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authorArnd Bergmann <arnd@arndb.de>2019-07-12 16:13:09 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2019-07-15 12:50:30 +0200
commitf4e4805e4bf7a06235d2aa216e1d00cb1f3bd0c1 (patch)
treee6271cf6068b577e31aaea504d5484d8f3d118bc /arch
parent0b774629512057b4becc705e2495220844e6e795 (diff)
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x86: kvm: avoid -Wsometimes-uninitized warning
Clang notices a code path in which some variables are never initialized, but fails to figure out that this can never happen on i386 because is_64_bit_mode() always returns false. arch/x86/kvm/hyperv.c:1610:6: error: variable 'ingpa' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] if (!longmode) { ^~~~~~~~~ arch/x86/kvm/hyperv.c:1632:55: note: uninitialized use occurs here trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa); ^~~~~ arch/x86/kvm/hyperv.c:1610:2: note: remove the 'if' if its condition is always true if (!longmode) { ^~~~~~~~~~~~~~~ arch/x86/kvm/hyperv.c:1595:18: note: initialize the variable 'ingpa' to silence this warning u64 param, ingpa, outgpa, ret = HV_STATUS_SUCCESS; ^ = 0 arch/x86/kvm/hyperv.c:1610:6: error: variable 'outgpa' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] arch/x86/kvm/hyperv.c:1610:6: error: variable 'param' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] Flip the condition around to avoid the conditional execution on i386. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/hyperv.c20
1 files changed, 9 insertions, 11 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index a39e38f13029..c10a8b10b203 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1594,7 +1594,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
{
u64 param, ingpa, outgpa, ret = HV_STATUS_SUCCESS;
uint16_t code, rep_idx, rep_cnt;
- bool fast, longmode, rep;
+ bool fast, rep;
/*
* hypercall generates UD from non zero cpl and real mode
@@ -1605,9 +1605,14 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
return 1;
}
- longmode = is_64_bit_mode(vcpu);
-
- if (!longmode) {
+#ifdef CONFIG_X86_64
+ if (is_64_bit_mode(vcpu)) {
+ param = kvm_rcx_read(vcpu);
+ ingpa = kvm_rdx_read(vcpu);
+ outgpa = kvm_r8_read(vcpu);
+ } else
+#endif
+ {
param = ((u64)kvm_rdx_read(vcpu) << 32) |
(kvm_rax_read(vcpu) & 0xffffffff);
ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
@@ -1615,13 +1620,6 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
(kvm_rsi_read(vcpu) & 0xffffffff);
}
-#ifdef CONFIG_X86_64
- else {
- param = kvm_rcx_read(vcpu);
- ingpa = kvm_rdx_read(vcpu);
- outgpa = kvm_r8_read(vcpu);
- }
-#endif
code = param & 0xffff;
fast = !!(param & HV_HYPERCALL_FAST_BIT);