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| author | Sean Christopherson <seanjc@google.com> | 2022-04-29 03:04:07 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-06-20 12:21:36 +0200 |
| commit | 943dfea8f166d62657057170dbe8667ec96247ca (patch) | |
| tree | 02aa86bdc95e36b5e2a4a854169a7b91fd2b1e7c /virt | |
| parent | KVM: x86/mmu: Shove refcounted page dependency into host_pfn_mapping_level() (diff) | |
| download | linux-943dfea8f166d62657057170dbe8667ec96247ca.tar.xz linux-943dfea8f166d62657057170dbe8667ec96247ca.zip | |
KVM: Do not zero initialize 'pfn' in hva_to_pfn()
Drop the unnecessary initialization of the local 'pfn' variable in
hva_to_pfn(). First and foremost, '0' is not an invalid pfn, it's a
perfectly valid pfn on most architectures. I.e. if hva_to_pfn() were to
return an "uninitializd" pfn, it would actually be interpeted as a legal
pfn by most callers.
Second, hva_to_pfn() can't return an uninitialized pfn as hva_to_pfn()
explicitly sets pfn to an error value (or returns an error value directly)
if a helper returns failure, and all helpers set the pfn on success.
The zeroing of 'pfn' was introduced by commit 2fc843117d64 ("KVM:
reorganize hva_to_pfn"), probably to avoid "uninitialized variable"
warnings on statements that return pfn. However, no compiler seems
to produce them, making the initialization unnecessary.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220429010416.2788472-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 04196096f9e4..5b8ae83e09d7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2609,7 +2609,7 @@ kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, bool write_fault, bool *writable) { struct vm_area_struct *vma; - kvm_pfn_t pfn = 0; + kvm_pfn_t pfn; int npages, r; /* we can do it either atomically or asynchronously, not both */ |