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authorChengming Zhou <zhouchengming@bytedance.com>2020-07-29 02:05:53 +0800
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2020-07-30 19:35:19 -0400
commit8a224ffb3f52b0027f6b7279854c71a31c48fc97 (patch)
treeb291727ca657356e28267f27f13c58ce5f7c46a1 /kernel/trace/ftrace.c
parent96b4833b6827a62c295b149213c68b559514c929 (diff)
ftrace: Setup correct FTRACE_FL_REGS flags for module
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>
Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index c141d347f71a..d052f856f1cf 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6198,8 +6198,11 @@ 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;
@@ -6378,8 +6381,8 @@ 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);