| Message ID | 20220825192540.1560559-1-scgl@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] KVM: s390: Pass initialized arg even if unused | expand |
On Thu, 25 Aug 2022 21:25:40 +0200 Janis Schoetterl-Glausch <scgl@linux.ibm.com> wrote: > 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> > --- > v1 -> v2 > * drop unlikely, WARN_ON_ONCE instead of WARN (thanks Heiko) > > 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 082ec5f2c3a5..0243b6e38d36 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:
Am 25.08.22 um 21:25 schrieb Janis Schoetterl-Glausch: > 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> Thanks applied. > --- > v1 -> v2 > * drop unlikely, WARN_ON_ONCE instead of WARN (thanks Heiko) > > 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 082ec5f2c3a5..0243b6e38d36 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:
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c index 082ec5f2c3a5..0243b6e38d36 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:
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> --- v1 -> v2 * drop unlikely, WARN_ON_ONCE instead of WARN (thanks Heiko) arch/s390/kvm/gaccess.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)