Re: [REVIEW][PATCH 14/22] signal/riscv: Use force_sig_fault where appropriate

From: Christoph Hellwig
Date: Sat Apr 21 2018 - 03:26:00 EST


On Fri, Apr 20, 2018 at 09:38:03AM -0500, Eric W. Biederman wrote:
> Filling in struct siginfo before calling force_sig_info a tedious and
> error prone process, where once in a great while the wrong fields
> are filled out, and siginfo has been inconsistently cleared.
>
> Simplify this process by using the helper force_sig_fault. Which
> takes as a parameters all of the information it needs, ensures
> all of the fiddly bits of filling in struct siginfo are done properly
> and then calls force_sig_info.
>
> In short about a 5 line reduction in code for every time force_sig_info
> is called, which makes the calling function clearer.
>
> Cc: Palmer Dabbelt <palmer@xxxxxxxxxx>
> Cc: Albert Ou <albert@xxxxxxxxxx>
> Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx
> Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
> ---
> arch/riscv/kernel/traps.c | 9 +--------
> 1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
> index 48aa6471cede..3087940008f4 100644
> --- a/arch/riscv/kernel/traps.c
> +++ b/arch/riscv/kernel/traps.c
> @@ -66,14 +66,7 @@ void die(struct pt_regs *regs, const char *str)
> static inline void do_trap_siginfo(int signo, int code,
> unsigned long addr, struct task_struct *tsk)
> {
> - siginfo_t info;
> -
> - clear_siginfo(&info);
> - info.si_signo = signo;
> - info.si_errno = 0;
> - info.si_code = code;
> - info.si_addr = (void __user *)addr;
> - force_sig_info(signo, &info, tsk);
> + force_sig_fault(signo, code, (void __user *)addr, tsk);
> }

Please kill the do_trap_siginfo helper and use force_sig_fault
directly in both callers.