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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 10:15:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 10:15:34 -0700
commit9497d7380b9c450830190c75aa43b25c278bb1f9 (patch)
tree019fe8a45676f873bf03746a671cc04bcc4512b0 /kernel
parentd0bbe0dd353af9521e9d8bc5236308c677b6f62a (diff)
parent09675bd395458543e70d19544f8046038a2fd053 (diff)
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
Diffstat (limited to 'kernel')
-rw-r--r--kernel/livepatch/core.c69
1 files changed, 17 insertions, 52 deletions
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 3f9f1d6b4c2e..284e2691e380 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -335,32 +335,20 @@ unlock:
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 @@ err:
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);