8b9e13d2de
In kvm_hv_flush_tlb(), 'data_offset' and 'consumed_xmm_halves' variables
are used in a mutually exclusive way: in 'hc->fast' we count in 'XMM
halves' and increase 'data_offset' otherwise. Coverity discovered, that in
one case both variables are incremented unconditionally. This doesn't seem
to cause any issues as the only user of 'data_offset'/'consumed_xmm_halves'
data is kvm_hv_get_tlb_flush_entries() -> kvm_hv_get_hc_data() which also
takes into account 'hc->fast' but is still worth fixing.
To make things explicit, put 'data_offset' and 'consumed_xmm_halves' to
'struct kvm_hv_hcall' as a union and use at call sites. This allows to
remove explicit 'data_offset'/'consumed_xmm_halves' parameters from
kvm_hv_get_hc_data()/kvm_get_sparse_vp_set()/kvm_hv_get_tlb_flush_entries()
helpers.
Note: 'struct kvm_hv_hcall' is allocated on stack in kvm_hv_hypercall() and
is not zeroed, consumers are supposed to initialize the appropriate field
if needed.
Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1527764 ("Uninitialized variables")
Fixes: 260970862c88 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221208102700.959630-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.