1 files changed, 66 insertions, 21 deletions

diff --git a/arch/x86/kernel/ksysfs.c b/arch/x86/kernel/ksysfs.c
index d0a19121c6a4..d547de9b3ed8 100644
--- a/arch/x86/kernel/ksysfs.c
+++ b/arch/x86/kernel/ksysfs.c
@@ -28,14 +28,14 @@ static ssize_t version_show(struct kobject *kobj,
 static struct kobj_attribute boot_params_version_attr = __ATTR_RO(version);
 
 static ssize_t boot_params_data_read(struct file *fp, struct kobject *kobj,
-				     struct bin_attribute *bin_attr,
+				     const struct bin_attribute *bin_attr,
 				     char *buf, loff_t off, size_t count)
 {
 	memcpy(buf, (void *)&boot_params + off, count);
 	return count;
 }
 
-static struct bin_attribute boot_params_data_attr = {
+static const struct bin_attribute boot_params_data_attr = {
 	.attr = {
 		.name = "data",
 		.mode = S_IRUGO,
@@ -49,7 +49,7 @@ static struct attribute *boot_params_version_attrs[] = {
 	NULL,
 };
 
-static struct bin_attribute *boot_params_data_attrs[] = {
+static const struct bin_attribute *const boot_params_data_attrs[] = {
 	&boot_params_data_attr,
 	NULL,
 };
@@ -91,26 +91,41 @@ static int get_setup_data_paddr(int nr, u64 *paddr)
 
 static int __init get_setup_data_size(int nr, size_t *size)
 {
-	int i = 0;
+	u64 pa_data = boot_params.hdr.setup_data, pa_next;
+	struct setup_indirect *indirect;
 	struct setup_data *data;
-	u64 pa_data = boot_params.hdr.setup_data;
+	int i = 0;
+	u32 len;
 
 	while (pa_data) {
 		data = memremap(pa_data, sizeof(*data), MEMREMAP_WB);
 		if (!data)
 			return -ENOMEM;
+		pa_next = data->next;
+
 		if (nr == i) {
-			if (data->type == SETUP_INDIRECT &&
-			    ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT)
-				*size = ((struct setup_indirect *)data->data)->len;
-			else
+			if (data->type == SETUP_INDIRECT) {
+				len = sizeof(*data) + data->len;
+				memunmap(data);
+				data = memremap(pa_data, len, MEMREMAP_WB);
+				if (!data)
+					return -ENOMEM;
+
+				indirect = (struct setup_indirect *)data->data;
+
+				if (indirect->type != SETUP_INDIRECT)
+					*size = indirect->len;
+				else
+					*size = data->len;
+			} else {
 				*size = data->len;
+			}
 
 			memunmap(data);
 			return 0;
 		}
 
-		pa_data = data->next;
+		pa_data = pa_next;
 		memunmap(data);
 		i++;
 	}
@@ -120,9 +135,11 @@ static int __init get_setup_data_size(int nr, size_t *size)
 static ssize_t type_show(struct kobject *kobj,
 			 struct kobj_attribute *attr, char *buf)
 {
+	struct setup_indirect *indirect;
+	struct setup_data *data;
 	int nr, ret;
 	u64 paddr;
-	struct setup_data *data;
+	u32 len;
 
 	ret = kobj_to_setup_data_nr(kobj, &nr);
 	if (ret)
@@ -135,23 +152,34 @@ static ssize_t type_show(struct kobject *kobj,
 	if (!data)
 		return -ENOMEM;
 
-	if (data->type == SETUP_INDIRECT)
-		ret = sprintf(buf, "0x%x\n", ((struct setup_indirect *)data->data)->type);
-	else
+	if (data->type == SETUP_INDIRECT) {
+		len = sizeof(*data) + data->len;
+		memunmap(data);
+		data = memremap(paddr, len, MEMREMAP_WB);
+		if (!data)
+			return -ENOMEM;
+
+		indirect = (struct setup_indirect *)data->data;
+
+		ret = sprintf(buf, "0x%x\n", indirect->type);
+	} else {
 		ret = sprintf(buf, "0x%x\n", data->type);
+	}
+
 	memunmap(data);
 	return ret;
 }
 
 static ssize_t setup_data_data_read(struct file *fp,
 				    struct kobject *kobj,
-				    struct bin_attribute *bin_attr,
+				    const struct bin_attribute *bin_attr,
 				    char *buf,
 				    loff_t off, size_t count)
 {
+	struct setup_indirect *indirect;
+	struct setup_data *data;
 	int nr, ret = 0;
 	u64 paddr, len;
-	struct setup_data *data;
 	void *p;
 
 	ret = kobj_to_setup_data_nr(kobj, &nr);
@@ -165,10 +193,27 @@ static ssize_t setup_data_data_read(struct file *fp,
 	if (!data)
 		return -ENOMEM;
 
-	if (data->type == SETUP_INDIRECT &&
-	    ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
-		paddr = ((struct setup_indirect *)data->data)->addr;
-		len = ((struct setup_indirect *)data->data)->len;
+	if (data->type == SETUP_INDIRECT) {
+		len = sizeof(*data) + data->len;
+		memunmap(data);
+		data = memremap(paddr, len, MEMREMAP_WB);
+		if (!data)
+			return -ENOMEM;
+
+		indirect = (struct setup_indirect *)data->data;
+
+		if (indirect->type != SETUP_INDIRECT) {
+			paddr = indirect->addr;
+			len = indirect->len;
+		} else {
+			/*
+			 * Even though this is technically undefined, return
+			 * the data as though it is a normal setup_data struct.
+			 * This will at least allow it to be inspected.
+			 */
+			paddr += sizeof(*data);
+			len = data->len;
+		}
 	} else {
 		paddr += sizeof(*data);
 		len = data->len;
@@ -213,7 +258,7 @@ static struct attribute *setup_data_type_attrs[] = {
 	NULL,
 };
 
-static struct bin_attribute *setup_data_data_attrs[] = {
+static const struct bin_attribute *const setup_data_data_attrs[] = {
 	&data_attr,
 	NULL,
 };