diff options
Diffstat (limited to 'fs/devfs-core.c')
| -rw-r--r-- | fs/devfs-core.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/fs/devfs-core.c b/fs/devfs-core.c index 30ad0e0508..3715e543e6 100644 --- a/fs/devfs-core.c +++ b/fs/devfs-core.c @@ -301,6 +301,37 @@ int devfs_remove(struct cdev *cdev) return 0; } +static bool region_overlap(loff_t starta, loff_t lena, + loff_t startb, loff_t lenb) +{ + if (starta + lena <= startb) + return 0; + if (startb + lenb <= starta) + return 0; + return 1; +} + +static int check_overlap(struct cdev *cdev, const char *name, loff_t offset, loff_t size) +{ + struct cdev *cpart; + + list_for_each_entry(cpart, &cdev->partitions, partition_entry) { + if (region_overlap(cpart->offset, cpart->size, + offset, size)) + goto conflict; + } + + return 0; + +conflict: + pr_err("New partition %s (0x%08llx-0x%08llx) on %s " + "overlaps with partition %s (0x%08llx-0x%08llx), not creating it\n", + name, offset, offset + size - 1, cpart->name, + cpart->name, cpart->offset, cpart->offset + cpart->size - 1); + + return -EINVAL; +} + static struct cdev *__devfs_add_partition(struct cdev *cdev, const struct devfs_partition *partinfo, loff_t *end) { @@ -336,6 +367,9 @@ static struct cdev *__devfs_add_partition(struct cdev *cdev, return ERR_PTR(-EINVAL); } + if (check_overlap(cdev, partinfo->name, offset, size)) + return ERR_PTR(-EINVAL); + if (IS_ENABLED(CONFIG_MTD) && cdev->mtd) { struct mtd_info *mtd; |