qemu-e2k/hw/ppc/pnv_pnor.c
Cédric Le Goater 957c52aed5 ppc/pnv: Fix check on block device before updating drive contents
Test is wrong and the backend can never updated. It could have led to
a QEMU crash but since the firmware deactivates flash access if a valid
layout is not detected, it went unnoticed.

Reported-by: Coverity CID 1465223
Fixes: 35dde57662 ("ppc/pnv: Add a PNOR model")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211102162905.762078-1-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-11-09 10:32:52 +11:00

142 lines
3.6 KiB
C

/*
* QEMU PowerNV PNOR simple model
*
* Copyright (c) 2015-2019, IBM Corporation.
*
* This code is licensed under the GPL version 2 or later. See the
* COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "qemu/units.h"
#include "sysemu/block-backend.h"
#include "sysemu/blockdev.h"
#include "hw/loader.h"
#include "hw/ppc/pnv_pnor.h"
#include "hw/qdev-properties.h"
#include "hw/qdev-properties-system.h"
static uint64_t pnv_pnor_read(void *opaque, hwaddr addr, unsigned size)
{
PnvPnor *s = PNV_PNOR(opaque);
uint64_t ret = 0;
int i;
for (i = 0; i < size; i++) {
ret |= (uint64_t) s->storage[addr + i] << (8 * (size - i - 1));
}
return ret;
}
static void pnv_pnor_update(PnvPnor *s, int offset, int size)
{
int offset_end;
int ret;
if (!s->blk || !blk_is_writable(s->blk)) {
return;
}
offset_end = offset + size;
offset = QEMU_ALIGN_DOWN(offset, BDRV_SECTOR_SIZE);
offset_end = QEMU_ALIGN_UP(offset_end, BDRV_SECTOR_SIZE);
ret = blk_pwrite(s->blk, offset, s->storage + offset,
offset_end - offset, 0);
if (ret < 0) {
error_report("Could not update PNOR offset=0x%" PRIx32" : %s", offset,
strerror(-ret));
}
}
static void pnv_pnor_write(void *opaque, hwaddr addr, uint64_t data,
unsigned size)
{
PnvPnor *s = PNV_PNOR(opaque);
int i;
for (i = 0; i < size; i++) {
s->storage[addr + i] = (data >> (8 * (size - i - 1))) & 0xFF;
}
pnv_pnor_update(s, addr, size);
}
/*
* TODO: Check endianness: skiboot is BIG, Aspeed AHB is LITTLE, flash
* is BIG.
*/
static const MemoryRegionOps pnv_pnor_ops = {
.read = pnv_pnor_read,
.write = pnv_pnor_write,
.endianness = DEVICE_BIG_ENDIAN,
.valid = {
.min_access_size = 1,
.max_access_size = 4,
},
};
static void pnv_pnor_realize(DeviceState *dev, Error **errp)
{
PnvPnor *s = PNV_PNOR(dev);
int ret;
if (s->blk) {
uint64_t perm = BLK_PERM_CONSISTENT_READ |
(blk_supports_write_perm(s->blk) ? BLK_PERM_WRITE : 0);
ret = blk_set_perm(s->blk, perm, BLK_PERM_ALL, errp);
if (ret < 0) {
return;
}
s->size = blk_getlength(s->blk);
if (s->size <= 0) {
error_setg(errp, "failed to get flash size");
return;
}
s->storage = blk_blockalign(s->blk, s->size);
if (blk_pread(s->blk, 0, s->storage, s->size) != s->size) {
error_setg(errp, "failed to read the initial flash content");
return;
}
} else {
s->storage = blk_blockalign(NULL, s->size);
memset(s->storage, 0xFF, s->size);
}
memory_region_init_io(&s->mmio, OBJECT(s), &pnv_pnor_ops, s,
TYPE_PNV_PNOR, s->size);
}
static Property pnv_pnor_properties[] = {
DEFINE_PROP_INT64("size", PnvPnor, size, 128 * MiB),
DEFINE_PROP_DRIVE("drive", PnvPnor, blk),
DEFINE_PROP_END_OF_LIST(),
};
static void pnv_pnor_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = pnv_pnor_realize;
device_class_set_props(dc, pnv_pnor_properties);
}
static const TypeInfo pnv_pnor_info = {
.name = TYPE_PNV_PNOR,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(PnvPnor),
.class_init = pnv_pnor_class_init,
};
static void pnv_pnor_register_types(void)
{
type_register_static(&pnv_pnor_info);
}
type_init(pnv_pnor_register_types)