| Message ID | 1490861708-27813-3-git-send-email-yamada.masahiro@socionext.com |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
On Thu, Mar 30, 2017 at 11:15 AM, Masahiro Yamada <yamada.masahiro@socionext.com> wrote: > > Some NAND controllers are using DMA engine requiring a specific > buffer alignment. The core provides no guarantee on the nand_buffers > pointers, which forces some drivers to allocate their own buffers > and pass the NAND_OWN_BUFFERS flag. > > Rework the nand_buffers allocation logic to allocate each buffer > independently. This should make most NAND controllers/DMA engine > happy, and allow us to get rid of these custom buf allocation in > NAND controller drivers. > > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> > @@ -4914,8 +4930,12 @@ void nand_cleanup(struct nand_chip *chip) > > /* Free bad block table memory */ > kfree(chip->bbt); > - if (!(chip->options & NAND_OWN_BUFFERS)) > + if (!(chip->options & NAND_OWN_BUFFERS)) { > + kfree(chip->buffers->databuf); > + kfree(chip->buffers->ecccode); > + kfree(chip->buffers->ecccalc); > kfree(chip->buffers); > + } It seems that chip->buffers might not be allocated at this point, for example if nand_cleanup is called during a failed probe. You should check if (chip->buffers != NULL) before freeing stuff inside it. When attempting to run linux-next on various imx6qdl-sabreauto boards they now panic on boot. This happens because they have nand chips in devicetree which are not physically populated on the board. This normally fails in nand_scan_ident but now crashes later in nand_cleanup. -- Regards, Leonard
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index f828ad7..e9d3195 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -4613,13 +4613,25 @@ int nand_scan_tail(struct mtd_info *mtd) } if (!(chip->options & NAND_OWN_BUFFERS)) { - nbuf = kzalloc(sizeof(*nbuf) + mtd->writesize - + mtd->oobsize * 3, GFP_KERNEL); + nbuf = kzalloc(sizeof(*nbuf), GFP_KERNEL); if (!nbuf) return -ENOMEM; - nbuf->ecccalc = (uint8_t *)(nbuf + 1); - nbuf->ecccode = nbuf->ecccalc + mtd->oobsize; - nbuf->databuf = nbuf->ecccode + mtd->oobsize; + nbuf->ecccalc = kmalloc(mtd->oobsize, GFP_KERNEL); + if (!nbuf->ecccalc) { + ret = -EINVAL; + goto err_free; + } + nbuf->ecccode = kmalloc(mtd->oobsize, GFP_KERNEL); + if (!nbuf->ecccode) { + ret = -EINVAL; + goto err_free; + } + nbuf->databuf = kmalloc(mtd->writesize + mtd->oobsize, + GFP_KERNEL); + if (!nbuf->databuf) { + ret = -EINVAL; + goto err_free; + } chip->buffers = nbuf; } else { @@ -4862,8 +4874,12 @@ int nand_scan_tail(struct mtd_info *mtd) /* Build bad block table */ return chip->scan_bbt(mtd); err_free: - if (!(chip->options & NAND_OWN_BUFFERS)) + if (!(chip->options & NAND_OWN_BUFFERS)) { + kfree(chip->buffers->databuf); + kfree(chip->buffers->ecccode); + kfree(chip->buffers->ecccalc); kfree(chip->buffers); + } return ret; } EXPORT_SYMBOL(nand_scan_tail); @@ -4914,8 +4930,12 @@ void nand_cleanup(struct nand_chip *chip) /* Free bad block table memory */ kfree(chip->bbt); - if (!(chip->options & NAND_OWN_BUFFERS)) + if (!(chip->options & NAND_OWN_BUFFERS)) { + kfree(chip->buffers->databuf); + kfree(chip->buffers->ecccode); + kfree(chip->buffers->ecccalc); kfree(chip->buffers); + } /* Free bad block descriptor memory */ if (chip->badblock_pattern && chip->badblock_pattern->options
Some NAND controllers are using DMA engine requiring a specific buffer alignment. The core provides no guarantee on the nand_buffers pointers, which forces some drivers to allocate their own buffers and pass the NAND_OWN_BUFFERS flag. Rework the nand_buffers allocation logic to allocate each buffer independently. This should make most NAND controllers/DMA engine happy, and allow us to get rid of these custom buf allocation in NAND controller drivers. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- Changes in v3: - Reword git-log Changes in v2: - Newly added drivers/mtd/nand/nand_base.c | 34 +++++++++++++++++++++++++++------- 1 file changed, 27 insertions(+), 7 deletions(-) -- 2.7.4 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/