X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fchar%2Fmem.c;h=82ab4365c1a47ff39a1ceb81244c2a0bfaa1807e;hb=90ad8654ffeb336af8c878fdf7bc72e2ac72467a;hp=8b86d0163e2d43f6912fac4a8a9ded81cd17d997;hpb=a91482bdcc2e0f6035702e46f1b99043a0893346;p=linux-2.6.git

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 8b86d0163..82ab4365c 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -114,13 +114,29 @@ static inline int valid_phys_addr_range(unsigned long addr, size_t *count)
 }
 #endif
 
+extern int page_is_ram(unsigned long pagenr);
+
+static inline int page_is_allowed(unsigned long pagenr)
+{ 
+ #ifdef CONFIG_X86
+	if (pagenr <= 256)
+		return 1;
+	if (!page_is_ram(pagenr))
+		return 1;
+	printk("Access to 0x%lx by %s denied \n", pagenr << PAGE_SHIFT, current->comm);
+	return 0;
+ #else
+       return 1;
+ #endif
+}
+
 static inline int range_is_allowed(unsigned long from, unsigned long to)
 {
 	unsigned long cursor;
 	
 	cursor = from >> PAGE_SHIFT;
-	while ((cursor << PAGE_SHIFT) < to) {
-		if (!devmem_is_allowed(cursor))
+	while ( (cursor << PAGE_SHIFT) < to) {
+		if (!page_is_allowed(cursor))
 			return 0;
 		cursor++;
 	}
@@ -146,7 +162,7 @@ static ssize_t do_write_mem(void *p, unsigned long realp,
 	}
 #endif
 	if (!range_is_allowed(realp, realp+count))
-		return -EPERM;
+		return -EFAULT;
 	copied = copy_from_user(p, buf, count);
 	if (copied) {
 		ssize_t ret = written + (count - copied);
@@ -191,7 +207,7 @@ static ssize_t read_mem(struct file * file, char __user * buf,
 	}
 #endif
 	if (!range_is_allowed(p, p+count))
-		return -EPERM;
+		return -EFAULT;
 	if (copy_to_user(buf, __va(p), count))
 		return -EFAULT;
 	read += count;
@@ -232,8 +248,8 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma)
 		
 	cursor = vma->vm_pgoff;
 	while ((cursor << PAGE_SHIFT) < offset + vma->vm_end-vma->vm_start) {
-		if (!devmem_is_allowed(cursor))
-			return -EPERM;
+		if (!page_is_allowed(cursor))
+			return -EFAULT;
 		cursor++;
 	}
 
@@ -311,6 +327,67 @@ static ssize_t read_kmem(struct file *file, char __user *buf,
  	return virtr + read;
 }
 
+/*
+ * This function writes to the *virtual* memory as seen by the kernel.
+ */
+static ssize_t write_kmem(struct file * file, const char __user * buf, 
+			  size_t count, loff_t *ppos)
+{
+	unsigned long p = *ppos;
+	ssize_t wrote = 0;
+	ssize_t virtr = 0;
+	ssize_t written;
+	char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
+	
+	return -EPERM;
+
+	if (p < (unsigned long) high_memory) {
+
+		wrote = count;
+		if (count > (unsigned long) high_memory - p)
+			wrote = (unsigned long) high_memory - p;
+
+		written = do_write_mem((void*)p, p, buf, wrote, ppos);
+		if (written != wrote)
+			return written;
+		wrote = written;
+		p += wrote;
+		buf += wrote;
+		count -= wrote;
+	}
+
+	if (count > 0) {
+		kbuf = (char *)__get_free_page(GFP_KERNEL);
+		if (!kbuf)
+			return wrote ? wrote : -ENOMEM;
+		while (count > 0) {
+			int len = count;
+
+			if (len > PAGE_SIZE)
+				len = PAGE_SIZE;
+			if (len) {
+				written = copy_from_user(kbuf, buf, len);
+				if (written) {
+					ssize_t ret;
+
+					free_page((unsigned long)kbuf);
+					ret = wrote + virtr + (len - written);
+					return ret ? ret : -EFAULT;
+				}
+			}
+			len = vwrite(kbuf, (char *)p, len);
+			count -= len;
+			buf += len;
+			virtr += len;
+			p += len;
+		}
+		free_page((unsigned long)kbuf);
+	}
+
+ 	*ppos = p;
+ 	return virtr + wrote;
+}
+
 #if defined(CONFIG_ISA) || !defined(__mc68000__)
 static ssize_t read_port(struct file * file, char __user * buf,
 			 size_t count, loff_t *ppos)
@@ -561,6 +638,7 @@ static struct file_operations mem_fops = {
 static struct file_operations kmem_fops = {
 	.llseek		= memory_lseek,
 	.read		= read_kmem,
+	.write		= write_kmem,
 	.mmap		= mmap_kmem,
 	.open		= open_kmem,
 };