qemu/target-tilegx/cpu.c
Markus Armbruster 4c315c2766 qdev: Protect device-list-properties against broken devices
Several devices don't survive object_unref(object_new(T)): they crash
or hang during cleanup, or they leave dangling pointers behind.

This breaks at least device-list-properties, because
qmp_device_list_properties() needs to create a device to find its
properties.  Broken in commit f4eb32b "qmp: show QOM properties in
device-list-properties", v2.1.  Example reproducer:

    $ qemu-system-aarch64 -nodefaults -display none -machine none -S -qmp stdio
    {"QMP": {"version": {"qemu": {"micro": 50, "minor": 4, "major": 2}, "package": ""}, "capabilities": []}}
    { "execute": "qmp_capabilities" }
    {"return": {}}
    { "execute": "device-list-properties", "arguments": { "typename": "pxa2xx-pcmcia" } }
    qemu-system-aarch64: /home/armbru/work/qemu/memory.c:1307: memory_region_finalize: Assertion `((&mr->subregions)->tqh_first == ((void *)0))' failed.
    Aborted (core dumped)
    [Exit 134 (SIGABRT)]

Unfortunately, I can't fix the problems in these devices right now.
Instead, add DeviceClass member cannot_destroy_with_object_finalize_yet
to mark them:

* Hang during cleanup (didn't debug, so I can't say why):
  "realview_pci", "versatile_pci".

* Dangling pointer in cpus: most CPUs, plus "allwinner-a10", "digic",
  "fsl,imx25", "fsl,imx31", "xlnx,zynqmp", because they create such
  CPUs

* Assert kvm_enabled(): "host-x86_64-cpu", host-i386-cpu",
  "host-powerpc64-cpu", "host-embedded-powerpc-cpu",
  "host-powerpc-cpu" (the powerpc ones can't currently reach the
  assertion, because the CPUs are only registered when KVM is enabled,
  but the assertion is arguably in the wrong place all the same)

Make qmp_device_list_properties() fail cleanly when the device is so
marked.  This improves device-list-properties from "crashes, hangs or
leaves dangling pointers behind" to "fails".  Not a complete fix, just
a better-than-nothing work-around.  In the above reproducer,
device-list-properties now fails with "Can't list properties of device
'pxa2xx-pcmcia'".

This also protects -device FOO,help, which uses the same machinery
since commit ef52358 "qdev-monitor: include QOM properties in -device
FOO, help output", v2.2.  Example reproducer:

    $ qemu-system-aarch64 -machine none -device pxa2xx-pcmcia,help

Before:

    qemu-system-aarch64: .../memory.c:1307: memory_region_finalize: Assertion `((&mr->subregions)->tqh_first == ((void *)0))' failed.

After:

    Can't list properties of device 'pxa2xx-pcmcia'

Cc: "Andreas Färber" <afaerber@suse.de>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Anthony Green <green@moxielogic.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Cc: Blue Swirl <blauwirbel@gmail.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Jia Liu <proljc@gmail.com>
Cc: Leon Alrae <leon.alrae@imgtec.com>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Walle <michael@walle.cc>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: qemu-ppc@nongnu.org
Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1443689999-12182-10-git-send-email-armbru@redhat.com>
2015-10-09 15:25:57 +02:00

186 lines
5.1 KiB
C

/*
* QEMU TILE-Gx CPU
*
* Copyright (c) 2015 Chen Gang
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see
* <http://www.gnu.org/licenses/lgpl-2.1.html>
*/
#include "cpu.h"
#include "qemu-common.h"
#include "hw/qdev-properties.h"
#include "migration/vmstate.h"
#include "linux-user/syscall_defs.h"
static void tilegx_cpu_dump_state(CPUState *cs, FILE *f,
fprintf_function cpu_fprintf, int flags)
{
static const char * const reg_names[TILEGX_R_COUNT] = {
"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
"r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
"r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
"r32", "r33", "r34", "r35", "r36", "r37", "r38", "r39",
"r40", "r41", "r42", "r43", "r44", "r45", "r46", "r47",
"r48", "r49", "r50", "r51", "bp", "tp", "sp", "lr"
};
TileGXCPU *cpu = TILEGX_CPU(cs);
CPUTLGState *env = &cpu->env;
int i;
for (i = 0; i < TILEGX_R_COUNT; i++) {
cpu_fprintf(f, "%-4s" TARGET_FMT_lx "%s",
reg_names[i], env->regs[i],
(i % 4) == 3 ? "\n" : " ");
}
cpu_fprintf(f, "PC " TARGET_FMT_lx " CEX " TARGET_FMT_lx "\n\n",
env->pc, env->spregs[TILEGX_SPR_CMPEXCH]);
}
TileGXCPU *cpu_tilegx_init(const char *cpu_model)
{
TileGXCPU *cpu;
cpu = TILEGX_CPU(object_new(TYPE_TILEGX_CPU));
object_property_set_bool(OBJECT(cpu), true, "realized", NULL);
return cpu;
}
static void tilegx_cpu_set_pc(CPUState *cs, vaddr value)
{
TileGXCPU *cpu = TILEGX_CPU(cs);
cpu->env.pc = value;
}
static bool tilegx_cpu_has_work(CPUState *cs)
{
return true;
}
static void tilegx_cpu_reset(CPUState *s)
{
TileGXCPU *cpu = TILEGX_CPU(s);
TileGXCPUClass *tcc = TILEGX_CPU_GET_CLASS(cpu);
CPUTLGState *env = &cpu->env;
tcc->parent_reset(s);
memset(env, 0, sizeof(CPUTLGState));
tlb_flush(s, 1);
}
static void tilegx_cpu_realizefn(DeviceState *dev, Error **errp)
{
CPUState *cs = CPU(dev);
TileGXCPUClass *tcc = TILEGX_CPU_GET_CLASS(dev);
cpu_reset(cs);
qemu_init_vcpu(cs);
tcc->parent_realize(dev, errp);
}
static void tilegx_cpu_initfn(Object *obj)
{
CPUState *cs = CPU(obj);
TileGXCPU *cpu = TILEGX_CPU(obj);
CPUTLGState *env = &cpu->env;
static bool tcg_initialized;
cs->env_ptr = env;
cpu_exec_init(cs, &error_abort);
if (tcg_enabled() && !tcg_initialized) {
tcg_initialized = true;
tilegx_tcg_init();
}
}
static void tilegx_cpu_do_interrupt(CPUState *cs)
{
cs->exception_index = -1;
}
static int tilegx_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw,
int mmu_idx)
{
TileGXCPU *cpu = TILEGX_CPU(cs);
/* The sigcode field will be filled in by do_signal in main.c. */
cs->exception_index = TILEGX_EXCP_SIGNAL;
cpu->env.excaddr = address;
cpu->env.signo = TARGET_SIGSEGV;
cpu->env.sigcode = 0;
return 1;
}
static bool tilegx_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
{
if (interrupt_request & CPU_INTERRUPT_HARD) {
tilegx_cpu_do_interrupt(cs);
return true;
}
return false;
}
static void tilegx_cpu_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
CPUClass *cc = CPU_CLASS(oc);
TileGXCPUClass *tcc = TILEGX_CPU_CLASS(oc);
tcc->parent_realize = dc->realize;
dc->realize = tilegx_cpu_realizefn;
tcc->parent_reset = cc->reset;
cc->reset = tilegx_cpu_reset;
cc->has_work = tilegx_cpu_has_work;
cc->do_interrupt = tilegx_cpu_do_interrupt;
cc->cpu_exec_interrupt = tilegx_cpu_exec_interrupt;
cc->dump_state = tilegx_cpu_dump_state;
cc->set_pc = tilegx_cpu_set_pc;
cc->handle_mmu_fault = tilegx_cpu_handle_mmu_fault;
cc->gdb_num_core_regs = 0;
/*
* Reason: tilegx_cpu_initfn() calls cpu_exec_init(), which saves
* the object in cpus -> dangling pointer after final
* object_unref().
*/
dc->cannot_destroy_with_object_finalize_yet = true;
}
static const TypeInfo tilegx_cpu_type_info = {
.name = TYPE_TILEGX_CPU,
.parent = TYPE_CPU,
.instance_size = sizeof(TileGXCPU),
.instance_init = tilegx_cpu_initfn,
.class_size = sizeof(TileGXCPUClass),
.class_init = tilegx_cpu_class_init,
};
static void tilegx_cpu_register_types(void)
{
type_register_static(&tilegx_cpu_type_info);
}
type_init(tilegx_cpu_register_types)