From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [for-next][PATCH 2/5] ftrace: Do not process STUB functions in ftrace_ops_list_func()
Date: Thu, 25 Apr 2019 12:28:10 -0400 [thread overview]
Message-ID: <20190425162843.751657930@goodmis.org> (raw)
In-Reply-To: 20190425162808.056301033@goodmis.org
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
The function_graph tracer has a stub function and its ops flag has the
FTRACE_OPS_FL_STUB set. As the function graph does not use the
ftrace_ops->func pointer but instead is called by a separate part of the
ftrace trampoline. The function_graph tracer still requires to pass in a
ftrace_ops that may also hold the hash of the functions to call. But there's
no reason to test that hash in the function tracing portion. Instead of
testing to see if we should call the stub function, just test if the ops has
FTRACE_OPS_FL_STUB set, and just skip it.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/ftrace.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index bf11e0553450..433a64f49532 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6260,6 +6260,9 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
preempt_disable_notrace();
do_for_each_ftrace_op(op, ftrace_ops_list) {
+ /* Stub functions don't need to be called nor tested */
+ if (op->flags & FTRACE_OPS_FL_STUB)
+ continue;
/*
* Check the following for each ops before calling their func:
* if RCU flag is set, then rcu_is_watching() must be true
--
2.20.1
next prev parent reply other threads:[~2019-04-25 16:28 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-25 16:28 [for-next][PATCH 0/5] tracing: function graph cleanups for the next merge window Steven Rostedt
2019-04-25 16:28 ` [for-next][PATCH 1/5] ftrace: Remove ASSIGN_OPS_HASH() macro from ftrace.c Steven Rostedt
2019-04-25 16:28 ` Steven Rostedt [this message]
2019-04-25 16:28 ` [for-next][PATCH 3/5] function_graph: Have selftest also emulate tr->reset() as it did with tr->init() Steven Rostedt
2019-04-25 16:28 ` [for-next][PATCH 4/5] function_graph: Use a ftrace_graph_ret_stub() for return Steven Rostedt
2019-04-25 16:28 ` [for-next][PATCH 5/5] function_graph: Place ftrace_graph_entry_stub() prototype in include/linux/ftrace.h Steven Rostedt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190425162843.751657930@goodmis.org \
--to=rostedt@goodmis.org \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).