xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge branch 'for-4.16/remove-immediate' into for-linus

Browse Source 
Pull 'immediate' feature removal from Miroslav Benes.
This commit is contained in:
Jiri Kosina
2018-01-31 16:33:52 +01:00
parent 8869016d3a d0807da78e
commit d05b695c25
8 changed files with 33 additions and 181 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
kernel/livepatch/core.c
View File

@@ -366,11 +366,6 @@ static int __klp_enable_patch(struct klp_patch *patch)
/*
* A reference is taken on the patch module to prevent it from being
* unloaded.
*
* Note: For immediate (no consistency model) patches we don't allow
* patch modules to unload since there is no safe/sane method to
* determine if a thread is still running in the patched code contained
* in the patch module once the ftrace registration is successful.
*/
if (!try_module_get(patch->mod))
return -ENODEV;
@@ -894,12 +889,7 @@ int klp_register_patch(struct klp_patch *patch)
if (!klp_initialized())
return -ENODEV;
/*
* Architectures without reliable stack traces have to set
* patch->immediate because there's currently no way to patch kthreads
* with the consistency model.
*/
if (!klp_have_reliable_stack() && !patch->immediate) {
if (!klp_have_reliable_stack()) {
pr_err("This architecture doesn't have support for the livepatch consistency model.\n");
return -ENOSYS;
}

49
kernel/livepatch/transition.c
View File

@@ -82,7 +82,6 @@ static void klp_complete_transition(void)
struct klp_func *func;
struct task_struct *g, *task;
unsigned int cpu;
bool immediate_func = false;
pr_debug("'%s': completing %s transition\n",
klp_transition_patch->mod->name,
@@ -104,16 +103,9 @@ static void klp_complete_transition(void)
klp_synchronize_transition();
}
if (klp_transition_patch->immediate)
goto done;
klp_for_each_object(klp_transition_patch, obj) {
klp_for_each_func(obj, func) {
klp_for_each_object(klp_transition_patch, obj)
klp_for_each_func(obj, func)
func->transition = false;
if (func->immediate)
immediate_func = true;
}
}
/* Prevent klp_ftrace_handler() from seeing KLP_UNDEFINED state */
if (klp_target_state == KLP_PATCHED)
@@ -132,7 +124,6 @@ static void klp_complete_transition(void)
task->patch_state = KLP_UNDEFINED;
}
done:
klp_for_each_object(klp_transition_patch, obj) {
if (!klp_is_object_loaded(obj))
continue;
@@ -146,16 +137,11 @@ done:
klp_target_state == KLP_PATCHED ? "patching" : "unpatching");
/*
* See complementary comment in __klp_enable_patch() for why we
* keep the module reference for immediate patches.
*
* klp_forced or immediate_func set implies unbounded increase of
* module's ref count if the module is disabled/enabled in a loop.
* klp_forced set implies unbounded increase of module's ref count if
* the module is disabled/enabled in a loop.
*/
if (!klp_forced && !klp_transition_patch->immediate &&
!immediate_func && klp_target_state == KLP_UNPATCHED) {
if (!klp_forced && klp_target_state == KLP_UNPATCHED)
module_put(klp_transition_patch->mod);
}
klp_target_state = KLP_UNDEFINED;
klp_transition_patch = NULL;
@@ -223,9 +209,6 @@ static int klp_check_stack_func(struct klp_func *func,
struct klp_ops *ops;
int i;
if (func->immediate)
return 0;
for (i = 0; i < trace->nr_entries; i++) {
address = trace->entries[i];
@@ -387,13 +370,6 @@ void klp_try_complete_transition(void)
WARN_ON_ONCE(klp_target_state == KLP_UNDEFINED);
/*
* If the patch can be applied or reverted immediately, skip the
* per-task transitions.
*/
if (klp_transition_patch->immediate)
goto success;
/*
* Try to switch the tasks to the target patch state by walking their
* stacks and looking for any to-be-patched or to-be-unpatched
@@ -437,7 +413,6 @@ void klp_try_complete_transition(void)
return;
}
success:
/* we're done, now cleanup the data structures */
klp_complete_transition();
}
@@ -457,13 +432,6 @@ void klp_start_transition(void)
klp_transition_patch->mod->name,
klp_target_state == KLP_PATCHED ? "patching" : "unpatching");
/*
* If the patch can be applied or reverted immediately, skip the
* per-task transitions.
*/
if (klp_transition_patch->immediate)
return;
/*
* Mark all normal tasks as needing a patch state update. They'll
* switch either in klp_try_complete_transition() or as they exit the
@@ -513,13 +481,6 @@ void klp_init_transition(struct klp_patch *patch, int state)
pr_debug("'%s': initializing %s transition\n", patch->mod->name,
klp_target_state == KLP_PATCHED ? "patching" : "unpatching");
/*
* If the patch can be applied or reverted immediately, skip the
* per-task transitions.
*/
if (patch->immediate)
return;
/*
* Initialize all tasks to the initial patch state to prepare them for
* switching to the target state.