[PATCH v2 3/3] asm-generic: syscall_get/set_arguments accept zero for number of arguments

[Will Deacon]

[extending CC list to add the ftrace guys]

On Thu, Oct 03, 2013 at 06:47:46AM +0100, AKASHI Takahiro wrote:
> There is a possibility of calling syscall_get_arguments() with zero as
> 'number of arguments(n)' in ftrace_syscall_enter().
> The comments in syscall_get_argumets() as well as syscall_set_arugments()
> are corrected to clarify that.

Probably also worth mentioning that all architectures deal with n + i == 0
(after your first two patches fixing up arm and arm64, anyway).

> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> ---
>  include/asm-generic/syscall.h |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/asm-generic/syscall.h b/include/asm-generic/syscall.h
> index 5b09392..49b35ab 100644
> --- a/include/asm-generic/syscall.h
> +++ b/include/asm-generic/syscall.h
> @@ -106,7 +106,7 @@ void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
>   * @task:	task of interest, must be blocked
>   * @regs:	task_pt_regs() of @task
>   * @i:		argument index [0,5]
> - * @n:		number of arguments; n+i must be [1,6].
> + * @n:		number of arguments; n+i must be [0,6].
>   * @args:	array filled with argument values
>   *
>   * Fetches @n arguments to the system call starting with the @i'th argument
> @@ -126,7 +126,7 @@ void syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
>   * @task:	task of interest, must be in system call entry tracing
>   * @regs:	task_pt_regs() of @task
>   * @i:		argument index [0,5]
> - * @n:		number of arguments; n+i must be [1,6].
> + * @n:		number of arguments; n+i must be [0,6].
>   * @args:	array of argument values to store
>   *
>   * Changes @n arguments to the system call starting with the @i'th argument.

Acked-by: Will Deacon <will.deacon at arm.com>

Will