After commit e999995c84c3 ("ftrace: cleanup ftrace_graph_caller enable
and disable") merged into the linux-next tree, the kernel test robot
([email protected]) 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 <[email protected]>
---
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
On Tue, May 24, 2022 at 07:17:18PM -0400, Steven Rostedt wrote:
> On Fri, 6 May 2022 11:27:37 +0800
> Chengming Zhou <[email protected]> wrote:
>
> > After commit e999995c84c3 ("ftrace: cleanup ftrace_graph_caller enable
> > and disable") merged into the linux-next tree, the kernel test robot
> > ([email protected]) 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 <[email protected]>
>
> The change this fixes was merged into the ARM tree and I do not have that
> code, so I can not apply this.
Ah, I missed this patch. The commit mentioned is in mainline now but I'm
happy to add it to the arm64 tree and send before -rc1.
--
Catalin
On Wed, 25 May 2022 09:31:36 +0100
Catalin Marinas <[email protected]> wrote:
> > The change this fixes was merged into the ARM tree and I do not have that
> > code, so I can not apply this.
>
> Ah, I missed this patch. The commit mentioned is in mainline now but I'm
> happy to add it to the arm64 tree and send before -rc1.
Please do, thanks.
Acked-by: Steven Rostedt (Google) <[email protected]>
-- Steve
The change this fixes was merged into the ARM tree and I do not have that
code, so I can not apply this.
-- Steve
On Fri, 6 May 2022 11:27:37 +0800
Chengming Zhou <[email protected]> wrote:
> After commit e999995c84c3 ("ftrace: cleanup ftrace_graph_caller enable
> and disable") merged into the linux-next tree, the kernel test robot
> ([email protected]) 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 <[email protected]>
> ---
> 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
On Fri, 6 May 2022 11:27:37 +0800, Chengming Zhou wrote:
> After commit e999995c84c3 ("ftrace: cleanup ftrace_graph_caller enable
> and disable") merged into the linux-next tree, the kernel test robot
> ([email protected]) 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]
>
> [...]
Applied to arm64 (for-next/core), thanks!
[1/1] ftrace/fgraph: fix increased missing-prototypes warnings
https://git.kernel.org/arm64/c/ff979b2a9d97
--
Catalin