kvm: Fix uninitialized cpuid_data

This error was reported by valgrind when running qemu-system-x86_64
with kvm:

==975== Conditional jump or move depends on uninitialised value(s)
==975==    at 0x521C38: cpuid_find_entry (kvm.c:176)
==975==    by 0x5235BA: kvm_arch_init_vcpu (kvm.c:686)
==975==    by 0x4D5175: kvm_init_vcpu (kvm-all.c:267)
==975==    by 0x45035B: qemu_kvm_cpu_thread_fn (cpus.c:858)
==975==    by 0xD361E0D: start_thread (pthread_create.c:311)
==975==    by 0xD65E9EC: clone (clone.S:113)
==975==  Uninitialised value was created by a stack allocation
==975==    at 0x5226E4: kvm_arch_init_vcpu (kvm.c:446)

Instead of adding more memset calls for parts of cpuid_data, the existing
calls were removed and cpuid_data is now initialized completely in one
call.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
This commit is contained in:
Stefan Weil 2013-11-06 22:35:27 +01:00 committed by Gleb Natapov
parent 3a902babf1
commit ef4cbe1434

View file

@ -456,11 +456,12 @@ int kvm_arch_init_vcpu(CPUState *cs)
uint32_t signature[3];
int r;
memset(&cpuid_data, 0, sizeof(cpuid_data));
cpuid_i = 0;
/* Paravirtualization CPUIDs */
c = &cpuid_data.entries[cpuid_i++];
memset(c, 0, sizeof(*c));
c->function = KVM_CPUID_SIGNATURE;
if (!hyperv_enabled(cpu)) {
memcpy(signature, "KVMKVMKVM\0\0\0", 12);
@ -474,7 +475,6 @@ int kvm_arch_init_vcpu(CPUState *cs)
c->edx = signature[2];
c = &cpuid_data.entries[cpuid_i++];
memset(c, 0, sizeof(*c));
c->function = KVM_CPUID_FEATURES;
c->eax = env->features[FEAT_KVM];
@ -483,13 +483,11 @@ int kvm_arch_init_vcpu(CPUState *cs)
c->eax = signature[0];
c = &cpuid_data.entries[cpuid_i++];
memset(c, 0, sizeof(*c));
c->function = HYPERV_CPUID_VERSION;
c->eax = 0x00001bbc;
c->ebx = 0x00060001;
c = &cpuid_data.entries[cpuid_i++];
memset(c, 0, sizeof(*c));
c->function = HYPERV_CPUID_FEATURES;
if (cpu->hyperv_relaxed_timing) {
c->eax |= HV_X64_MSR_HYPERCALL_AVAILABLE;
@ -500,7 +498,6 @@ int kvm_arch_init_vcpu(CPUState *cs)
}
c = &cpuid_data.entries[cpuid_i++];
memset(c, 0, sizeof(*c));
c->function = HYPERV_CPUID_ENLIGHTMENT_INFO;
if (cpu->hyperv_relaxed_timing) {
c->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
@ -511,13 +508,11 @@ int kvm_arch_init_vcpu(CPUState *cs)
c->ebx = cpu->hyperv_spinlock_attempts;
c = &cpuid_data.entries[cpuid_i++];
memset(c, 0, sizeof(*c));
c->function = HYPERV_CPUID_IMPLEMENT_LIMITS;
c->eax = 0x40;
c->ebx = 0x40;
c = &cpuid_data.entries[cpuid_i++];
memset(c, 0, sizeof(*c));
c->function = KVM_CPUID_SIGNATURE_NEXT;
memcpy(signature, "KVMKVMKVM\0\0\0", 12);
c->eax = 0;