* [PATCH] mmc: sdhci: cast unsigned int to unsigned long long to avoid unexpeted error
@ 2016-09-13 7:06 Haibo Chen
2016-09-13 8:36 ` Adrian Hunter
0 siblings, 1 reply; 4+ messages in thread
From: Haibo Chen @ 2016-09-13 7:06 UTC (permalink / raw)
To: adrian.hunter, ulf.hansson; +Cc: linux-mmc
Potentially overflowing expression 1000000 * data->timeout_clks with
type unsigned int is evaluated using 32-bit arithmetic, and then used
in a context that expects an expression of type unsigned long long.
To avoid overflow, cast 1000000U to type unsigned long long.
Special thanks to coverity <http://www.coverity.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
---
drivers/mmc/host/sdhci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 4805566..0e9f495 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -687,7 +687,7 @@ static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd)
* host->clock is in Hz. target_timeout is in us.
* Hence, us = 1000000 * cycles / Hz. Round up.
*/
- val = 1000000 * data->timeout_clks;
+ val = (unsigned long long)1000000 * data->timeout_clks;
if (do_div(val, host->clock))
target_timeout++;
target_timeout += val;
--
1.9.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] mmc: sdhci: cast unsigned int to unsigned long long to avoid unexpeted error
2016-09-13 7:06 [PATCH] mmc: sdhci: cast unsigned int to unsigned long long to avoid unexpeted error Haibo Chen
@ 2016-09-13 8:36 ` Adrian Hunter
2016-10-14 9:12 ` Adrian Hunter
0 siblings, 1 reply; 4+ messages in thread
From: Adrian Hunter @ 2016-09-13 8:36 UTC (permalink / raw)
To: Haibo Chen, ulf.hansson; +Cc: linux-mmc
On 13/09/16 10:06, Haibo Chen wrote:
> Potentially overflowing expression 1000000 * data->timeout_clks with
> type unsigned int is evaluated using 32-bit arithmetic, and then used
> in a context that expects an expression of type unsigned long long.
>
> To avoid overflow, cast 1000000U to type unsigned long long.
> Special thanks to coverity <http://www.coverity.com>
Let's leave out the web link - it is enough to say it was found with Coverity.
>
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Needs a fixes tag and cc stable.
> ---
> drivers/mmc/host/sdhci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 4805566..0e9f495 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -687,7 +687,7 @@ static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd)
> * host->clock is in Hz. target_timeout is in us.
> * Hence, us = 1000000 * cycles / Hz. Round up.
> */
> - val = 1000000 * data->timeout_clks;
> + val = (unsigned long long)1000000 * data->timeout_clks;
Please use 1000000ULL instead of a cast.
> if (do_div(val, host->clock))
> target_timeout++;
> target_timeout += val;
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mmc: sdhci: cast unsigned int to unsigned long long to avoid unexpeted error
2016-09-13 8:36 ` Adrian Hunter
@ 2016-10-14 9:12 ` Adrian Hunter
2016-10-14 9:53 ` Bough Chen
0 siblings, 1 reply; 4+ messages in thread
From: Adrian Hunter @ 2016-10-14 9:12 UTC (permalink / raw)
To: Haibo Chen, ulf.hansson; +Cc: linux-mmc
On 13/09/16 11:36, Adrian Hunter wrote:
> On 13/09/16 10:06, Haibo Chen wrote:
>> Potentially overflowing expression 1000000 * data->timeout_clks with
>> type unsigned int is evaluated using 32-bit arithmetic, and then used
>> in a context that expects an expression of type unsigned long long.
>>
>> To avoid overflow, cast 1000000U to type unsigned long long.
>> Special thanks to coverity <http://www.coverity.com>
>
> Let's leave out the web link - it is enough to say it was found with Coverity.
>
>>
>> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Do you plan to re-submit this?
>
> Needs a fixes tag and cc stable.
>
>> ---
>> drivers/mmc/host/sdhci.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index 4805566..0e9f495 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -687,7 +687,7 @@ static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd)
>> * host->clock is in Hz. target_timeout is in us.
>> * Hence, us = 1000000 * cycles / Hz. Round up.
>> */
>> - val = 1000000 * data->timeout_clks;
>> + val = (unsigned long long)1000000 * data->timeout_clks;
>
> Please use 1000000ULL instead of a cast.
>
>> if (do_div(val, host->clock))
>> target_timeout++;
>> target_timeout += val;
>>
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH] mmc: sdhci: cast unsigned int to unsigned long long to avoid unexpeted error
2016-10-14 9:12 ` Adrian Hunter
@ 2016-10-14 9:53 ` Bough Chen
0 siblings, 0 replies; 4+ messages in thread
From: Bough Chen @ 2016-10-14 9:53 UTC (permalink / raw)
To: Adrian Hunter, ulf.hansson; +Cc: linux-mmc
> -----Original Message-----
> From: linux-mmc-owner@vger.kernel.org [mailto:linux-mmc-
> owner@vger.kernel.org] On Behalf Of Adrian Hunter
> Sent: Friday, October 14, 2016 5:12 PM
> To: Bough Chen <haibo.chen@nxp.com>; ulf.hansson@linaro.org
> Cc: linux-mmc@vger.kernel.org
> Subject: Re: [PATCH] mmc: sdhci: cast unsigned int to unsigned long long to
> avoid unexpeted error
>
> On 13/09/16 11:36, Adrian Hunter wrote:
> > On 13/09/16 10:06, Haibo Chen wrote:
> >> Potentially overflowing expression 1000000 * data->timeout_clks with
> >> type unsigned int is evaluated using 32-bit arithmetic, and then used
> >> in a context that expects an expression of type unsigned long long.
> >>
> >> To avoid overflow, cast 1000000U to type unsigned long long.
> >> Special thanks to coverity <http://www.coverity.com>
> >
> > Let's leave out the web link - it is enough to say it was found with Coverity.
> >
> >>
> >> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
>
> Do you plan to re-submit this?
>
Yes, I will re-submit this soon.
> >
> > Needs a fixes tag and cc stable.
> >
> >> ---
> >> drivers/mmc/host/sdhci.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> >> index 4805566..0e9f495 100644
> >> --- a/drivers/mmc/host/sdhci.c
> >> +++ b/drivers/mmc/host/sdhci.c
> >> @@ -687,7 +687,7 @@ static u8 sdhci_calc_timeout(struct sdhci_host *host,
> struct mmc_command *cmd)
> >> * host->clock is in Hz. target_timeout is in us.
> >> * Hence, us = 1000000 * cycles / Hz. Round up.
> >> */
> >> - val = 1000000 * data->timeout_clks;
> >> + val = (unsigned long long)1000000 * data->timeout_clks;
> >
> > Please use 1000000ULL instead of a cast.
> >
> >> if (do_div(val, host->clock))
> >> target_timeout++;
> >> target_timeout += val;
> >>
> >
> >
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the
> body of a message to majordomo@vger.kernel.org More majordomo info at
> http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-10-14 13:26 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-09-13 7:06 [PATCH] mmc: sdhci: cast unsigned int to unsigned long long to avoid unexpeted error Haibo Chen
2016-09-13 8:36 ` Adrian Hunter
2016-10-14 9:12 ` Adrian Hunter
2016-10-14 9:53 ` Bough Chen
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