Silence compiler warning in arch/x86/kvm/emulate.c

Compiler warning:

 CC [M]  arch/x86/kvm/emulate.o
arch/x86/kvm/emulate.c: In function "__do_insn_fetch_bytes":
arch/x86/kvm/emulate.c:814:9: warning: "linear" may be used uninitialized in this function [-Wmaybe-uninitialized]

GCC is smart enough to realize that the inlined __linearize may return before
setting the value of linear, but not smart enough to realize the same
X86EMU_CONTINUE blocks actual use of the value.  However, the value of
'linear' can only be set to one value, so hoisting the one line of code
upwards makes GCC happy with the code.

Reported-by: Aruna Hewapathirane <aruna.hewapathirane@gmail.com>
Tested-by: Aruna Hewapathirane <aruna.hewapathirane@gmail.com>
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index e7a4fde5d631031908b6f336d9ecc40e7a3a413d..b372a7557c16c7d8391fffafdf0b1c74b49c4822 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -650,6 +650,7 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
        u16 sel;
 
        la = seg_base(ctxt, addr.seg) + addr.ea;
        u16 sel;
 
        la = seg_base(ctxt, addr.seg) + addr.ea;

+       *linear = la;

        *max_size = 0;
        switch (mode) {
        case X86EMUL_MODE_PROT64:
        *max_size = 0;
        switch (mode) {
        case X86EMUL_MODE_PROT64:


@@ -693,7 +694,6 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
        }
        if (insn_aligned(ctxt, size) && ((la & (size - 1)) != 0))
                return emulate_gp(ctxt, 0);
        }
        if (insn_aligned(ctxt, size) && ((la & (size - 1)) != 0))
                return emulate_gp(ctxt, 0);

-       *linear = la;

        return X86EMUL_CONTINUE;
 bad:
        if (addr.seg == VCPU_SREG_SS)
        return X86EMUL_CONTINUE;
 bad:
        if (addr.seg == VCPU_SREG_SS)