From de80424f706682e8bba27c60bcd2a9c1b4a5e875 Mon Sep 17 00:00:00 2001 From: Bruno Pena Date: Sat, 9 Nov 2019 15:23:58 +0100 Subject: [PATCH] kernel: mtd: Make subpartitions inherit parent's access mode MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Currently it's not possible to effectively mark a "firmware" partition as read-only. The sub-partitions "kernel", "rootfs" and "rootfs_data" are always created as read-write (ignoring the parent access mode). This patch enforces the access mode of sub-partitions to match the parent partition, which is useful for recovery images that are meant to be fully read-only to avoid accidental damage from end-user. An example of such implementation (read-only firmware image) is the recovery image used on the Zsun-SD100 [1]. Please note the related patch for fstools [2] to enable this read-only concept. [1] https://github.com/brunompena/zsun-resources [2] http://lists.infradead.org/pipermail/openwrt-devel/2020-January/021043.html Signed-off-by: Bruno Pena [removed already obsolete 4.9 kernel patch] Signed-off-by: Petr Å tetiar --- ...inherit-parent-partition-access-mode.patch | 60 +++++++++++++++++++ ...inherit-parent-partition-access-mode.patch | 60 +++++++++++++++++++ 2 files changed, 120 insertions(+) create mode 100644 target/linux/generic/hack-4.14/401-inherit-parent-partition-access-mode.patch create mode 100644 target/linux/generic/hack-4.19/401-inherit-parent-partition-access-mode.patch diff --git a/target/linux/generic/hack-4.14/401-inherit-parent-partition-access-mode.patch b/target/linux/generic/hack-4.14/401-inherit-parent-partition-access-mode.patch new file mode 100644 index 0000000000..dbbe68ff4a --- /dev/null +++ b/target/linux/generic/hack-4.14/401-inherit-parent-partition-access-mode.patch @@ -0,0 +1,60 @@ +--- a/drivers/mtd/mtdchar.c ++++ b/drivers/mtd/mtdchar.c +@@ -595,7 +595,10 @@ + /* Sanitize user input */ + p.devname[BLKPG_DEVNAMELTH - 1] = '\0'; + +- return mtd_add_partition(mtd, p.devname, p.start, p.length); ++ /* No mtd flags masking required */ ++ uint32_t mask_flags = 0; ++ ++ return mtd_add_partition(mtd, p.devname, p.start, p.length, mask_flags); + + case BLKPG_DEL_PARTITION: + +--- a/drivers/mtd/mtdpart.c ++++ b/drivers/mtd/mtdpart.c +@@ -726,7 +726,7 @@ + } + + int mtd_add_partition(struct mtd_info *parent, const char *name, +- long long offset, long long length) ++ long long offset, long long length, uint32_t mask_flags) + { + struct mtd_partition part; + struct mtd_part *new; +@@ -747,6 +747,7 @@ + part.name = name; + part.size = length; + part.offset = offset; ++ part.mask_flags = mask_flags; + + new = allocate_partition(parent, &part, -1, offset); + if (IS_ERR(new)) +@@ -855,10 +856,14 @@ + /* adjust partition offsets */ + parts[i].offset += slave->offset; + ++ /* adjust partition mask */ ++ parts[i].mask_flags = !(slave->mtd.flags & MTD_WRITEABLE) ? MTD_WRITEABLE : 0; ++ + mtd_add_partition(slave->parent, + parts[i].name, + parts[i].offset, +- parts[i].size); ++ parts[i].size, ++ parts[i].mask_flags); + } + + kfree(parts); +--- a/include/linux/mtd/partitions.h ++++ b/include/linux/mtd/partitions.h +@@ -114,7 +114,7 @@ + + int mtd_is_partition(const struct mtd_info *mtd); + int mtd_add_partition(struct mtd_info *master, const char *name, +- long long offset, long long length); ++ long long offset, long long length, uint32_t mask_flags); + int mtd_del_partition(struct mtd_info *master, int partno); + struct mtd_info *mtdpart_get_master(const struct mtd_info *mtd); + uint64_t mtdpart_get_offset(const struct mtd_info *mtd); diff --git a/target/linux/generic/hack-4.19/401-inherit-parent-partition-access-mode.patch b/target/linux/generic/hack-4.19/401-inherit-parent-partition-access-mode.patch new file mode 100644 index 0000000000..61dd0369a6 --- /dev/null +++ b/target/linux/generic/hack-4.19/401-inherit-parent-partition-access-mode.patch @@ -0,0 +1,60 @@ +--- a/drivers/mtd/mtdchar.c ++++ b/drivers/mtd/mtdchar.c +@@ -583,7 +583,10 @@ + /* Sanitize user input */ + p.devname[BLKPG_DEVNAMELTH - 1] = '\0'; + +- return mtd_add_partition(mtd, p.devname, p.start, p.length); ++ /* No mtd flags masking required */ ++ uint32_t mask_flags = 0; ++ ++ return mtd_add_partition(mtd, p.devname, p.start, p.length, mask_flags); + + case BLKPG_DEL_PARTITION: + +--- a/drivers/mtd/mtdpart.c ++++ b/drivers/mtd/mtdpart.c +@@ -679,7 +679,7 @@ + } + + int mtd_add_partition(struct mtd_info *parent, const char *name, +- long long offset, long long length) ++ long long offset, long long length, uint32_t mask_flags) + { + struct mtd_partition part; + struct mtd_part *new; +@@ -700,6 +700,7 @@ + part.name = name; + part.size = length; + part.offset = offset; ++ part.mask_flags = mask_flags; + + new = allocate_partition(parent, &part, -1, offset); + if (IS_ERR(new)) +@@ -808,10 +809,14 @@ + /* adjust partition offsets */ + parts[i].offset += slave->offset; + ++ /* adjust partition mask */ ++ parts[i].mask_flags = !(slave->mtd.flags & MTD_WRITEABLE) ? MTD_WRITEABLE : 0; ++ + mtd_add_partition(slave->parent, + parts[i].name, + parts[i].offset, +- parts[i].size); ++ parts[i].size, ++ parts[i].mask_flags); + } + + kfree(parts); +--- a/include/linux/mtd/partitions.h ++++ b/include/linux/mtd/partitions.h +@@ -114,7 +114,7 @@ + + int mtd_is_partition(const struct mtd_info *mtd); + int mtd_add_partition(struct mtd_info *master, const char *name, +- long long offset, long long length); ++ long long offset, long long length, uint32_t mask_flags); + int mtd_del_partition(struct mtd_info *master, int partno); + struct mtd_info *mtdpart_get_master(const struct mtd_info *mtd); + uint64_t mtdpart_get_offset(const struct mtd_info *mtd); -- 2.30.2