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* [PATCH bpf-next] bpf: fix compiler warning with CONFIG_MODULES=n
@ 2019-06-26  0:35 Yonghong Song
  2019-06-26  1:16 ` Song Liu
  2019-06-26 14:32 ` Daniel Borkmann
  0 siblings, 2 replies; 3+ messages in thread
From: Yonghong Song @ 2019-06-26  0:35 UTC (permalink / raw)
  To: ast, daniel, netdev, bpf; +Cc: kernel-team, arnd

With CONFIG_MODULES=n, the following compiler warning occurs:
  /data/users/yhs/work/net-next/kernel/trace/bpf_trace.c:605:13: warning:
      ‘do_bpf_send_signal’ defined but not used [-Wunused-function]
  static void do_bpf_send_signal(struct irq_work *entry)

The __init function send_signal_irq_work_init(), which calls
do_bpf_send_signal(), is defined under CONFIG_MODULES. Hence,
when CONFIG_MODULES=n, nobody calls static function do_bpf_send_signal(),
hence the warning.

The init function send_signal_irq_work_init() should work without
CONFIG_MODULES. Moving it out of CONFIG_MODULES
code section fixed the compiler warning, and also make bpf_send_signal()
helper work without CONFIG_MODULES.

Fixes: 8b401f9ed244 ("bpf: implement bpf_send_signal() helper")
Reported-By: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 kernel/trace/bpf_trace.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index c102c240bb0b..ca1255d14576 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1431,6 +1431,20 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
 	return err;
 }
 
+static int __init send_signal_irq_work_init(void)
+{
+	int cpu;
+	struct send_signal_irq_work *work;
+
+	for_each_possible_cpu(cpu) {
+		work = per_cpu_ptr(&send_signal_work, cpu);
+		init_irq_work(&work->irq_work, do_bpf_send_signal);
+	}
+	return 0;
+}
+
+subsys_initcall(send_signal_irq_work_init);
+
 #ifdef CONFIG_MODULES
 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
 			    void *module)
@@ -1478,18 +1492,5 @@ static int __init bpf_event_init(void)
 	return 0;
 }
 
-static int __init send_signal_irq_work_init(void)
-{
-	int cpu;
-	struct send_signal_irq_work *work;
-
-	for_each_possible_cpu(cpu) {
-		work = per_cpu_ptr(&send_signal_work, cpu);
-		init_irq_work(&work->irq_work, do_bpf_send_signal);
-	}
-	return 0;
-}
-
 fs_initcall(bpf_event_init);
-subsys_initcall(send_signal_irq_work_init);
 #endif /* CONFIG_MODULES */
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH bpf-next] bpf: fix compiler warning with CONFIG_MODULES=n
  2019-06-26  0:35 [PATCH bpf-next] bpf: fix compiler warning with CONFIG_MODULES=n Yonghong Song
@ 2019-06-26  1:16 ` Song Liu
  2019-06-26 14:32 ` Daniel Borkmann
  1 sibling, 0 replies; 3+ messages in thread
From: Song Liu @ 2019-06-26  1:16 UTC (permalink / raw)
  To: Yonghong Song
  Cc: Alexei Starovoitov, Daniel Borkmann, Networking, bpf, Kernel Team, arnd



> On Jun 25, 2019, at 5:35 PM, Yonghong Song <yhs@fb.com> wrote:
> 
> With CONFIG_MODULES=n, the following compiler warning occurs:
>  /data/users/yhs/work/net-next/kernel/trace/bpf_trace.c:605:13: warning:
>      ‘do_bpf_send_signal’ defined but not used [-Wunused-function]
>  static void do_bpf_send_signal(struct irq_work *entry)
> 
> The __init function send_signal_irq_work_init(), which calls
> do_bpf_send_signal(), is defined under CONFIG_MODULES. Hence,
> when CONFIG_MODULES=n, nobody calls static function do_bpf_send_signal(),
> hence the warning.
> 
> The init function send_signal_irq_work_init() should work without
> CONFIG_MODULES. Moving it out of CONFIG_MODULES
> code section fixed the compiler warning, and also make bpf_send_signal()
> helper work without CONFIG_MODULES.
> 
> Fixes: 8b401f9ed244 ("bpf: implement bpf_send_signal() helper")
> Reported-By: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Yonghong Song <yhs@fb.com>

Thanks for the fix!

Acked-by: Song Liu <songliubraving@fb.com>


> ---
> kernel/trace/bpf_trace.c | 27 ++++++++++++++-------------
> 1 file changed, 14 insertions(+), 13 deletions(-)
> 
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index c102c240bb0b..ca1255d14576 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1431,6 +1431,20 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
> 	return err;
> }
> 
> +static int __init send_signal_irq_work_init(void)
> +{
> +	int cpu;
> +	struct send_signal_irq_work *work;
> +
> +	for_each_possible_cpu(cpu) {
> +		work = per_cpu_ptr(&send_signal_work, cpu);
> +		init_irq_work(&work->irq_work, do_bpf_send_signal);
> +	}
> +	return 0;
> +}
> +
> +subsys_initcall(send_signal_irq_work_init);
> +
> #ifdef CONFIG_MODULES
> static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
> 			    void *module)
> @@ -1478,18 +1492,5 @@ static int __init bpf_event_init(void)
> 	return 0;
> }
> 
> -static int __init send_signal_irq_work_init(void)
> -{
> -	int cpu;
> -	struct send_signal_irq_work *work;
> -
> -	for_each_possible_cpu(cpu) {
> -		work = per_cpu_ptr(&send_signal_work, cpu);
> -		init_irq_work(&work->irq_work, do_bpf_send_signal);
> -	}
> -	return 0;
> -}
> -
> fs_initcall(bpf_event_init);
> -subsys_initcall(send_signal_irq_work_init);
> #endif /* CONFIG_MODULES */
> -- 
> 2.17.1
> 


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH bpf-next] bpf: fix compiler warning with CONFIG_MODULES=n
  2019-06-26  0:35 [PATCH bpf-next] bpf: fix compiler warning with CONFIG_MODULES=n Yonghong Song
  2019-06-26  1:16 ` Song Liu
@ 2019-06-26 14:32 ` Daniel Borkmann
  1 sibling, 0 replies; 3+ messages in thread
From: Daniel Borkmann @ 2019-06-26 14:32 UTC (permalink / raw)
  To: Yonghong Song, ast, netdev, bpf; +Cc: kernel-team, arnd

On 06/26/2019 02:35 AM, Yonghong Song wrote:
> With CONFIG_MODULES=n, the following compiler warning occurs:
>   /data/users/yhs/work/net-next/kernel/trace/bpf_trace.c:605:13: warning:
>       ‘do_bpf_send_signal’ defined but not used [-Wunused-function]
>   static void do_bpf_send_signal(struct irq_work *entry)
> 
> The __init function send_signal_irq_work_init(), which calls
> do_bpf_send_signal(), is defined under CONFIG_MODULES. Hence,
> when CONFIG_MODULES=n, nobody calls static function do_bpf_send_signal(),
> hence the warning.
> 
> The init function send_signal_irq_work_init() should work without
> CONFIG_MODULES. Moving it out of CONFIG_MODULES
> code section fixed the compiler warning, and also make bpf_send_signal()
> helper work without CONFIG_MODULES.
> 
> Fixes: 8b401f9ed244 ("bpf: implement bpf_send_signal() helper")
> Reported-By: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Yonghong Song <yhs@fb.com>

Applied, thanks!

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2019-06-26 14:32 UTC | newest]

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2019-06-26  0:35 [PATCH bpf-next] bpf: fix compiler warning with CONFIG_MODULES=n Yonghong Song
2019-06-26  1:16 ` Song Liu
2019-06-26 14:32 ` Daniel Borkmann

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