On 09/19/2016 02:53 AM, Tom Rini wrote: > On Tue, Sep 13, 2016 at 04:27:57PM +0800, Haibo Chen wrote: > >> Suspicious implicit sign extension exist. ext_csd[] is defined >> as "u8", capacity is defined as u64, so u8 is promoted to signed >> int first int the "|" expersion, then the sign extended to u64. >> if the tmp sign value is largeer than 0x7fffffff, after the sign >> extension, the upper bits of the result will all be 1. >> Thanks to coverity <http://www.coverity.com> >> >> e.g. >> u8 data_8; >> u64 data_64; >> >> data_8 = 0x80; >> data_64 = data_8 << 24; //0xffffffff80000000 >> data_64 = ((u64)data_8) << 24; //0x80000000 >> >> Signed-off-by: Haibo Chen <haibo.c...@nxp.com> > > Please add a 'Reported-by: Coverity' and you can include the CID if you > like.
I think cid doesn't need to change type. > >> --- >> drivers/mmc/mmc.c | 8 ++++---- >> 1 file changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c >> index 43ea0bb..c1d1dc6 100644 >> --- a/drivers/mmc/mmc.c >> +++ b/drivers/mmc/mmc.c >> @@ -1176,10 +1176,10 @@ static int mmc_startup(struct mmc *mmc) >> * ext_csd's capacity is valid if the value is more >> * than 2GB >> */ >> - capacity = ext_csd[EXT_CSD_SEC_CNT] << 0 >> - | ext_csd[EXT_CSD_SEC_CNT + 1] << 8 >> - | ext_csd[EXT_CSD_SEC_CNT + 2] << 16 >> - | ext_csd[EXT_CSD_SEC_CNT + 3] << 24; >> + capacity = ((u64)ext_csd[EXT_CSD_SEC_CNT]) << 0 >> + | ((u64)ext_csd[EXT_CSD_SEC_CNT + 1]) >> << 8 >> + | ((u64)ext_csd[EXT_CSD_SEC_CNT + 2]) >> << 16 >> + | ((u64)ext_csd[EXT_CSD_SEC_CNT + 3]) >> << 24; >> capacity *= MMC_MAX_BLOCK_LEN; >> if ((capacity >> 20) > 2 * 1024) >> mmc->capacity_user = capacity; > > Can't we just move capacity down to a u8 instead? Thanks! Maybe not to move down to a u8..because it's displayed the real capacity for storage. And i wonder that coverity didn't report about the line 1294? Best Regards, Jaehoon Chung > > > > _______________________________________________ > U-Boot mailing list > U-Boot@lists.denx.de > http://lists.denx.de/mailman/listinfo/u-boot > _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
