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| author | Arnd Bergmann <arnd@arndb.de> | 2019-07-12 16:13:09 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-07-15 12:50:30 +0200 |
| commit | f4e4805e4bf7a06235d2aa216e1d00cb1f3bd0c1 (patch) | |
| tree | e6271cf6068b577e31aaea504d5484d8f3d118bc | |
| parent | 0b774629512057b4becc705e2495220844e6e795 (diff) | |
| download | linux-f4e4805e4bf7a06235d2aa216e1d00cb1f3bd0c1.tar.gz linux-f4e4805e4bf7a06235d2aa216e1d00cb1f3bd0c1.tar.bz2 linux-f4e4805e4bf7a06235d2aa216e1d00cb1f3bd0c1.zip | |
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>
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 20 |
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); |