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KVM: x86: Make kvm_get_dr() return a value, not use an out parameter

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Convert kvm_get_dr()'s output parameter to a return value, and clean up
most of the mess that was created by forcing callers to provide a pointer.

No functional change intended.

Acked-by: Mathias Krause <minipli@grsecurity.net>
Reviewed-by: Mathias Krause <minipli@grsecurity.net>
Link: https://lore.kernel.org/r/20240209220752.388160-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson 2024-02-09 14:07:51 -08:00
parent 64435aaa4a
commit fc5375dd8c
8 changed files with 21 additions and 49 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/include/asm/kvm_host.h
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@ -2045,7 +2045,7 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3);
int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4);
int kvm_set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8);
int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val);
void kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val);
unsigned long kvm_get_dr(struct kvm_vcpu *vcpu, int dr);
unsigned long kvm_get_cr8(struct kvm_vcpu *vcpu);
void kvm_lmsw(struct kvm_vcpu *vcpu, unsigned long msw);
int kvm_emulate_xsetbv(struct kvm_vcpu *vcpu);

17
arch/x86/kvm/emulate.c
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@ -3013,7 +3013,7 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
ret = em_push(ctxt);
}
ops->get_dr(ctxt, 7, &dr7);
dr7 = ops->get_dr(ctxt, 7);
ops->set_dr(ctxt, 7, dr7 & ~(DR_LOCAL_ENABLE_MASK | DR_LOCAL_SLOWDOWN));
return ret;
@ -3868,15 +3868,6 @@ static int check_cr_access(struct x86_emulate_ctxt *ctxt)
return X86EMUL_CONTINUE;
}
static int check_dr7_gd(struct x86_emulate_ctxt *ctxt)
{
unsigned long dr7;
ctxt->ops->get_dr(ctxt, 7, &dr7);
return dr7 & DR7_GD;
}
static int check_dr_read(struct x86_emulate_ctxt *ctxt)
{
int dr = ctxt->modrm_reg;
@ -3889,10 +3880,10 @@ static int check_dr_read(struct x86_emulate_ctxt *ctxt)
if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5))
return emulate_ud(ctxt);
if (check_dr7_gd(ctxt)) {
if (ctxt->ops->get_dr(ctxt, 7) & DR7_GD) {
ulong dr6;
ctxt->ops->get_dr(ctxt, 6, &dr6);
dr6 = ctxt->ops->get_dr(ctxt, 6);
dr6 &= ~DR_TRAP_BITS;
dr6 |= DR6_BD | DR6_ACTIVE_LOW;
ctxt->ops->set_dr(ctxt, 6, dr6);
@ -5451,7 +5442,7 @@ twobyte_insn:
ctxt->dst.val = ops->get_cr(ctxt, ctxt->modrm_reg);
break;
case 0x21: /* mov from dr to reg */
ops->get_dr(ctxt, ctxt->modrm_reg, &ctxt->dst.val);
ctxt->dst.val = ops->get_dr(ctxt, ctxt->modrm_reg);
break;
case 0x40 ... 0x4f: /* cmov */
if (test_cc(ctxt->b, ctxt->eflags))

2
arch/x86/kvm/kvm_emulate.h
View File

@ -203,7 +203,7 @@ struct x86_emulate_ops {
ulong (*get_cr)(struct x86_emulate_ctxt *ctxt, int cr);
int (*set_cr)(struct x86_emulate_ctxt *ctxt, int cr, ulong val);
int (*cpl)(struct x86_emulate_ctxt *ctxt);
void (*get_dr)(struct x86_emulate_ctxt *ctxt, int dr, ulong *dest);
ulong (*get_dr)(struct x86_emulate_ctxt *ctxt, int dr);
int (*set_dr)(struct x86_emulate_ctxt *ctxt, int dr, ulong value);
int (*set_msr_with_filter)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 data);
int (*get_msr_with_filter)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 *pdata);

15
arch/x86/kvm/smm.c
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@ -184,7 +184,6 @@ static void enter_smm_save_state_32(struct kvm_vcpu *vcpu,
struct kvm_smram_state_32 *smram)
{
struct desc_ptr dt;
unsigned long val;
int i;
smram->cr0 = kvm_read_cr0(vcpu);
@ -195,10 +194,8 @@ static void enter_smm_save_state_32(struct kvm_vcpu *vcpu,
for (i = 0; i < 8; i++)
smram->gprs[i] = kvm_register_read_raw(vcpu, i);
kvm_get_dr(vcpu, 6, &val);
smram->dr6 = (u32)val;
kvm_get_dr(vcpu, 7, &val);
smram->dr7 = (u32)val;
smram->dr6 = (u32)kvm_get_dr(vcpu, 6);
smram->dr7 = (u32)kvm_get_dr(vcpu, 7);
enter_smm_save_seg_32(vcpu, &smram->tr, &smram->tr_sel, VCPU_SREG_TR);
enter_smm_save_seg_32(vcpu, &smram->ldtr, &smram->ldtr_sel, VCPU_SREG_LDTR);
@ -231,7 +228,6 @@ static void enter_smm_save_state_64(struct kvm_vcpu *vcpu,
struct kvm_smram_state_64 *smram)
{
struct desc_ptr dt;
unsigned long val;
int i;
for (i = 0; i < 16; i++)
@ -240,11 +236,8 @@ static void enter_smm_save_state_64(struct kvm_vcpu *vcpu,
smram->rip = kvm_rip_read(vcpu);
smram->rflags = kvm_get_rflags(vcpu);
kvm_get_dr(vcpu, 6, &val);
smram->dr6 = val;
kvm_get_dr(vcpu, 7, &val);
smram->dr7 = val;
smram->dr6 = kvm_get_dr(vcpu, 6);
smram->dr7 = kvm_get_dr(vcpu, 7);
smram->cr0 = kvm_read_cr0(vcpu);
smram->cr3 = kvm_read_cr3(vcpu);

7
arch/x86/kvm/svm/svm.c
View File

@ -2735,7 +2735,6 @@ static int dr_interception(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
int reg, dr;
unsigned long val;
int err = 0;
/*
@ -2763,11 +2762,9 @@ static int dr_interception(struct kvm_vcpu *vcpu)
dr = svm->vmcb->control.exit_code - SVM_EXIT_READ_DR0;
if (dr >= 16) { /* mov to DRn */
dr -= 16;
val = kvm_register_read(vcpu, reg);
err = kvm_set_dr(vcpu, dr, val);
err = kvm_set_dr(vcpu, dr, kvm_register_read(vcpu, reg));
} else {
kvm_get_dr(vcpu, dr, &val);
kvm_register_write(vcpu, reg, val);
kvm_register_write(vcpu, reg, kvm_get_dr(vcpu, dr));
}
return kvm_complete_insn_gp(vcpu, err);

2
arch/x86/kvm/vmx/nested.c
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@ -4433,7 +4433,7 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
(vm_entry_controls_get(to_vmx(vcpu)) & VM_ENTRY_IA32E_MODE);
if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_DEBUG_CONTROLS)
kvm_get_dr(vcpu, 7, (unsigned long *)&vmcs12->guest_dr7);
vmcs12->guest_dr7 = kvm_get_dr(vcpu, 7);
if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_EFER)
vmcs12->guest_ia32_efer = vcpu->arch.efer;

5
arch/x86/kvm/vmx/vmx.c
View File

@ -5566,10 +5566,7 @@ static int handle_dr(struct kvm_vcpu *vcpu)
reg = DEBUG_REG_ACCESS_REG(exit_qualification);
if (exit_qualification & TYPE_MOV_FROM_DR) {
unsigned long val;
kvm_get_dr(vcpu, dr, &val);
kvm_register_write(vcpu, reg, val);
kvm_register_write(vcpu, reg, kvm_get_dr(vcpu, dr));
err = 0;
} else {
err = kvm_set_dr(vcpu, dr, kvm_register_read(vcpu, reg));

20
arch/x86/kvm/x86.c
View File

@ -1399,22 +1399,19 @@ int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
}
EXPORT_SYMBOL_GPL(kvm_set_dr);
void kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
unsigned long kvm_get_dr(struct kvm_vcpu *vcpu, int dr)
{
size_t size = ARRAY_SIZE(vcpu->arch.db);
switch (dr) {
case 0 ... 3:
*val = vcpu->arch.db[array_index_nospec(dr, size)];
break;
return vcpu->arch.db[array_index_nospec(dr, size)];
case 4:
case 6:
*val = vcpu->arch.dr6;
break;
return vcpu->arch.dr6;
case 5:
default: /* 7 */
*val = vcpu->arch.dr7;
break;
return vcpu->arch.dr7;
}
}
EXPORT_SYMBOL_GPL(kvm_get_dr);
@ -5509,7 +5506,6 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu,
struct kvm_debugregs *dbgregs)
{
unsigned long val;
unsigned int i;
memset(dbgregs, 0, sizeof(*dbgregs));
@ -5518,8 +5514,7 @@ static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu,
for (i = 0; i < ARRAY_SIZE(vcpu->arch.db); i++)
dbgregs->db[i] = vcpu->arch.db[i];
kvm_get_dr(vcpu, 6, &val);
dbgregs->dr6 = val;
dbgregs->dr6 = kvm_get_dr(vcpu, 6);
dbgregs->dr7 = vcpu->arch.dr7;
}
@ -8173,10 +8168,9 @@ static void emulator_wbinvd(struct x86_emulate_ctxt *ctxt)
kvm_emulate_wbinvd_noskip(emul_to_vcpu(ctxt));
}
static void emulator_get_dr(struct x86_emulate_ctxt *ctxt, int dr,
unsigned long *dest)
static unsigned long emulator_get_dr(struct x86_emulate_ctxt *ctxt, int dr)
{
kvm_get_dr(emul_to_vcpu(ctxt), dr, dest);
return kvm_get_dr(emul_to_vcpu(ctxt), dr);
}
static int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr,