* [PATCH] mtd: cast to u64 to avoid unexpected error [not found] <CGME20180823072813eucas1p2a534b4be94a3a2bc3480adcefca2ca22@eucas1p2.samsung.com> @ 2018-08-23 7:28 ` Huijin Park 2018-10-31 13:55 ` Boris Brezillon 0 siblings, 1 reply; 3+ messages in thread From: Huijin Park @ 2018-08-23 7:28 UTC (permalink / raw) To: Marek Vasut Cc: Boris Brezillon, Huijin Park, bbanghj.park, linux-mtd, linux-kernel From: "huijin.park" <huijin.park@samsung.com> the params->size is defined as "u64" and, "info->sector_size" and "info->n_sectors" is defined as unsgined and u16 thus, u64 data might have strange data(loss data) if data is overflow. this patch cast it to u64. Signed-off-by: huijin.park <huijin.park@samsung.com> --- drivers/mtd/spi-nor/spi-nor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index d9c368c..527f281 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -2459,7 +2459,7 @@ static int spi_nor_init_params(struct spi_nor *nor, memset(params, 0, sizeof(*params)); /* Set SPI NOR sizes. */ - params->size = info->sector_size * info->n_sectors; + params->size = (u64)info->sector_size * (u64)info->n_sectors; params->page_size = info->page_size; /* (Fast) Read settings. */ -- 1.7.9.5 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] mtd: cast to u64 to avoid unexpected error 2018-08-23 7:28 ` [PATCH] mtd: cast to u64 to avoid unexpected error Huijin Park @ 2018-10-31 13:55 ` Boris Brezillon 2018-11-12 16:12 ` Huijin Park 0 siblings, 1 reply; 3+ messages in thread From: Boris Brezillon @ 2018-10-31 13:55 UTC (permalink / raw) To: Huijin Park; +Cc: Marek Vasut, linux-mtd, bbanghj.park, linux-kernel Hi Huijin, Subject prefix should be "mtd: spi-nor: ...", and please replace "unexpected error" by "unsigned int overflows". On Thu, 23 Aug 2018 03:28:02 -0400 Huijin Park <huijin.park@samsung.com> wrote: > From: "huijin.park" <huijin.park@samsung.com> > > the params->size is defined as "u64" > and, "info->sector_size" and "info->n_sectors" is defined as unsgined and u16 ^ are ^ unsigned > thus, u64 data might have strange data(loss data) if data is overflow. ^ if the result overflows an unsigned int. > this patch cast it to u64. ^casts info->sector_size to an u64. > > Signed-off-by: huijin.park <huijin.park@samsung.com> > --- > drivers/mtd/spi-nor/spi-nor.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c > index d9c368c..527f281 100644 > --- a/drivers/mtd/spi-nor/spi-nor.c > +++ b/drivers/mtd/spi-nor/spi-nor.c > @@ -2459,7 +2459,7 @@ static int spi_nor_init_params(struct spi_nor *nor, > memset(params, 0, sizeof(*params)); > > /* Set SPI NOR sizes. */ > - params->size = info->sector_size * info->n_sectors; > + params->size = (u64)info->sector_size * (u64)info->n_sectors; ^ this cast is not needed. BTW, I doubt we'll ever have to deal with NORs that are more than 4GB, but making static code analysis tools happy and enforcing code correctness is important too. > params->page_size = info->page_size; > > /* (Fast) Read settings. */ Regards, Boris ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] mtd: cast to u64 to avoid unexpected error 2018-10-31 13:55 ` Boris Brezillon @ 2018-11-12 16:12 ` Huijin Park 0 siblings, 0 replies; 3+ messages in thread From: Huijin Park @ 2018-11-12 16:12 UTC (permalink / raw) To: boris.brezillon; +Cc: huijin.park, marek.vasut, linux-mtd, linux-kernel Hi Boris Thanks for review. I will send patch again. On Wed, Oct 31, 2018 at 10:55 PM Boris Brezillon <boris.brezillon@bootlin.com> wrote: > > Hi Huijin, > > Subject prefix should be "mtd: spi-nor: ...", and please replace > "unexpected error" by "unsigned int overflows". > > On Thu, 23 Aug 2018 03:28:02 -0400 > Huijin Park <huijin.park@samsung.com> wrote: > > > From: "huijin.park" <huijin.park@samsung.com> > > > > the params->size is defined as "u64" > > and, "info->sector_size" and "info->n_sectors" is defined as unsgined and u16 > > ^ are ^ unsigned > > > thus, u64 data might have strange data(loss data) if data is overflow. > > ^ if the result > overflows an unsigned int. > > > this patch cast it to u64. > > ^casts info->sector_size to an u64. > > > > > Signed-off-by: huijin.park <huijin.park@samsung.com> > > --- > > drivers/mtd/spi-nor/spi-nor.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c > > index d9c368c..527f281 100644 > > --- a/drivers/mtd/spi-nor/spi-nor.c > > +++ b/drivers/mtd/spi-nor/spi-nor.c > > @@ -2459,7 +2459,7 @@ static int spi_nor_init_params(struct spi_nor *nor, > > memset(params, 0, sizeof(*params)); > > > > /* Set SPI NOR sizes. */ > > - params->size = info->sector_size * info->n_sectors; > > + params->size = (u64)info->sector_size * (u64)info->n_sectors; > > ^ this cast is not needed. > > BTW, I doubt we'll ever have to deal with NORs that are more than 4GB, > but making static code analysis tools happy and enforcing code > correctness is important too. > I agree that enforcing code correctness is important as your said too. > > params->page_size = info->page_size; > > > > /* (Fast) Read settings. */ > > Regards, > > Boris Thanks & best regards, Huijin ^ permalink raw reply [flat|nested] 3+ messages in thread
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2018-08-23 7:28 ` [PATCH] mtd: cast to u64 to avoid unexpected error Huijin Park
2018-10-31 13:55 ` Boris Brezillon
2018-11-12 16:12 ` Huijin Park
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