1 files changed, 55 insertions, 0 deletions
diff --git a/include/linux/kernel_read_file.h b/include/linux/kernel_read_file.h
new file mode 100644
index 000000000000..90451e2e12bd
--- /dev/null
+++ b/include/linux/kernel_read_file.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_KERNEL_READ_FILE_H
+#define _LINUX_KERNEL_READ_FILE_H
+
+#include <linux/file.h>
+#include <linux/types.h>
+
+/* This is a list of *what* is being read, not *how* nor *where*. */
+#define __kernel_read_file_id(id) \
+	id(UNKNOWN, unknown)		\
+	id(FIRMWARE, firmware)		\
+	id(MODULE, kernel-module)		\
+	id(KEXEC_IMAGE, kexec-image)		\
+	id(KEXEC_INITRAMFS, kexec-initramfs)	\
+	id(POLICY, security-policy)		\
+	id(X509_CERTIFICATE, x509-certificate)	\
+	id(MAX_ID, )
+
+#define __fid_enumify(ENUM, dummy) READING_ ## ENUM,
+#define __fid_stringify(dummy, str) #str,
+
+enum kernel_read_file_id {
+	__kernel_read_file_id(__fid_enumify)
+};
+
+static const char * const kernel_read_file_str[] = {
+	__kernel_read_file_id(__fid_stringify)
+};
+
+static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
+{
+	if ((unsigned int)id >= READING_MAX_ID)
+		return kernel_read_file_str[READING_UNKNOWN];
+
+	return kernel_read_file_str[id];
+}
+
+ssize_t kernel_read_file(struct file *file, loff_t offset,
+			 void **buf, size_t buf_size,
+			 size_t *file_size,
+			 enum kernel_read_file_id id);
+ssize_t kernel_read_file_from_path(const char *path, loff_t offset,
+				   void **buf, size_t buf_size,
+				   size_t *file_size,
+				   enum kernel_read_file_id id);
+ssize_t kernel_read_file_from_path_initns(const char *path, loff_t offset,
+					  void **buf, size_t buf_size,
+					  size_t *file_size,
+					  enum kernel_read_file_id id);
+ssize_t kernel_read_file_from_fd(int fd, loff_t offset,
+				 void **buf, size_t buf_size,
+				 size_t *file_size,
+				 enum kernel_read_file_id id);
+
+#endif /* _LINUX_KERNEL_READ_FILE_H */