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) & 0xffffffff);
                ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
                        (kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffffff);
                outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
                        (kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffffff);
        }
#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) & 0xffffffff);
                 ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
                         (kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffffff);
                 outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
                         (kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffffff);
         }
         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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