[PATCH v4 01/10] livepatch: Create and include UAPI headers

Joe Lawrence
2019-05-09T14:39:12Z

From: Josh Poimboeuf <jpoimboe@redhat.com>

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@redhat.com>
Signed-off-by: Joao Moreira <jmoreira@suse.de>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
---
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 09f43f1bdd15..52842fa37261 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9016,6 +9016,7 @@ R: Joe Lawrence <joe.lawrence@redhat.com>
S: Maintained
F: kernel/livepatch/
F: include/linux/livepatch.h
+F: include/uapi/linux/livepatch.h
F: arch/x86/include/asm/livepatch.h
F: arch/x86/kernel/livepatch.c
F: Documentation/livepatch/
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index 53551f470722..16b48e8b29a2 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -25,6 +25,7 @@
#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@redhat.com>
+ */
+
+#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 eb0ee10a1981..3d9ed895b252 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -235,7 +235,7 @@ static int klp_resolve_symbols(Elf_Shdr *relasec, struct module *pmod)

/* Format: .klp.sym.objname.symname,sympos */
cnt = sscanf(strtab + sym->st_name,
- ".klp.sym.%55[^.].%127[^,],%lu",
+ KLP_SYM_PREFIX "%55[^.].%127[^,],%lu",
objname, symname, &sympos);
if (cnt != 3) {
pr_err("symbol %s has an incorrectly formatted name\n",
@@ -281,7 +281,7 @@ static int klp_write_object_relocations(struct module *pmod,
* See comment in klp_resolve_symbols() for an explanation
* of the selected field width value.
*/
- cnt = sscanf(secname, ".klp.rela.%55[^.]", sec_objname);
+ cnt = sscanf(secname, KLP_RELA_PREFIX "%55[^.]", sec_objname);
if (cnt != 1) {
pr_err("section %s has an incorrectly formatted name\n",
secname);
--
2.20.1