mirror of https://github.com/dynup/kpatch
Merge pull request #477 from spartacus06/compat2
add livepatch API support
This commit is contained in:
Josh Poimboeuf
commit
ac7ddc55dd
|
|
@ -4,15 +4,15 @@ KPATCH_MAKE = $(MAKE) -C $(KPATCH_BUILD) M=$(PWD)
|
|||
|
||||
obj-m += kpatch-$(KPATCH_NAME).o
|
||||
|
||||
kpatch-$(KPATCH_NAME)-objs += kpatch-patch-hook.o kpatch.lds output.o
|
||||
kpatch-$(KPATCH_NAME)-objs += patch-hook.o kpatch.lds output.o
|
||||
|
||||
all: kpatch-$(KPATCH_NAME).ko
|
||||
|
||||
kpatch-$(KPATCH_NAME).ko:
|
||||
$(KPATCH_MAKE) kpatch-$(KPATCH_NAME).ko
|
||||
|
||||
kpatch-patch-hook.o: kpatch-patch-hook.c
|
||||
$(KPATCH_MAKE) kpatch-patch-hook.o
|
||||
patch-hook.o: patch-hook.c kpatch-patch-hook.c livepatch-patch-hook.c
|
||||
$(KPATCH_MAKE) patch-hook.o
|
||||
|
||||
clean:
|
||||
$(RM) -Rf .*.o.cmd .*.ko.cmd .tmp_versions *.o *.ko *.mod.c \
|
||||
|
|
|
|||
|
|
@ -0,0 +1,297 @@
|
|||
/*
|
||||
* Copyright (C) 2013-2014 Josh Poimboeuf <jpoimboe@redhat.com>
|
||||
* Copyright (C) 2014 Seth Jennings <sjenning@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, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA,
|
||||
* 02110-1301, USA.
|
||||
*/
|
||||
|
||||
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
||||
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/list.h>
|
||||
#include <linux/slab.h>
|
||||
|
||||
#include <linux/livepatch.h>
|
||||
|
||||
#include "kpatch-patch.h"
|
||||
|
||||
/*
|
||||
* There are quite a few similar structures at play in this file:
|
||||
* - livepatch.h structs prefixed with klp_*
|
||||
* - kpatch-patch.h structs prefixed with kpatch_patch_*
|
||||
* - local scaffolding structs prefixed with patch_*
|
||||
*
|
||||
* The naming of the struct variables follows this convention:
|
||||
* - livepatch struct being with "l" (e.g. lfunc)
|
||||
* - kpatch_patch structs being with "k" (e.g. kfunc)
|
||||
* - local scaffolding structs have no prefix (e.g. func)
|
||||
*
|
||||
* The program reads in kpatch_patch structures, arranges them into the
|
||||
* scaffold structures, then creates a livepatch structure suitable for
|
||||
* registration with the livepatch kernel API. The scaffold structs only
|
||||
* exist to allow the construction of the klp_patch struct. Once that is
|
||||
* done, the scaffold structs are no longer needed.
|
||||
*/
|
||||
|
||||
struct klp_patch *lpatch;
|
||||
|
||||
static LIST_HEAD(patch_objects);
|
||||
static int patch_objects_nr;
|
||||
struct patch_object {
|
||||
struct list_head list;
|
||||
struct list_head funcs;
|
||||
struct list_head relocs;
|
||||
const char *name;
|
||||
int funcs_nr, relocs_nr;
|
||||
};
|
||||
|
||||
struct patch_func {
|
||||
struct list_head list;
|
||||
struct kpatch_patch_func *kfunc;
|
||||
};
|
||||
|
||||
struct patch_reloc {
|
||||
struct list_head list;
|
||||
struct kpatch_patch_dynrela *kdynrela;
|
||||
};
|
||||
|
||||
static struct patch_object *patch_alloc_new_object(const char *name)
|
||||
{
|
||||
struct patch_object *object;
|
||||
|
||||
object = kzalloc(sizeof(*object), GFP_KERNEL);
|
||||
if (!object)
|
||||
return NULL;
|
||||
INIT_LIST_HEAD(&object->funcs);
|
||||
INIT_LIST_HEAD(&object->relocs);
|
||||
if (strcmp(name, "vmlinux"))
|
||||
object->name = name;
|
||||
list_add(&object->list, &patch_objects);
|
||||
patch_objects_nr++;
|
||||
return object;
|
||||
}
|
||||
|
||||
static struct patch_object *patch_find_object_by_name(const char *name)
|
||||
{
|
||||
struct patch_object *object;
|
||||
|
||||
list_for_each_entry(object, &patch_objects, list)
|
||||
if ((!strcmp(name, "vmlinux") && !object->name) ||
|
||||
!strcmp(object->name, name))
|
||||
return object;
|
||||
return patch_alloc_new_object(name);
|
||||
}
|
||||
|
||||
static int patch_add_func_to_object(struct kpatch_patch_func *kfunc)
|
||||
{
|
||||
struct patch_func *func;
|
||||
struct patch_object *object;
|
||||
|
||||
func = kzalloc(sizeof(*func), GFP_KERNEL);
|
||||
if (!func)
|
||||
return -ENOMEM;
|
||||
INIT_LIST_HEAD(&func->list);
|
||||
func->kfunc = kfunc;
|
||||
|
||||
object = patch_find_object_by_name(kfunc->objname);
|
||||
if (!object) {
|
||||
kfree(func);
|
||||
return -ENOMEM;
|
||||
}
|
||||
list_add(&func->list, &object->funcs);
|
||||
object->funcs_nr++;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int patch_add_reloc_to_object(struct kpatch_patch_dynrela *kdynrela)
|
||||
{
|
||||
struct patch_reloc *reloc;
|
||||
struct patch_object *object;
|
||||
|
||||
reloc = kzalloc(sizeof(*reloc), GFP_KERNEL);
|
||||
if (!reloc)
|
||||
return -ENOMEM;
|
||||
INIT_LIST_HEAD(&reloc->list);
|
||||
reloc->kdynrela = kdynrela;
|
||||
|
||||
object = patch_find_object_by_name(kdynrela->objname);
|
||||
if (!object) {
|
||||
kfree(reloc);
|
||||
return -ENOMEM;
|
||||
}
|
||||
list_add(&reloc->list, &object->relocs);
|
||||
object->relocs_nr++;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void patch_free_scaffold(void) {
|
||||
struct patch_func *func, *safefunc;
|
||||
struct patch_reloc *reloc, *safereloc;
|
||||
struct patch_object *object, *safeobject;
|
||||
|
||||
list_for_each_entry_safe(object, safeobject, &patch_objects, list) {
|
||||
list_for_each_entry_safe(func, safefunc,
|
||||
&object->funcs, list) {
|
||||
list_del(&func->list);
|
||||
kfree(func);
|
||||
}
|
||||
list_for_each_entry_safe(reloc, safereloc,
|
||||
&object->relocs, list) {
|
||||
list_del(&reloc->list);
|
||||
kfree(reloc);
|
||||
}
|
||||
list_del(&object->list);
|
||||
kfree(object);
|
||||
}
|
||||
}
|
||||
|
||||
static void patch_free_livepatch(struct klp_patch *patch)
|
||||
{
|
||||
struct klp_object *object;
|
||||
|
||||
if (patch) {
|
||||
for (object = patch->objs; object && object->funcs; object++) {
|
||||
if (object->funcs)
|
||||
kfree(object->funcs);
|
||||
if (object->relocs)
|
||||
kfree(object->relocs);
|
||||
}
|
||||
if (patch->objs)
|
||||
kfree(patch->objs);
|
||||
kfree(patch);
|
||||
}
|
||||
}
|
||||
|
||||
extern struct kpatch_patch_func __kpatch_funcs[], __kpatch_funcs_end[];
|
||||
extern struct kpatch_patch_dynrela __kpatch_dynrelas[], __kpatch_dynrelas_end[];
|
||||
|
||||
static int __init patch_init(void)
|
||||
{
|
||||
struct kpatch_patch_func *kfunc;
|
||||
struct kpatch_patch_dynrela *kdynrela;
|
||||
struct klp_object *lobjects, *lobject;
|
||||
struct klp_func *lfuncs, *lfunc;
|
||||
struct klp_reloc *lrelocs, *lreloc;
|
||||
struct patch_object *object;
|
||||
struct patch_func *func;
|
||||
struct patch_reloc *reloc;
|
||||
int ret = 0, i, j;
|
||||
|
||||
/* organize functions and relocs by object in scaffold */
|
||||
for (kfunc = __kpatch_funcs;
|
||||
kfunc != __kpatch_funcs_end;
|
||||
kfunc++) {
|
||||
ret = patch_add_func_to_object(kfunc);
|
||||
if (ret)
|
||||
goto out;
|
||||
}
|
||||
|
||||
for (kdynrela = __kpatch_dynrelas;
|
||||
kdynrela != __kpatch_dynrelas_end;
|
||||
kdynrela++) {
|
||||
ret = patch_add_reloc_to_object(kdynrela);
|
||||
if (ret)
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* past this point, only possible return code is -ENOMEM */
|
||||
ret = -ENOMEM;
|
||||
|
||||
/* allocate and fill livepatch structures */
|
||||
lpatch = kzalloc(sizeof(*lpatch), GFP_KERNEL);
|
||||
if (!lpatch)
|
||||
goto out;
|
||||
|
||||
lobjects = kzalloc(sizeof(*lobjects) * (patch_objects_nr+1),
|
||||
GFP_KERNEL);
|
||||
if (!lobjects)
|
||||
goto out;
|
||||
lpatch->mod = THIS_MODULE;
|
||||
lpatch->objs = lobjects;
|
||||
|
||||
i = 0;
|
||||
list_for_each_entry(object, &patch_objects, list) {
|
||||
lobject = &lobjects[i];
|
||||
lobject->name = object->name;
|
||||
lfuncs = kzalloc(sizeof(struct klp_func) *
|
||||
(object->funcs_nr+1), GFP_KERNEL);
|
||||
if (!lfuncs)
|
||||
goto out;
|
||||
lobject->funcs = lfuncs;
|
||||
j = 0;
|
||||
list_for_each_entry(func, &object->funcs, list) {
|
||||
lfunc = &lfuncs[j];
|
||||
lfunc->old_name = func->kfunc->name;
|
||||
lfunc->new_func = (void *)func->kfunc->new_addr;
|
||||
lfunc->old_addr = func->kfunc->old_addr;
|
||||
j++;
|
||||
}
|
||||
|
||||
lrelocs = kzalloc(sizeof(struct klp_reloc) *
|
||||
(object->relocs_nr+1), GFP_KERNEL);
|
||||
if (!lrelocs)
|
||||
goto out;
|
||||
lobject->relocs = lrelocs;
|
||||
j = 0;
|
||||
list_for_each_entry(reloc, &object->relocs, list) {
|
||||
lreloc = &lrelocs[j];
|
||||
lreloc->loc = reloc->kdynrela->dest;
|
||||
lreloc->val = reloc->kdynrela->src;
|
||||
lreloc->type = reloc->kdynrela->type;
|
||||
lreloc->name = reloc->kdynrela->name;
|
||||
lreloc->addend = reloc->kdynrela->addend;
|
||||
lreloc->external = reloc->kdynrela->external;
|
||||
j++;
|
||||
}
|
||||
|
||||
i++;
|
||||
}
|
||||
|
||||
/*
|
||||
* Once the patch structure that the live patching API expects
|
||||
* has been built, we can release the scaffold structure.
|
||||
*/
|
||||
patch_free_scaffold();
|
||||
|
||||
ret = klp_register_patch(lpatch);
|
||||
if (ret) {
|
||||
patch_free_livepatch(lpatch);
|
||||
return ret;
|
||||
}
|
||||
|
||||
ret = klp_enable_patch(lpatch);
|
||||
if (ret) {
|
||||
WARN_ON(klp_unregister_patch(lpatch));
|
||||
patch_free_livepatch(lpatch);
|
||||
return ret;
|
||||
}
|
||||
|
||||
return 0;
|
||||
out:
|
||||
patch_free_livepatch(lpatch);
|
||||
patch_free_scaffold();
|
||||
return ret;
|
||||
}
|
||||
|
||||
static void __exit patch_exit(void)
|
||||
{
|
||||
WARN_ON(klp_unregister_patch(lpatch));
|
||||
}
|
||||
|
||||
module_init(patch_init);
|
||||
module_exit(patch_exit);
|
||||
MODULE_LICENSE("GPL");
|
||||
|
|
@ -0,0 +1,25 @@
|
|||
/*
|
||||
* Copyright (C) 2015 Seth Jennings <sjenning@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, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA,
|
||||
* 02110-1301, USA.
|
||||
*/
|
||||
|
||||
#if IS_ENABLED(CONFIG_LIVE_PATCHING)
|
||||
#include "livepatch-patch-hook.c"
|
||||
#else
|
||||
#include "kpatch-patch-hook.c"
|
||||
#endif
|
||||
|
||||
Loading…
Reference in New Issue