Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 23 Apr 2018 12:11:23 -0700 (PDT)
Subject:     Re: [REVIEW][PATCH 14/22] signal/riscv: Use force_sig_fault where appropriate
In-Reply-To: <20180420143811.9994-14-ebiederm@xmission.com>
CC:     linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
        ebiederm@xmission.com, albert@sifive.com,
        linux-riscv@lists.infradead.org
From:   Palmer Dabbelt <palmer@sifive.com>
To:     ebiederm@xmission.com
Message-ID: <mhng-77d5b15b-866b-464a-a256-6c7b84726ce3@palmer-si-x1c4>
Mime-Version: 1.0 (MHng)
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, 20 Apr 2018 07:38:03 PDT (-0700), ebiederm@xmission.com 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@sifive.com>
> Cc: Albert Ou <albert@sifive.com>
> Cc: linux-riscv@lists.infradead.org
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
> ---
>  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);
>  }
>
>  void do_trap(struct pt_regs *regs, int signo, int code,

If I understand this correctly, any change in behavior this causes would have 
been a bug on our end not filling out siginfo correctly?  In that case then 
feel free to add an

    Acked-by: Palmer Dabbelt <palmer@sifive.com>

Thanks!