From: Josh Poimboeuf <jpoimboe@redhat.com>
Subject: livepatch: create and include UAPI headers
Patch-mainline: Submitted, https://lore.kernel.org/lkml/20170829190140.401-1-jmoreira@suse.de/
References: fate#326849
Replace hard-coded values in kernel/livepatch/core.c with defines and put
them into a new UAPI file so they can also be used by klp-convert, an elf
processing tool for formatting live patching relocations properly.
Define macros KLP_MODULE_RELOC and KLP_SYMPOS in
include/linux/livepatch.h to improve user-friendliness of the
livepatch annotation process.
Update MAINTAINERS.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Joao Moreira <jmoreira@suse.de>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
---
MAINTAINERS | 1 +
include/linux/livepatch.h | 12 ++++++++++++
include/uapi/linux/livepatch.h | 28 ++++++++++++++++++++++++++++
kernel/livepatch/core.c | 4 ++--
4 files changed, 43 insertions(+), 2 deletions(-)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7728,6 +7728,7 @@ R: Petr Mladek <pmladek@suse.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/
--- 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)
@@ -230,6 +231,17 @@ void *klp_shadow_get_or_alloc(void *obj,
void klp_shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor);
void klp_shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor);
+/* Used to annotate symbol relocations in live patches */
+#define KLP_MODULE_RELOC(obj) \
+ struct klp_module_reloc \
+ __attribute__((__section__(".klp.module_relocs." #obj)))
+
+#define KLP_SYMPOS(symbol, pos) \
+ { \
+ .sym = &symbol, \
+ .sympos = pos, \
+ },
+
#else /* !CONFIG_LIVEPATCH */
static inline int klp_module_coming(struct module *mod) { return 0; }
--- /dev/null
+++ b/include/uapi/linux/livepatch.h
@@ -0,0 +1,28 @@
+/*
+ * livepatch.h - Kernel Live Patching Core
+ *
+ * Copyright (C) 2016 Josh Poimboeuf <jpoimboe@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _UAPI_LIVEPATCH_H
+#define _UAPI_LIVEPATCH_H
+
+#include <linux/types.h>
+
+#define KLP_RELA_PREFIX ".klp.rela."
+#define KLP_SYM_PREFIX ".klp.sym."
+
+#endif /* _UAPI_LIVEPATCH_H */
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -261,7 +261,7 @@ static int klp_resolve_symbols(Elf_Shdr
/* 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",
@@ -307,7 +307,7 @@ static int klp_write_object_relocations(
* 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);