On 24.02.22 12:36, Claudio Imbrenda wrote:
On Wed, 23 Feb 2022 18:44:20 +0200
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
While in this particular case it would not be a (critical) issue,
the pattern itself is bad and error prone in case somebody blindly
copies to their code.
Don't cast parameter to unsigned long pointer in the bit operations.
Instead copy to a local variable on stack of a proper type and use.
Fixes: d77e64141e32 ("KVM: s390: implement GISA IPM related primitives")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
arch/s390/include/asm/kvm_host.h | 5 ++++-
arch/s390/kvm/interrupt.c | 6 +++---
2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index a22c9266ea05..f1c4a1b9b360 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -867,7 +867,10 @@ struct kvm_s390_gisa {
u8 reserved03[11];
u32 airq_count;
} g1;
- struct {
+ struct { /* as a 256-bit bitmap */
+ DECLARE_BITMAP(b, 256);
+ } bitmap;
+ struct { /* as a set of 64-bit words */
u64 word[4];
} u64;
};
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index db933c252dbc..04e055cbd080 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -304,7 +304,7 @@ static inline int gisa_in_alert_list(struct kvm_s390_gisa *gisa)
static inline void gisa_set_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gisc)
{
- set_bit_inv(IPM_BIT_OFFSET + gisc, (unsigned long *) gisa);
+ set_bit_inv(IPM_BIT_OFFSET + gisc, gisa->bitmap.b);
wouldn't it be enough to pass gisa->u64.word here?
then no cast would be necessary
we do that at several places
arch/s390/kernel/processor.c: for_each_set_bit_inv(bit, (long
*)&stfle_fac_list, MAX_FACILITY_BIT)
arch/s390/kvm/interrupt.c: set_bit_inv(IPM_BIT_OFFSET + gisc, (unsigned
long *) gisa);
arch/s390/kvm/kvm-s390.c: set_bit_inv(vcpu->vcpu_id, (unsigned long *)
sca->mcn);
arch/s390/kvm/kvm-s390.c: set_bit_inv(vcpu->vcpu_id, (unsigned long *)
&sca->mcn);
}
static inline u8 gisa_get_ipm(struct kvm_s390_gisa *gisa)
@@ -314,12 +314,12 @@ static inline u8 gisa_get_ipm(struct kvm_s390_gisa *gisa)
static inline void gisa_clear_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gisc)
{
- clear_bit_inv(IPM_BIT_OFFSET + gisc, (unsigned long *) gisa);
+ clear_bit_inv(IPM_BIT_OFFSET + gisc, gisa->bitmap.b);
}
static inline int gisa_tac_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gisc)
{
- return test_and_clear_bit_inv(IPM_BIT_OFFSET + gisc, (unsigned long *) gisa);
+ return test_and_clear_bit_inv(IPM_BIT_OFFSET + gisc, gisa->bitmap.b);
}
static inline unsigned long pending_irqs_no_gisa(struct kvm_vcpu *vcpu)
