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Diffstat (limited to 'kernel/livepatch/patch.c')
-rw-r--r--kernel/livepatch/patch.c37
1 files changed, 11 insertions, 26 deletions
diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c
index e8029aea67f1..90408500e5a3 100644
--- a/kernel/livepatch/patch.c
+++ b/kernel/livepatch/patch.c
@@ -49,14 +49,15 @@ static void notrace klp_ftrace_handler(unsigned long ip,
ops = container_of(fops, struct klp_ops, fops);
+ /*
+ * The ftrace_test_recursion_trylock() will disable preemption,
+ * which is required for the variant of synchronize_rcu() that is
+ * used to allow patching functions where RCU is not watching.
+ * See klp_synchronize_transition() for more details.
+ */
bit = ftrace_test_recursion_trylock(ip, parent_ip);
if (WARN_ON_ONCE(bit < 0))
return;
- /*
- * A variant of synchronize_rcu() is used to allow patching functions
- * where RCU is not watching, see klp_synchronize_transition().
- */
- preempt_disable_notrace();
func = list_first_or_null_rcu(&ops->func_stack, struct klp_func,
stack_node);
@@ -94,9 +95,9 @@ static void notrace klp_ftrace_handler(unsigned long ip,
patch_state = current->patch_state;
- WARN_ON_ONCE(patch_state == KLP_UNDEFINED);
+ WARN_ON_ONCE(patch_state == KLP_TRANSITION_IDLE);
- if (patch_state == KLP_UNPATCHED) {
+ if (patch_state == KLP_TRANSITION_UNPATCHED) {
/*
* Use the previously patched version of the function.
* If no previous patches exist, continue with the
@@ -117,26 +118,12 @@ static void notrace klp_ftrace_handler(unsigned long ip,
if (func->nop)
goto unlock;
- klp_arch_set_pc(fregs, (unsigned long)func->new_func);
+ ftrace_regs_set_instruction_pointer(fregs, (unsigned long)func->new_func);
unlock:
- preempt_enable_notrace();
ftrace_test_recursion_unlock(bit);
}
-/*
- * Convert a function address into the appropriate ftrace location.
- *
- * Usually this is just the address of the function, but on some architectures
- * it's more complicated so allow them to provide a custom behaviour.
- */
-#ifndef klp_get_ftrace_location
-static unsigned long klp_get_ftrace_location(unsigned long faddr)
-{
- return faddr;
-}
-#endif
-
static void klp_unpatch_func(struct klp_func *func)
{
struct klp_ops *ops;
@@ -153,8 +140,7 @@ static void klp_unpatch_func(struct klp_func *func)
if (list_is_singular(&ops->func_stack)) {
unsigned long ftrace_loc;
- ftrace_loc =
- klp_get_ftrace_location((unsigned long)func->old_func);
+ ftrace_loc = ftrace_location((unsigned long)func->old_func);
if (WARN_ON(!ftrace_loc))
return;
@@ -186,8 +172,7 @@ static int klp_patch_func(struct klp_func *func)
if (!ops) {
unsigned long ftrace_loc;
- ftrace_loc =
- klp_get_ftrace_location((unsigned long)func->old_func);
+ ftrace_loc = ftrace_location((unsigned long)func->old_func);
if (!ftrace_loc) {
pr_err("failed to find location for function '%s'\n",
func->old_name);