v4.19.13 snapshot.
diff --git a/include/linux/elfnote.h b/include/linux/elfnote.h
new file mode 100644
index 0000000..f236f5b
--- /dev/null
+++ b/include/linux/elfnote.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_ELFNOTE_H
+#define _LINUX_ELFNOTE_H
+/*
+ * Helper macros to generate ELF Note structures, which are put into a
+ * PT_NOTE segment of the final vmlinux image. These are useful for
+ * including name-value pairs of metadata into the kernel binary (or
+ * modules?) for use by external programs.
+ *
+ * Each note has three parts: a name, a type and a desc. The name is
+ * intended to distinguish the note's originator, so it would be a
+ * company, project, subsystem, etc; it must be in a suitable form for
+ * use in a section name. The type is an integer which is used to tag
+ * the data, and is considered to be within the "name" namespace (so
+ * "FooCo"'s type 42 is distinct from "BarProj"'s type 42). The
+ * "desc" field is the actual data. There are no constraints on the
+ * desc field's contents, though typically they're fairly small.
+ *
+ * All notes from a given NAME are put into a section named
+ * .note.NAME. When the kernel image is finally linked, all the notes
+ * are packed into a single .notes section, which is mapped into the
+ * PT_NOTE segment. Because notes for a given name are grouped into
+ * the same section, they'll all be adjacent the output file.
+ *
+ * This file defines macros for both C and assembler use. Their
+ * syntax is slightly different, but they're semantically similar.
+ *
+ * See the ELF specification for more detail about ELF notes.
+ */
+
+#ifdef __ASSEMBLER__
+/*
+ * Generate a structure with the same shape as Elf{32,64}_Nhdr (which
+ * turn out to be the same size and shape), followed by the name and
+ * desc data with appropriate padding. The 'desctype' argument is the
+ * assembler pseudo op defining the type of the data e.g. .asciz while
+ * 'descdata' is the data itself e.g. "hello, world".
+ *
+ * e.g. ELFNOTE(XYZCo, 42, .asciz, "forty-two")
+ * ELFNOTE(XYZCo, 12, .long, 0xdeadbeef)
+ */
+#define ELFNOTE_START(name, type, flags) \
+.pushsection .note.name, flags,@note ; \
+ .balign 4 ; \
+ .long 2f - 1f /* namesz */ ; \
+ .long 4484f - 3f /* descsz */ ; \
+ .long type ; \
+1:.asciz #name ; \
+2:.balign 4 ; \
+3:
+
+#define ELFNOTE_END \
+4484:.balign 4 ; \
+.popsection ;
+
+#define ELFNOTE(name, type, desc) \
+ ELFNOTE_START(name, type, "") \
+ desc ; \
+ ELFNOTE_END
+
+#else /* !__ASSEMBLER__ */
+#include <linux/elf.h>
+/*
+ * Use an anonymous structure which matches the shape of
+ * Elf{32,64}_Nhdr, but includes the name and desc data. The size and
+ * type of name and desc depend on the macro arguments. "name" must
+ * be a literal string, and "desc" must be passed by value. You may
+ * only define one note per line, since __LINE__ is used to generate
+ * unique symbols.
+ */
+#define _ELFNOTE_PASTE(a,b) a##b
+#define _ELFNOTE(size, name, unique, type, desc) \
+ static const struct { \
+ struct elf##size##_note _nhdr; \
+ unsigned char _name[sizeof(name)] \
+ __attribute__((aligned(sizeof(Elf##size##_Word)))); \
+ typeof(desc) _desc \
+ __attribute__((aligned(sizeof(Elf##size##_Word)))); \
+ } _ELFNOTE_PASTE(_note_, unique) \
+ __used \
+ __attribute__((section(".note." name), \
+ aligned(sizeof(Elf##size##_Word)), \
+ unused)) = { \
+ { \
+ sizeof(name), \
+ sizeof(desc), \
+ type, \
+ }, \
+ name, \
+ desc \
+ }
+#define ELFNOTE(size, name, type, desc) \
+ _ELFNOTE(size, name, __LINE__, type, desc)
+
+#define ELFNOTE32(name, type, desc) ELFNOTE(32, name, type, desc)
+#define ELFNOTE64(name, type, desc) ELFNOTE(64, name, type, desc)
+#endif /* __ASSEMBLER__ */
+
+#endif /* _LINUX_ELFNOTE_H */