Re: [PATCH] kprobes: Fix to init kprobes in subsys_initcall

Anders Roxell
2019-06-03T20:33:24Z

On Mon, 3 Jun 2019 at 15:04, Masami Hiramatsu <mhiramat@kernel.org> wrote:
>
> Since arm64 kernel initializes breakpoint trap vector in arch_initcall(),
> initializing kprobe (and run smoke test) in postcore_initcall() causes
> a kernel panic.
>
> To fix this issue, move the kprobe initialization in subsys_initcall()
> (which is called right afer the arch_initcall).
>
> In-kernel kprobe users (ftrace and bpf) are using fs_initcall() which is
> called after subsys_initcall(), so this shouldn't cause more problem.
>
> Reported-by: Anders Roxell <anders.roxell@linaro.org>
> Fixes: b5f8b32c93b2 ("kprobes: Initialize kprobes at postcore_initcall")
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>

Tested-by: Anders Roxell <anders.roxell@linaro.org>

Cheers,
Anders

> ---
> kernel/kprobes.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 54aaaad00a47..5471efbeb937 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -2289,7 +2289,7 @@ static int __init init_kprobes(void)
> init_test_probes();
> return err;
> }
> -postcore_initcall(init_kprobes);
> +subsys_initcall(init_kprobes);
>
> #ifdef CONFIG_DEBUG_FS
> static void report_probe(struct seq_file *pi, struct kprobe *p,
>