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KVM: s390: Pass initialized arg even if unused

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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>
This commit is contained in:
Janis Schoetterl-Glausch 2022-08-25 21:25:40 +02:00 committed by Janosch Frank
parent e8c924a4fb
commit b3cefd6bf1
1 changed files with 13 additions and 3 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

16
arch/s390/kvm/gaccess.c
View file

@ -489,6 +489,8 @@ enum prot_type {
PROT_TYPE_ALC = 2, PROT_TYPE_ALC = 2,
PROT_TYPE_DAT = 3, PROT_TYPE_DAT = 3,
PROT_TYPE_IEP = 4, 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, 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) { switch (code) {
case PGM_PROTECTION: case PGM_PROTECTION:
switch (prot) { switch (prot) {
case PROT_NONE:
/* We should never get here, acts like termination */
WARN_ON_ONCE(1);
break;
case PROT_TYPE_IEP: case PROT_TYPE_IEP:
tec->b61 = 1; tec->b61 = 1;
fallthrough; fallthrough;
@ -968,8 +974,10 @@ static int guest_range_to_gpas(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
return rc; return rc;
} else { } else {
gpa = kvm_s390_real_to_abs(vcpu, ga); 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; rc = PGM_ADDRESSING;
prot = PROT_NONE;
}
} }
if (rc) if (rc)
return trans_exc(vcpu, rc, ga, ar, mode, prot); 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) if (rc == PGM_PROTECTION && try_storage_prot_override)
rc = access_guest_page_with_key(vcpu->kvm, mode, gpas[idx], rc = access_guest_page_with_key(vcpu->kvm, mode, gpas[idx],
data, fragment_len, PAGE_SPO_ACC); data, fragment_len, PAGE_SPO_ACC);
if (rc == PGM_PROTECTION)
prot = PROT_TYPE_KEYC;
if (rc) if (rc)
break; break;
len -= fragment_len; len -= fragment_len;
@ -1123,6 +1129,10 @@ int access_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
if (rc > 0) { if (rc > 0) {
bool terminate = (mode == GACC_STORE) && (idx > 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); rc = trans_exc_ending(vcpu, rc, ga, ar, mode, prot, terminate);
} }
out_unlock: out_unlock: