freebsd-dev/stand/i386/common/bootargs.h
Ian Lepore 7297dc4441 Fix args cross-threading between gptboot(8) and loader(8) with zfs support.
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.
2018-12-04 16:43:50 +00:00

160 lines
4.9 KiB
C

/*-
* Copyright (c) 2012 Andriy Gapon <avg@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms are freely
* permitted provided that the above copyright notice and this
* paragraph and the following disclaimer are duplicated in all
* such forms.
*
* This software is provided "AS IS" and without any express or
* implied warranties, including, without limitation, the implied
* warranties of merchantability and fitness for a particular
* purpose.
*
* $FreeBSD$
*/
#ifndef _BOOT_I386_ARGS_H_
#define _BOOT_I386_ARGS_H_
#define KARGS_FLAGS_CD 0x0001 /* .bootdev is a bios CD dev */
#define KARGS_FLAGS_PXE 0x0002 /* .pxeinfo is valid */
#define KARGS_FLAGS_ZFS 0x0004 /* .zfspool is valid, EXTARG is zfs_boot_args */
#define KARGS_FLAGS_EXTARG 0x0008 /* variably sized extended argument */
#define KARGS_FLAGS_GELI 0x0010 /* EXTARG is geli_boot_args */
#define BOOTARGS_SIZE 24 /* sizeof(struct bootargs) */
#define BA_BOOTFLAGS 8 /* offsetof(struct bootargs, bootflags) */
#define BA_BOOTINFO 20 /* offsetof(struct bootargs, bootinfo) */
#define BI_SIZE 48 /* offsetof(struct bootinfo, bi_size) */
/*
* We reserve some space above BTX allocated stack for the arguments
* and certain data that could hang off them. Currently only struct bootinfo
* is supported in that category. The bootinfo is placed at the top
* of the arguments area and the actual arguments are placed at ARGOFF offset
* from the top and grow towards the top. Hopefully we have enough space
* for bootinfo and the arguments to not run into each other.
* Arguments area below ARGOFF is reserved for future use.
*/
#define ARGSPACE 0x1000 /* total size of the BTX args area */
#define ARGOFF 0x800 /* actual args offset within the args area */
#define ARGADJ (ARGSPACE - ARGOFF)
#ifndef __ASSEMBLER__
/*
* This struct describes the contents of the stack on entry to btxldr.S. This
* is the data that follows the return address, so it begins at 4(%esp). On
* the sending side, this data is passed as individual args to __exec(). On the
* receiving side, code in btxldr.S copies the data from the entry stack to a
* known fixed location in the new address space. Then, btxcsu.S sets the
* global variable __args to point to that known fixed location before calling
* main(), which casts __args to a struct bootargs pointer to access the data.
* The btxldr.S code is aware of KARGS_FLAGS_EXTARG, and if it's set, the extra
* args data is copied along with the other bootargs from the entry stack to the
* fixed location in the new address space.
*
* The bootinfo field is actually a pointer to a bootinfo struct that has been
* converted to uint32_t using VTOP(). On the receiving side it must be
* converted back to a pointer using PTOV(). Code in btxldr.S is aware of this
* field and if it's non-NULL it copies the data it points to into another known
* fixed location, and adjusts the bootinfo field to point to that new location.
*/
struct bootargs
{
uint32_t howto;
uint32_t bootdev;
uint32_t bootflags;
union {
struct {
uint32_t pxeinfo;
uint32_t reserved;
};
uint64_t zfspool;
};
uint32_t bootinfo;
/*
* If KARGS_FLAGS_EXTARG is set in bootflags, then the above fields
* are followed by a uint32_t field that specifies a size of the
* extended arguments (including the size field).
*/
};
#ifdef LOADER_GELI_SUPPORT
#include <crypto/intake.h>
#include "geliboot.h"
#endif
/*
* geli_boot_data is embedded in geli_boot_args (passed from gptboot to loader)
* and in zfs_boot_args (passed from zfsboot and gptzfsboot to loader).
*/
struct geli_boot_data
{
union {
char gelipw[256];
struct {
char notapw; /*
* single null byte to stop keybuf
* being interpreted as a password
*/
uint32_t keybuf_sentinel;
#ifdef LOADER_GELI_SUPPORT
struct keybuf *keybuf;
#else
void *keybuf;
#endif
};
};
};
#ifdef LOADER_GELI_SUPPORT
static inline void
export_geli_boot_data(struct geli_boot_data *gbdata)
{
gbdata->notapw = '\0';
gbdata->keybuf_sentinel = KEYBUF_SENTINEL;
gbdata->keybuf = malloc(sizeof(struct keybuf) +
(GELI_MAX_KEYS * sizeof(struct keybuf_ent)));
geli_export_key_buffer(gbdata->keybuf);
}
static inline void
import_geli_boot_data(struct geli_boot_data *gbdata)
{
if (gbdata->gelipw[0] != '\0') {
setenv("kern.geom.eli.passphrase", gbdata->gelipw, 1);
explicit_bzero(gbdata->gelipw, sizeof(gbdata->gelipw));
} else if (gbdata->keybuf_sentinel == KEYBUF_SENTINEL) {
geli_import_key_buffer(gbdata->keybuf);
}
}
#endif /* LOADER_GELI_SUPPORT */
struct geli_boot_args
{
uint32_t size;
struct geli_boot_data gelidata;
};
struct zfs_boot_args
{
uint32_t size;
uint32_t reserved;
uint64_t pool;
uint64_t root;
uint64_t primary_pool;
uint64_t primary_vdev;
struct geli_boot_data gelidata;
};
#endif /*__ASSEMBLER__*/
#endif /* !_BOOT_I386_ARGS_H_ */