[PATCH] x86/CPUID: don't use UB shift when library is built as 32-bit

[PATCH] x86/CPUID: don't use UB shift when library is built as 32-bit

[Jan Beulich]

At least the insn emulator test harness will continue to be buildable
(and ought to continue to be usable) also as a 32-bit binary. (Right now
the CPU policy test harness is, too, but there it may be less relevant
to keep it functional, just like e.g. we don't support fuzzing the insn
emulator in 32-bit mode.) Hence the library code needs to cope with
this.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/lib/x86/cpuid.c
+++ b/xen/lib/x86/cpuid.c
@@ -165,7 +165,7 @@ void x86_cpuid_policy_fill_native(struct
         for ( i = 2; i < min_t(unsigned int, 63,
                                ARRAY_SIZE(p->xstate.raw)); ++i )
         {
-            if ( xstates & (1ul << i) )
+            if ( xstates & (1ull << i) )
                 cpuid_count_leaf(0xd, i, &p->xstate.raw[i]);
         }
     }

Re: [PATCH] x86/CPUID: don't use UB shift when library is built as 32-bit

[Andrew Cooper]

On 09/11/2020 10:53, Jan Beulich wrote:
> At least the insn emulator test harness will continue to be buildable
> (and ought to continue to be usable) also as a 32-bit binary. (Right now
> the CPU policy test harness is, too, but there it may be less relevant
> to keep it functional, just like e.g. we don't support fuzzing the insn
> emulator in 32-bit mode.) Hence the library code needs to cope with
> this.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>