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ftrace: Use direct_ops hash in unregister_ftrace_direct

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Now when we have *direct_multi interface the direct_functions
hash is no longer owned just by direct_ops. It's also used by
any other ftrace_ops passed to *direct_multi interface.

Thus to find out that we are unregistering the last function
from direct_ops, we need to check directly direct_ops's hash.

Link: https://lkml.kernel.org/r/20211206182032.87248-2-jolsa@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Fixes: f64dd4627e ("ftrace: Add multi direct register/unregister interface")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Jiri Olsa 2021-12-06 19:20:30 +01:00 committed by Steven Rostedt (VMware)
parent 48b27b6b51
commit 7d5b7cad79
1 changed files with 3 additions and 1 deletions
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4
kernel/trace/ftrace.c
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@ -5217,6 +5217,7 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
{
struct ftrace_direct_func *direct;
struct ftrace_func_entry *entry;
struct ftrace_hash *hash;
int ret = -ENODEV;
mutex_lock(&direct_mutex);
@ -5225,7 +5226,8 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
if (!entry)
goto out_unlock;
if (direct_functions->count == 1)
hash = direct_ops.func_hash->filter_hash;
if (hash->count == 1)
unregister_ftrace_function(&direct_ops);
ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0);