improvement.
Signed-off-by: Michael Chang <mchang@suse.com>
---
grub-core/disk/lvm.c | 79 ++++++++++++++++++++++++--------------------
1 file changed, 43 insertions(+), 36 deletions(-)
diff --git a/grub-core/disk/lvm.c b/grub-core/disk/lvm.c
index 0c32c95f9..ea260b47e 100644
--- a/grub-core/disk/lvm.c
+++ b/grub-core/disk/lvm.c
@@ -140,9 +140,11 @@ grub_lvm_detect (grub_disk_t disk,
grub_err_t err;
grub_uint64_t mda_offset, mda_size;
grub_size_t ptr;
+ grub_uint64_t mda_raw_offset, mda_raw_size;
char buf[GRUB_LVM_LABEL_SIZE];
char vg_id[GRUB_LVM_ID_STRLEN+1];
char pv_id[GRUB_LVM_ID_STRLEN+1];
+ char mdah_buf[sizeof (struct grub_lvm_mda_header) + sizeof (struct
grub_lvm_raw_locn)];
char *metadatabuf, *mda_end, *vgname;
const char *p, *q;
struct grub_lvm_label_header *lh = (struct grub_lvm_label_header *) buf;
@@ -220,21 +222,15 @@ grub_lvm_detect (grub_disk_t disk,
dlocn++;
mda_offset = grub_le_to_cpu64 (dlocn->offset);
- mda_size = grub_le_to_cpu64 (dlocn->size);
/* It's possible to have multiple copies of metadata areas, we just use the
first one. */
-
- /* Allocate buffer space for the circular worst-case scenario. */
- metadatabuf = grub_calloc (2, mda_size);
- if (! metadatabuf)
+ err = grub_disk_read (disk, 0, mda_offset, sizeof (mdah_buf), mdah_buf);
+ if (err)
goto fail;
- err = grub_disk_read (disk, 0, mda_offset, mda_size, metadatabuf);
- if (err)
- goto fail2;
+ mdah = (struct grub_lvm_mda_header *) mdah_buf;
- mdah = (struct grub_lvm_mda_header *) metadatabuf;
if ((grub_strncmp ((char *)mdah->magic, GRUB_LVM_FMTT_MAGIC,
sizeof (mdah->magic)))
|| (grub_le_to_cpu32 (mdah->version) != GRUB_LVM_FMTT_VERSION))
@@ -244,42 +240,58 @@ grub_lvm_detect (grub_disk_t disk,
#ifdef GRUB_UTIL
grub_util_info ("unknown LVM metadata header");
#endif
- goto fail2;
+ goto fail;
}
rlocn = mdah->raw_locns;
- if (grub_le_to_cpu64 (rlocn->offset) >= grub_le_to_cpu64 (mda_size))
+
+ mda_size = grub_le_to_cpu64 (mdah->size);
+ mda_raw_size = grub_le_to_cpu64 (rlocn->size);
+ mda_raw_offset = grub_le_to_cpu64 (rlocn->offset);
+
+ if (mda_raw_offset >= mda_size)
{
#ifdef GRUB_UTIL
grub_util_info ("metadata offset is beyond end of metadata area");
#endif
- goto fail2;
+ goto fail;
}
- if (grub_le_to_cpu64 (rlocn->offset) + grub_le_to_cpu64 (rlocn->size) >
- grub_le_to_cpu64 (mdah->size))
+ metadatabuf = grub_malloc (mda_raw_size);
+
+ if (! metadatabuf)
+ goto fail;
+
+ if (mda_raw_offset + mda_raw_size > mda_size)
{
- if (2 * mda_size < GRUB_LVM_MDA_HEADER_SIZE ||
- (grub_le_to_cpu64 (rlocn->offset) + grub_le_to_cpu64 (rlocn->size) -
- grub_le_to_cpu64 (mdah->size) > mda_size - GRUB_LVM_MDA_HEADER_SIZE))
- {
-#ifdef GRUB_UTIL
- grub_util_info ("cannot copy metadata wrap in circular buffer");
-#endif
- goto fail2;
- }
+ err = grub_disk_read (disk, 0,
+ mda_offset + mda_raw_offset,
+ mda_size - mda_raw_offset,
+ metadatabuf);
+ if (err)
+ goto fail2;
/* Metadata is circular. Copy the wrap in place. */
- grub_memcpy (metadatabuf + mda_size,
- metadatabuf + GRUB_LVM_MDA_HEADER_SIZE,
- grub_le_to_cpu64 (rlocn->offset) +
- grub_le_to_cpu64 (rlocn->size) -
- grub_le_to_cpu64 (mdah->size));
+ err = grub_disk_read (disk, 0,
+ mda_offset + GRUB_LVM_MDA_HEADER_SIZE,
+ mda_raw_offset + mda_raw_size - mda_size,
+ metadatabuf + mda_size - mda_raw_offset);
+ if (err)
+ goto fail2;
+ }
+ else
+ {
+ err = grub_disk_read (disk, 0,
+ mda_offset + mda_raw_offset,
+ mda_raw_size,
+ metadatabuf);
+ if (err)
+ goto fail2;
}
- if (grub_add ((grub_size_t)metadatabuf,
- (grub_size_t)grub_le_to_cpu64 (rlocn->offset),
- &ptr))
+ p = q = metadatabuf;
+
+ if (grub_add ((grub_size_t)metadatabuf, (grub_size_t)mda_raw_size, &ptr))
{
error_parsing_metadata:
#ifdef GRUB_UTIL
@@ -288,11 +300,6 @@ grub_lvm_detect (grub_disk_t disk,
goto fail2;
}
- p = q = (char *)ptr;
-
- if (grub_add (ptr, (grub_size_t) grub_le_to_cpu64 (rlocn->size), &ptr))
- goto error_parsing_metadata;
-
mda_end = (char *)ptr;
while (*q != ' ' && q < mda_end)