[PATCH V4 2/2] mtd: extract TRX parser out of bcm47xxpart into a separated module
Brian Norris
computersforpeace at gmail.com
Thu May 11 11:31:42 PDT 2017
Hi,
On Thu, Mar 30, 2017 at 02:35:27PM +0200, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal at milecki.pl>
>
> This makes TRX parsing code reusable with other platforms and parsers.
>
> Please note this patch doesn't really change anything in the existing
> code, just moves it. There is still some place for improvement (e.g.
> working on non-hacky method of checking rootfs format) but it's not
> really a subject of this change.
>
> Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
> ---
> V2: A totally rebased & refreshed version.
> ---
> drivers/mtd/Kconfig | 4 ++
> drivers/mtd/Makefile | 1 +
> drivers/mtd/bcm47xxpart.c | 97 +------------------------------
> drivers/mtd/parsers/Kconfig | 8 +++
> drivers/mtd/parsers/Makefile | 1 +
> drivers/mtd/parsers/parser_trx.c | 119 +++++++++++++++++++++++++++++++++++++++
> 6 files changed, 136 insertions(+), 94 deletions(-)
> create mode 100644 drivers/mtd/parsers/Kconfig
> create mode 100644 drivers/mtd/parsers/Makefile
> create mode 100644 drivers/mtd/parsers/parser_trx.c
>
> diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
> index e83a279f1217..5a2d71729b9a 100644
> --- a/drivers/mtd/Kconfig
> +++ b/drivers/mtd/Kconfig
> @@ -155,6 +155,10 @@ config MTD_BCM47XX_PARTS
> This provides partitions parser for devices based on BCM47xx
> boards.
>
> +menu "Partition parsers"
> +source "drivers/mtd/parsers/Kconfig"
> +endmenu
Is "parsers" a better name than "partitions"? I proposed moving
everything to "partitions" previously.
> +
> comment "User Modules And Translation Layers"
>
> #
> diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
> index 99bb9a1f6e16..151d60df303a 100644
> --- a/drivers/mtd/Makefile
> +++ b/drivers/mtd/Makefile
> @@ -13,6 +13,7 @@ obj-$(CONFIG_MTD_AFS_PARTS) += afs.o
> obj-$(CONFIG_MTD_AR7_PARTS) += ar7part.o
> obj-$(CONFIG_MTD_BCM63XX_PARTS) += bcm63xxpart.o
> obj-$(CONFIG_MTD_BCM47XX_PARTS) += bcm47xxpart.o
> +obj-y += parsers/
>
> # 'Users' - code which presents functionality to userspace.
> obj-$(CONFIG_MTD_BLKDEVS) += mtd_blkdevs.o
> diff --git a/drivers/mtd/bcm47xxpart.c b/drivers/mtd/bcm47xxpart.c
> index d10fa6c8f074..66ce72fd1426 100644
> --- a/drivers/mtd/bcm47xxpart.c
> +++ b/drivers/mtd/bcm47xxpart.c
> @@ -43,7 +43,6 @@
> #define ML_MAGIC2 0x26594131
> #define TRX_MAGIC 0x30524448
> #define SHSQ_MAGIC 0x71736873 /* shsq (weird ZTE H218N endianness) */
> -#define UBI_EC_MAGIC 0x23494255 /* UBI# */
>
> struct trx_header {
> uint32_t magic;
> @@ -62,89 +61,6 @@ static void bcm47xxpart_add_part(struct mtd_partition *part, const char *name,
> part->mask_flags = mask_flags;
> }
>
> -static const char *bcm47xxpart_trx_data_part_name(struct mtd_info *master,
> - size_t offset)
> -{
> - uint32_t buf;
> - size_t bytes_read;
> - int err;
> -
> - err = mtd_read(master, offset, sizeof(buf), &bytes_read,
> - (uint8_t *)&buf);
> - if (err && !mtd_is_bitflip(err)) {
> - pr_err("mtd_read error while parsing (offset: 0x%X): %d\n",
> - offset, err);
> - goto out_default;
> - }
> -
> - if (buf == UBI_EC_MAGIC)
> - return "ubi";
> -
> -out_default:
> - return "rootfs";
> -}
> -
> -static int bcm47xxpart_parse_trx(struct mtd_info *master,
> - struct mtd_partition *trx,
> - struct mtd_partition *parts,
> - size_t parts_len)
> -{
> - struct trx_header header;
> - size_t bytes_read;
> - int curr_part = 0;
> - int i, err;
> -
> - if (parts_len < 3) {
> - pr_warn("No enough space to add TRX partitions!\n");
> - return -ENOMEM;
> - }
> -
> - err = mtd_read(master, trx->offset, sizeof(header), &bytes_read,
> - (uint8_t *)&header);
> - if (err && !mtd_is_bitflip(err)) {
> - pr_err("mtd_read error while reading TRX header: %d\n", err);
> - return err;
> - }
> -
> - i = 0;
> -
> - /* We have LZMA loader if offset[2] points to sth */
> - if (header.offset[2]) {
> - bcm47xxpart_add_part(&parts[curr_part++], "loader",
> - trx->offset + header.offset[i], 0);
> - i++;
> - }
> -
> - if (header.offset[i]) {
> - bcm47xxpart_add_part(&parts[curr_part++], "linux",
> - trx->offset + header.offset[i], 0);
> - i++;
> - }
> -
> - if (header.offset[i]) {
> - size_t offset = trx->offset + header.offset[i];
> - const char *name = bcm47xxpart_trx_data_part_name(master,
> - offset);
> -
> - bcm47xxpart_add_part(&parts[curr_part++], name, offset, 0);
> - i++;
> - }
> -
> - /*
> - * Assume that every partition ends at the beginning of the one it is
> - * followed by.
> - */
> - for (i = 0; i < curr_part; i++) {
> - u64 next_part_offset = (i < curr_part - 1) ?
> - parts[i + 1].offset :
> - trx->offset + trx->size;
> -
> - parts[i].size = next_part_offset - parts[i].offset;
> - }
> -
> - return curr_part;
> -}
> -
> /**
> * bcm47xxpart_bootpartition - gets index of TRX partition used by bootloader
> *
> @@ -362,17 +278,10 @@ static int bcm47xxpart_parse(struct mtd_info *master,
> for (i = 0; i < trx_num; i++) {
> struct mtd_partition *trx = &parts[trx_parts[i]];
>
> - if (i == bcm47xxpart_bootpartition()) {
> - int num_parts;
> -
> - num_parts = bcm47xxpart_parse_trx(master, trx,
> - parts + curr_part,
> - BCM47XXPART_MAX_PARTS - curr_part);
> - if (num_parts > 0)
> - curr_part += num_parts;
> - } else {
> + if (i == bcm47xxpart_bootpartition())
> + trx->format = "trx";
> + else
> trx->name = "failsafe";
> - }
> }
>
> *pparts = parts;
> diff --git a/drivers/mtd/parsers/Kconfig b/drivers/mtd/parsers/Kconfig
> new file mode 100644
> index 000000000000..ebb697a52698
> --- /dev/null
> +++ b/drivers/mtd/parsers/Kconfig
> @@ -0,0 +1,8 @@
> +config MTD_PARSER_TRX
> + tristate "Parser for TRX format partitions"
> + depends on MTD && (BCM47XX || ARCH_BCM_5301X)
> + help
> + TRX is a firmware format used by Broadcom on their devices. It
> + may contain up to 3/4 partitions (depending on the version).
> + This driver will parse TRX header and report at least two partitions:
> + kernel and rootfs.
> diff --git a/drivers/mtd/parsers/Makefile b/drivers/mtd/parsers/Makefile
> new file mode 100644
> index 000000000000..4d9024e0be3b
> --- /dev/null
> +++ b/drivers/mtd/parsers/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_MTD_PARSER_TRX) += parser_trx.o
> diff --git a/drivers/mtd/parsers/parser_trx.c b/drivers/mtd/parsers/parser_trx.c
> new file mode 100644
> index 000000000000..f35e28148808
> --- /dev/null
> +++ b/drivers/mtd/parsers/parser_trx.c
> @@ -0,0 +1,119 @@
> +/*
> + * Parser for TRX format partitions
> + *
> + * Copyright (C) 2012 - 2017 Rafał Miłecki <rafal at milecki.pl>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/partitions.h>
> +
> +#define TRX_PARSER_MAX_PARTS 4
> +
> +/* Magics */
> +#define UBI_EC_MAGIC 0x23494255 /* UBI# */
> +
> +struct trx_header {
> + uint32_t magic;
> + uint32_t length;
> + uint32_t crc32;
> + uint16_t flags;
> + uint16_t version;
> + uint32_t offset[3];
> +} __packed;
> +
> +static const char *parser_trx_data_part_name(struct mtd_info *master,
> + size_t offset)
> +{
> + uint32_t buf;
> + size_t bytes_read;
> + int err;
> +
> + err = mtd_read(master, offset, sizeof(buf), &bytes_read,
> + (uint8_t *)&buf);
> + if (err && !mtd_is_bitflip(err)) {
> + pr_err("mtd_read error while parsing (offset: 0x%X): %d\n",
> + offset, err);
> + goto out_default;
> + }
> +
> + if (buf == UBI_EC_MAGIC)
> + return "ubi";
> +
> +out_default:
> + return "rootfs";
> +}
> +
> +static int parser_trx_parse(struct mtd_info *mtd,
> + const struct mtd_partition **pparts,
> + struct mtd_part_parser_data *data)
So, this function doesn't do any validation that this is *actually* a
TRX partition? I think it needs to do *some* level of validation if it's
going to be an independent parser driver like this. See my comments on
your other patch.
(I also can't say that I understand the parent bcm47xxpart format/parser
very well; it really looks like a collection of hacks, so maybe
validation is impossible...)
> +{
> + struct mtd_partition *parts;
> + struct mtd_partition *part;
> + struct trx_header trx;
> + size_t bytes_read;
> + uint8_t curr_part = 0, i = 0;
> + int err;
> +
> + parts = kzalloc(sizeof(struct mtd_partition) * TRX_PARSER_MAX_PARTS,
> + GFP_KERNEL);
> + if (!parts)
> + return -ENOMEM;
> +
> + err = mtd_read(mtd, 0, sizeof(trx), &bytes_read, (uint8_t *)&trx);
> + if (err) {
> + pr_err("MTD reading error: %d\n", err);
> + return err;
You're leaking 'parts' here. (smatch noticed this.)
> + }
> +
> + /* We have LZMA loader if offset[2] points to sth */
Not that this is new, but I have no idea what "sth" is.
> + if (trx.offset[2]) {
> + part = &parts[curr_part++];
> + part->name = "loader";
> + part->offset = trx.offset[i];
> + i++;
> + }
> +
> + if (trx.offset[i]) {
> + part = &parts[curr_part++];
> + part->name = "linux";
> + part->offset = trx.offset[i];
> + i++;
> + }
> +
> + if (trx.offset[i]) {
> + part = &parts[curr_part++];
> + part->name = parser_trx_data_part_name(mtd, trx.offset[i]);
> + part->offset = trx.offset[i];
> + i++;
> + }
> +
> + /*
> + * Assume that every partition ends at the beginning of the one it is
> + * followed by.
> + */
> + for (i = 0; i < curr_part; i++) {
> + u64 next_part_offset = (i < curr_part - 1) ?
> + parts[i + 1].offset : mtd->size;
> +
> + parts[i].size = next_part_offset - parts[i].offset;
> + }
> +
> + *pparts = parts;
> + return i;
> +};
> +
> +static struct mtd_part_parser mtd_parser_trx = {
> + .parse_fn = parser_trx_parse,
> + .name = "trx",
> +};
> +module_mtd_part_parser(mtd_parser_trx);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Parser for TRX format partitions");
Brian
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