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loader: efipart should check disk size from partition table

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While testing 32bit UEFI OVMF (which has bug about how the disk size
is presented), I did witness the errors from blkio->ReadBlocks().

It became apparent we can not entirely trust UEFI interfaces either,
so additional checks are needed.

So we use disk_ioctl(DIOCGMEDIASIZE) for disks, with fallback of
Media->LastBlock for other media.

In addition, we need to check if there is media present.

+ small fixes for error printout, and avoiding multiple blk * 512.

Reviewed by:	allanjude
Approved by:	allanjude (mentor)
Differential Revision:	https://reviews.freebsd.org/D10197
This commit is contained in:
tsoome 2017-03-30 16:23:31 +00:00
parent 21ffe1a952
commit 30249cacdc
1 changed files with 28 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
sys/boot/efi/libefi/efipart.c
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@ -834,8 +834,10 @@ efipart_readwrite(EFI_BLOCK_IO *blkio, int rw, daddr_t blk, daddr_t nblks,
return (ENOSYS);
}
if (EFI_ERROR(status))
printf("%s: rw=%d, status=%lu\n", __func__, rw, (u_long)status);
if (EFI_ERROR(status)) {
printf("%s: rw=%d, blk=%ju size=%ju status=%lu\n", __func__, rw,
blk, nblks, EFI_ERROR_CODE(status));
}
return (efi_status_to_errno(status));
}
@ -859,6 +861,10 @@ efipart_strategy(void *devdata, int rw, daddr_t blk, size_t size,
if (pd == NULL)
return (EINVAL);
if (pd->pd_blkio->Media->RemovableMedia &&
!pd->pd_blkio->Media->MediaPresent)
return (EIO);
bcd.dv_strategy = efipart_realstrategy;
bcd.dv_devdata = devdata;
bcd.dv_cache = pd->pd_bcache;
@ -878,7 +884,7 @@ efipart_realstrategy(void *devdata, int rw, daddr_t blk, size_t size,
pdinfo_list_t *pdi;
pdinfo_t *pd;
EFI_BLOCK_IO *blkio;
off_t off;
uint64_t off, disk_blocks, d_offset = 0;
char *blkbuf;
size_t blkoff, blksz;
int error;
@ -902,11 +908,24 @@ efipart_realstrategy(void *devdata, int rw, daddr_t blk, size_t size,
return (EIO);
off = blk * 512;
/*
* Get disk blocks, this value is either for whole disk or for
* partition.
*/
disk_blocks = 0;
if (dev->d_dev->dv_type == DEVT_DISK) {
if (disk_ioctl(dev, DIOCGMEDIASIZE, &disk_blocks) == 0) {
/* DIOCGMEDIASIZE does return bytes. */
disk_blocks /= blkio->Media->BlockSize;
}
d_offset = dev->d_offset;
}
if (disk_blocks == 0)
disk_blocks = blkio->Media->LastBlock + 1 - d_offset;
/* make sure we don't read past disk end */
if ((off + size) / blkio->Media->BlockSize - 1 >
blkio->Media->LastBlock) {
size = blkio->Media->LastBlock + 1 -
off / blkio->Media->BlockSize;
if ((off + size) / blkio->Media->BlockSize > d_offset + disk_blocks) {
size = d_offset + disk_blocks - off / blkio->Media->BlockSize;
size = size * blkio->Media->BlockSize;
}
@ -914,9 +933,9 @@ efipart_realstrategy(void *devdata, int rw, daddr_t blk, size_t size,
*rsize = size;
if ((size % blkio->Media->BlockSize == 0) &&
((blk * 512) % blkio->Media->BlockSize == 0))
(off % blkio->Media->BlockSize == 0))
return (efipart_readwrite(blkio, rw,
blk * 512 / blkio->Media->BlockSize,
off / blkio->Media->BlockSize,
size / blkio->Media->BlockSize, buf));
/*