Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1390517
| From | Josh Poimboeuf <jpoimboe@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [RFC PATCH v2 13/18] livepatch: separate enabled and patched states |
| Date | 2016-04-28 22:50 +0200 |
| Message-ID | <rt12P-1W5-41@gated-at.bofh.it> (permalink) |
| References | <rt12N-1W5-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Once we have a consistency model, patches and their objects will be
enabled and disabled at different times. For example, when a patch is
disabled, its loaded objects' funcs can remain registered with ftrace
indefinitely until the unpatching operation is complete and they're no
longer in use.
It's less confusing if we give them different names: patches can be
enabled or disabled; objects (and their funcs) can be patched or
unpatched:
- Enabled means that a patch is logically enabled (but not necessarily
fully applied).
- Patched means that an object's funcs are registered with ftrace and
added to the klp_ops func stack.
Also, since these states are binary, represent them with booleans
instead of ints.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
include/linux/livepatch.h | 17 ++++-------
kernel/livepatch/core.c | 72 +++++++++++++++++++++++------------------------
2 files changed, 42 insertions(+), 47 deletions(-)
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index a8c6c9c..9ba26c5 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -28,11 +28,6 @@
#include <asm/livepatch.h>
-enum klp_state {
- KLP_DISABLED,
- KLP_ENABLED
-};
-
/**
* struct klp_func - function structure for live patching
* @old_name: name of the function to be patched
@@ -41,8 +36,8 @@ enum klp_state {
* can be found (optional)
* @old_addr: the address of the function being patched
* @kobj: kobject for sysfs resources
- * @state: tracks function-level patch application state
* @stack_node: list node for klp_ops func_stack list
+ * @patched: the func has been added to the klp_ops list
*/
struct klp_func {
/* external */
@@ -60,8 +55,8 @@ struct klp_func {
/* internal */
unsigned long old_addr;
struct kobject kobj;
- enum klp_state state;
struct list_head stack_node;
+ bool patched;
};
/**
@@ -71,7 +66,7 @@ struct klp_func {
* @kobj: kobject for sysfs resources
* @mod: kernel module associated with the patched object
* (NULL for vmlinux)
- * @state: tracks object-level patch application state
+ * @patched: the object's funcs have been added to the klp_ops list
*/
struct klp_object {
/* external */
@@ -81,7 +76,7 @@ struct klp_object {
/* internal */
struct kobject kobj;
struct module *mod;
- enum klp_state state;
+ bool patched;
};
/**
@@ -90,7 +85,7 @@ struct klp_object {
* @objs: object entries for kernel objects to be patched
* @list: list node for global list of registered patches
* @kobj: kobject for sysfs resources
- * @state: tracks patch-level application state
+ * @enabled: the patch is enabled (but operation may be incomplete)
*/
struct klp_patch {
/* external */
@@ -100,7 +95,7 @@ struct klp_patch {
/* internal */
struct list_head list;
struct kobject kobj;
- enum klp_state state;
+ bool enabled;
};
#define klp_for_each_object(patch, obj) \
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 6ea6880..2b59230 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -350,11 +350,11 @@ static unsigned long klp_get_ftrace_location(unsigned long faddr)
}
#endif
-static void klp_disable_func(struct klp_func *func)
+static void klp_unpatch_func(struct klp_func *func)
{
struct klp_ops *ops;
- if (WARN_ON(func->state != KLP_ENABLED))
+ if (WARN_ON(!func->patched))
return;
if (WARN_ON(!func->old_addr))
return;
@@ -380,10 +380,10 @@ static void klp_disable_func(struct klp_func *func)
list_del_rcu(&func->stack_node);
}
- func->state = KLP_DISABLED;
+ func->patched = false;
}
-static int klp_enable_func(struct klp_func *func)
+static int klp_patch_func(struct klp_func *func)
{
struct klp_ops *ops;
int ret;
@@ -391,7 +391,7 @@ static int klp_enable_func(struct klp_func *func)
if (WARN_ON(!func->old_addr))
return -EINVAL;
- if (WARN_ON(func->state != KLP_DISABLED))
+ if (WARN_ON(func->patched))
return -EINVAL;
ops = klp_find_ops(func->old_addr);
@@ -439,7 +439,7 @@ static int klp_enable_func(struct klp_func *func)
list_add_rcu(&func->stack_node, &ops->func_stack);
}
- func->state = KLP_ENABLED;
+ func->patched = true;
return 0;
@@ -450,36 +450,36 @@ err:
return ret;
}
-static void klp_disable_object(struct klp_object *obj)
+static void klp_unpatch_object(struct klp_object *obj)
{
struct klp_func *func;
klp_for_each_func(obj, func)
- if (func->state == KLP_ENABLED)
- klp_disable_func(func);
+ if (func->patched)
+ klp_unpatch_func(func);
- obj->state = KLP_DISABLED;
+ obj->patched = false;
}
-static int klp_enable_object(struct klp_object *obj)
+static int klp_patch_object(struct klp_object *obj)
{
struct klp_func *func;
int ret;
- if (WARN_ON(obj->state != KLP_DISABLED))
+ if (WARN_ON(obj->patched))
return -EINVAL;
if (WARN_ON(!klp_is_object_loaded(obj)))
return -EINVAL;
klp_for_each_func(obj, func) {
- ret = klp_enable_func(func);
+ ret = klp_patch_func(func);
if (ret) {
- klp_disable_object(obj);
+ klp_unpatch_object(obj);
return ret;
}
}
- obj->state = KLP_ENABLED;
+ obj->patched = true;
return 0;
}
@@ -490,17 +490,17 @@ static int __klp_disable_patch(struct klp_patch *patch)
/* enforce stacking: only the last enabled patch can be disabled */
if (!list_is_last(&patch->list, &klp_patches) &&
- list_next_entry(patch, list)->state == KLP_ENABLED)
+ list_next_entry(patch, list)->enabled)
return -EBUSY;
pr_notice("disabling patch '%s'\n", patch->mod->name);
klp_for_each_object(patch, obj) {
- if (obj->state == KLP_ENABLED)
- klp_disable_object(obj);
+ if (obj->patched)
+ klp_unpatch_object(obj);
}
- patch->state = KLP_DISABLED;
+ patch->enabled = false;
return 0;
}
@@ -524,7 +524,7 @@ int klp_disable_patch(struct klp_patch *patch)
goto err;
}
- if (patch->state == KLP_DISABLED) {
+ if (!patch->enabled) {
ret = -EINVAL;
goto err;
}
@@ -542,12 +542,12 @@ static int __klp_enable_patch(struct klp_patch *patch)
struct klp_object *obj;
int ret;
- if (WARN_ON(patch->state != KLP_DISABLED))
+ if (WARN_ON(patch->enabled))
return -EINVAL;
/* enforce stacking: only the first disabled patch can be enabled */
if (patch->list.prev != &klp_patches &&
- list_prev_entry(patch, list)->state == KLP_DISABLED)
+ !list_prev_entry(patch, list)->enabled)
return -EBUSY;
pr_notice_once("tainting kernel with TAINT_LIVEPATCH\n");
@@ -559,12 +559,12 @@ static int __klp_enable_patch(struct klp_patch *patch)
if (!klp_is_object_loaded(obj))
continue;
- ret = klp_enable_object(obj);
+ ret = klp_patch_object(obj);
if (ret)
goto unregister;
}
- patch->state = KLP_ENABLED;
+ patch->enabled = true;
return 0;
@@ -622,20 +622,20 @@ static ssize_t enabled_store(struct kobject *kobj, struct kobj_attribute *attr,
if (ret)
return -EINVAL;
- if (val != KLP_DISABLED && val != KLP_ENABLED)
+ if (val > 1)
return -EINVAL;
patch = container_of(kobj, struct klp_patch, kobj);
mutex_lock(&klp_mutex);
- if (val == patch->state) {
+ if (patch->enabled == val) {
/* already in requested state */
ret = -EINVAL;
goto err;
}
- if (val == KLP_ENABLED) {
+ if (val) {
ret = __klp_enable_patch(patch);
if (ret)
goto err;
@@ -660,7 +660,7 @@ static ssize_t enabled_show(struct kobject *kobj,
struct klp_patch *patch;
patch = container_of(kobj, struct klp_patch, kobj);
- return snprintf(buf, PAGE_SIZE-1, "%d\n", patch->state);
+ return snprintf(buf, PAGE_SIZE-1, "%d\n", patch->enabled);
}
static struct kobj_attribute enabled_kobj_attr = __ATTR_RW(enabled);
@@ -751,7 +751,7 @@ static void klp_free_patch(struct klp_patch *patch)
static int klp_init_func(struct klp_object *obj, struct klp_func *func)
{
INIT_LIST_HEAD(&func->stack_node);
- func->state = KLP_DISABLED;
+ func->patched = false;
/* The format for the sysfs directory is <function,sympos> where sympos
* is the nth occurrence of this symbol in kallsyms for the patched
@@ -794,7 +794,7 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj)
if (!obj->funcs)
return -EINVAL;
- obj->state = KLP_DISABLED;
+ obj->patched = false;
obj->mod = NULL;
klp_find_object_module(obj);
@@ -835,7 +835,7 @@ static int klp_init_patch(struct klp_patch *patch)
mutex_lock(&klp_mutex);
- patch->state = KLP_DISABLED;
+ patch->enabled = false;
ret = kobject_init_and_add(&patch->kobj, &klp_ktype_patch,
klp_root_kobj, "%s", patch->mod->name);
@@ -881,7 +881,7 @@ int klp_unregister_patch(struct klp_patch *patch)
goto out;
}
- if (patch->state == KLP_ENABLED) {
+ if (patch->enabled) {
ret = -EBUSY;
goto out;
}
@@ -968,13 +968,13 @@ int klp_module_coming(struct module *mod)
goto err;
}
- if (patch->state == KLP_DISABLED)
+ if (!patch->enabled)
break;
pr_notice("applying patch '%s' to loading module '%s'\n",
patch->mod->name, obj->mod->name);
- ret = klp_enable_object(obj);
+ ret = klp_patch_object(obj);
if (ret) {
pr_warn("failed to apply patch '%s' to module '%s' (%d)\n",
patch->mod->name, obj->mod->name, ret);
@@ -1025,10 +1025,10 @@ void klp_module_going(struct module *mod)
if (!klp_is_module(obj) || strcmp(obj->name, mod->name))
continue;
- if (patch->state != KLP_DISABLED) {
+ if (patch->enabled) {
pr_notice("reverting patch '%s' on unloading module '%s'\n",
patch->mod->name, obj->mod->name);
- klp_disable_object(obj);
+ klp_unpatch_object(obj);
}
klp_free_object_loaded(obj);
--
2.4.11
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[RFC PATCH v2 00/18] livepatch: hybrid consistency model Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 22:50 +0200
[RFC PATCH v2 14/18] livepatch: remove unnecessary object loaded check Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 22:50 +0200
[RFC PATCH v2 10/18] livepatch/powerpc: add TIF_PATCH_PENDING thread flag Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 22:50 +0200
Re: [RFC PATCH v2 10/18] livepatch/powerpc: add TIF_PATCH_PENDING thread flag Petr Mladek <pmladek@suse.com> - 2016-05-03 11:10 +0200
Re: [RFC PATCH v2 10/18] livepatch/powerpc: add TIF_PATCH_PENDING thread flag Miroslav Benes <mbenes@suse.cz> - 2016-05-03 14:10 +0200
[RFC PATCH v2 16/18] livepatch: store function sizes Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 22:50 +0200
[RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 22:50 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Andy Lutomirski <luto@amacapital.net> - 2016-04-29 20:10 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Andy Lutomirski <luto@amacapital.net> - 2016-04-29 22:20 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-29 22:30 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Andy Lutomirski <luto@amacapital.net> - 2016-04-29 22:40 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-29 23:30 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Andy Lutomirski <luto@amacapital.net> - 2016-04-29 23:40 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Jiri Kosina <jikos@kernel.org> - 2016-04-30 00:20 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-30 01:00 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Andy Lutomirski <luto@amacapital.net> - 2016-04-30 02:20 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-30 00:50 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Andy Lutomirski <luto@amacapital.net> - 2016-04-30 02:10 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-02 16:00 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Andy Lutomirski <luto@amacapital.net> - 2016-05-02 18:00 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-02 19:40 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Andy Lutomirski <luto@amacapital.net> - 2016-05-02 20:20 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Ingo Molnar <mingo@kernel.org> - 2016-05-02 20:40 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-02 21:50 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Jiri Kosina <jikos@kernel.org> - 2016-05-02 22:00 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Jiri Kosina <jikos@kernel.org> - 2016-05-02 22:10 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Andy Lutomirski <luto@amacapital.net> - 2016-05-03 02:50 +0200
RE: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking David Laight <David.Laight@ACULAB.COM> - 2016-05-04 17:20 +0200
Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-29 22:20 +0200
[RFC PATCH v2 09/18] livepatch/x86: add TIF_PATCH_PENDING thread flag Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 22:50 +0200
Re: [RFC PATCH v2 09/18] livepatch/x86: add TIF_PATCH_PENDING thread flag Andy Lutomirski <luto@amacapital.net> - 2016-04-29 20:10 +0200
Re: [RFC PATCH v2 09/18] livepatch/x86: add TIF_PATCH_PENDING thread flag Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-29 22:20 +0200
[RFC PATCH v2 02/18] x86/asm/head: use a common function for starting CPUs Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 22:50 +0200
[RFC PATCH v2 13/18] livepatch: separate enabled and patched states Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 22:50 +0200
Re: [RFC PATCH v2 13/18] livepatch: separate enabled and patched states Petr Mladek <pmladek@suse.com> - 2016-05-03 11:40 +0200
Re: [RFC PATCH v2 13/18] livepatch: separate enabled and patched states Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-03 15:50 +0200
[RFC PATCH v2 06/18] x86: dump_trace() error handling Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 22:50 +0200
Re: [RFC PATCH v2 06/18] x86: dump_trace() error handling Minfei Huang <mnghuan@gmail.com> - 2016-04-29 15:50 +0200
Re: [RFC PATCH v2 06/18] x86: dump_trace() error handling Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-29 16:10 +0200
[RFC PATCH v2 03/18] x86/asm/head: standardize the bottom of the stack for idle tasks Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 23:00 +0200
Re: [RFC PATCH v2 03/18] x86/asm/head: standardize the bottom of the stack for idle tasks Brian Gerst <brgerst@gmail.com> - 2016-04-29 20:50 +0200
Re: [RFC PATCH v2 03/18] x86/asm/head: standardize the bottom of the stack for idle tasks Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-29 22:30 +0200
Re: [RFC PATCH v2 03/18] x86/asm/head: standardize the bottom of the stack for idle tasks Andy Lutomirski <luto@kernel.org> - 2016-04-29 21:40 +0200
Re: [RFC PATCH v2 03/18] x86/asm/head: standardize the bottom of the stack for idle tasks Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-29 23:00 +0200
Re: [RFC PATCH v2 03/18] x86/asm/head: standardize the bottom of the stack for idle tasks Andy Lutomirski <luto@amacapital.net> - 2016-04-29 23:40 +0200
Re: [RFC PATCH v2 03/18] x86/asm/head: standardize the bottom of the stack for idle tasks Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-30 01:30 +0200
Re: [RFC PATCH v2 03/18] x86/asm/head: standardize the bottom of the stack for idle tasks Andy Lutomirski <luto@amacapital.net> - 2016-04-30 02:20 +0200
[RFC PATCH v2 04/18] x86: move _stext marker before head code Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 23:00 +0200
[RFC PATCH v2 01/18] x86/asm/head: clean up initial stack variable Josh Poimboeuf <jpoimboe@redhat.com> - 2016-04-28 23:00 +0200
Re: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Petr Mladek <pmladek@suse.com> - 2016-05-04 10:50 +0200
Re: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-04 18:00 +0200
Re: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Miroslav Benes <mbenes@suse.cz> - 2016-05-05 11:50 +0200
Re: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Petr Mladek <pmladek@suse.com> - 2016-05-05 15:10 +0200
barriers: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Petr Mladek <pmladek@suse.com> - 2016-05-04 14:40 +0200
Re: barriers: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Peter Zijlstra <peterz@infradead.org> - 2016-05-04 16:00 +0200
Re: barriers: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-04 19:00 +0200
Re: barriers: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Petr Mladek <pmladek@suse.com> - 2016-05-04 16:20 +0200
Re: barriers: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-04 19:30 +0200
Re: barriers: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Petr Mladek <pmladek@suse.com> - 2016-05-05 13:30 +0200
Re: barriers: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Miroslav Benes <mbenes@suse.cz> - 2016-05-09 17:50 +0200
Re: barriers: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-04 19:10 +0200
Re: barriers: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Petr Mladek <pmladek@suse.com> - 2016-05-05 12:30 +0200
klp_task_patch: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Petr Mladek <pmladek@suse.com> - 2016-05-04 16:50 +0200
Re: klp_task_patch: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Jiri Kosina <jikos@kernel.org> - 2016-05-04 17:00 +0200
Re: klp_task_patch: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-04 20:00 +0200
Re: klp_task_patch: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Petr Mladek <pmladek@suse.com> - 2016-05-05 14:00 +0200
Re: klp_task_patch: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-06 14:40 +0200
Re: klp_task_patch: was: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Petr Mladek <pmladek@suse.com> - 2016-05-09 14:30 +0200
Re: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Petr Mladek <pmladek@suse.com> - 2016-05-06 13:40 +0200
Re: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-06 14:50 +0200
Re: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Miroslav Benes <mbenes@suse.cz> - 2016-05-09 11:50 +0200
Re: [RFC PATCH v2 17/18] livepatch: change to a per-task consistency model Miroslav Benes <mbenes@suse.cz> - 2016-05-10 13:50 +0200
csiph-web