[PATCH v15 03/15] FWU: Add FWU metadata access driver for GPT partitioned block devices

Sughosh Ganu sughosh.ganu at linaro.org
Fri Oct 21 18:27:45 CEST 2022


hi Ilias,

On Fri, 21 Oct 2022 at 20:33, Ilias Apalodimas
<ilias.apalodimas at linaro.org> wrote:
>
> Hi Sughosh
>
> > +{
> > +     int ret;
> > +     u32 len, blk_start, blkcnt;
> > +     struct disk_partition info;
> > +
> > +     ALLOC_CACHE_ALIGN_BUFFER_PAD(struct fwu_mdata, mdata_aligned, 1,
> > +                                  desc->blksz);
> > +
> > +     if (!mdata)
> > +             return -ENOMEM;
>
> ENOMEM is usually for allocation failures this is an -EINVAL
>
> > +
> > +     ret = gpt_get_mdata_disk_part(desc, &info, part_num);
> > +     if (ret < 0) {
> > +             printf("Unable to get the FWU metadata partition\n");
> > +             return -ENOENT;
> > +     }
> > +
> > +     len = sizeof(*mdata);
> > +     blkcnt = BLOCK_CNT(len, desc);
> > +     if (blkcnt > info.size) {
> > +             log_debug("Block count exceeds FWU metadata partition size\n");
> > +             return -ERANGE;
> > +     }
> > +
> > +     blk_start = info.start;
> > +     if (access == MDATA_READ) {
> > +             if (blk_dread(desc, blk_start, blkcnt, mdata_aligned) != blkcnt) {
> > +                     log_debug("Error reading FWU metadata from the device\n");
> > +                     return -EIO;
> > +             }
> > +             memcpy(mdata, mdata_aligned, sizeof(struct fwu_mdata));
> > +     } else {
>
> else if ?
>
> > +             if (blk_dwrite(desc, blk_start, blkcnt, mdata) != blkcnt) {
> > +                     log_debug("Error writing FWU metadata to the device\n");
> > +                     return -EIO;
> > +             }
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int fwu_gpt_update_mdata(struct udevice *dev, struct fwu_mdata *mdata)
> > +{
> > +     int ret;
> > +     struct blk_desc *desc;
> > +     uint mdata_parts[2];
> > +     struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
> > +
> > +     desc = dev_get_uclass_plat(priv->blk_dev);
>
> dev_get_uclass_plat might return NULL,  gpt_read_write_mdata() doesn't check
> against NULL and then it ends up calling gpt_get_mdata_disk_part() which
> then calls part_get_info().  I don't think anyone checks for the desc ptr
>
> And I think this is a problem  overall in all the callbacks belowe that
> invoke dev_get_uclass_plat()

dev_get_uclass_plat() returns NULL only when the dev parameter passed
to the function is NULL. And that won't happen since that would mean
that the mdata_dev is NULL, and in such a scenario the driver's probe
function would fail. So these functions would not get called with desc
being NULL.

-sughosh

>
> > +
> > +     ret = gpt_get_mdata_partitions(desc, mdata_parts);
> > +     if (ret < 0) {
> > +             log_debug("Error getting the FWU metadata partitions\n");
> > +             return -ENOENT;
> > +     }
> > +
> > +     /* First write the primary partition */
> > +     ret = gpt_read_write_mdata(desc, mdata, MDATA_WRITE, mdata_parts[0]);
> > +     if (ret < 0) {
> > +             log_debug("Updating primary FWU metadata partition failed\n");
> > +             return ret;
> > +     }
> > +
> > +     /* And now the replica */
> > +     ret = gpt_read_write_mdata(desc, mdata, MDATA_WRITE, mdata_parts[1]);
> > +     if (ret < 0) {
> > +             log_debug("Updating secondary FWU metadata partition failed\n");
> > +             return ret;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int gpt_get_mdata(struct blk_desc *desc, struct fwu_mdata *mdata)
> > +{
> > +     int ret;
> > +     uint mdata_parts[2];
> > +
> > +     ret = gpt_get_mdata_partitions(desc, mdata_parts);
> > +
> > +     if (ret < 0) {
> > +             log_debug("Error getting the FWU metadata partitions\n");
> > +             return -ENOENT;
> > +     }
> > +
> > +     ret = gpt_read_write_mdata(desc, mdata, MDATA_READ, mdata_parts[0]);
> > +     if (ret < 0) {
> > +             log_debug("Failed to read the FWU metadata from the device\n");
> > +             return -EIO;
> > +     }
> > +
> > +     ret = fwu_verify_mdata(mdata, 1);
> > +     if (!ret)
> > +             return 0;
> > +
> > +     /*
> > +      * Verification of the primary FWU metadata copy failed.
> > +      * Try to read the replica.
> > +      */
> > +     memset(mdata, '\0', sizeof(struct fwu_mdata));
> > +     ret = gpt_read_write_mdata(desc, mdata, MDATA_READ, mdata_parts[1]);
> > +     if (ret < 0) {
> > +             log_debug("Failed to read the FWU metadata from the device\n");
> > +             return -EIO;
> > +     }
> > +
> > +     ret = fwu_verify_mdata(mdata, 0);
> > +     if (!ret)
> > +             return 0;
> > +
> > +     /* Both the FWU metadata copies are corrupted. */
> > +     return -EIO;
> > +}
> > +
> > +static int fwu_gpt_get_mdata(struct udevice *dev, struct fwu_mdata *mdata)
> > +{
> > +     struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
> > +
> > +     return gpt_get_mdata(dev_get_uclass_plat(priv->blk_dev), mdata);
> > +}
> > +
> > +static int fwu_gpt_get_mdata_partitions(struct udevice *dev, uint *mdata_parts)
> > +{
> > +     struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
> > +
> > +     return gpt_get_mdata_partitions(dev_get_uclass_plat(priv->blk_dev),
> > +                                     mdata_parts);
> > +}
> > +
> > +static int fwu_gpt_read_mdata_partition(struct udevice *dev,
> > +                                     struct fwu_mdata *mdata, uint part_num)
> > +{
> > +     struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
> > +
> > +     return gpt_read_write_mdata(dev_get_uclass_plat(priv->blk_dev),
> > +                                 mdata, MDATA_READ, part_num);
> > +}
> > +
> > +static int fwu_gpt_write_mdata_partition(struct udevice *dev,
> > +                                     struct fwu_mdata *mdata, uint part_num)
> > +{
> > +     struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
> > +
> > +     return gpt_read_write_mdata(dev_get_uclass_plat(priv->blk_dev),
> > +                                 mdata, MDATA_WRITE, part_num);
> > +}
> > +
> > +static int fwu_get_mdata_device(struct udevice *dev, struct udevice **mdata_dev)
> > +{
> > +     u32 phandle;
> > +     int ret, size;
> > +     struct udevice *parent;
> > +     const fdt32_t *phandle_p = NULL;
> > +
> > +     phandle_p = dev_read_prop(dev, "fwu-mdata-store", &size);
> > +     if (!phandle_p) {
> > +             log_debug("fwu-mdata-store property not found\n");
> > +             return -ENOENT;
> > +     }
> > +
> > +     phandle = fdt32_to_cpu(*phandle_p);
> > +
> > +     ret = device_get_global_by_ofnode(ofnode_get_by_phandle(phandle),
> > +                                       &parent);
> > +     if (ret)
> > +             return ret;
> > +
> > +     return blk_get_from_parent(parent, mdata_dev);
> > +}
> > +
> > +static int fwu_mdata_gpt_blk_probe(struct udevice *dev)
> > +{
> > +     int ret;
> > +     struct udevice *mdata_dev = NULL;
> > +     struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
> > +
> > +     ret = fwu_get_mdata_device(dev, &mdata_dev);
> > +     if (ret)
> > +             return ret;
> > +
> > +     priv->blk_dev = mdata_dev;
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct fwu_mdata_ops fwu_gpt_blk_ops = {
> > +     .get_mdata = fwu_gpt_get_mdata,
> > +     .update_mdata = fwu_gpt_update_mdata,
> > +     .get_mdata_part_num = fwu_gpt_get_mdata_partitions,
> > +     .read_mdata_partition = fwu_gpt_read_mdata_partition,
> > +     .write_mdata_partition = fwu_gpt_write_mdata_partition,
> > +};
> > +
> > +static const struct udevice_id fwu_mdata_ids[] = {
> > +     { .compatible = "u-boot,fwu-mdata-gpt" },
> > +     { }
> > +};
> > +
> > +U_BOOT_DRIVER(fwu_mdata_gpt_blk) = {
> > +     .name           = "fwu-mdata-gpt-blk",
> > +     .id             = UCLASS_FWU_MDATA,
> > +     .of_match       = fwu_mdata_ids,
> > +     .ops            = &fwu_gpt_blk_ops,
> > +     .probe          = fwu_mdata_gpt_blk_probe,
> > +     .priv_auto      = sizeof(struct fwu_mdata_gpt_blk_priv),
> > +};
> > diff --git a/include/fwu.h b/include/fwu.h
> > index a83ea19534..ce99c02618 100644
> > --- a/include/fwu.h
> > +++ b/include/fwu.h
> > @@ -14,6 +14,10 @@
> >  struct fwu_mdata;
> >  struct udevice;
> >
> > +struct fwu_mdata_gpt_blk_priv {
> > +     struct udevice *blk_dev;
> > +};
> > +
> >  /**
> >   * @mdata_check: check the validity of the FWU metadata partitions
> >   * @get_mdata() - Get a FWU metadata copy
> > --
> > 2.34.1
> >
>
> Regards
> /Ilias


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