MFC r360836:

loader: vdev_read() can corrupt memory

When reading less than sector size but from sector boundary,
the vdev_read() will read full sector into the provided buffer
and therefore corrupting memory past buffer end.

MFC r348471: stand: zfs: Free bouncebuf on error path in vdev_read

r344226 inadvertently added this path in which we return from failure on an
lseek and do not free bouncebuf on the way out.

Partial revert r350338: stable/11 part

The stand/libsa changes were not supposed to ride along with this revision;
backing out the stable/11 part and re-applying the MFC.

Pointy hat: kevans

MFC r348328: bectl(8): Address Coverity complaints

CID 1400451: case 0 is missing a break/return and falling through to the
default case. waitpid(0, ...) makes little sense in the child, we likely
wanted to terminate immediately.

CID 1400453: size argument uses sizeof(char **) instead of sizeof(char *)
and is assigned to a char **; sizeof's match but "this isn't a portable
assumption".

CID: 1400451, 1400453

MFC r337871, r339970, r342151, r342161, r343123-r343124, r344226, r344234,
r344248, r344387

r337871:
pkgfs_init: Initialize pkg

new_package may not set *pp if it errors out, leaving pkg uninitialized.

r339970:
Remove unnecessary include from libstand.

r342151:
loader: zfs reader should not probe partitionless disks

First of all, normal setups can not boot such pools as the tools
do not support installing boot programs.

Secondly, for proper pool configuration detection, we need to checks all
four label copies on disk, 2 from front and 2 from the end of the disk,
but zfs label does not contain the size of the disk - so we depend on
firmware to report the correct disk size or use information from the
partition table.

Without partition table, we only can rely on firmware to report and support
disk IO properly.

There is a specific case: 8TB disks are reported by BIOS to have 4294967295
sectors (0x00000000ffffffff), the sectors reported by OS is 15628053168
(0x00000003a3812ab0), so the reported size is less than actual but is hitting
32-bit max. Unfortuantely the real limit must be even lower because probing
this disk in this system will wnd up with hung system.

UEFI boot of this system seems not to be affected.

r342161:
loader: zfs reader should not probe partitionless disks (UEFI case)

With r342151 I did fix the BIOS version of zfs_probe_dev() from accessing
the whole disk, but the fix was not complete - we actually did not check
if the device name was really for whole disk. Since UEFI version
is only calling the zfs_probe_dev() with partitions and not with whole
disk, the UEFI loader was not able to find the zfs pools.

This update does correct the issue by calling archsw.arch_getdev() to
translate the device name back to dev_desc, and we have whole disk when both
partition and slice values are -1.

r343123:
loader should ignore active multi_vdev_crash_dump feature on zpool

Since the loader zfs reader does not need to read the dump zvol, we can
just enable the feature.

illumos issue #9051 https://www.illumos.org/issues/9051

r343124:
libsa: add asprintf()

asprintf() is a nice tool for string processing.

r344226:
Fix memory corruption bug introduced in r325310

The bug occurred when a bounce buffer was used and the requested read
size was greater than the size of the bounce buffer. This commit also
rewrites the read logic so that it is easier to systematically verify
all alignment and size cases.

r344234:
It turns out r344226 narrowed the overrun bug but did not eliminate it entirely

This commit fixes a remaining output buffer overrun in the
single-sector case when there is a non-zero tail.

r344248:
cd9660: dirmatch fails to unmatch when name is prefix for directory record

Loader does fail to properly match the file name in directory record and
does open file based on prefix match.

For fix, we check the name lengths first.

r344387:
loader: really fix cd9660 dirmatch

The cd9660_open() does pass whole path to dirmatch() and we need to
compare only the current path component, not full path.

Additinally, skip over duplicate / (if any) and check if the last component
in the path was meant to be directory (having trailing /). If it is in fact
a file, error out.

MFC various libsa fixes: r337037-r337039, r337065, r337412-r337413, r337874,
r338535, r338540, r339651, r339992-r339993, r340026

r337037:
libsa: pointer differs in signedness

A small cleanup, fix the argument type and while there, replace (char *)0 with
NULL.

r337038:
libsa: bootp is using pointers with different sign

Just change bp_file to char and same for variable s.

r337039:
libsa: assignment to char * from u_char *

Cast to char * instead of u_char *

r337065:
libsa: dereferencing type-punned pointer in cd9660

The warning is given by gcc build, but it is good to fix anyhow.
use bcopy instead of direct assignment.

r337412:
libsa: dos_checksum() should take unsigned chars

Fix pointers to integers with different sign issue.

r337413:
libsa: gzipfs.c converts pointers to integer types with different sign

Signed versus unsigned char.

r337874:
libsa: zfs_probe() needs to set spa to NULL

Silence the warning about possibly uninitialized use of spa.

r338535:
libsa: memory leak in tftp_open()

tftpfile is allocated just above and needs to be freed.

r338540:
libsa: validate tftp_makereq() after we did reset the read

The name check referred in the comment is not the only possible error source,
we need to validate the result.

r339651:
libsa: re-send ACK for older data packets in tftp

In current tftp code we drop out-of-order packets; however, we should play
nice and re-send ACK for older data packets we are receiving. This will
hopefully stop server repeating those packets we already have received.
Note we do not answer duplicates from "previous" session (that is, session
with different port number), those will eventually time out.

r339992:
libsa: tftp should not read past file end

When we have the file size via tsize option, use it to make sure we
will not attempt to read past file end.

r339993:
libsa: tftp should use calloc

instead of malloc() memset(), use calloc().

r340026:
libsa: cstyle cleanup tftp.c

No functinal changes intended.