| Message ID | 20230606231252.94838-5-william.zhang@broadcom.com |
|---|---|
| State | Changes Requested |
| Delegated to: | Miquel Raynal |
| Headers | show |
| Series | mtd: rawnand: brcmnand: driver and doc updates | expand |
Hi William, william.zhang@broadcom.com wrote on Tue, 6 Jun 2023 16:12:44 -0700: > When the oob buffer length is not in multiple of words, the oob write > function does out-of-bounds read on the oob source buffer at the last > iteration. Fix that by always checking length limit on the oob buffer > read and fill with 0xff when reaching the end of the buffer to the oob > registers. > > Fixes: 27c5b17cd1b1 ("mtd: nand: add NAND driver "library" for Broadcom STB NAND controller") > Signed-off-by: William Zhang <william.zhang@broadcom.com> > Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> > --- > > drivers/mtd/nand/raw/brcmnand/brcmnand.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c > index 20832857c4aa..d920e88c7f5b 100644 > --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c > +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c > @@ -1486,10 +1486,10 @@ static int write_oob_to_regs(struct brcmnand_controller *ctrl, int i, > > for (j = 0; j < tbytes; j += 4) > oob_reg_write(ctrl, j, > - (oob[j + 0] << 24) | > - (oob[j + 1] << 16) | > - (oob[j + 2] << 8) | > - (oob[j + 3] << 0)); > + (((j < tbytes) ? oob[j] : 0xff) << 24) | > + (((j + 1 < tbytes) ? oob[j + 1] : 0xff) << 16) | > + (((j + 2 < tbytes) ? oob[j + 2] : 0xff) << 8) | > + ((j + 3 < tbytes) ? oob[j + 3] : 0xff)); This is a lot of additional operations which most of the time are not relevant. I would instead got for one less iteration in the for loop when there is unaligned data, and then dedicated if/else to fill the missing bytes. > return tbytes; > } > Thanks, Miquèl
diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c index 20832857c4aa..d920e88c7f5b 100644 --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c @@ -1486,10 +1486,10 @@ static int write_oob_to_regs(struct brcmnand_controller *ctrl, int i, for (j = 0; j < tbytes; j += 4) oob_reg_write(ctrl, j, - (oob[j + 0] << 24) | - (oob[j + 1] << 16) | - (oob[j + 2] << 8) | - (oob[j + 3] << 0)); + (((j < tbytes) ? oob[j] : 0xff) << 24) | + (((j + 1 < tbytes) ? oob[j + 1] : 0xff) << 16) | + (((j + 2 < tbytes) ? oob[j + 2] : 0xff) << 8) | + ((j + 3 < tbytes) ? oob[j + 3] : 0xff)); return tbytes; }
When the oob buffer length is not in multiple of words, the oob write function does out-of-bounds read on the oob source buffer at the last iteration. Fix that by always checking length limit on the oob buffer read and fill with 0xff when reaching the end of the buffer to the oob registers. Fixes: 27c5b17cd1b1 ("mtd: nand: add NAND driver "library" for Broadcom STB NAND controller") Signed-off-by: William Zhang <william.zhang@broadcom.com> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> --- drivers/mtd/nand/raw/brcmnand/brcmnand.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)