Hi,
On 05/05/2018 10:23 PM, Wang YanQing wrote:
> I meet strange filesystem corruption issue recently, the reason
> is there are overlaps partitions in cmdline partition argument.
>
> This patch add verifier for cmdline partition, then if there are
> overlaps partitions, cmdline_partition will log a warning.
>
> Signed-off-by: Wang YanQing
> ---
> Changes
> v2-v3:
> 1:Fix log one pair of overlaps partitions twice in cmdline_parts_verifier.
> 2:Fix out of bound access in cmdline_parts_verifier.
>
> v1-v2:
> 1:Don't treat overlaps partition as a error, but log a warning.
>
> block/partitions/cmdline.c | 66
> ++
> 1 file changed, 66 insertions(+)
>
> diff --git a/block/partitions/cmdline.c b/block/partitions/cmdline.c
> index e333583..fefcc72 100644
> --- a/block/partitions/cmdline.c
> +++ b/block/partitions/cmdline.c
> @@ -58,6 +58,71 @@ 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("\n");
> + pr_warn("Overlaps partitions being used in command line partition.\n");
"Overlapping partitions are used in the command line
partitions.\n"
> + pr_warn("Don't use filesystems on overlaps partitions:\n");
"Don't use filesystems on overlapping partitions:\n"
> +}
> +
> +static inline void overlaps_warns_tailer(void)
> +{
> + pr_warn("\n");
> +}
> +
> +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].\n",
> + 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);
> + }
> + }
> + }
> +
> + if (!header)
> + overlaps_warns_tailer();
> +}
> +
> /*
> * Purpose: allocate cmdline partitions.
> * Returns:
> @@ -93,6 +158,7 @@ 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, (void *)state);
>
> strlcat(state->pp_buf, "\n", PAGE_SIZE);
>
>
--
~Randy
