diff options
| author | Chengming Zhou <zhouchengming@bytedance.com> | 2020-07-29 02:05:54 +0800 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-07-30 22:45:31 -0400 |
| commit | c5f51572a7fdff5be9e67c231de593155f394ab3 (patch) | |
| tree | dda7c7bcb4e8c08e54f9d9864e31116c843f5676 /kernel/trace | |
| parent | 8a224ffb3f52b0027f6b7279854c71a31c48fc97 (diff) | |
ftrace: Do not let direct or IPMODIFY ftrace_ops be added to module and set trampolines
When inserting a module, we find all ftrace_ops referencing it on the
ftrace_ops_list. But FTRACE_OPS_FL_DIRECT and FTRACE_OPS_FL_IPMODIFY
flags are special, and should not be set automatically. So warn and
skip ftrace_ops that have these two flags set and adding new code.
Also check if only one ftrace_ops references the module, in which case
we can use a trampoline as an optimization.
Link: https://lkml.kernel.org/r/20200728180554.65203-2-zhouchengming@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/ftrace.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index d052f856f1cf..f433cb44300a 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6199,9 +6199,17 @@ static int referenced_filters(struct dyn_ftrace *rec) for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { if (ops_references_rec(ops, rec)) { + if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT)) + continue; + if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY)) + continue; cnt++; if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) rec->flags |= FTRACE_FL_REGS; + if (cnt == 1 && ops->trampoline) + rec->flags |= FTRACE_FL_TRAMP; + else + rec->flags &= ~FTRACE_FL_TRAMP; } } |