Re: [PATCH] arch: x86: kvm: x86.c: Cleaning up uninitialized variables
03.06.2014 16:04, Paolo Bonzini wrote:
> Il 01/06/2014 01:05, Rickard Strandqvist ha scritto:
>> There is a risk that the variable will be used without being initialized.
>>
>> This was largely found by using a static code analysis program called
>> cppcheck.
>>
>> Signed-off-by: Rickard Strandqvist
>
> No, there isn't. The full context looks like this:
>
> longmode = is_long_mode(vcpu) && cs_l == 1;
> if (!longmode) {
> param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
> (kvm_register_read(vcpu, VCPU_REGS_RAX) & 0x);
> ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
> (kvm_register_read(vcpu, VCPU_REGS_RCX) & 0x);
> outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
> (kvm_register_read(vcpu, VCPU_REGS_RSI) & 0x);
> }
> #ifdef CONFIG_X86_64
> else {
> param = kvm_register_read(vcpu, VCPU_REGS_RCX);
> ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
> outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
> }
> #endif
>
> and longmode must be zero if !CONFIG_X86_64:
This is not the first time this code is attempted to be changed.
Maybe adding an additional #ifdef..endif around the longmode
assignment and the "if" above will solve this for good?
Or maybe something like this:
#ifdef CONFIG_X86_64
if (!(is_long_mode(vcpu) && cs_l == 1)) {
#else
if (1) {
#endif
param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RAX) & 0x);
ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RCX) & 0x);
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) & 0x);
}
else {
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
}
, to make it all explicit and obvious?
Thanks,
/mjt
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Re: [PATCH] arch: x86: kvm: x86.c: Cleaning up uninitialized variables
Il 03/06/2014 15:06, Michael Tokarev ha scritto:
03.06.2014 16:04, Paolo Bonzini wrote:
Il 01/06/2014 01:05, Rickard Strandqvist ha scritto:
There is a risk that the variable will be used without being initialized.
This was largely found by using a static code analysis program called cppcheck.
Signed-off-by: Rickard Strandqvist
No, there isn't. The full context looks like this:
longmode = is_long_mode(vcpu) && cs_l == 1;
if (!longmode) {
param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RAX) & 0x);
ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RCX) & 0x);
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) & 0x);
}
#ifdef CONFIG_X86_64
else {
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
}
#endif
and longmode must be zero if !CONFIG_X86_64:
This is not the first time this code is attempted to be changed.
Maybe adding an additional #ifdef..endif around the longmode
assignment and the "if" above will solve this for good?
Or maybe something like this:
#ifdef CONFIG_X86_64
if (!(is_long_mode(vcpu) && cs_l == 1)) {
#else
if (1) {
#endif
param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RAX) & 0x);
ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RCX) & 0x);
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) & 0x);
}
else {
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
}
, to make it all explicit and obvious?
... and ugly too.
If the first person who got the answer had reported a bug against
cppcheck, this perhaps would have been avoided.
Paolo
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Re: [PATCH] arch: x86: kvm: x86.c: Cleaning up uninitialized variables
Il 01/06/2014 01:05, Rickard Strandqvist ha scritto:
> There is a risk that the variable will be used without being initialized.
>
> This was largely found by using a static code analysis program called
> cppcheck.
>
> Signed-off-by: Rickard Strandqvist
No, there isn't. The full context looks like this:
longmode = is_long_mode(vcpu) && cs_l == 1;
if (!longmode) {
param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RAX) & 0x);
ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RCX) & 0x);
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) & 0x);
}
#ifdef CONFIG_X86_64
else {
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
}
#endif
and longmode must be zero if !CONFIG_X86_64:
static inline int is_long_mode(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_X86_64
return vcpu->arch.efer & EFER_LMA;
#else
return 0;
#endif
}
So it's the static checker that cannot understand #ifdef well
enough and ought to be fixed.
Paolo
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Re: [PATCH] arch: x86: kvm: x86.c: Cleaning up uninitialized variables
Il 01/06/2014 01:05, Rickard Strandqvist ha scritto:
There is a risk that the variable will be used without being initialized.
This was largely found by using a static code analysis program called
cppcheck.
Signed-off-by: Rickard Strandqvist rickard_strandqv...@spectrumdigital.se
No, there isn't. The full context looks like this:
longmode = is_long_mode(vcpu) cs_l == 1;
if (!longmode) {
param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RAX) 0x);
ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RCX) 0x);
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) 0x);
}
#ifdef CONFIG_X86_64
else {
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
}
#endif
and longmode must be zero if !CONFIG_X86_64:
static inline int is_long_mode(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_X86_64
return vcpu-arch.efer EFER_LMA;
#else
return 0;
#endif
}
So it's the static checker that cannot understand #ifdef well
enough and ought to be fixed.
Paolo
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Re: [PATCH] arch: x86: kvm: x86.c: Cleaning up uninitialized variables
Il 03/06/2014 15:06, Michael Tokarev ha scritto:
03.06.2014 16:04, Paolo Bonzini wrote:
Il 01/06/2014 01:05, Rickard Strandqvist ha scritto:
There is a risk that the variable will be used without being initialized.
This was largely found by using a static code analysis program called cppcheck.
Signed-off-by: Rickard Strandqvist rickard_strandqv...@spectrumdigital.se
No, there isn't. The full context looks like this:
longmode = is_long_mode(vcpu) cs_l == 1;
if (!longmode) {
param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RAX) 0x);
ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RCX) 0x);
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) 0x);
}
#ifdef CONFIG_X86_64
else {
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
}
#endif
and longmode must be zero if !CONFIG_X86_64:
This is not the first time this code is attempted to be changed.
Maybe adding an additional #ifdef..endif around the longmode
assignment and the if above will solve this for good?
Or maybe something like this:
#ifdef CONFIG_X86_64
if (!(is_long_mode(vcpu) cs_l == 1)) {
#else
if (1) {
#endif
param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RAX) 0x);
ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RCX) 0x);
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) 0x);
}
else {
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
}
, to make it all explicit and obvious?
... and ugly too.
If the first person who got the answer had reported a bug against
cppcheck, this perhaps would have been avoided.
Paolo
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] arch: x86: kvm: x86.c: Cleaning up uninitialized variables
03.06.2014 16:04, Paolo Bonzini wrote:
Il 01/06/2014 01:05, Rickard Strandqvist ha scritto:
There is a risk that the variable will be used without being initialized.
This was largely found by using a static code analysis program called
cppcheck.
Signed-off-by: Rickard Strandqvist rickard_strandqv...@spectrumdigital.se
No, there isn't. The full context looks like this:
longmode = is_long_mode(vcpu) cs_l == 1;
if (!longmode) {
param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RAX) 0x);
ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RCX) 0x);
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) 0x);
}
#ifdef CONFIG_X86_64
else {
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
}
#endif
and longmode must be zero if !CONFIG_X86_64:
This is not the first time this code is attempted to be changed.
Maybe adding an additional #ifdef..endif around the longmode
assignment and the if above will solve this for good?
Or maybe something like this:
#ifdef CONFIG_X86_64
if (!(is_long_mode(vcpu) cs_l == 1)) {
#else
if (1) {
#endif
param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RAX) 0x);
ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RCX) 0x);
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) 0x);
}
else {
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
}
, to make it all explicit and obvious?
Thanks,
/mjt
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH] arch: x86: kvm: x86.c: Cleaning up uninitialized variables
There is a risk that the variable will be used without being initialized.
This was largely found by using a static code analysis program called cppcheck.
Signed-off-by: Rickard Strandqvist
---
arch/x86/kvm/x86.c |8 ++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 20316c6..88bf642 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5691,13 +5691,17 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) & 0x);
}
-#ifdef CONFIG_X86_64
else {
+#ifdef CONFIG_X86_64
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
- }
+#else
+ param = 0;
+ ingpa = 0;
+ outgpa = 0;
#endif
+ }
code = param & 0x;
fast = (param >> 16) & 0x1;
--
1.7.10.4
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[PATCH] arch: x86: kvm: x86.c: Cleaning up uninitialized variables
There is a risk that the variable will be used without being initialized.
This was largely found by using a static code analysis program called cppcheck.
Signed-off-by: Rickard Strandqvist rickard_strandqv...@spectrumdigital.se
---
arch/x86/kvm/x86.c |8 ++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 20316c6..88bf642 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5691,13 +5691,17 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) 0x);
}
-#ifdef CONFIG_X86_64
else {
+#ifdef CONFIG_X86_64
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
- }
+#else
+ param = 0;
+ ingpa = 0;
+ outgpa = 0;
#endif
+ }
code = param 0x;
fast = (param 16) 0x1;
--
1.7.10.4
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