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From: Michael Snyder <msnyder@vmware.com>
To: Mark Kettenis <mark.kettenis@xs4all.nl>
Cc: "jan.kratochvil@redhat.com" <jan.kratochvil@redhat.com>,
	 "gdb-patches@sourceware.org" <gdb-patches@sourceware.org>,
	"dje@google.com" <dje@google.com>
Subject: Re: [RFA] off by one array reference in i386-low.c/i386_show_dr
Date: Sun, 27 Feb 2011 22:05:00 -0000	[thread overview]
Message-ID: <4D6AC963.5040404@vmware.com> (raw)
In-Reply-To: <201102272142.p1RLgURF009060@glazunov.sibelius.xs4all.nl>

Mark Kettenis wrote:
>> Date: Sun, 27 Feb 2011 13:27:31 -0800
>> From: Michael Snyder <msnyder@vmware.com>
>>
>>>> --- i386-low.c	1 Jan 2011 15:33:24 -0000	1.5
>>>> +++ i386-low.c	26 Feb 2011 22:48:38 -0000
>>> /* A macro to loop over all debug registers.  */
>>> #define ALL_DEBUG_REGISTERS(i)  for (i = 0; i < DR_NADDR; i++)
>>>> @@ -195,7 +195,7 @@ i386_show_dr (struct i386_debug_reg_stat
>>>   ALL_DEBUG_REGISTERS(i)
>>>     {
>>>       printf_unfiltered ("\
>>>>  \tDR%d: addr=0x%s, ref.count=%d  DR%d: addr=0x%s, ref.count=%d\n",
>>>>  	      i, paddress (state->dr_mirror[i]),
>>>>  	      state->dr_ref_count[i],
>>>> -	      i + 1, paddress (state->dr_mirror[i + 1]),
>>>> +	      i + 1, paddress (state->dr_mirror[i]),
>>>>  	      state->dr_ref_count[i + 1]);
>>>>        i++;
>>>>      }
>>> ->
>>> 	CONTROL (DR7): 0000000000090101          STATUS (DR6): 0000000000004000
>>> 	DR0: addr=0x0000000001c31f30, ref.count=1  DR1: addr=0x0000000000000000, ref.count=0
>>> 	DR2: addr=0x0000000000000000, ref.count=0  DR3: addr=0x0000000000000000, ref.count=0
>>>
>>> I do not see a bug there; still it could be better commented.
>> The bug is that when "i" is 3, "i + 1" is 4, and the array only runs
>> from 0 to 3.
> 
> But i can't be 3.


Ah, ok, I'm finally seeing it.
So this is a false positive from Coverity.
This patch withdrawn.

Thanks for the review.


  reply	other threads:[~2011-02-27 22:00 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-26 23:24 Michael Snyder
2011-02-27 16:47 ` Jan Kratochvil
2011-02-27 21:33   ` Michael Snyder
2011-02-27 21:41     ` Jan Kratochvil
2011-02-27 21:50     ` Mark Kettenis
2011-02-27 22:05       ` Michael Snyder [this message]
2011-02-27 17:01 ` Pedro Alves

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