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s390/kvm: remove explicit -EFAULT return code checking on guest access

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Let's change to the paradigm that every return code from guest memory
access functions that is not zero translates to -EFAULT and do not
explictly compare.
Explictly comparing the return value with -EFAULT has already shown to
be a bit fragile. In addition this is closer to the handling of
copy_to/from_user functions, which imho is in general a good idea.

Also shorten the return code handling in interrupt.c a bit.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Heiko Carstens 2013-03-05 13:14:43 +01:00 committed by Marcelo Tosatti
parent 59a1fa2d80
commit dc5008b9bf
3 changed files with 74 additions and 177 deletions
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4
arch/s390/kvm/intercept.c
View file

@ -45,7 +45,7 @@ static int handle_lctlg(struct kvm_vcpu *vcpu)
do {
rc = get_guest_u64(vcpu, useraddr,
&vcpu->arch.sie_block->gcr[reg]);
if (rc == -EFAULT) {
if (rc) {
kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
break;
}
@ -79,7 +79,7 @@ static int handle_lctl(struct kvm_vcpu *vcpu)
reg = reg1;
do {
rc = get_guest_u32(vcpu, useraddr, &val);
if (rc == -EFAULT) {
if (rc) {
kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
break;
}

241
arch/s390/kvm/interrupt.c
View file

@ -180,7 +180,7 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
struct kvm_s390_interrupt_info *inti)
{
const unsigned short table[] = { 2, 4, 4, 6 };
int rc, exception = 0;
int rc = 0;
switch (inti->type) {
case KVM_S390_INT_EMERGENCY:
@ -188,74 +188,38 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
vcpu->stat.deliver_emergency_signal++;
trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type,
inti->emerg.code, 0);
rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x1201);
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u16(vcpu, __LC_EXT_CPU_ADDR, inti->emerg.code);
if (rc == -EFAULT)
exception = 1;
rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_EXT_NEW_PSW, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x1201);
rc |= put_guest_u16(vcpu, __LC_EXT_CPU_ADDR, inti->emerg.code);
rc |= copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
rc |= copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_EXT_NEW_PSW, sizeof(psw_t));
break;
case KVM_S390_INT_EXTERNAL_CALL:
VCPU_EVENT(vcpu, 4, "%s", "interrupt: sigp ext call");
vcpu->stat.deliver_external_call++;
trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type,
inti->extcall.code, 0);
rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x1202);
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u16(vcpu, __LC_EXT_CPU_ADDR, inti->extcall.code);
if (rc == -EFAULT)
exception = 1;
rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_EXT_NEW_PSW, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x1202);
rc |= put_guest_u16(vcpu, __LC_EXT_CPU_ADDR, inti->extcall.code);
rc |= copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
rc |= copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_EXT_NEW_PSW, sizeof(psw_t));
break;
case KVM_S390_INT_SERVICE:
VCPU_EVENT(vcpu, 4, "interrupt: sclp parm:%x",
inti->ext.ext_params);
vcpu->stat.deliver_service_signal++;
trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type,
inti->ext.ext_params, 0);
rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x2401);
if (rc == -EFAULT)
exception = 1;
rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_EXT_NEW_PSW, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u32(vcpu, __LC_EXT_PARAMS, inti->ext.ext_params);
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x2401);
rc |= copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
rc |= copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_EXT_NEW_PSW, sizeof(psw_t));
rc |= put_guest_u32(vcpu, __LC_EXT_PARAMS, inti->ext.ext_params);
break;
case KVM_S390_INT_VIRTIO:
VCPU_EVENT(vcpu, 4, "interrupt: virtio parm:%x,parm64:%llx",
inti->ext.ext_params, inti->ext.ext_params2);
@ -263,34 +227,16 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type,
inti->ext.ext_params,
inti->ext.ext_params2);
rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x2603);
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u16(vcpu, __LC_EXT_CPU_ADDR, 0x0d00);
if (rc == -EFAULT)
exception = 1;
rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_EXT_NEW_PSW, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u32(vcpu, __LC_EXT_PARAMS, inti->ext.ext_params);
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u64(vcpu, __LC_EXT_PARAMS2,
inti->ext.ext_params2);
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x2603);
rc |= put_guest_u16(vcpu, __LC_EXT_CPU_ADDR, 0x0d00);
rc |= copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
rc |= copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_EXT_NEW_PSW, sizeof(psw_t));
rc |= put_guest_u32(vcpu, __LC_EXT_PARAMS, inti->ext.ext_params);
rc |= put_guest_u64(vcpu, __LC_EXT_PARAMS2,
inti->ext.ext_params2);
break;
case KVM_S390_SIGP_STOP:
VCPU_EVENT(vcpu, 4, "%s", "interrupt: cpu stop");
vcpu->stat.deliver_stop_signal++;
@ -313,18 +259,14 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
vcpu->stat.deliver_restart_signal++;
trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type,
0, 0);
rc = copy_to_guest(vcpu, offsetof(struct _lowcore,
restart_old_psw), &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
offsetof(struct _lowcore, restart_psw), sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = copy_to_guest(vcpu,
offsetof(struct _lowcore, restart_old_psw),
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
rc |= copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
offsetof(struct _lowcore, restart_psw),
sizeof(psw_t));
atomic_clear_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
break;
case KVM_S390_PROGRAM_INT:
VCPU_EVENT(vcpu, 4, "interrupt: pgm check code:%x, ilc:%x",
inti->pgm.code,
@ -332,24 +274,13 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
vcpu->stat.deliver_program_int++;
trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type,
inti->pgm.code, 0);
rc = put_guest_u16(vcpu, __LC_PGM_INT_CODE, inti->pgm.code);
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u16(vcpu, __LC_PGM_ILC,
table[vcpu->arch.sie_block->ipa >> 14]);
if (rc == -EFAULT)
exception = 1;
rc = copy_to_guest(vcpu, __LC_PGM_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_PGM_NEW_PSW, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u16(vcpu, __LC_PGM_INT_CODE, inti->pgm.code);
rc |= put_guest_u16(vcpu, __LC_PGM_ILC,
table[vcpu->arch.sie_block->ipa >> 14]);
rc |= copy_to_guest(vcpu, __LC_PGM_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
rc |= copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_PGM_NEW_PSW, sizeof(psw_t));
break;
case KVM_S390_MCHK:
@ -358,24 +289,13 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type,
inti->mchk.cr14,
inti->mchk.mcic);
rc = kvm_s390_vcpu_store_status(vcpu,
KVM_S390_STORE_STATUS_PREFIXED);
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u64(vcpu, __LC_MCCK_CODE, inti->mchk.mcic);
if (rc == -EFAULT)
exception = 1;
rc = copy_to_guest(vcpu, __LC_MCK_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_MCK_NEW_PSW, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = kvm_s390_vcpu_store_status(vcpu,
KVM_S390_STORE_STATUS_PREFIXED);
rc |= put_guest_u64(vcpu, __LC_MCCK_CODE, inti->mchk.mcic);
rc |= copy_to_guest(vcpu, __LC_MCK_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
rc |= copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_MCK_NEW_PSW, sizeof(psw_t));
break;
case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
@ -388,67 +308,44 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
vcpu->stat.deliver_io_int++;
trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type,
param0, param1);
rc = put_guest_u16(vcpu, __LC_SUBCHANNEL_ID,
inti->io.subchannel_id);
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u16(vcpu, __LC_SUBCHANNEL_NR,
inti->io.subchannel_nr);
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u32(vcpu, __LC_IO_INT_PARM,
inti->io.io_int_parm);
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u32(vcpu, __LC_IO_INT_WORD,
inti->io.io_int_word);
if (rc == -EFAULT)
exception = 1;
rc = copy_to_guest(vcpu, __LC_IO_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_IO_NEW_PSW, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = put_guest_u16(vcpu, __LC_SUBCHANNEL_ID,
inti->io.subchannel_id);
rc |= put_guest_u16(vcpu, __LC_SUBCHANNEL_NR,
inti->io.subchannel_nr);
rc |= put_guest_u32(vcpu, __LC_IO_INT_PARM,
inti->io.io_int_parm);
rc |= put_guest_u32(vcpu, __LC_IO_INT_WORD,
inti->io.io_int_word);
rc |= copy_to_guest(vcpu, __LC_IO_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
rc |= copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_IO_NEW_PSW, sizeof(psw_t));
break;
}
default:
BUG();
}
if (exception) {
if (rc) {
printk("kvm: The guest lowcore is not mapped during interrupt "
"delivery, killing userspace\n");
"delivery, killing userspace\n");
do_exit(SIGKILL);
}
}
static int __try_deliver_ckc_interrupt(struct kvm_vcpu *vcpu)
{
int rc, exception = 0;
int rc;
if (psw_extint_disabled(vcpu))
return 0;
if (!(vcpu->arch.sie_block->gcr[0] & 0x800ul))
return 0;
rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x1004);
if (rc == -EFAULT)
exception = 1;
rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_EXT_NEW_PSW, sizeof(psw_t));
if (rc == -EFAULT)
exception = 1;
if (exception) {
rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x1004);
rc |= copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
&vcpu->arch.sie_block->gpsw, sizeof(psw_t));
rc |= copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
__LC_EXT_NEW_PSW, sizeof(psw_t));
if (rc) {
printk("kvm: The guest lowcore is not mapped during interrupt "
"delivery, killing userspace\n");
do_exit(SIGKILL);

6
arch/s390/kvm/priv.c
View file

@ -108,7 +108,7 @@ static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
}
rc = put_guest_u16(vcpu, useraddr, vcpu->vcpu_id);
if (rc == -EFAULT) {
if (rc) {
kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
goto out;
}
@ -230,7 +230,7 @@ static int handle_stfl(struct kvm_vcpu *vcpu)
rc = copy_to_guest(vcpu, offsetof(struct _lowcore, stfl_fac_list),
&facility_list, sizeof(facility_list));
if (rc == -EFAULT)
if (rc)
kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
else {
VCPU_EVENT(vcpu, 5, "store facility list value %x",
@ -348,7 +348,7 @@ static int handle_stidp(struct kvm_vcpu *vcpu)
}
rc = put_guest_u64(vcpu, operand2, vcpu->arch.stidp_data);
if (rc == -EFAULT) {
if (rc) {
kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
goto out;
}