linux-kernel - Re: [PATCH] drivers/misc/kgdbts.c: remove eprintk

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Date:	Sun, 4 Nov 2012 20:58:18 +0100 (CET)
From:	Julia Lawall <julia.lawall@...6.fr>
To:	Arnd Bergmann <arnd@...db.de>
cc:	walter harms <wharms@....de>, kernel-janitors@...r.kernel.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jason Wessel <jason.wessel@...driver.com>,
	kgdb-bugreport@...ts.sourceforge.net, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] drivers/misc/kgdbts.c: remove eprintk



On Sun, 4 Nov 2012, Arnd Bergmann wrote:

> On Saturday 03 November 2012, Julia Lawall wrote:
>> @@ -113,10 +113,6 @@
>>                 printk(KERN_INFO a); \
>>                 touch_nmi_watchdog();   \
>>         } while (0)
>> -#define eprintk(a...) do { \
>> -               printk(KERN_ERR a); \
>> -               WARN_ON(1); \
>> -       } while (0)
>>   #define MAX_CONFIG_LEN                40
>>
>>   static struct kgdb_io kgdbts_io_ops;
>> @@ -323,7 +319,7 @@ static int check_and_rewind_pc(char *put_str, char *arg)
>>                 v2printk("Emul: rewind hit single step bp\n");
>>                 restart_from_top_after_write = 1;
>>         } else if (strcmp(arg, "silent") && ip + offset != addr) {
>> -               eprintk("kgdbts: BP mismatch %lx expected %lx\n",
>> +               WARN(1, KERN_ERR "kgdbts: BP mismatch %lx expected %lx\n",
>>                            ip + offset, addr);
>>                 return 1;
>>         }
>
> Hmm, I did not think that WARN() took a KERN_ERR argument, which should
> really be implied here. Looking at the code, it really seems to be required
> at the moment, but only 5 out of 117 callers use it this way.
>
> Any idea what is going on here?

I'm not sure to understand the 5 and 117.  Using grep, I get 30 with 
KERN_ERR, 61 with some KERN thing, and 1207 without KERN.  If things are 
set up such that warn_slowpath_fmt is called, then that function adds
KERN_WARNING.  There is an alternate definition of __WARN_printf that just 
does a printk.

So if eprintk wants KERN_ERR, then it seems that rewriting it with WARN is 
not a good idea.  I will check whether this problems arises with the other 
printks and WARNs that I suggested to merge.

thanks,
julia
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