long isn't on a page boundary,
- * and that it is in the task area before calling this: this routine does
- * no checking.
- *
- * Now keeps R/W state of page so that a text page stays readonly
- * even if a debugger scribbles breakpoints into it.  -M.U-
- */
-static void put_long(struct task_struct * tsk, struct vm_area_struct * vma, unsigned long addr,
-	unsigned long data)
-{
-	pgd_t *pgdir;
-	pmd_t *pgmiddle;
-	pte_t *pgtable;
-	unsigned long page;
-
-repeat:
-	pgdir = pgd_offset(vma->vm_mm, addr);
-	if (!pgd_present(*pgdir)) {
-		handle_mm_fault(tsk, vma, addr, 1);
-		goto repeat;
-	}
-	if (pgd_bad(*pgdir)) {
-		printk("ptrace: bad page directory %08lx\n", pgd_val(*pgdir));
-		pgd_clear(pgdir);
-		return;
-	}
-	pgmiddle = pmd_offset(pgdir, addr);
-	if (pmd_none(*pgmiddle)) {
-		handle_mm_fault(tsk, vma, addr, 1);
-		goto repeat;
-	}
-	if (pmd_bad(*pgmiddle)) {
-		printk("ptrace: bad page middle %08lx\n", pmd_val(*pgmiddle));
-		pmd_clear(pgmiddle);
-		return;
-	}
-	pgtable = pte_offset(pgmiddle, addr);
-	if (!pte_present(*pgtable)) {
-		handle_mm_fault(tsk, vma, addr, 1);
-		goto repeat;
-	}
-	page = pte_page(*pgtable);
-	if (!pte_write(*pgtable)) {
-		handle_mm_fault(tsk, vma, addr, 1);
-		goto repeat;
-	}
-/* this is a hack for non-kernel-mapped video buffers and similar */
-	if (MAP_NR(page) < max_mapnr)
-		*(unsigned long *) (page + (addr & ~PAGE_MASK)) = data;
-/* we're bypassing pagetables, so we have to set the dirty bit ourselves */
-/* this should also re-instate whatever read-only mode there was before */
-	set_pte(pgtable, pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
-	flush_tlb();
-}
-
-/*
- * This routine checks the page boundaries, and that the offset is
- * within the task area. It then calls get_long() to read a long.
- */
-static int read_long(struct task_struct * tsk, unsigned long addr,
-	unsigned long * result)
-{
-	struct vm_area_struct * vma = find_extend_vma(tsk, addr);
-
-	if (!vma)
-		return -EIO;
-	if ((addr & ~PAGE_MASK) > PAGE_SIZE-sizeof(long)) {
-		unsigned long low,high;
-		struct vm_area_struct * vma_high = vma;
-
-		if (addr + sizeof(long) >= vma->vm_end) {
-			vma_high = vma->vm_next;
-			if (!vma_high || vma_high->vm_start != vma->vm_end)
-				return -EIO;
-		}
-		low = get_long(tsk, vma, addr & ~(sizeof(long)-1));
-		high = get_long(tsk, vma_high, (addr+sizeof(long)) & ~(sizeof(long)-1));
-		switch (addr & (sizeof(long)-1)) {
-			case 1:
-				low >>= 8;
-				low |= high << 24;
-				break;
-			case 2:
-				low >>= 16;
-				low |= high << 16;
-				break;
-			case 3:
-				low >>= 24;
-				low |= high << 8;
-				break;
-		}
-		*result = low;
-	} else
-		*result = get_long(tsk, vma, addr);
-	return 0;
-}
-
-/*
- * This routine checks the page boundaries, and that the offset is
- * within the task area. It then calls put_long() to write a long.
- */
-static int write_long(struct task_struct * tsk, unsigned long addr,
-	unsigned long data)
-{
-	struct vm_area_struct * vma = find_extend_vma(tsk, addr);
-
-	if (!vma)
-		return -EIO;
-	if ((addr & ~PAGE_MASK) > PAGE_SIZE-sizeof(long)) {
-		unsigned long low,high;
-		struct vm_area_struct * vma_high = vma;
-
-		if (addr + sizeof(long) >= vma->vm_end) {
-			vma_high = vma->vm_next;
-			if (!vma_high || vma_high->vm_start != vma->vm_end)
-				return -EIO;
-		}
-		low = get_long(tsk, vma, addr & ~(sizeof(long)-1));
-		high = get_long(tsk, vma_high, (addr+sizeof(long)) & ~(sizeof(long)-1));
-		switch (addr & (sizeof(long)-1)) {
-			case 0: /* shouldn't happen, but safety first */
-				low = data;
-				break;
-			case 1:
-				low &= 0x000000ff;
-				low |= data << 8;
-				high &= ~0xff;
-				high |= data >> 24;
-				break;
-			case 2:
-				low &= 0x0000ffff;
-				low |= data << 16;
-				high &= ~0xffff;
-				high |= data >> 16;
-				break;
-			case 3:
-				low &= 0x00ffffff;
-				low |= data << 24;
-				high &= ~0xffffff;
-				high |= data >> 8;
-				break;
-		}
-		put_long(tsk, vma, addr & ~(sizeof(long)-1),low);
-		put_long(tsk, vma_high, (addr+sizeof(long)) & ~(sizeof(long)-1),high);
-	} else
-		put_long(tsk, vma, addr, data);
-	return 0;
-}
-
 static int putreg(struct task_struct *child,
 	unsigned long regno, unsigned long value)
 {
@@ -402,12 +203,13 @@
 		case PTRACE_PEEKTEXT: /* read word at location addr. */ 
 		case PTRACE_PEEKDATA: {
 			unsigned long tmp;
+			int copied;
 
-			down(&child->mm->mmap_sem);
-			ret = read_long(child, addr, &tmp);
-			up(&child->mm->mmap_sem);
-			if (ret >= 0)
-				ret = put_user(tmp,(unsigned long *) data);
+			copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
+			ret = -EIO;
+			if (copied != sizeof(tmp))
+				goto out;
+			ret = put_user(tmp,(unsigned long *) data);
 			goto out;
 		}
 
@@ -436,9 +238,10 @@
       /* when I and D space are separate, this will have to be fixed. */
 		case PTRACE_POKETEXT: /* write the word at location addr. */
 		case PTRACE_POKEDATA:
-			down(&child->mm->mmap_sem);
-			ret = write_long(child,addr,data);
-			up(&child->mm->mmap_sem);
+			ret = 0;
+			if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
+				goto out;
+			ret = -EIO;
 			goto out;
 
 		case PTRACE_POKEUSR: /* write the word at location addr in the USER area */