Adding unregister_ftrace_direct_ips function that allows
to unregister array of ip addresses and trampolines for
direct filter. the interface is:
int unregister_ftrace_direct_ips(unsigned long *ips,
unsigned long *addrs,
int count);
It wil be used in following patches to unregister bpf
trampolines in batch mode.
Signed-off-by: Jiri Olsa <jo...@kernel.org>
---
include/linux/ftrace.h | 2 ++
kernel/trace/ftrace.c | 51 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 53 insertions(+)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 9ed52755667a..24525473043e 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -293,6 +293,8 @@ int ftrace_modify_direct_caller(struct ftrace_func_entry
*entry,
unsigned long ftrace_find_rec_direct(unsigned long ip);
int register_ftrace_direct_ips(unsigned long *ips, unsigned long *addrs,
int count);
+int unregister_ftrace_direct_ips(unsigned long *ips, unsigned long *addrs,
+ int count);
#else
# define ftrace_direct_func_count 0
static inline int register_ftrace_direct(unsigned long ip, unsigned long addr)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 770bcd1a245a..15a13e6c1f31 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5374,6 +5374,57 @@ int unregister_ftrace_direct(unsigned long ip, unsigned
long addr)
}
EXPORT_SYMBOL_GPL(unregister_ftrace_direct);
+int unregister_ftrace_direct_ips(unsigned long *ips, unsigned long *addrs,
+ int count)
+{
+ struct ftrace_direct_func *direct;
+ struct ftrace_func_entry *entry;
+ int i, del = 0, ret = -ENODEV;
+
+ mutex_lock(&direct_mutex);
+
+ for (i = 0; i < count; i++) {
+ entry = find_direct_entry(&ips[i], NULL);
+ if (!entry)
+ goto out_unlock;
+ del++;
+ }
+
+ if (direct_functions->count - del == 0)
+ unregister_ftrace_function(&direct_ops);
+
+ ret = ftrace_set_filter_ips(&direct_ops, ips, count, 1);
+
+ WARN_ON(ret);
+
+ for (i = 0; i < count; i++) {
+ entry = __ftrace_lookup_ip(direct_functions, ips[i]);
+ if (WARN_ON(!entry))
+ continue;
+
+ remove_hash_entry(direct_functions, entry);
+
+ direct = ftrace_find_direct_func(addrs[i]);
+ if (!WARN_ON(!direct)) {
+ /* This is the good path (see the ! before WARN) */
+ direct->count--;
+ WARN_ON(direct->count < 0);
+ if (!direct->count) {
+ list_del_rcu(&direct->next);
+ synchronize_rcu_tasks();
+ kfree(direct);
+ kfree(entry);
+ ftrace_direct_func_count--;
+ }
+ }
+ }
+ out_unlock:
+ mutex_unlock(&direct_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(unregister_ftrace_direct_ips);
+
static struct ftrace_ops stub_ops = {
.func = ftrace_stub,
};
--
2.26.2
