From: Dan Carpenter <error27@gmail.com>
To: kernel-janitors@vger.kernel.org
Subject: Re: bug report: signedness issue in ds3232_update_alarm()
Date: Thu, 28 Oct 2010 10:58:40 +0000 [thread overview]
Message-ID: <20101028105840.GB6062@bicker> (raw)
In-Reply-To: <20101028083503.GZ6062@bicker>
On Thu, Oct 28, 2010 at 06:15:46PM +0800, Lan Chunhe-B25806 wrote:
> Of course, bcd2bin()/Time is never less than zero. But it is fault
> tolerant.
> When time has exceptional data, it set time to the default value.
>
Sorry, I still don't understand what you're trying to do. This showed
up on my bug scanner, and I've studied it but as far as I can see it
doesn't do anything. I've created a sample program to demonstrate what
I mean.
It passes every possible non-zero value to bcd2bin() and counts how many
of the returns are negative.
regards,
dan carpenter
#include <stdio.h>
unsigned bcd2bin(unsigned char val)
{
return (val & 0x0f) + (val >> 4) * 10;
}
int main(int argc, char **argv)
{
unsigned char x;
int useful = 0;
for (x = 1; x; x++) {
if (bcd2bin(x) < 0)
useful++;
}
printf("useful = %d\n", useful);
return 0;
}
next prev parent reply other threads:[~2010-10-28 10:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-28 8:35 bug report: signedness issue in ds3232_update_alarm() Dan Carpenter
2010-10-28 8:55 ` Dan Carpenter
2010-10-28 10:15 ` Lan Chunhe-B25806
2010-10-28 10:58 ` Dan Carpenter [this message]
2010-10-28 11:17 ` Lan Chunhe-B25806
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