[PATCH 2/4] fwu: move meta-data management in core
Etienne Carriere
etienne.carriere at linaro.org
Mon Nov 7 18:23:59 CET 2022
Hello Jassi,
On Fri, 4 Nov 2022 at 03:43, <jassisinghbrar at gmail.com> wrote:
>
> From: Jassi Brar <jaswinder.singh at linaro.org>
>
> Instead of each i/f having to implement their own meta-data verification
> and storage, move the logic in common code. This simplifies the i/f code
> much simpler and compact.
>
> Signed-off-by: Jassi Brar <jaswinder.singh at linaro.org>
> ---
> drivers/fwu-mdata/fwu-mdata-uclass.c | 34 +++++++
> include/fwu.h | 41 ++++++++
> lib/fwu_updates/fwu.c | 136 ++++++++++++++++++++++++++-
> 3 files changed, 207 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/fwu-mdata/fwu-mdata-uclass.c b/drivers/fwu-mdata/fwu-mdata-uclass.c
> index b477e9603f..ded9902971 100644
> --- a/drivers/fwu-mdata/fwu-mdata-uclass.c
> +++ b/drivers/fwu-mdata/fwu-mdata-uclass.c
> @@ -16,6 +16,40 @@
> #include <linux/types.h>
> #include <u-boot/crc.h>
>
> +/**
> + * fwu_read_mdata() - Wrapper around fwu_mdata_ops.read_mdata()
> + *
> + * Return: 0 if OK, -ve on error
> + */
> +int fwu_read_mdata(struct udevice *dev, struct fwu_mdata *mdata, bool primary);
> +{
> + const struct fwu_mdata_ops *ops = device_get_ops(dev);
> +
> + if (!ops->read_mdata) {
> + log_debug("read_mdata() method not defined\n");
> + return -ENOSYS;
> + }
> +
> + return ops->read_mdata(dev, mdata, primary);
> +}
> +
> +/**
> + * fwu_write_mdata() - Wrapper around fwu_mdata_ops.write_mdata()
> + *
> + * Return: 0 if OK, -ve on error
> + */
> +int fwu_write_mdata(struct udevice *dev, struct fwu_mdata *mdata, bool primary);
> +{
> + const struct fwu_mdata_ops *ops = device_get_ops(dev);
> +
> + if (!ops->write_mdata) {
> + log_debug("write_mdata() method not defined\n");
> + return -ENOSYS;
> + }
> +
> + return ops->write_mdata(dev, mdata, primary);
> +}
> +
> /**
> * fwu_get_mdata_part_num() - Get the FWU metadata partition numbers
> * @dev: FWU metadata device
> diff --git a/include/fwu.h b/include/fwu.h
> index 0919ced812..1a700c9e6a 100644
> --- a/include/fwu.h
> +++ b/include/fwu.h
> @@ -24,6 +24,26 @@ struct fwu_mdata_gpt_blk_priv {
> * @update_mdata() - Update the FWU metadata copy
> */
> struct fwu_mdata_ops {
> + /**
> + * read_mdata() - Populate the asked FWU metadata copy
> + * @dev: FWU metadata device
> + * @mdata: Copy of the FWU metadata
> + * @primary: If primary or secondary copy of meta-data is to be read
> + *
> + * Return: 0 if OK, -ve on error
> + */
> + int (*read_mdata)(struct udevice *dev, struct fwu_mdata *mdata, bool primary);
> +
> + /**
> + * write_mdata() - Write the given FWU metadata copy
> + * @dev: FWU metadata device
> + * @mdata: Copy of the FWU metadata
> + * @primary: If primary or secondary copy of meta-data is to be written
> + *
> + * Return: 0 if OK, -ve on error
> + */
> + int (*write_mdata)(struct udevice *dev, struct fwu_mdata *mdata, bool primary);
> +
> /**
> * check_mdata() - Check if the FWU metadata is valid
> * @dev: FWU device
> @@ -126,6 +146,27 @@ struct fwu_mdata_ops {
> EFI_GUID(0x0c996046, 0xbcc0, 0x4d04, 0x85, 0xec, \
> 0xe1, 0xfc, 0xed, 0xf1, 0xc6, 0xf8)
>
> +/**
> + * fwu_read_mdata() - Wrapper around fwu_mdata_ops.read_mdata()
> + */
> +int fwu_read_mdata(struct udevice *dev, struct fwu_mdata *mdata, bool primary);
> +
> +/**
> + * fwu_write_mdata() - Wrapper around fwu_mdata_ops.write_mdata()
> + */
> +int fwu_write_mdata(struct udevice *dev, struct fwu_mdata *mdata, bool primary);
> +
> +/**
> + * fwu_get_verified_mdata() - Read, verify and return the FWU metadata
> + *
> + * Read both the metadata copies from the storage media, verify their checksum,
> + * and ascertain that both copies match. If one of the copies has gone bad,
> + * restore it from the good copy.
> + *
> + * Return: 0 if OK, -ve on error
> +*/
> +int fwu_get_verified_mdata(struct fwu_mdata *mdata);
Nitpicking: would you be ok to rename this function to fwu_get_mdata().
When getting fwu mdata, we obviously expect to get reliable data.
> +
> /**
> * fwu_check_mdata_validity() - Check for validity of the FWU metadata copies
> *
> diff --git a/lib/fwu_updates/fwu.c b/lib/fwu_updates/fwu.c
> index 5313d07302..3d51b91ed5 100644
> --- a/lib/fwu_updates/fwu.c
> +++ b/lib/fwu_updates/fwu.c
> @@ -15,13 +15,13 @@
> #include <linux/errno.h>
> #include <linux/types.h>
>
> +#include <u-boot/crc.h>
> +
> +static struct fwu_mdata g_mdata = { 0 };
Can remove "= { 0 };"
> +static struct udevice *g_dev;
> static u8 in_trial;
> static u8 boottime_check;
>
> -#include <linux/errno.h>
> -#include <linux/types.h>
> -#include <u-boot/crc.h>
> -
> enum {
> IMAGE_ACCEPT_SET = 1,
> IMAGE_ACCEPT_CLEAR,
> @@ -161,6 +161,134 @@ static int fwu_get_image_type_id(u8 *image_index, efi_guid_t *image_type_id)
> return -ENOENT;
> }
>
> +/**
> + * fwu_sync_mdata() - Update given meta-data partition(s) with the copy provided
> + * @mdata: FWU metadata structure
> + * @part: Bitmask of FWU metadata partitions to be written to
> + *
> + * Return: 0 if OK, -ve on error
> + */
> +static int fwu_sync_mdata(struct fwu_mdata *mdata, int part)
> +{
> + void *buf = &mdata->version;
> + int err = 0;
> +
> + /*
> + * Calculate the crc32 for the updated FWU metadata
> + * and put the updated value in the FWU metadata crc32
> + * field
> + */
> + mdata->crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32));
> +
> + if (part & PRIMARY_PART)
> + err = fwu_write_mdata(g_dev, mdata, true);
> +
> + if (err) {
> + log_err("Unable to write primary mdata\n");
> + return err;
> + }
> +
> + if (part & SECONDARY_PART)
> + err = fwu_write_mdata(g_dev, mdata, false);
> +
> + if (err) {
> + log_err("Unable to write secondary mdata\n");
> + return err;
> + }
> +
> + /* update the cached copy of meta-data */
> + memcpy(&g_mdata, mdata, sizeof(struct fwu_mdata));
> +
> + return 0;
> +}
> +
> +static inline int mdata_crc_check(struct fwu_mdata *mdata)
> +{
> + u32 calc_crc32 = crc32(0, &mdata->version, sizeof(*mdata) - sizeof(u32));
Add an empty line below the above definition.
> + return calc_crc32 == mdata->crc32 ? 0 : -EINVAL;
> +}
> +
> +/**
> + * fwu_get_verified_mdata() - Read, verify and return the FWU metadata
> + *
> + * Read both the metadata copies from the storage media, verify their checksum,
> + * and ascertain that both copies match. If one of the copies has gone bad,
> + * restore it from the good copy.
> + *
> + * Return: 0 if OK, -ve on error
> + */
> +int fwu_get_verified_mdata(struct fwu_mdata *mdata)
> +{
> + int err;
> + bool pri_ok, sec_ok;
> + struct fwu_mdata s, *p_mdata, *s_mdata;
> +
> + p_mdata = &g_mdata;
> + s_mdata = &s;
> +
> + /* if mdata already read and ready */
> + err = mdata_crc_check(p_mdata, true);
2nd argument to be removed. Ditto for the other occurrences of
mdata_crc_check() calls.
Note here I would pass straight &g_mdata as argument rather than
p_mdata indirection, for clarity.
> + if (!err) {
> + if (mdata)
> + memcpy(mdata, p_mdata, sizeof(struct fwu_mdata));
> + return 0;
> + }
> + /* else read, verify and, if needed, fix mdata */
> +
> + pri_ok = false;
> + err = fwu_read_mdata(g_dev, p_mdata, true);
> + if (!err) {
> + err = mdata_crc_check(p_mdata, true);
> + if (!err)
> + pri_ok = true;
> + else
> + log_debug("primary mdata: crc32 failed\n");
> + }
> +
> + sec_ok = false;
> + err = fwu_read_mdata(g_dev, s_mdata, false);
> + if (!err) {
> + err = mdata_crc_check(s_mdata, false);
> + if (!err)
> + sec_ok = true;
> + else
> + log_debug("secondary mdata: crc32 failed\n");
> + }
> +
> + if (pri_ok && sec_ok) {
> + /*
> + * Before returning, check that both the
> + * FWU metadata copies are the same. If not,
> + * populate the secondary partition from the
> + * primary partition copy.
> + */
> + if (memcmp(p_mdata, s_mdata, sizeof(struct fwu_mdata))) {
> + log_info("Both FWU metadata copies are valid but do not match.");
> + log_info(" Restoring the secondary partition from the primary\n");
> + sec_ok = false;
> + }
> + }
> +
> + if (!pri_ok) {
> + memcpy(p_mdata, s_mdata, sizeof(struct fwu_mdata));
> + err = fwu_sync_mdata(p_mdata, PRIMARY_PART);
Should test return value.
> + }
> +
> + if (!sec_ok) {
> + memcpy(s_mdata, p_mdata, sizeof(struct fwu_mdata));
> + err = fwu_sync_mdata(s_mdata, SECONDARY_PART);
Ditto
> + }
> +
> + /* make sure atleast one copy is good */
s/atleast/at least/
> + err = mdata_crc_check(p_mdata, true);
This is not needed, it's been already verified unless we want to catch
the case !pri_ok && !sec_ok. I think this case should be explicitly
handled above with a nice console trace message/
if (!pri_ok && !sec_ok) {
log_err("No reliable fwu mdata found\n");
return -EINVAL;
}
> + if (err)
> + log_debug("mdata saving... crc32 failed\n");
> + else if (mdata)
> + memcpy(mdata, p_mdata, sizeof(struct fwu_mdata));
> +
> + return err;
> +}
> +
> /**
> * fwu_verify_mdata() - Verify the FWU metadata
> * @mdata: FWU metadata structure
> --
> 2.25.1
>
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