qemu-e2k/hw/nvram/mac_nvram.c

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/*
* PowerMac NVRAM emulation
*
* Copyright (c) 2005-2007 Fabrice Bellard
* Copyright (c) 2007 Jocelyn Mayer
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "hw/nvram/chrp_nvram.h"
#include "hw/ppc/mac.h"
#include "hw/qdev-properties.h"
#include "migration/vmstate.h"
#include "qemu/cutils.h"
#include "qemu/module.h"
#include "trace.h"
#include <zlib.h>
#define DEF_SYSTEM_SIZE 0xc10
/* macio style NVRAM device */
static void macio_nvram_writeb(void *opaque, hwaddr addr,
uint64_t value, unsigned size)
{
MacIONVRAMState *s = opaque;
addr = (addr >> s->it_shift) & (s->size - 1);
trace_macio_nvram_write(addr, value);
s->data[addr] = value;
}
static uint64_t macio_nvram_readb(void *opaque, hwaddr addr,
unsigned size)
{
MacIONVRAMState *s = opaque;
uint32_t value;
addr = (addr >> s->it_shift) & (s->size - 1);
value = s->data[addr];
trace_macio_nvram_read(addr, value);
return value;
}
static const MemoryRegionOps macio_nvram_ops = {
.read = macio_nvram_readb,
.write = macio_nvram_writeb,
.valid.min_access_size = 1,
.valid.max_access_size = 4,
.impl.min_access_size = 1,
.impl.max_access_size = 1,
.endianness = DEVICE_BIG_ENDIAN,
};
static const VMStateDescription vmstate_macio_nvram = {
.name = "macio_nvram",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_VBUFFER_UINT32(data, MacIONVRAMState, 0, NULL, size),
VMSTATE_END_OF_LIST()
}
};
static void macio_nvram_reset(DeviceState *dev)
{
}
static void macio_nvram_realizefn(DeviceState *dev, Error **errp)
{
SysBusDevice *d = SYS_BUS_DEVICE(dev);
MacIONVRAMState *s = MACIO_NVRAM(dev);
s->data = g_malloc0(s->size);
memory_region_init_io(&s->mem, OBJECT(s), &macio_nvram_ops, s,
"macio-nvram", s->size << s->it_shift);
sysbus_init_mmio(d, &s->mem);
}
qdev: Unrealize must not fail Devices may have component devices and buses. Device realization may fail. Realization is recursive: a device's realize() method realizes its components, and device_set_realized() realizes its buses (which should in turn realize the devices on that bus, except bus_set_realized() doesn't implement that, yet). When realization of a component or bus fails, we need to roll back: unrealize everything we realized so far. If any of these unrealizes failed, the device would be left in an inconsistent state. Must not happen. device_set_realized() lets it happen: it ignores errors in the roll back code starting at label child_realize_fail. Since realization is recursive, unrealization must be recursive, too. But how could a partly failed unrealize be rolled back? We'd have to re-realize, which can fail. This design is fundamentally broken. device_set_realized() does not roll back at all. Instead, it keeps unrealizing, ignoring further errors. It can screw up even for a device with no buses: if the lone dc->unrealize() fails, it still unregisters vmstate, and calls listeners' unrealize() callback. bus_set_realized() does not roll back either. Instead, it stops unrealizing. Fortunately, no unrealize method can fail, as we'll see below. To fix the design error, drop parameter @errp from all the unrealize methods. Any unrealize method that uses @errp now needs an update. This leads us to unrealize() methods that can fail. Merely passing it to another unrealize method cannot cause failure, though. Here are the ones that do other things with @errp: * virtio_serial_device_unrealize() Fails when qbus_set_hotplug_handler() fails, but still does all the other work. On failure, the device would stay realized with its resources completely gone. Oops. Can't happen, because qbus_set_hotplug_handler() can't actually fail here. Pass &error_abort to qbus_set_hotplug_handler() instead. * hw/ppc/spapr_drc.c's unrealize() Fails when object_property_del() fails, but all the other work is already done. On failure, the device would stay realized with its vmstate registration gone. Oops. Can't happen, because object_property_del() can't actually fail here. Pass &error_abort to object_property_del() instead. * spapr_phb_unrealize() Fails and bails out when remove_drcs() fails, but other work is already done. On failure, the device would stay realized with some of its resources gone. Oops. remove_drcs() fails only when chassis_from_bus()'s object_property_get_uint() fails, and it can't here. Pass &error_abort to remove_drcs() instead. Therefore, no unrealize method can fail before this patch. device_set_realized()'s recursive unrealization via bus uses object_property_set_bool(). Can't drop @errp there, so pass &error_abort. We similarly unrealize with object_property_set_bool() elsewhere, always ignoring errors. Pass &error_abort instead. Several unrealize methods no longer handle errors from other unrealize methods: virtio_9p_device_unrealize(), virtio_input_device_unrealize(), scsi_qdev_unrealize(), ... Much of the deleted error handling looks wrong anyway. One unrealize methods no longer ignore such errors: usb_ehci_pci_exit(). Several realize methods no longer ignore errors when rolling back: v9fs_device_realize_common(), pci_qdev_unrealize(), spapr_phb_realize(), usb_qdev_realize(), vfio_ccw_realize(), virtio_device_realize(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200505152926.18877-17-armbru@redhat.com>
2020-05-05 17:29:24 +02:00
static void macio_nvram_unrealizefn(DeviceState *dev)
{
MacIONVRAMState *s = MACIO_NVRAM(dev);
g_free(s->data);
}
static Property macio_nvram_properties[] = {
DEFINE_PROP_UINT32("size", MacIONVRAMState, size, 0),
DEFINE_PROP_UINT32("it_shift", MacIONVRAMState, it_shift, 0),
DEFINE_PROP_END_OF_LIST()
};
static void macio_nvram_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
dc->realize = macio_nvram_realizefn;
dc->unrealize = macio_nvram_unrealizefn;
dc->reset = macio_nvram_reset;
dc->vmsd = &vmstate_macio_nvram;
device_class_set_props(dc, macio_nvram_properties);
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
}
static const TypeInfo macio_nvram_type_info = {
.name = TYPE_MACIO_NVRAM,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(MacIONVRAMState),
.class_init = macio_nvram_class_init,
};
static void macio_nvram_register_types(void)
{
type_register_static(&macio_nvram_type_info);
}
/* Set up a system OpenBIOS NVRAM partition */
static void pmac_format_nvram_partition_of(MacIONVRAMState *nvr, int off,
int len)
{
int sysp_end;
/* OpenBIOS nvram variables partition */
sysp_end = chrp_nvram_create_system_partition(&nvr->data[off],
nvram: Exit QEMU if NVRAM cannot contain all -prom-env data Since commit 61f20b9dc5b7 ("spapr_nvram: Pre-initialize the NVRAM to support the -prom-env parameter"), pseries machines can pre-initialize the "system" partition in the NVRAM with the data passed to all -prom-env parameters on the QEMU command line. In this case it is assumed that all the data fits in 64 KiB, but the user can easily pass more and crash QEMU: $ qemu-system-ppc64 -M pseries $(for ((x=0;x<128;x++)); do \ echo -n " -prom-env " ; printf "%0.sx" {1..1024}; \ done) # this requires ~128 Kib malloc(): corrupted top size Aborted (core dumped) This happens because we don't check if all the prom-env data fits in the NVRAM and chrp_nvram_set_var() happily memcpy() it passed the buffer. This crash affects basically all ppc/ppc64 machine types that use -prom-env: - pseries (all versions) - g3beige - mac99 and also sparc/sparc64 machine types: - LX - SPARCClassic - SPARCbook - SS-10 - SS-20 - SS-4 - SS-5 - SS-600MP - Voyager - sun4u - sun4v Add a max_len argument to chrp_nvram_create_system_partition() so that it can check the available size before writing to memory. Since NVRAM is populated at machine init, it seems reasonable to consider this error as fatal. So, instead of reporting an error when we detect that the NVRAM is too small and adapt all machine types to handle it, we simply exit QEMU in all cases. This is still better than crashing. If someone wants another behavior, I guess this can be reworked later. Tested with: $ yes q | \ (for arch in ppc ppc64 sparc sparc64; do \ echo == $arch ==; \ qemu=${arch}-softmmu/qemu-system-$arch; \ for mach in $($qemu -M help | awk '! /^Supported/ { print $1 }'); do \ echo $mach; \ $qemu -M $mach -monitor stdio -nodefaults -nographic \ $(for ((x=0;x<128;x++)); do \ echo -n " -prom-env " ; printf "%0.sx" {1..1024}; \ done) >/dev/null; \ done; echo; \ done) Without the patch, affected machine types cause QEMU to report some memory corruption and crash: malloc(): corrupted top size free(): invalid size *** stack smashing detected ***: terminated With the patch, QEMU prints the following message and exits: NVRAM is too small. Try to pass less data to -prom-env It seems that the conditions for the crash have always existed, but it affects pseries, the machine type I care for, since commit 61f20b9dc5b7 only. Fixes: 61f20b9dc5b7 ("spapr_nvram: Pre-initialize the NVRAM to support the -prom-env parameter") RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1867739 Reported-by: John Snow <jsnow@redhat.com> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Greg Kurz <groug@kaod.org> Message-Id: <159736033937.350502.12402444542194031035.stgit@bahia.lan> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-14 01:12:19 +02:00
DEF_SYSTEM_SIZE, len) + off;
/* Free space partition */
chrp_nvram_create_free_partition(&nvr->data[sysp_end], len - sysp_end);
}
#define OSX_NVRAM_SIGNATURE (0x5A)
/* Set up a Mac OS X NVRAM partition */
static void pmac_format_nvram_partition_osx(MacIONVRAMState *nvr, int off,
int len)
{
uint32_t start = off;
ChrpNvramPartHdr *part_header;
unsigned char *data = &nvr->data[start];
/* empty partition */
part_header = (ChrpNvramPartHdr *)data;
part_header->signature = OSX_NVRAM_SIGNATURE;
pstrcpy(part_header->name, sizeof(part_header->name), "wwwwwwwwwwww");
chrp_nvram_finish_partition(part_header, len);
/* Generation */
stl_be_p(&data[20], 2);
/* Adler32 checksum */
stl_be_p(&data[16], adler32(0, &data[20], len - 20));
}
/* Set up NVRAM with OF and OSX partitions */
void pmac_format_nvram_partition(MacIONVRAMState *nvr, int len)
{
/*
* Mac OS X expects side "B" of the flash at the second half of NVRAM,
* so we use half of the chip for OF and the other half for a free OSX
* partition.
*/
pmac_format_nvram_partition_of(nvr, 0, len / 2);
pmac_format_nvram_partition_osx(nvr, len / 2, len / 2);
}
type_init(macio_nvram_register_types)