On Sun, 22 Feb 2026 12:37:39 +0530 Padmarao Begari <[email protected]> wrote:
> Add a 'part dupcheck' subcommand that scans all block devices for > duplicate partition UUIDs. This helps detect situations where the > same disk image has been flashed to multiple boot devices (e.g., > USB stick and UFS), which can lead to unpredictable boot behavior > when using PARTUUID-based root filesystem specifications. It > iterates all block devices using blk_foreach_probe() and checks > partition UUIDs via part_get_info(). > > When duplicates are found, a warning is printed for each occurrence: > > Warning: duplicate PARTUUID 20c5fba5-0171-457f-b9cd-f5129cd07228 > first seen on usb_mass_storage.lun0:3 > also on ufs_scsi.id0lun0:3 > > Add Kconfig option `CMD_PART_DUPCHECK` and update the `part` help > text accordingly. It would be nice to also check the partition label, which is also used sometimes in the boot process. > Signed-off-by: John Toomey <[email protected]> > Signed-off-by: Padmarao Begari <[email protected]> > --- > Changes in v2: > -Add own kconfig symbol for dupcheck subcommand and guard it. > --- > cmd/Kconfig | 7 ++++ > cmd/part.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++- > 2 files changed, 110 insertions(+), 1 deletion(-) > > diff --git a/cmd/Kconfig b/cmd/Kconfig > index 322ebe600c5..73d27fe2e28 100644 > --- a/cmd/Kconfig > +++ b/cmd/Kconfig > @@ -1663,6 +1663,13 @@ config CMD_PART > Read and display information about the partition table on > various media. > > +config CMD_PART_DUPCHECK > + bool "part dupcheck" > + depends on CMD_PART > + help > + Enable the 'part dupcheck' sub-command under 'part' to scan the > + current partition table and report any duplicate partition UUIDs. > + > config CMD_PCI > bool "pci - Access PCI devices" > help > diff --git a/cmd/part.c b/cmd/part.c > index 975a0a08a99..c4df5053936 100644 > --- a/cmd/part.c > +++ b/cmd/part.c > @@ -15,9 +15,12 @@ > * Pavel Bartusek <[email protected]> > */ > > +#include <blk.h> > #include <config.h> > #include <command.h> > +#include <dm.h> > #include <env.h> > +#include <malloc.h> > #include <part.h> > #include <stdio.h> > #include <vsprintf.h> > @@ -246,6 +249,97 @@ static int do_part_type(int argc, char *const argv[]) > } > #endif > > +#if CONFIG_IS_ENABLED(CMD_PART_DUPCHECK) > +struct part_seen { > + char uuid[UUID_STR_LEN + 1]; > + struct udevice *dev; > + int part; > +}; > + > +static int do_part_dupcheck(int argc, char *const argv[]) > +{ > + struct part_seen *seen; > + int count = 0; > + int duplicates = 0; > + int max_entries; > + int dev_count; > + struct udevice *dev; > + > + if (argc) > + return CMD_RET_USAGE; > + > + dev_count = blk_count_devices(BLKF_BOTH); > + if (!dev_count) { > + printf("No block devices found\n"); > + return CMD_RET_SUCCESS; > + } > + > + max_entries = dev_count * MAX_SEARCH_PARTITIONS; > + seen = calloc(max_entries, sizeof(*seen)); > + if (!seen) { > + printf("Unable to allocate dupcheck table (%d entries)\n", > + max_entries); > + return CMD_RET_FAILURE; > + } > + > + blk_foreach_probe(BLKF_BOTH, dev) { > + struct blk_desc *desc = dev_get_uclass_plat(dev); > + > + for (int part = 1; part <= MAX_SEARCH_PARTITIONS; part++) { > + struct disk_partition info; > + int first_match = -1; > + > + if (part_get_info(desc, part, &info)) > + continue; > + if (!info.uuid[0]) > + continue; > + > + for (int i = 0; i < count; i++) { > + if (strcmp(seen[i].uuid, info.uuid)) > + continue; > + if (first_match == -1) { > + printf("Warning: duplicate PARTUUID > %s\n", > + info.uuid); > + printf(" first seen on %s:%d\n", > + seen[i].dev->name, > + seen[i].part); > + printf(" also on %s:%d\n", > + dev->name, part); > + duplicates++; > + first_match = i; > + } else { > + printf(" also on %s:%d\n", > + seen[i].dev->name, > + seen[i].part); > + } > + } If you have 3 partitions (A,B,C) with the same uuid you will report the information twice: When processing B: "Warning ... first seen on A:x / also on B:x" When processing C: "Warning ... first seen on A:x / also on C:x / also on B:x" Also this means the duplicates variable will be incremented to 2 which is confusing for the print in my last comment: > + > + if (count >= max_entries) { > + printf("Error: dupcheck capacity %d > entries\n", > + max_entries); > + printf(" exceeded\n"); Weird print here: Maybe something like that: "Error: dupcheck capacity exceeded (%d entries)" > + free(seen); > + return CMD_RET_FAILURE; > + } > + > + strlcpy(seen[count].uuid, info.uuid, > + sizeof(seen[0].uuid)); > + seen[count].dev = dev; > + seen[count].part = part; > + count++; > + } > + } > + > + if (duplicates) > + printf("Found %d duplicate(s) among %d partitions checked\n", > + duplicates, count); So with 3 partitions using the same uuid, it will report "Found 2 duplicate(s) ..." Which can be confusing. We should report either "1 UUID duplication" or "3 copies of the same UUID" > + > + free(seen); > + > + return duplicates ? CMD_RET_FAILURE : CMD_RET_SUCCESS; > +} > +#endif > + > static int do_part_types(int argc, char * const argv[]) > { > struct part_driver *drv = ll_entry_start(struct part_driver, > @@ -291,6 +385,10 @@ static int do_part(struct cmd_tbl *cmdtp, int flag, int > argc, #ifdef CONFIG_PARTITION_TYPE_GUID > else if (!strcmp(argv[1], "type")) > return do_part_type(argc - 2, argv + 2); > +#endif > +#if CONFIG_IS_ENABLED(CMD_PART_DUPCHECK) > + else if (!strcmp(argv[1], "dupcheck")) > + return do_part_dupcheck(argc - 2, argv + 2); > #endif > return CMD_RET_USAGE; > } > @@ -328,5 +426,9 @@ U_BOOT_CMD( > "part set <interface> <dev> type\n" > " - set partition type for a device\n" > "part types\n" > - " - list supported partition table types" > + " - list supported partition table types\n" > +#if CONFIG_IS_ENABLED(CMD_PART_DUPCHECK) > + "part dupcheck\n" > + " - scan all block devices for duplicate partition UUIDs" > +#endif > ); -- Köry Maincent, Bootlin Embedded Linux and kernel engineering https://bootlin.com
