diff options
| author | Chengming Zhou <zhouchengming@bytedance.com> | 2020-07-29 02:05:53 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-21 11:02:08 +0200 |
| commit | ea3d57bcaa1387b2b0f01024f172581296eef9ce (patch) | |
| tree | 943e545ee79cd67cdd1141b6581a1b485d927ab2 /kernel | |
| parent | b26574812577750346fc12ed869f845ac386c7fb (diff) | |
ftrace: Setup correct FTRACE_FL_REGS flags for module
commit 8a224ffb3f52b0027f6b7279854c71a31c48fc97 upstream.
When module loaded and enabled, we will use __ftrace_replace_code
for module if any ftrace_ops referenced it found. But we will get
wrong ftrace_addr for module rec in ftrace_get_addr_new, because
rec->flags has not been setup correctly. It can cause the callback
function of a ftrace_ops has FTRACE_OPS_FL_SAVE_REGS to be called
with pt_regs set to NULL.
So setup correct FTRACE_FL_REGS flags for rec when we call
referenced_filters to find ftrace_ops references it.
Link: https://lkml.kernel.org/r/20200728180554.65203-1-zhouchengming@bytedance.com
Cc: stable@vger.kernel.org
Fixes: 8c4f3c3fa9681 ("ftrace: Check module functions being traced on reload")
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ftrace.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 2ae98f8bce81..4d1be82e7011 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4987,8 +4987,11 @@ static int referenced_filters(struct dyn_ftrace *rec) int cnt = 0; for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { - if (ops_references_rec(ops, rec)) - cnt++; + if (ops_references_rec(ops, rec)) { + cnt++; + if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) + rec->flags |= FTRACE_FL_REGS; + } } return cnt; @@ -5084,8 +5087,8 @@ void ftrace_module_enable(struct module *mod) if (ftrace_start_up) cnt += referenced_filters(rec); - /* This clears FTRACE_FL_DISABLED */ - rec->flags = cnt; + rec->flags &= ~FTRACE_FL_DISABLED; + rec->flags += cnt; if (ftrace_start_up && cnt) { int failed = __ftrace_replace_code(rec, 1); |