Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching updates from Jiri Kosina:
"These are mostly smaller things that got accumulated during the
development cycle. The unified solution is still being worked on and
is not mature enough for 4.1 yet.
- s390 livepatching support, from Jiri Slaby (has Ack from s390
maintainers)
- error handling simplification, from Josh Poimboeuf
- two minor code cleanups from Josh Poimboeuf and Miroslav Benes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
livepatch: add support on s390
livepatch: remove unnecessary call to klp_find_object_module()
livepatch: simplify disable error path
livepatch: remove extern specifier from header files
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 373cd5b..b2d7ec1 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -133,6 +133,7 @@
select HAVE_KPROBES
select HAVE_KRETPROBES
select HAVE_KVM if 64BIT
+ select HAVE_LIVEPATCH
select HAVE_MEMBLOCK
select HAVE_MEMBLOCK_NODE_MAP
select HAVE_MEMBLOCK_PHYS_MAP
@@ -159,6 +160,8 @@
source "kernel/Kconfig.freezer"
+source "kernel/livepatch/Kconfig"
+
menu "Processor type and features"
config HAVE_MARCH_Z900_FEATURES
diff --git a/arch/s390/include/asm/livepatch.h b/arch/s390/include/asm/livepatch.h
new file mode 100644
index 0000000..7aa7991
--- /dev/null
+++ b/arch/s390/include/asm/livepatch.h
@@ -0,0 +1,43 @@
+/*
+ * livepatch.h - s390-specific Kernel Live Patching Core
+ *
+ * Copyright (c) 2013-2015 SUSE
+ * Authors: Jiri Kosina
+ * Vojtech Pavlik
+ * Jiri Slaby
+ */
+
+/*
+ * 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.
+ */
+
+#ifndef ASM_LIVEPATCH_H
+#define ASM_LIVEPATCH_H
+
+#include <linux/module.h>
+
+#ifdef CONFIG_LIVEPATCH
+static inline int klp_check_compiler_support(void)
+{
+ return 0;
+}
+
+static inline int klp_write_module_reloc(struct module *mod, unsigned long
+ type, unsigned long loc, unsigned long value)
+{
+ /* not supported yet */
+ return -ENOSYS;
+}
+
+static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
+{
+ regs->psw.addr = ip;
+}
+#else
+#error Live patching support is disabled; check CONFIG_LIVEPATCH
+#endif
+
+#endif
diff --git a/arch/x86/include/asm/livepatch.h b/arch/x86/include/asm/livepatch.h
index a455a53..2d29197b 100644
--- a/arch/x86/include/asm/livepatch.h
+++ b/arch/x86/include/asm/livepatch.h
@@ -32,8 +32,8 @@
#endif
return 0;
}
-extern int klp_write_module_reloc(struct module *mod, unsigned long type,
- unsigned long loc, unsigned long value);
+int klp_write_module_reloc(struct module *mod, unsigned long type,
+ unsigned long loc, unsigned long value);
static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
{
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index 95023fd..ee6dbb3 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -123,10 +123,10 @@
enum klp_state state;
};
-extern int klp_register_patch(struct klp_patch *);
-extern int klp_unregister_patch(struct klp_patch *);
-extern int klp_enable_patch(struct klp_patch *);
-extern int klp_disable_patch(struct klp_patch *);
+int klp_register_patch(struct klp_patch *);
+int klp_unregister_patch(struct klp_patch *);
+int klp_enable_patch(struct klp_patch *);
+int klp_disable_patch(struct klp_patch *);
#endif /* CONFIG_LIVEPATCH */
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 3f9f1d6..284e269 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -335,32 +335,20 @@
rcu_read_unlock();
}
-static int klp_disable_func(struct klp_func *func)
+static void klp_disable_func(struct klp_func *func)
{
struct klp_ops *ops;
- int ret;
- if (WARN_ON(func->state != KLP_ENABLED))
- return -EINVAL;
-
- if (WARN_ON(!func->old_addr))
- return -EINVAL;
+ WARN_ON(func->state != KLP_ENABLED);
+ WARN_ON(!func->old_addr);
ops = klp_find_ops(func->old_addr);
if (WARN_ON(!ops))
- return -EINVAL;
+ return;
if (list_is_singular(&ops->func_stack)) {
- ret = unregister_ftrace_function(&ops->fops);
- if (ret) {
- pr_err("failed to unregister ftrace handler for function '%s' (%d)\n",
- func->old_name, ret);
- return ret;
- }
-
- ret = ftrace_set_filter_ip(&ops->fops, func->old_addr, 1, 0);
- if (ret)
- pr_warn("function unregister succeeded but failed to clear the filter\n");
+ WARN_ON(unregister_ftrace_function(&ops->fops));
+ WARN_ON(ftrace_set_filter_ip(&ops->fops, func->old_addr, 1, 0));
list_del_rcu(&func->stack_node);
list_del(&ops->node);
@@ -370,8 +358,6 @@
}
func->state = KLP_DISABLED;
-
- return 0;
}
static int klp_enable_func(struct klp_func *func)
@@ -432,23 +418,15 @@
return ret;
}
-static int klp_disable_object(struct klp_object *obj)
+static void klp_disable_object(struct klp_object *obj)
{
struct klp_func *func;
- int ret;
- for (func = obj->funcs; func->old_name; func++) {
- if (func->state != KLP_ENABLED)
- continue;
-
- ret = klp_disable_func(func);
- if (ret)
- return ret;
- }
+ for (func = obj->funcs; func->old_name; func++)
+ if (func->state == KLP_ENABLED)
+ klp_disable_func(func);
obj->state = KLP_DISABLED;
-
- return 0;
}
static int klp_enable_object(struct klp_object *obj)
@@ -464,22 +442,19 @@
for (func = obj->funcs; func->old_name; func++) {
ret = klp_enable_func(func);
- if (ret)
- goto unregister;
+ if (ret) {
+ klp_disable_object(obj);
+ return ret;
+ }
}
obj->state = KLP_ENABLED;
return 0;
-
-unregister:
- WARN_ON(klp_disable_object(obj));
- return ret;
}
static int __klp_disable_patch(struct klp_patch *patch)
{
struct klp_object *obj;
- int ret;
/* enforce stacking: only the last enabled patch can be disabled */
if (!list_is_last(&patch->list, &klp_patches) &&
@@ -489,12 +464,8 @@
pr_notice("disabling patch '%s'\n", patch->mod->name);
for (obj = patch->objs; obj->funcs; obj++) {
- if (obj->state != KLP_ENABLED)
- continue;
-
- ret = klp_disable_object(obj);
- if (ret)
- return ret;
+ if (obj->state == KLP_ENABLED)
+ klp_disable_object(obj);
}
patch->state = KLP_DISABLED;
@@ -553,8 +524,6 @@
pr_notice("enabling patch '%s'\n", patch->mod->name);
for (obj = patch->objs; obj->funcs; obj++) {
- klp_find_object_module(obj);
-
if (!klp_is_object_loaded(obj))
continue;
@@ -945,7 +914,6 @@
{
struct module *pmod = patch->mod;
struct module *mod = obj->mod;
- int ret;
if (patch->state == KLP_DISABLED)
goto disabled;
@@ -953,10 +921,7 @@
pr_notice("reverting patch '%s' on unloading module '%s'\n",
pmod->name, mod->name);
- ret = klp_disable_object(obj);
- if (ret)
- pr_warn("failed to revert patch '%s' on module '%s' (%d)\n",
- pmod->name, mod->name, ret);
+ klp_disable_object(obj);
disabled:
klp_free_object_loaded(obj);