From: Janis Schoetterl-Glausch scgl@linux.ibm.com
[ Upstream commit b3cefd6bf16e7234ffbd4209f6083060f4e35f59 ]
This silences smatch warnings reported by kbuild bot: arch/s390/kvm/gaccess.c:859 guest_range_to_gpas() error: uninitialized symbol 'prot'. arch/s390/kvm/gaccess.c:1064 access_guest_with_key() error: uninitialized symbol 'prot'.
This is because it cannot tell that the value is not used in this case. The trans_exc* only examine prot if code is PGM_PROTECTION. Pass a dummy value for other codes.
Reported-by: kernel test robot lkp@intel.com Reported-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Janis Schoetterl-Glausch scgl@linux.ibm.com Reviewed-by: Claudio Imbrenda imbrenda@linux.ibm.com Link: https://lore.kernel.org/r/20220825192540.1560559-1-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger borntraeger@linux.ibm.com Signed-off-by: Janosch Frank frankja@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/kvm/gaccess.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c index 227ed0009354..0e82bf85e59b 100644 --- a/arch/s390/kvm/gaccess.c +++ b/arch/s390/kvm/gaccess.c @@ -489,6 +489,8 @@ enum prot_type { PROT_TYPE_ALC = 2, PROT_TYPE_DAT = 3, PROT_TYPE_IEP = 4, + /* Dummy value for passing an initialized value when code != PGM_PROTECTION */ + PROT_NONE, };
static int trans_exc_ending(struct kvm_vcpu *vcpu, int code, unsigned long gva, u8 ar, @@ -504,6 +506,10 @@ static int trans_exc_ending(struct kvm_vcpu *vcpu, int code, unsigned long gva, switch (code) { case PGM_PROTECTION: switch (prot) { + case PROT_NONE: + /* We should never get here, acts like termination */ + WARN_ON_ONCE(1); + break; case PROT_TYPE_IEP: tec->b61 = 1; fallthrough; @@ -968,8 +974,10 @@ static int guest_range_to_gpas(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, return rc; } else { gpa = kvm_s390_real_to_abs(vcpu, ga); - if (kvm_is_error_gpa(vcpu->kvm, gpa)) + if (kvm_is_error_gpa(vcpu->kvm, gpa)) { rc = PGM_ADDRESSING; + prot = PROT_NONE; + } } if (rc) return trans_exc(vcpu, rc, ga, ar, mode, prot); @@ -1112,8 +1120,6 @@ int access_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, if (rc == PGM_PROTECTION && try_storage_prot_override) rc = access_guest_page_with_key(vcpu->kvm, mode, gpas[idx], data, fragment_len, PAGE_SPO_ACC); - if (rc == PGM_PROTECTION) - prot = PROT_TYPE_KEYC; if (rc) break; len -= fragment_len; @@ -1123,6 +1129,10 @@ int access_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, if (rc > 0) { bool terminate = (mode == GACC_STORE) && (idx > 0);
+ if (rc == PGM_PROTECTION) + prot = PROT_TYPE_KEYC; + else + prot = PROT_NONE; rc = trans_exc_ending(vcpu, rc, ga, ar, mode, prot, terminate); } out_unlock: