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    Subject[PATCH 30/74] x86, lto: Fix AMD K6 indirect call check
    Date
    From: Andi Kleen <ak@linux.intel.com>

    The AMD K6 errata check relies on timing a indirect call.
    But the way it was written it could be optimized to a direct call.
    Force gcc to actually do a indirect call and not just
    constant resolve the target address.

    Signed-off-by: Andi Kleen <ak@linux.intel.com>
    ---
    arch/x86/kernel/cpu/amd.c | 2 +-
    1 files changed, 1 insertions(+), 1 deletions(-)

    diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
    index 2c02d92..cb72014 100644
    --- a/arch/x86/kernel/cpu/amd.c
    +++ b/arch/x86/kernel/cpu/amd.c
    @@ -116,7 +116,7 @@ static void __cpuinit init_amd_k6(struct cpuinfo_x86 *c)
    */

    n = K6_BUG_LOOP;
    - f_vide = vide;
    + asm("" : "=r" (f_vide) : "0" (vide));
    rdtscl(d);
    while (n--)
    f_vide();
    --
    1.7.7.6


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