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Commit 9497d738 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents d0bbe0dd 09675bd3

arch/s390/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -133,6 +133,7 @@ config S390 
	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 "init/Kconfig" 


source "kernel/Kconfig.freezer"



source "kernel/livepatch/Kconfig"



menu "Processor type and features"



config HAVE_MARCH_Z900_FEATURES

arch/s390/include/asm/livepatch.h

0 → 100644
+43 −0
Original line number Diff line number Diff line 
/*

 * 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

arch/x86/include/asm/livepatch.h

+2 −2
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ static inline int klp_check_compiler_support(void) 
#endif

	return 0;

}

extern int klp_write_module_reloc(struct module *mod, unsigned long type,

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)

include/linux/livepatch.h

+4 −4
Original line number Diff line number Diff line
@@ -123,10 +123,10 @@ struct klp_patch { 
	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 */

kernel/livepatch/core.c

+17 −52
Original line number Diff line number Diff line
@@ -335,32 +335,20 @@ static void notrace klp_ftrace_handler(unsigned long ip, 
	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 @@ static int klp_disable_func(struct klp_func *func) 
	}



	func->state = KLP_DISABLED;



	return 0;

}



static int klp_enable_func(struct klp_func *func)
@@ -432,23 +418,15 @@ static int klp_enable_func(struct klp_func *func) 
	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 @@ static int klp_enable_object(struct klp_object *obj) 


	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 @@ static int __klp_disable_patch(struct klp_patch *patch) 
	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 @@ static int __klp_enable_patch(struct klp_patch *patch) 
	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 @@ static void klp_module_notify_going(struct klp_patch *patch, 
{

	struct module *pmod = patch->mod;

	struct module *mod = obj->mod;

	int ret;



	if (patch->state == KLP_DISABLED)

		goto disabled;
@@ -953,10 +921,7 @@ static void klp_module_notify_going(struct klp_patch *patch, 
	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);