Am Freitag, den 24.07.2009, 18:58 +0200 schrieb Felix Zielcke:
>
>
> With this [0] partition table grub-probe currently loops forever:
>
> kern/disk.c:389: Reading `hd1'...
> partmap/pc.c:142: partition 0: flag 0x0, type 0x5, start 0x0, len
> 0x11177330
> partmap/pc.c:142: partition 1: flag 0x0, type 0x0, start 0x0, len 0x0
> partmap/pc.c:142: partition 2: flag 0x0, type 0x0, start 0x0, len 0x0
> partmap/pc.c:142: partition 3: flag 0x0, type 0x0, start 0x0, len 0x0
> kern/disk.c:389: Reading `hd1'...
> partmap/pc.c:142: partition 0: flag 0x0, type 0x5, start 0x0, len
> 0x11177330
> partmap/pc.c:142: partition 1: flag 0x0, type 0x0, start 0x0, len 0x0
> partmap/pc.c:142: partition 2: flag 0x0, type 0x0, start 0x0, len 0x0
> partmap/pc.c:142: partition 3: flag 0x0, type 0x0, start 0x0, len 0x0
> [...]
>
> This patch fixes it, but probable there's a better fix.
>
>
> [0]
> http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=5;filename=corrupt-table.dat;att=1;bug=519223
>
Here's a new one after comments from Vladimir on IRC
loop count is increased to 100'000 and partitions with a starting sector
of 0 are ignored.
--
Felix Zielcke
2009-07-24 Felix Zielcke <fziel...@z-51.de>
* partmap/pc.c (pc_partition_map_iterate): Don't loop forever
in case the partition table is corrupted. Also ignore partitions
with a starting sector of 0.
diff --git a/partmap/pc.c b/partmap/pc.c
index 6f68ecf..ab58b3d 100644
--- a/partmap/pc.c
+++ b/partmap/pc.c
@@ -97,6 +97,7 @@ pc_partition_map_iterate (grub_disk_t disk,
struct grub_pc_partition_mbr mbr;
struct grub_pc_partition_disk_label label;
struct grub_disk raw;
+ int loop;
/* Enforce raw disk access. */
raw = *disk;
@@ -108,11 +109,13 @@ pc_partition_map_iterate (grub_disk_t disk,
p.data = &pcdata;
p.partmap = &grub_pc_partition_map;
- while (1)
+ loop = 0;
+ while (loop < 100000)
{
int i;
struct grub_pc_partition_entry *e;
+ loop++;
/* Read the MBR. */
if (grub_disk_read (&raw, p.offset, 0, sizeof (mbr), &mbr))
goto finish;
@@ -143,7 +146,7 @@ pc_partition_map_iterate (grub_disk_t disk,
return grub_error (GRUB_ERR_BAD_PART_TABLE, "dummy mbr");
/* If this partition is a normal one, call the hook. */
- if (! grub_pc_partition_is_empty (e->type)
+ if (e->start != 0 && ! grub_pc_partition_is_empty (e->type)
&& ! grub_pc_partition_is_extended (e->type))
{
pcdata.dos_part++;
@@ -206,7 +209,7 @@ pc_partition_map_iterate (grub_disk_t disk,
{
e = mbr.entries + i;
- if (grub_pc_partition_is_extended (e->type))
+ if (e->start != 0 && grub_pc_partition_is_extended (e->type))
{
p.offset = pcdata.ext_offset + grub_le_to_cpu32 (e->start);
if (! pcdata.ext_offset)
@@ -221,6 +224,8 @@ pc_partition_map_iterate (grub_disk_t disk,
break;
}
+ if (loop == 100000)
+ return grub_error (GRUB_ERR_BAD_PART_TABLE, "Corrupted partition table
found.");
finish:
return grub_errno;
}
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