2022-11-01 07:37:15

by Bo Liu

Subject: [PATCH] KVM: replace ternary operator with min()

Fix the following coccicheck warning:

virt/kvm/kvm_main.c:5289:10-11: WARNING opportunity for min()
virt/kvm/kvm_main.c:5218:10-11: WARNING opportunity for min()

min() macro is defined in include/linux/minmax.h. It avoids
multiple evaluations of the arguments when non-constant and
performs strict type-checking.

Signed-off-by: Bo Liu <[email protected]>
---
virt/kvm/kvm_main.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3f383f27d3d7..45a56a9600e1 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -5215,7 +5215,7 @@ int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
if (!bus)
return -ENOMEM;
r = __kvm_io_bus_write(vcpu, bus, &range, val);
- return r < 0 ? r : 0;
+ return min(r, 0);
}
EXPORT_SYMBOL_GPL(kvm_io_bus_write);

@@ -5286,7 +5286,7 @@ int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
if (!bus)
return -ENOMEM;
r = __kvm_io_bus_read(vcpu, bus, &range, val);
- return r < 0 ? r : 0;
+ return min(r, 0);
}

/* Caller must hold slots_lock. */
--
2.27.0

2022-11-01 11:28:59

by David Laight

Subject: RE: [PATCH] KVM: replace ternary operator with min()

From: Bo Liu
> Sent: 01 November 2022 07:25
>
> Fix the following coccicheck warning:
>
> virt/kvm/kvm_main.c:5289:10-11: WARNING opportunity for min()
...
> - return r < 0 ? r : 0;
> + return min(r, 0);

As has been repeatedly pointer out this is bogus.
min() should only be used for 'sizes'.

David

-
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