[PATCH v6 09/10] KVM: s390: Return failure in case of failure in kvm_s390_set_cmma_bits()

From: Claudio Imbrenda

Date: Tue Jun 23 2026 - 11:38:30 EST


If the allocation of the bits array failed, kvm_s390_set_cmma_bits()
would return 0 instead of an error code.

Rework the function to use the __free() macros and thus simplify the
code flow; when the above mentioned allocation fails, simply return
-ENOMEM.

Fixes: e38c884df921 ("KVM: s390: Switch to new gmap")
Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
---
arch/s390/kvm/kvm-s390.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 91cf7a3c55c7..c08a63a1bfb9 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2313,8 +2313,8 @@ static int kvm_s390_get_cmma_bits(struct kvm *kvm,
static int kvm_s390_set_cmma_bits(struct kvm *kvm,
const struct kvm_s390_cmma_log *args)
{
- struct kvm_s390_mmu_cache *mc;
- u8 *bits = NULL;
+ struct kvm_s390_mmu_cache *mc __free(kvm_s390_mmu_cache) = NULL;
+ u8 *bits __free(kvfree) = NULL;
int r = 0;

if (!kvm->arch.use_cmma)
@@ -2334,18 +2334,16 @@ static int kvm_s390_set_cmma_bits(struct kvm *kvm,
return -ENOMEM;
bits = vmalloc(array_size(sizeof(*bits), args->count));
if (!bits)
- goto out;
+ return -ENOMEM;

r = copy_from_user(bits, (void __user *)args->values, args->count);
- if (r) {
- r = -EFAULT;
- goto out;
- }
+ if (r)
+ return -EFAULT;

do {
r = kvm_s390_mmu_cache_topup(mc);
if (r)
- break;
+ return r;
scoped_guard(read_lock, &kvm->mmu_lock) {
r = dat_set_cmma_bits(mc, kvm->arch.gmap->asce, args->start_gfn,
args->count, args->mask, bits);
@@ -2353,9 +2351,7 @@ static int kvm_s390_set_cmma_bits(struct kvm *kvm,
} while (r == -ENOMEM);

set_bit(GMAP_FLAG_USES_CMM, &kvm->arch.gmap->flags);
-out:
- kvm_s390_free_mmu_cache(mc);
- vfree(bits);
+
return r;
}

--
2.54.0