qemu/hw/block/fdc-isa.c
Peter Maydell 11b4666161 hw/block/fdc-isa: Assert that isa_fdc_get_drive_max_chs() found something
Coverity complains about an overflow in isa_fdc_get_drive_max_chs()
that can happen if the loop over fd_formats never finds a match,
because we initialize *maxc to 0 and then at the end of the
function decrement it.

This can't ever actually happen because fd_formats has at least
one entry for each FloppyDriveType, so we must at least once
find a match and update *maxc, *maxh and *maxs. Assert that we
did find a match, which should keep Coverity happy and will also
detect possible bugs in the data in fd_formats.

Resolves: Coverity CID 1547663
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240731143617.3391947-6-peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2024-08-06 10:22:52 +02:00

347 lines
11 KiB
C

/*
* QEMU Floppy disk emulator (Intel 82078)
*
* Copyright (c) 2003, 2007 Jocelyn Mayer
* Copyright (c) 2008 Hervé Poussineau
*
* 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.
*/
/*
* The controller is used in Sun4m systems in a slightly different
* way. There are changes in DOR register and DMA is not available.
*/
#include "qemu/osdep.h"
#include "hw/block/fdc.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "qemu/timer.h"
#include "hw/acpi/acpi_aml_interface.h"
#include "hw/irq.h"
#include "hw/isa/isa.h"
#include "hw/qdev-properties.h"
#include "hw/qdev-properties-system.h"
#include "migration/vmstate.h"
#include "hw/block/block.h"
#include "sysemu/block-backend.h"
#include "sysemu/blockdev.h"
#include "sysemu/sysemu.h"
#include "exec/ioport.h"
#include "qemu/log.h"
#include "qemu/main-loop.h"
#include "qemu/module.h"
#include "trace.h"
#include "qom/object.h"
#include "fdc-internal.h"
OBJECT_DECLARE_SIMPLE_TYPE(FDCtrlISABus, ISA_FDC)
struct FDCtrlISABus {
/*< private >*/
ISADevice parent_obj;
/*< public >*/
uint32_t iobase;
uint32_t irq;
uint32_t dma;
struct FDCtrl state;
PortioList portio_list;
int32_t bootindexA;
int32_t bootindexB;
};
static void fdctrl_external_reset_isa(DeviceState *d)
{
FDCtrlISABus *isa = ISA_FDC(d);
FDCtrl *s = &isa->state;
fdctrl_reset(s, 0);
}
void isa_fdc_init_drives(ISADevice *fdc, DriveInfo **fds)
{
fdctrl_init_drives(&ISA_FDC(fdc)->state.bus, fds);
}
static const MemoryRegionPortio fdc_portio_list[] = {
{ 1, 5, 1, .read = fdctrl_read, .write = fdctrl_write },
{ 7, 1, 1, .read = fdctrl_read, .write = fdctrl_write },
PORTIO_END_OF_LIST(),
};
static void isabus_fdc_realize(DeviceState *dev, Error **errp)
{
ISADevice *isadev = ISA_DEVICE(dev);
ISABus *bus = isa_bus_from_device(isadev);
FDCtrlISABus *isa = ISA_FDC(dev);
FDCtrl *fdctrl = &isa->state;
Error *err = NULL;
isa_register_portio_list(isadev, &isa->portio_list,
isa->iobase, fdc_portio_list, fdctrl,
"fdc");
fdctrl->irq = isa_bus_get_irq(bus, isa->irq);
fdctrl->dma_chann = isa->dma;
if (fdctrl->dma_chann != -1) {
IsaDmaClass *k;
fdctrl->dma = isa_bus_get_dma(bus, isa->dma);
if (!fdctrl->dma) {
error_setg(errp, "ISA controller does not support DMA");
return;
}
k = ISADMA_GET_CLASS(fdctrl->dma);
k->register_channel(fdctrl->dma, fdctrl->dma_chann,
&fdctrl_transfer_handler, fdctrl);
}
qdev_set_legacy_instance_id(dev, isa->iobase, 2);
fdctrl_realize_common(dev, fdctrl, &err);
if (err != NULL) {
error_propagate(errp, err);
return;
}
}
FloppyDriveType isa_fdc_get_drive_type(ISADevice *fdc, int i)
{
FDCtrlISABus *isa = ISA_FDC(fdc);
return isa->state.drives[i].drive;
}
static void isa_fdc_get_drive_max_chs(FloppyDriveType type, uint8_t *maxc,
uint8_t *maxh, uint8_t *maxs)
{
const FDFormat *fdf;
*maxc = *maxh = *maxs = 0;
for (fdf = fd_formats; fdf->drive != FLOPPY_DRIVE_TYPE_NONE; fdf++) {
if (fdf->drive != type) {
continue;
}
if (*maxc < fdf->max_track) {
*maxc = fdf->max_track;
}
if (*maxh < fdf->max_head) {
*maxh = fdf->max_head;
}
if (*maxs < fdf->last_sect) {
*maxs = fdf->last_sect;
}
}
/* fd_formats must contain at least one entry per FloppyDriveType */
assert(*maxc);
(*maxc)--;
}
static Aml *build_fdinfo_aml(int idx, FloppyDriveType type)
{
Aml *dev, *fdi;
uint8_t maxc, maxh, maxs;
isa_fdc_get_drive_max_chs(type, &maxc, &maxh, &maxs);
dev = aml_device("FLP%c", 'A' + idx);
aml_append(dev, aml_name_decl("_ADR", aml_int(idx)));
fdi = aml_package(16);
aml_append(fdi, aml_int(idx)); /* Drive Number */
aml_append(fdi,
aml_int(cmos_get_fd_drive_type(type))); /* Device Type */
/*
* the values below are the limits of the drive, and are thus independent
* of the inserted media
*/
aml_append(fdi, aml_int(maxc)); /* Maximum Cylinder Number */
aml_append(fdi, aml_int(maxs)); /* Maximum Sector Number */
aml_append(fdi, aml_int(maxh)); /* Maximum Head Number */
/*
* SeaBIOS returns the below values for int 0x13 func 0x08 regardless of
* the drive type, so shall we
*/
aml_append(fdi, aml_int(0xAF)); /* disk_specify_1 */
aml_append(fdi, aml_int(0x02)); /* disk_specify_2 */
aml_append(fdi, aml_int(0x25)); /* disk_motor_wait */
aml_append(fdi, aml_int(0x02)); /* disk_sector_siz */
aml_append(fdi, aml_int(0x12)); /* disk_eot */
aml_append(fdi, aml_int(0x1B)); /* disk_rw_gap */
aml_append(fdi, aml_int(0xFF)); /* disk_dtl */
aml_append(fdi, aml_int(0x6C)); /* disk_formt_gap */
aml_append(fdi, aml_int(0xF6)); /* disk_fill */
aml_append(fdi, aml_int(0x0F)); /* disk_head_sttl */
aml_append(fdi, aml_int(0x08)); /* disk_motor_strt */
aml_append(dev, aml_name_decl("_FDI", fdi));
return dev;
}
void isa_fdc_set_iobase(ISADevice *fdc, hwaddr iobase)
{
FDCtrlISABus *isa = ISA_FDC(fdc);
fdc->ioport_id = iobase;
isa->iobase = iobase;
portio_list_set_address(&isa->portio_list, isa->iobase);
}
void isa_fdc_set_enabled(ISADevice *fdc, bool enabled)
{
portio_list_set_enabled(&ISA_FDC(fdc)->portio_list, enabled);
}
int cmos_get_fd_drive_type(FloppyDriveType fd0)
{
int val;
switch (fd0) {
case FLOPPY_DRIVE_TYPE_144:
/* 1.44 Mb 3"5 drive */
val = 4;
break;
case FLOPPY_DRIVE_TYPE_288:
/* 2.88 Mb 3"5 drive */
val = 5;
break;
case FLOPPY_DRIVE_TYPE_120:
/* 1.2 Mb 5"5 drive */
val = 2;
break;
case FLOPPY_DRIVE_TYPE_NONE:
default:
val = 0;
break;
}
return val;
}
static void build_fdc_aml(AcpiDevAmlIf *adev, Aml *scope)
{
FDCtrlISABus *isa = ISA_FDC(adev);
Aml *dev;
Aml *crs;
int i;
#define ACPI_FDE_MAX_FD 4
uint32_t fde_buf[5] = {
0, 0, 0, 0, /* presence of floppy drives #0 - #3 */
cpu_to_le32(2) /* tape presence (2 == never present) */
};
crs = aml_resource_template();
aml_append(crs,
aml_io(AML_DECODE16, isa->iobase + 2, isa->iobase + 2, 0x00, 0x04));
aml_append(crs,
aml_io(AML_DECODE16, isa->iobase + 7, isa->iobase + 7, 0x00, 0x01));
aml_append(crs, aml_irq_no_flags(isa->irq));
aml_append(crs,
aml_dma(AML_COMPATIBILITY, AML_NOTBUSMASTER, AML_TRANSFER8, isa->dma));
dev = aml_device("FDC0");
aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0700")));
aml_append(dev, aml_name_decl("_CRS", crs));
for (i = 0; i < MIN(MAX_FD, ACPI_FDE_MAX_FD); i++) {
FloppyDriveType type = isa_fdc_get_drive_type(ISA_DEVICE(adev), i);
if (type < FLOPPY_DRIVE_TYPE_NONE) {
fde_buf[i] = cpu_to_le32(1); /* drive present */
aml_append(dev, build_fdinfo_aml(i, type));
}
}
aml_append(dev, aml_name_decl("_FDE",
aml_buffer(sizeof(fde_buf), (uint8_t *)fde_buf)));
aml_append(scope, dev);
}
static const VMStateDescription vmstate_isa_fdc = {
.name = "fdc",
.version_id = 2,
.minimum_version_id = 2,
.fields = (const VMStateField[]) {
VMSTATE_STRUCT(state, FDCtrlISABus, 0, vmstate_fdc, FDCtrl),
VMSTATE_END_OF_LIST()
}
};
static Property isa_fdc_properties[] = {
DEFINE_PROP_UINT32("iobase", FDCtrlISABus, iobase, 0x3f0),
DEFINE_PROP_UINT32("irq", FDCtrlISABus, irq, 6),
DEFINE_PROP_UINT32("dma", FDCtrlISABus, dma, 2),
DEFINE_PROP_SIGNED("fdtypeA", FDCtrlISABus, state.qdev_for_drives[0].type,
FLOPPY_DRIVE_TYPE_AUTO, qdev_prop_fdc_drive_type,
FloppyDriveType),
DEFINE_PROP_SIGNED("fdtypeB", FDCtrlISABus, state.qdev_for_drives[1].type,
FLOPPY_DRIVE_TYPE_AUTO, qdev_prop_fdc_drive_type,
FloppyDriveType),
DEFINE_PROP_SIGNED("fallback", FDCtrlISABus, state.fallback,
FLOPPY_DRIVE_TYPE_288, qdev_prop_fdc_drive_type,
FloppyDriveType),
DEFINE_PROP_END_OF_LIST(),
};
static void isabus_fdc_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
AcpiDevAmlIfClass *adevc = ACPI_DEV_AML_IF_CLASS(klass);
dc->desc = "virtual floppy controller";
dc->realize = isabus_fdc_realize;
dc->fw_name = "fdc";
dc->reset = fdctrl_external_reset_isa;
dc->vmsd = &vmstate_isa_fdc;
adevc->build_dev_aml = build_fdc_aml;
device_class_set_props(dc, isa_fdc_properties);
set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
}
static void isabus_fdc_instance_init(Object *obj)
{
FDCtrlISABus *isa = ISA_FDC(obj);
device_add_bootindex_property(obj, &isa->bootindexA,
"bootindexA", "/floppy@0",
DEVICE(obj));
device_add_bootindex_property(obj, &isa->bootindexB,
"bootindexB", "/floppy@1",
DEVICE(obj));
}
static const TypeInfo isa_fdc_info = {
.name = TYPE_ISA_FDC,
.parent = TYPE_ISA_DEVICE,
.instance_size = sizeof(FDCtrlISABus),
.class_init = isabus_fdc_class_init,
.instance_init = isabus_fdc_instance_init,
.interfaces = (InterfaceInfo[]) {
{ TYPE_ACPI_DEV_AML_IF },
{ },
},
};
static void isa_fdc_register_types(void)
{
type_register_static(&isa_fdc_info);
}
type_init(isa_fdc_register_types)