1 files changed, 57 insertions, 0 deletions
diff --git a/block/partitions/cmdline.c b/block/partitions/cmdline.c
index e333583ab38c..60fb3df9897c 100644
--- a/block/partitions/cmdline.c
+++ b/block/partitions/cmdline.c
@@ -58,6 +58,62 @@ static int __init cmdline_parts_setup(char *s)
 }
 __setup("blkdevparts=", cmdline_parts_setup);
 
+static bool has_overlaps(sector_t from, sector_t size,
+			 sector_t from2, sector_t size2)
+{
+	sector_t end = from + size;
+	sector_t end2 = from2 + size2;
+
+	if (from >= from2 && from < end2)
+		return true;
+
+	if (end > from2 && end <= end2)
+		return true;
+
+	if (from2 >= from && from2 < end)
+		return true;
+
+	if (end2 > from && end2 <= end)
+		return true;
+
+	return false;
+}
+
+static inline void overlaps_warns_header(void)
+{
+	pr_warn("Overlapping partitions are used in command line partitions.");
+	pr_warn("Don't use filesystems on overlapping partitions:");
+}
+
+static void cmdline_parts_verifier(int slot, struct parsed_partitions *state)
+{
+	int i;
+	bool header = true;
+
+	for (; slot < state->limit && state->parts[slot].has_info; slot++) {
+		for (i = slot+1; i < state->limit && state->parts[i].has_info;
+		     i++) {
+			if (has_overlaps(state->parts[slot].from,
+					 state->parts[slot].size,
+					 state->parts[i].from,
+					 state->parts[i].size)) {
+				if (header) {
+					header = false;
+					overlaps_warns_header();
+				}
+				pr_warn("%s[%llu,%llu] overlaps with "
+					"%s[%llu,%llu].",
+					state->parts[slot].info.volname,
+					(u64)state->parts[slot].from << 9,
+					(u64)state->parts[slot].size << 9,
+					state->parts[i].info.volname,
+					(u64)state->parts[i].from << 9,
+					(u64)state->parts[i].size << 9);
+			}
+		}
+	}
+}
+
 /*
  * Purpose: allocate cmdline partitions.
  * Returns:
@@ -93,6 +149,7 @@ int cmdline_partition(struct parsed_partitions *state)
 	disk_size = get_capacity(state->bdev->bd_disk) << 9;
 
 	cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state);
+	cmdline_parts_verifier(1, state);
 
 	strlcat(state->pp_buf, "\n", PAGE_SIZE);