qemu-e2k/target/openrisc/cpu.c
Stafford Horne e8f0ab0cd6 target/openrisc: Do not reset delay slot flag on early tb exit
This was found when running linux crypto algorithm selftests used by
wireguard.  We found that randomly the tests would fail.  We found
through investigation that a combination of a tick timer interrupt,
raised when executing a delay slot instruction at a page boundary caused
the issue.

This was caused when handling the TB_EXIT_REQUESTED case in cpu_tb_exec.
On OpenRISC, which doesn't implement synchronize_from_tb, set_pc was
being used as a fallback.  The OpenRISC set_pc implementation clears
dflag, which caused the exception handling logic to not account for the
delay slot.  This was the bug, because it meant when execution resumed
after the interrupt was handling it resumed in the wrong place.

Fix this by implementing synchronize_from_tb which simply updates pc,
and not clear the delay slot flag.

Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Stafford Horne <shorne@gmail.com>
2022-05-15 10:33:01 +09:00

297 lines
8.4 KiB
C

/*
* QEMU OpenRISC CPU
*
* Copyright (c) 2012 Jia Liu <proljc@gmail.com>
*
* 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/>.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/qemu-print.h"
#include "cpu.h"
#include "exec/exec-all.h"
static void openrisc_cpu_set_pc(CPUState *cs, vaddr value)
{
OpenRISCCPU *cpu = OPENRISC_CPU(cs);
cpu->env.pc = value;
cpu->env.dflag = 0;
}
static void openrisc_cpu_synchronize_from_tb(CPUState *cs,
const TranslationBlock *tb)
{
OpenRISCCPU *cpu = OPENRISC_CPU(cs);
cpu->env.pc = tb->pc;
}
static bool openrisc_cpu_has_work(CPUState *cs)
{
return cs->interrupt_request & (CPU_INTERRUPT_HARD |
CPU_INTERRUPT_TIMER);
}
static void openrisc_disas_set_info(CPUState *cpu, disassemble_info *info)
{
info->print_insn = print_insn_or1k;
}
static void openrisc_cpu_reset(DeviceState *dev)
{
CPUState *s = CPU(dev);
OpenRISCCPU *cpu = OPENRISC_CPU(s);
OpenRISCCPUClass *occ = OPENRISC_CPU_GET_CLASS(cpu);
occ->parent_reset(dev);
memset(&cpu->env, 0, offsetof(CPUOpenRISCState, end_reset_fields));
cpu->env.pc = 0x100;
cpu->env.sr = SR_FO | SR_SM;
cpu->env.lock_addr = -1;
s->exception_index = -1;
cpu_set_fpcsr(&cpu->env, 0);
#ifndef CONFIG_USER_ONLY
cpu->env.picmr = 0x00000000;
cpu->env.picsr = 0x00000000;
cpu->env.ttmr = 0x00000000;
#endif
}
#ifndef CONFIG_USER_ONLY
static void openrisc_cpu_set_irq(void *opaque, int irq, int level)
{
OpenRISCCPU *cpu = (OpenRISCCPU *)opaque;
CPUState *cs = CPU(cpu);
uint32_t irq_bit;
if (irq > 31 || irq < 0) {
return;
}
irq_bit = 1U << irq;
if (level) {
cpu->env.picsr |= irq_bit;
} else {
cpu->env.picsr &= ~irq_bit;
}
if (cpu->env.picsr & cpu->env.picmr) {
cpu_interrupt(cs, CPU_INTERRUPT_HARD);
} else {
cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
cpu->env.picsr = 0;
}
}
#endif
static void openrisc_cpu_realizefn(DeviceState *dev, Error **errp)
{
CPUState *cs = CPU(dev);
OpenRISCCPUClass *occ = OPENRISC_CPU_GET_CLASS(dev);
Error *local_err = NULL;
cpu_exec_realizefn(cs, &local_err);
if (local_err != NULL) {
error_propagate(errp, local_err);
return;
}
qemu_init_vcpu(cs);
cpu_reset(cs);
occ->parent_realize(dev, errp);
}
static void openrisc_cpu_initfn(Object *obj)
{
OpenRISCCPU *cpu = OPENRISC_CPU(obj);
cpu_set_cpustate_pointers(cpu);
#ifndef CONFIG_USER_ONLY
qdev_init_gpio_in_named(DEVICE(cpu), openrisc_cpu_set_irq, "IRQ", NR_IRQS);
#endif
}
/* CPU models */
static ObjectClass *openrisc_cpu_class_by_name(const char *cpu_model)
{
ObjectClass *oc;
char *typename;
typename = g_strdup_printf(OPENRISC_CPU_TYPE_NAME("%s"), cpu_model);
oc = object_class_by_name(typename);
g_free(typename);
if (oc != NULL && (!object_class_dynamic_cast(oc, TYPE_OPENRISC_CPU) ||
object_class_is_abstract(oc))) {
return NULL;
}
return oc;
}
static void or1200_initfn(Object *obj)
{
OpenRISCCPU *cpu = OPENRISC_CPU(obj);
cpu->env.vr = 0x13000008;
cpu->env.upr = UPR_UP | UPR_DMP | UPR_IMP | UPR_PICP | UPR_TTP | UPR_PMP;
cpu->env.cpucfgr = CPUCFGR_NSGF | CPUCFGR_OB32S | CPUCFGR_OF32S |
CPUCFGR_EVBARP;
/* 1Way, TLB_SIZE entries. */
cpu->env.dmmucfgr = (DMMUCFGR_NTW & (0 << 2))
| (DMMUCFGR_NTS & (ctz32(TLB_SIZE) << 2));
cpu->env.immucfgr = (IMMUCFGR_NTW & (0 << 2))
| (IMMUCFGR_NTS & (ctz32(TLB_SIZE) << 2));
}
static void openrisc_any_initfn(Object *obj)
{
OpenRISCCPU *cpu = OPENRISC_CPU(obj);
cpu->env.vr = 0x13000040; /* Obsolete VER + UVRP for new SPRs */
cpu->env.vr2 = 0; /* No version specific id */
cpu->env.avr = 0x01030000; /* Architecture v1.3 */
cpu->env.upr = UPR_UP | UPR_DMP | UPR_IMP | UPR_PICP | UPR_TTP | UPR_PMP;
cpu->env.cpucfgr = CPUCFGR_NSGF | CPUCFGR_OB32S | CPUCFGR_OF32S |
CPUCFGR_AVRP | CPUCFGR_EVBARP | CPUCFGR_OF64A32S;
/* 1Way, TLB_SIZE entries. */
cpu->env.dmmucfgr = (DMMUCFGR_NTW & (0 << 2))
| (DMMUCFGR_NTS & (ctz32(TLB_SIZE) << 2));
cpu->env.immucfgr = (IMMUCFGR_NTW & (0 << 2))
| (IMMUCFGR_NTS & (ctz32(TLB_SIZE) << 2));
}
#ifndef CONFIG_USER_ONLY
#include "hw/core/sysemu-cpu-ops.h"
static const struct SysemuCPUOps openrisc_sysemu_ops = {
.get_phys_page_debug = openrisc_cpu_get_phys_page_debug,
};
#endif
#include "hw/core/tcg-cpu-ops.h"
static const struct TCGCPUOps openrisc_tcg_ops = {
.initialize = openrisc_translate_init,
.synchronize_from_tb = openrisc_cpu_synchronize_from_tb,
#ifndef CONFIG_USER_ONLY
.tlb_fill = openrisc_cpu_tlb_fill,
.cpu_exec_interrupt = openrisc_cpu_exec_interrupt,
.do_interrupt = openrisc_cpu_do_interrupt,
#endif /* !CONFIG_USER_ONLY */
};
static void openrisc_cpu_class_init(ObjectClass *oc, void *data)
{
OpenRISCCPUClass *occ = OPENRISC_CPU_CLASS(oc);
CPUClass *cc = CPU_CLASS(occ);
DeviceClass *dc = DEVICE_CLASS(oc);
device_class_set_parent_realize(dc, openrisc_cpu_realizefn,
&occ->parent_realize);
device_class_set_parent_reset(dc, openrisc_cpu_reset, &occ->parent_reset);
cc->class_by_name = openrisc_cpu_class_by_name;
cc->has_work = openrisc_cpu_has_work;
cc->dump_state = openrisc_cpu_dump_state;
cc->set_pc = openrisc_cpu_set_pc;
cc->gdb_read_register = openrisc_cpu_gdb_read_register;
cc->gdb_write_register = openrisc_cpu_gdb_write_register;
#ifndef CONFIG_USER_ONLY
dc->vmsd = &vmstate_openrisc_cpu;
cc->sysemu_ops = &openrisc_sysemu_ops;
#endif
cc->gdb_num_core_regs = 32 + 3;
cc->disas_set_info = openrisc_disas_set_info;
cc->tcg_ops = &openrisc_tcg_ops;
}
/* Sort alphabetically by type name, except for "any". */
static gint openrisc_cpu_list_compare(gconstpointer a, gconstpointer b)
{
ObjectClass *class_a = (ObjectClass *)a;
ObjectClass *class_b = (ObjectClass *)b;
const char *name_a, *name_b;
name_a = object_class_get_name(class_a);
name_b = object_class_get_name(class_b);
if (strcmp(name_a, "any-" TYPE_OPENRISC_CPU) == 0) {
return 1;
} else if (strcmp(name_b, "any-" TYPE_OPENRISC_CPU) == 0) {
return -1;
} else {
return strcmp(name_a, name_b);
}
}
static void openrisc_cpu_list_entry(gpointer data, gpointer user_data)
{
ObjectClass *oc = data;
const char *typename;
char *name;
typename = object_class_get_name(oc);
name = g_strndup(typename,
strlen(typename) - strlen("-" TYPE_OPENRISC_CPU));
qemu_printf(" %s\n", name);
g_free(name);
}
void cpu_openrisc_list(void)
{
GSList *list;
list = object_class_get_list(TYPE_OPENRISC_CPU, false);
list = g_slist_sort(list, openrisc_cpu_list_compare);
qemu_printf("Available CPUs:\n");
g_slist_foreach(list, openrisc_cpu_list_entry, NULL);
g_slist_free(list);
}
#define DEFINE_OPENRISC_CPU_TYPE(cpu_model, initfn) \
{ \
.parent = TYPE_OPENRISC_CPU, \
.instance_init = initfn, \
.name = OPENRISC_CPU_TYPE_NAME(cpu_model), \
}
static const TypeInfo openrisc_cpus_type_infos[] = {
{ /* base class should be registered first */
.name = TYPE_OPENRISC_CPU,
.parent = TYPE_CPU,
.instance_size = sizeof(OpenRISCCPU),
.instance_init = openrisc_cpu_initfn,
.abstract = true,
.class_size = sizeof(OpenRISCCPUClass),
.class_init = openrisc_cpu_class_init,
},
DEFINE_OPENRISC_CPU_TYPE("or1200", or1200_initfn),
DEFINE_OPENRISC_CPU_TYPE("any", openrisc_any_initfn),
};
DEFINE_TYPES(openrisc_cpus_type_infos)