diff options
Diffstat (limited to 'kernel/livepatch/transition.c')
| -rw-r--r-- | kernel/livepatch/transition.c | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index 5683ac0d2566..30187b1d8275 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -9,7 +9,6 @@ #include <linux/cpu.h> #include <linux/stacktrace.h> -#include <linux/tracehook.h> #include "core.h" #include "patch.h" #include "transition.h" @@ -611,9 +610,23 @@ void klp_reverse_transition(void) /* Called from copy_process() during fork */ void klp_copy_process(struct task_struct *child) { - child->patch_state = current->patch_state; - /* TIF_PATCH_PENDING gets copied in setup_thread_stack() */ + /* + * The parent process may have gone through a KLP transition since + * the thread flag was copied in setup_thread_stack earlier. Bring + * the task flag up to date with the parent here. + * + * The operation is serialized against all klp_*_transition() + * operations by the tasklist_lock. The only exception is + * klp_update_patch_state(current), but we cannot race with + * that because we are current. + */ + if (test_tsk_thread_flag(current, TIF_PATCH_PENDING)) + set_tsk_thread_flag(child, TIF_PATCH_PENDING); + else + clear_tsk_thread_flag(child, TIF_PATCH_PENDING); + + child->patch_state = current->patch_state; } /* @@ -641,6 +654,13 @@ void klp_force_transition(void) for_each_possible_cpu(cpu) klp_update_patch_state(idle_task(cpu)); - klp_for_each_patch(patch) - patch->forced = true; + /* Set forced flag for patches being removed. */ + if (klp_target_state == KLP_UNPATCHED) + klp_transition_patch->forced = true; + else if (klp_transition_patch->replace) { + klp_for_each_patch(patch) { + if (patch != klp_transition_patch) + patch->forced = true; + } + } } |