From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [PATCH] mmc: sdhci: cast unsigned int to unsigned long long to avoid unexpeted error Date: Fri, 14 Oct 2016 12:12:27 +0300 Message-ID: References: <1473750418-23111-1-git-send-email-haibo.chen@nxp.com> <3603c63f-f007-12cc-677b-f39924628335@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from mga05.intel.com ([192.55.52.43]:22548 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751195AbcJNJRR (ORCPT ); Fri, 14 Oct 2016 05:17:17 -0400 In-Reply-To: <3603c63f-f007-12cc-677b-f39924628335@intel.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Haibo Chen , ulf.hansson@linaro.org Cc: linux-mmc@vger.kernel.org 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 > > Let's leave out the web link - it is enough to say it was found with Coverity. > >> >> Signed-off-by: Haibo Chen 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; >> > >