[RFC PATCH v2 19/20] x86: Access the setup data through debugfs un-encrypted

[Tom Lendacky]

Since the setup data is in memory in the clear, it must be accessed as
un-encrypted.  Always use ioremap (similar to sysfs setup data support)
to map the data.

Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
---
 arch/x86/kernel/kdebugfs.c |   30 +++++++++++-------------------
 1 file changed, 11 insertions(+), 19 deletions(-)

diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c
index bdb83e4..a58a82e 100644
--- a/arch/x86/kernel/kdebugfs.c
+++ b/arch/x86/kernel/kdebugfs.c
@@ -48,17 +48,13 @@ static ssize_t setup_data_read(struct file *file, char 
__user *user_buf,
 
        pa = node->paddr + sizeof(struct setup_data) + pos;
        pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT);
-       if (PageHighMem(pg)) {
-               p = ioremap_cache(pa, count);
-               if (!p)
-                       return -ENXIO;
-       } else
-               p = __va(pa);
+       p = ioremap_cache(pa, count);
+       if (!p)
+               return -ENXIO;
 
        remain = copy_to_user(user_buf, p, count);
 
-       if (PageHighMem(pg))
-               iounmap(p);
+       iounmap(p);
 
        if (remain)
                return -EFAULT;
@@ -127,15 +123,12 @@ static int __init create_setup_data_nodes(struct dentry 
*parent)
                }
 
                pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT);
-               if (PageHighMem(pg)) {
-                       data = ioremap_cache(pa_data, sizeof(*data));
-                       if (!data) {
-                               kfree(node);
-                               error = -ENXIO;
-                               goto err_dir;
-                       }
-               } else
-                       data = __va(pa_data);
+               data = ioremap_cache(pa_data, sizeof(*data));
+               if (!data) {
+                       kfree(node);
+                       error = -ENXIO;
+                       goto err_dir;
+               }
 
                node->paddr = pa_data;
                node->type = data->type;
@@ -143,8 +136,7 @@ static int __init create_setup_data_nodes(struct dentry 
*parent)
                error = create_setup_data_node(d, no, node);
                pa_data = data->next;
 
-               if (PageHighMem(pg))
-                       iounmap(data);
+               iounmap(data);
                if (error)
                        goto err_dir;
                no++;

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