From: Chengming Zhou <zhouchengming@bytedance.com>
To: rostedt@goodmis.org, mingo@redhat.com, linux-kernel@vger.kernel.org
Cc: songmuchun@bytedance.com, zhouchengming@bytedance.com
Subject: [PATCH 2/2] ftrace: setup correct flags before replace code of module rec
Date: Tue, 28 Jul 2020 18:27:20 +0800 [thread overview]
Message-ID: <20200728102720.46837-2-zhouchengming@bytedance.com> (raw)
In-Reply-To: <20200728102720.46837-1-zhouchengming@bytedance.com>
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.
So setup correct rec->flags when we call referenced_filters to find
ftrace_ops references it.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
kernel/trace/ftrace.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index fca01a168ae5..00087dea0174 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6190,8 +6190,17 @@ 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_DIRECT)
+ rec->flags |= FTRACE_FL_DIRECT;
+ 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;
+ }
}
return cnt;
@@ -6373,7 +6382,8 @@ void ftrace_module_enable(struct module *mod)
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);
--
2.20.1
next prev parent reply other threads:[~2020-07-28 10:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-28 10:27 [PATCH 1/2] ftrace: clear module from hash of all ftrace ops Chengming Zhou
2020-07-28 10:27 ` Chengming Zhou [this message]
2020-07-28 13:02 ` [PATCH 2/2] ftrace: setup correct flags before replace code of module rec Steven Rostedt
2020-07-28 17:29 ` [External] " Chengming Zhou
2020-07-28 12:53 ` [PATCH 1/2] ftrace: clear module from hash of all ftrace ops Steven Rostedt
2020-07-28 16:59 ` [External] " Chengming Zhou
2020-07-28 17:26 ` Steven Rostedt
2020-07-31 4:00 ` Chengming Zhou
2020-08-10 2:54 ` [ftrace] a89282bc45: WARNING:possible_circular_locking_dependency_detected kernel test robot
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