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Date:   Tue, 21 Jul 2020 19:08:34 +0800
From:   Nick Hu <nickhu@andestech.com>
To:     Christoph Hellwig <hch@lst.de>
CC:     <green.hu@gmail.com>, <deanbo422@gmail.com>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] nds32: remove dump_instr
Message-ID: <20200721110834.GB19721@atcfdc88>
References: <20200720114448.205876-1-hch@lst.de>
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On Mon, Jul 20, 2020 at 01:44:47PM +0200, Christoph Hellwig wrote:
> dump_inst has a return before actually doing anything, so just drop the
> whole thing.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/nds32/kernel/traps.c | 35 -----------------------------------
>  1 file changed, 35 deletions(-)
> 
> diff --git a/arch/nds32/kernel/traps.c b/arch/nds32/kernel/traps.c
> index 6a9772ba739276..b66f889bc6df9b 100644
> --- a/arch/nds32/kernel/traps.c
> +++ b/arch/nds32/kernel/traps.c
> @@ -62,40 +62,6 @@ void dump_mem(const char *lvl, unsigned long bottom, unsigned long top)
>  
>  EXPORT_SYMBOL(dump_mem);
>  
> -static void dump_instr(struct pt_regs *regs)
> -{
> -	unsigned long addr = instruction_pointer(regs);
> -	mm_segment_t fs;
> -	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
> -	int i;
> -
> -	return;
> -	/*
> -	 * We need to switch to kernel mode so that we can use __get_user
> -	 * to safely read from kernel space.  Note that we now dump the
> -	 * code first, just in case the backtrace kills us.
> -	 */
> -	fs = get_fs();
> -	set_fs(KERNEL_DS);
> -
> -	pr_emerg("Code: ");
> -	for (i = -4; i < 1; i++) {
> -		unsigned int val, bad;
> -
> -		bad = __get_user(val, &((u32 *) addr)[i]);
> -
> -		if (!bad) {
> -			p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
> -		} else {
> -			p += sprintf(p, "bad PC value");
> -			break;
> -		}
> -	}
> -	pr_emerg("Code: %s\n", str);
> -
> -	set_fs(fs);
> -}
> -
>  #define LOOP_TIMES (100)
>  static void __dump(struct task_struct *tsk, unsigned long *base_reg,
>  		   const char *loglvl)
> @@ -179,7 +145,6 @@ void die(const char *str, struct pt_regs *regs, int err)
>  
>  	if (!user_mode(regs) || in_interrupt()) {
>  		dump_mem("Stack: ", regs->sp, (regs->sp + PAGE_SIZE) & PAGE_MASK);
> -		dump_instr(regs);
>  		dump_stack();
>  	}
>  
> -- 
> 2.27.0
>

Acked-by: Nick Hu <nickhu@andestech.com>