Re: [PATCH v2 10/16] KVM: PPC: Book3S PR: Remove uninitialized_var() usage
From: Nick Desaulniers <hidden>
Date: 2020-06-22 17:23:09
Also in:
linux-block, linux-clk, linux-doc, linux-ide, linux-mm, linux-spi, linux-wireless, lkml
On Fri, Jun 19, 2020 at 8:30 PM Kees Cook [off-list ref] wrote:
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings (e.g.
"unused variable"). If the compiler thinks it is uninitialized, either
simply initialize the variable or make compiler changes. As a precursor
to removing[2] this[3] macro[4], just remove this variable since it was
actually unused:
arch/powerpc/kvm/book3s_pr.c:1832:16: warning: unused variable 'vrsave' [-Wunused-variable]
unsigned long vrsave;
^
[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ (local)
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ (local)
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ (local)
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ (local)
Suggested-by: Nathan Chancellor <redacted>
Fixes: f05ed4d56e9c ("KVM: PPC: Split out code from book3s.c into book3s_pr.c")
Signed-off-by: Kees Cook <redacted>Reviewed-by: Nick Desaulniers <redacted>
quoted hunk ↗ jump to hunk
--- arch/powerpc/kvm/book3s_pr.c | 3 --- 1 file changed, 3 deletions(-)diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index ef54f917bdaf..ed12dfbf9bb5 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c@@ -1828,9 +1828,6 @@ static int kvmppc_vcpu_run_pr(struct kvm_vcpu *vcpu) { struct kvm_run *run = vcpu->run; int ret; -#ifdef CONFIG_ALTIVEC - unsigned long uninitialized_var(vrsave); -#endif /* Check if we can run the vcpu at all */ if (!vcpu->arch.sane) { --
-- Thanks, ~Nick Desaulniers