[RFC PATCH v6 01/12] livepatch: Create and include UAPI headers

[Joe Lawrence]

From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

Define klp prefixes in include/uapi/linux/livepatch.h, and use them for
replacing hard-coded values in kernel/livepatch/core.c.

Update MAINTAINERS.

Note: Add defines to uapi as these are also to be used by a newly
introduced klp-convert script.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Joao Moreira <jmoreira@xxxxxxx>
Signed-off-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
---
 MAINTAINERS                    |  1 +
 include/linux/livepatch.h      |  1 +
 include/uapi/linux/livepatch.h | 15 +++++++++++++++
 kernel/livepatch/core.c        |  4 ++--
 4 files changed, 19 insertions(+), 2 deletions(-)
 create mode 100644 include/uapi/linux/livepatch.h

diff --git a/MAINTAINERS b/MAINTAINERS
index f41088418aae..3fce79715663 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11132,6 +11132,7 @@ F:	arch/powerpc/include/asm/livepatch.h
 F:	arch/s390/include/asm/livepatch.h
 F:	arch/x86/include/asm/livepatch.h
 F:	include/linux/livepatch.h
+F:	include/uapi/linux/livepatch.h
 F:	kernel/livepatch/
 F:	lib/livepatch/
 F:	samples/livepatch/
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index 2614247a9781..0fb05aae091a 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -13,6 +13,7 @@
 #include <linux/ftrace.h>
 #include <linux/completion.h>
 #include <linux/list.h>
+#include <uapi/linux/livepatch.h>
 
 #if IS_ENABLED(CONFIG_LIVEPATCH)
 
diff --git a/include/uapi/linux/livepatch.h b/include/uapi/linux/livepatch.h
new file mode 100644
index 000000000000..e19430918a07
--- /dev/null
+++ b/include/uapi/linux/livepatch.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+
+/*
+ * livepatch.h - Kernel Live Patching Core
+ *
+ * Copyright (C) 2016 Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
+ */
+
+#ifndef _UAPI_LIVEPATCH_H
+#define _UAPI_LIVEPATCH_H
+
+#define KLP_RELA_PREFIX		".klp.rela."
+#define KLP_SYM_PREFIX		".klp.sym."
+
+#endif /* _UAPI_LIVEPATCH_H */
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 585494ec464f..79b380777a0b 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -227,7 +227,7 @@ static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab,
 
 		/* Format: .klp.sym.sym_objname.sym_name,sympos */
 		cnt = sscanf(strtab + sym->st_name,
-			     ".klp.sym.%55[^.].%127[^,],%lu",
+			     KLP_SYM_PREFIX "%55[^.].%127[^,],%lu",
 			     sym_objname, sym_name, &sympos);
 		if (cnt != 3) {
 			pr_err("symbol %s has an incorrectly formatted name\n",
@@ -298,7 +298,7 @@ int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs,
 	 * See comment in klp_resolve_symbols() for an explanation
 	 * of the selected field width value.
 	 */
-	cnt = sscanf(shstrtab + sec->sh_name, ".klp.rela.%55[^.]",
+	cnt = sscanf(shstrtab + sec->sh_name, KLP_RELA_PREFIX "%55[^.]",
 		     sec_objname);
 	if (cnt != 1) {
 		pr_err("section %s has an incorrectly formatted name\n",
-- 
2.26.3