From: Chengming Zhou <zhouchengming@bytedance.com>
To: rostedt@goodmis.org, mark.rutland@arm.com, catalin.marinas@arm.com
Cc: linux-kernel@vger.kernel.org, kbuild-all@lists.01.org,
lkp@intel.com, zhouchengming@bytedance.com
Subject: [PATCH] ftrace/fgraph: fix increased missing-prototypes warnings
Date: Fri, 6 May 2022 11:27:37 +0800 [thread overview]
Message-ID: <20220506032737.23375-1-zhouchengming@bytedance.com> (raw)
After commit e999995c84c3 ("ftrace: cleanup ftrace_graph_caller enable
and disable") merged into the linux-next tree, the kernel test robot
(lkp@intel.com) has send out report that there are increased missing-prototypes
warnings caused by that commit.
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 \
O=build_dir ARCH=sh SHELL=/bin/bash kernel/trace/
warning: no previous prototype for 'ftrace_enable_ftrace_graph_caller' [-Wmissing-prototypes]
warning: no previous prototype for 'ftrace_disable_ftrace_graph_caller' [-Wmissing-prototypes]
warning: no previous prototype for 'ftrace_return_to_handler' [-Wmissing-prototypes]
warning: no previous prototype for 'ftrace_graph_sleep_time_control' [-Wmissing-prototypes]
BTW there are so many missing-prototypes warnings if build kernel with "W=1".
The increased warnings for 'ftrace_[enable,disable]_ftrace_graph_caller'
is caused by CONFIG_FUNCTION_GRAPH_TRACER && !CONFIG_DYNAMIC_FTRACE,
so the declarations in <linux/ftrace.h> can't be seen in fgraph.c.
And this warning can't reproduce on x86_64 since x86_64 select
HAVE_FUNCTION_GRAPH_TRACER only when DYNAMIC_FTRACE, so fgraph.c will
always see the declarations in <linux/ftrace.h>.
This patch fix the increased warnings by put the definitions in
CONFIG_DYNAMIC_FTRACE although there are no real problems exist.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
---
kernel/trace/fgraph.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 289311680c29..2cd374294be7 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -30,6 +30,7 @@ int ftrace_graph_active;
/* Both enabled by default (can be cleared by function_graph tracer flags */
static bool fgraph_sleep_time = true;
+#ifdef CONFIG_DYNAMIC_FTRACE
/*
* archs can override this function if they must do something
* to enable hook for graph tracer.
@@ -47,6 +48,7 @@ int __weak ftrace_disable_ftrace_graph_caller(void)
{
return 0;
}
+#endif
/**
* ftrace_graph_stop - set to permanently disable function graph tracing
--
2.36.0
next reply other threads:[~2022-05-06 3:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-06 3:27 Chengming Zhou [this message]
2022-05-06 3:33 ` [PATCH] ftrace/fgraph: fix increased missing-prototypes warnings Chengming Zhou
2022-05-24 23:17 ` Steven Rostedt
2022-05-25 8:31 ` Catalin Marinas
2022-05-25 11:30 ` Steven Rostedt
2022-06-01 18:23 ` Catalin Marinas
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