freebsd-dev/sys/dev/efidev/efirt.c
Kyle Evans 3395e43a04 efirt: Don't enter EFI context early, convert addrs to KVA instead
efi_enter here was needed because efi_runtime dereference causes a fault
outside of EFI context, due to runtime table living in runtime service
space. This may cause problems early in boot, though, so instead access it
by converting paddr to KVA for access.

While here, remove the other direct PHYS_TO_DMAP calls and the explicit DMAP
requirement from efidev.

Reviewed by:	kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D16591
2018-08-04 21:41:10 +00:00

463 lines
11 KiB
C

/*-
* Copyright (c) 2004 Marcel Moolenaar
* Copyright (c) 2001 Doug Rabson
* Copyright (c) 2016 The FreeBSD Foundation
* All rights reserved.
*
* Portions of this software were developed by Konstantin Belousov
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/efi.h>
#include <sys/kernel.h>
#include <sys/linker.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/clock.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/vmmeter.h>
#include <machine/fpu.h>
#include <machine/efi.h>
#include <machine/metadata.h>
#include <machine/vmparam.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
static struct efi_systbl *efi_systbl;
/*
* The following pointers point to tables in the EFI runtime service data pages.
* Care should be taken to make sure that we've properly entered the EFI runtime
* environment (efi_enter()) before dereferencing them.
*/
static struct efi_cfgtbl *efi_cfgtbl;
static struct efi_rt *efi_runtime;
static int efi_status2err[25] = {
0, /* EFI_SUCCESS */
ENOEXEC, /* EFI_LOAD_ERROR */
EINVAL, /* EFI_INVALID_PARAMETER */
ENOSYS, /* EFI_UNSUPPORTED */
EMSGSIZE, /* EFI_BAD_BUFFER_SIZE */
EOVERFLOW, /* EFI_BUFFER_TOO_SMALL */
EBUSY, /* EFI_NOT_READY */
EIO, /* EFI_DEVICE_ERROR */
EROFS, /* EFI_WRITE_PROTECTED */
EAGAIN, /* EFI_OUT_OF_RESOURCES */
EIO, /* EFI_VOLUME_CORRUPTED */
ENOSPC, /* EFI_VOLUME_FULL */
ENXIO, /* EFI_NO_MEDIA */
ESTALE, /* EFI_MEDIA_CHANGED */
ENOENT, /* EFI_NOT_FOUND */
EACCES, /* EFI_ACCESS_DENIED */
ETIMEDOUT, /* EFI_NO_RESPONSE */
EADDRNOTAVAIL, /* EFI_NO_MAPPING */
ETIMEDOUT, /* EFI_TIMEOUT */
EDOOFUS, /* EFI_NOT_STARTED */
EALREADY, /* EFI_ALREADY_STARTED */
ECANCELED, /* EFI_ABORTED */
EPROTO, /* EFI_ICMP_ERROR */
EPROTO, /* EFI_TFTP_ERROR */
EPROTO /* EFI_PROTOCOL_ERROR */
};
static int efi_enter(void);
static void efi_leave(void);
static int
efi_status_to_errno(efi_status status)
{
u_long code;
code = status & 0x3ffffffffffffffful;
return (code < nitems(efi_status2err) ? efi_status2err[code] : EDOOFUS);
}
static struct mtx efi_lock;
static bool
efi_is_in_map(struct efi_md *map, int ndesc, int descsz, vm_offset_t addr)
{
struct efi_md *p;
int i;
for (i = 0, p = map; i < ndesc; i++, p = efi_next_descriptor(p,
descsz)) {
if ((p->md_attr & EFI_MD_ATTR_RT) == 0)
continue;
if (addr >= (uintptr_t)p->md_virt &&
addr < (uintptr_t)p->md_virt + p->md_pages * PAGE_SIZE)
return (true);
}
return (false);
}
static int
efi_init(void)
{
struct efi_map_header *efihdr;
struct efi_md *map;
struct efi_rt *rtdm;
caddr_t kmdp;
size_t efisz;
int ndesc, rt_disabled;
rt_disabled = 0;
TUNABLE_INT_FETCH("efi.rt.disabled", &rt_disabled);
if (rt_disabled == 1)
return (0);
mtx_init(&efi_lock, "efi", NULL, MTX_DEF);
if (efi_systbl_phys == 0) {
if (bootverbose)
printf("EFI systbl not available\n");
return (0);
}
efi_systbl = (struct efi_systbl *)efi_phys_to_kva(efi_systbl_phys);
if (efi_systbl == NULL || efi_systbl->st_hdr.th_sig != EFI_SYSTBL_SIG) {
efi_systbl = NULL;
if (bootverbose)
printf("EFI systbl signature invalid\n");
return (0);
}
efi_cfgtbl = (efi_systbl->st_cfgtbl == 0) ? NULL :
(struct efi_cfgtbl *)efi_systbl->st_cfgtbl;
if (efi_cfgtbl == NULL) {
if (bootverbose)
printf("EFI config table is not present\n");
}
kmdp = preload_search_by_type("elf kernel");
if (kmdp == NULL)
kmdp = preload_search_by_type("elf64 kernel");
efihdr = (struct efi_map_header *)preload_search_info(kmdp,
MODINFO_METADATA | MODINFOMD_EFI_MAP);
if (efihdr == NULL) {
if (bootverbose)
printf("EFI map is not present\n");
return (0);
}
efisz = (sizeof(struct efi_map_header) + 0xf) & ~0xf;
map = (struct efi_md *)((uint8_t *)efihdr + efisz);
if (efihdr->descriptor_size == 0)
return (ENOMEM);
ndesc = efihdr->memory_size / efihdr->descriptor_size;
if (!efi_create_1t1_map(map, ndesc, efihdr->descriptor_size)) {
if (bootverbose)
printf("EFI cannot create runtime map\n");
return (ENOMEM);
}
efi_runtime = (efi_systbl->st_rt == 0) ? NULL :
(struct efi_rt *)efi_systbl->st_rt;
if (efi_runtime == NULL) {
if (bootverbose)
printf("EFI runtime services table is not present\n");
efi_destroy_1t1_map();
return (ENXIO);
}
#if defined(__aarch64__) || defined(__amd64__)
/*
* Some UEFI implementations have multiple implementations of the
* RS->GetTime function. They switch from one we can only use early
* in the boot process to one valid as a RunTime service only when we
* call RS->SetVirtualAddressMap. As this is not always the case, e.g.
* with an old loader.efi, check if the RS->GetTime function is within
* the EFI map, and fail to attach if not.
*/
rtdm = (struct efi_rt *)efi_phys_to_kva((uintptr_t)efi_runtime);
if (rtdm == NULL || !efi_is_in_map(map, ndesc, efihdr->descriptor_size,
(vm_offset_t)rtdm->rt_gettime)) {
if (bootverbose)
printf(
"EFI runtime services table has an invalid pointer\n");
efi_runtime = NULL;
efi_destroy_1t1_map();
return (ENXIO);
}
#endif
return (0);
}
static void
efi_uninit(void)
{
/* Most likely disabled by tunable */
if (efi_runtime == NULL)
return;
efi_destroy_1t1_map();
efi_systbl = NULL;
efi_cfgtbl = NULL;
efi_runtime = NULL;
mtx_destroy(&efi_lock);
}
int
efi_rt_ok(void)
{
if (efi_runtime == NULL)
return (ENXIO);
return (0);
}
static int
efi_enter(void)
{
struct thread *td;
pmap_t curpmap;
if (efi_runtime == NULL)
return (ENXIO);
td = curthread;
curpmap = &td->td_proc->p_vmspace->vm_pmap;
PMAP_LOCK(curpmap);
mtx_lock(&efi_lock);
fpu_kern_enter(td, NULL, FPU_KERN_NOCTX);
return (efi_arch_enter());
}
static void
efi_leave(void)
{
struct thread *td;
pmap_t curpmap;
efi_arch_leave();
curpmap = &curproc->p_vmspace->vm_pmap;
td = curthread;
fpu_kern_leave(td, NULL);
mtx_unlock(&efi_lock);
PMAP_UNLOCK(curpmap);
}
int
efi_get_table(struct uuid *uuid, void **ptr)
{
struct efi_cfgtbl *ct;
u_long count;
if (efi_cfgtbl == NULL || efi_systbl == NULL)
return (ENXIO);
count = efi_systbl->st_entries;
ct = efi_cfgtbl;
while (count--) {
if (!bcmp(&ct->ct_uuid, uuid, sizeof(*uuid))) {
*ptr = (void *)efi_phys_to_kva(ct->ct_data);
return (0);
}
ct++;
}
return (ENOENT);
}
static int
efi_get_time_locked(struct efi_tm *tm, struct efi_tmcap *tmcap)
{
efi_status status;
int error;
EFI_TIME_OWNED()
error = efi_enter();
if (error != 0)
return (error);
status = efi_runtime->rt_gettime(tm, tmcap);
efi_leave();
error = efi_status_to_errno(status);
return (error);
}
int
efi_get_time(struct efi_tm *tm)
{
struct efi_tmcap dummy;
int error;
if (efi_runtime == NULL)
return (ENXIO);
EFI_TIME_LOCK()
/*
* UEFI spec states that the Capabilities argument to GetTime is
* optional, but some UEFI implementations choke when passed a NULL
* pointer. Pass a dummy efi_tmcap, even though we won't use it,
* to workaround such implementations.
*/
error = efi_get_time_locked(tm, &dummy);
EFI_TIME_UNLOCK()
return (error);
}
int
efi_get_time_capabilities(struct efi_tmcap *tmcap)
{
struct efi_tm dummy;
int error;
if (efi_runtime == NULL)
return (ENXIO);
EFI_TIME_LOCK()
error = efi_get_time_locked(&dummy, tmcap);
EFI_TIME_UNLOCK()
return (error);
}
int
efi_reset_system(void)
{
int error;
error = efi_enter();
if (error != 0)
return (error);
efi_runtime->rt_reset(EFI_RESET_WARM, 0, 0, NULL);
efi_leave();
return (EIO);
}
static int
efi_set_time_locked(struct efi_tm *tm)
{
efi_status status;
int error;
EFI_TIME_OWNED();
error = efi_enter();
if (error != 0)
return (error);
status = efi_runtime->rt_settime(tm);
efi_leave();
error = efi_status_to_errno(status);
return (error);
}
int
efi_set_time(struct efi_tm *tm)
{
int error;
if (efi_runtime == NULL)
return (ENXIO);
EFI_TIME_LOCK()
error = efi_set_time_locked(tm);
EFI_TIME_UNLOCK()
return (error);
}
int
efi_var_get(efi_char *name, struct uuid *vendor, uint32_t *attrib,
size_t *datasize, void *data)
{
efi_status status;
int error;
error = efi_enter();
if (error != 0)
return (error);
status = efi_runtime->rt_getvar(name, vendor, attrib, datasize, data);
efi_leave();
error = efi_status_to_errno(status);
return (error);
}
int
efi_var_nextname(size_t *namesize, efi_char *name, struct uuid *vendor)
{
efi_status status;
int error;
error = efi_enter();
if (error != 0)
return (error);
status = efi_runtime->rt_scanvar(namesize, name, vendor);
efi_leave();
error = efi_status_to_errno(status);
return (error);
}
int
efi_var_set(efi_char *name, struct uuid *vendor, uint32_t attrib,
size_t datasize, void *data)
{
efi_status status;
int error;
error = efi_enter();
if (error != 0)
return (error);
status = efi_runtime->rt_setvar(name, vendor, attrib, datasize, data);
efi_leave();
error = efi_status_to_errno(status);
return (error);
}
static int
efirt_modevents(module_t m, int event, void *arg __unused)
{
switch (event) {
case MOD_LOAD:
return (efi_init());
case MOD_UNLOAD:
efi_uninit();
return (0);
case MOD_SHUTDOWN:
return (0);
default:
return (EOPNOTSUPP);
}
}
static moduledata_t efirt_moddata = {
.name = "efirt",
.evhand = efirt_modevents,
.priv = NULL,
};
/* After fpuinitstate, before efidev */
DECLARE_MODULE(efirt, efirt_moddata, SI_SUB_DRIVERS, SI_ORDER_SECOND);
MODULE_VERSION(efirt, 1);