When loader(8) is built with zfs support enabled, it assumes that any extarg
data present is a zfs_boot_args struct, but if the first-stage loader was
gptboot(8) the extarg data is actually a geli_boot_args struct. Luckily,
zfsboot(8) and gptzfsboot(8) have always passed KARGS_FLAGS_ZFS along with
KARGS_FLAGS_EXTARG, so we can use KARGS_FLAGS_ZFS to decide whether the
extarg data is a zfs_boot_args struct.
To avoid similar problems in the future, gptboot(8) now passes a new
KARGS_FLAGS_GELI to indicate that extarg data is geli_boot_args. In
loader(8), if the neither KARGS_FLAGS_ZFS nor KARGS_FLAGS_GELI is set but
extarg data is present (which will be the case for gptboot compiled before
this change), we now check for the known size of the geli_boot_args struct
passed by the older versions of gptboot as a way of confirming what type of
extarg data is present.
In a semi-related tidying up, since loader's main() has already decided
what type of extarg data is present and set the global 'zargs' var
accordingly, don't repeat the check in extract_currdev, just check whether
zargs is NULL or not.
X-MFC after: a few days, along with prior related changes.
of args data between gptboot/zfsboot and loader(8).
Despite what seems like a lot of changes here, there are no actual
changes in behavior, or in the data layout in the structures involved.
This is just eliminating identical code pasted into multiple locations.
In detail, the changes are...
- Move struct zfs_boot_args definition from libsa/zfs/libzfs.h to
i386/common/bootargs.h because it is specific to x86 booting and the
handoff between zfsboot and loader, and has no relation to the zfs
library code in general.
- The geli_boot_args and zfs_boot_args structs both contain an identical
set of member variables containing geli information. Extract this out
to a new geli_boot_data struct, and embed it in the arg-passing structs.
- Provide new routines geli_import_boot_data() and geli_export_boot_data()
that can be shared between gptboot, zfsboot, and loader instead of
pasting identical code into several different .c files.
- Remove some checks for a NULL pointer that can never be true because the
pointer being tested was set using pointer math (kargs + 1) and that can
never result in NULL in this code.
weren't needed, and their existance interfered with things in subtle
ways. One of these subtle ways was that malloc could be different
based on what files were included when (even within the same .c file,
it turns out). Move to a single malloc implementation as well by
adding the calls to setheap() to gptboot.c and zfsboot.c. Once upon a
time, these boot loaders strove to not use libstand. However, with the
proliferation of features, that striving is too hard for too little
gain and lead to stupid mistakes.
This fixes the GELI-enabled (but not even using) boot environment. The
geli routines were calling libstand malloc but zfsboot.c and gptboot.c
were using the mini libstand malloc, so this failed when we tried to
probe for GELI partitions. Subtle changes in build order when moving
to self-contained stand build in r326593 toggled what it used from one
type to another due to odd nesting of the zfs implementation code that
differed subtly between zfsloader and zfsboot.
Sponsored by: Netflix
