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@@ -107,6 +107,8 @@ static ssize_t read_mem(struct file *file, char __user *buf,
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phys_addr_t p = *ppos;
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ssize_t read, sz;
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void *ptr;
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+ char *bounce;
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+ int err;
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if (p != *ppos)
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return 0;
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@@ -129,15 +131,22 @@ static ssize_t read_mem(struct file *file, char __user *buf,
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}
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#endif
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+ bounce = kmalloc(PAGE_SIZE, GFP_KERNEL);
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+ if (!bounce)
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+ return -ENOMEM;
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+
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while (count > 0) {
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unsigned long remaining;
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int allowed;
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sz = size_inside_page(p, count);
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+ err = -EPERM;
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allowed = page_is_allowed(p >> PAGE_SHIFT);
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if (!allowed)
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- return -EPERM;
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+ goto failed;
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+
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+ err = -EFAULT;
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if (allowed == 2) {
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/* Show zeros for restricted memory. */
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remaining = clear_user(buf, sz);
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@@ -149,24 +158,32 @@ static ssize_t read_mem(struct file *file, char __user *buf,
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*/
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ptr = xlate_dev_mem_ptr(p);
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if (!ptr)
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- return -EFAULT;
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-
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- remaining = copy_to_user(buf, ptr, sz);
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+ goto failed;
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+ err = probe_kernel_read(bounce, ptr, sz);
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unxlate_dev_mem_ptr(p, ptr);
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+ if (err)
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+ goto failed;
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+
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+ remaining = copy_to_user(buf, bounce, sz);
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}
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if (remaining)
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- return -EFAULT;
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+ goto failed;
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buf += sz;
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p += sz;
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count -= sz;
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read += sz;
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}
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+ kfree(bounce);
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*ppos += read;
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return read;
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+
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+failed:
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+ kfree(bounce);
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+ return err;
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}
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static ssize_t write_mem(struct file *file, const char __user *buf,
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