On Tue, May 24, 2022 at 03:50:17PM +0100, Jon Hunter wrote:
> Hi Ard,
>
> On 28/03/2022 14:47, Ard Biesheuvel wrote:
> > The Spectre-BHB mitigations were inadvertently left disabled for
> > Cortex-A15, due to the fact that cpu_v7_bugs_init() is not called in
> > that case. So fix that.
> >
> > Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> > ---
> > arch/arm/mm/proc-v7-bugs.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
> > index 06dbfb968182..fb9f3eb6bf48 100644
> > --- a/arch/arm/mm/proc-v7-bugs.c
> > +++ b/arch/arm/mm/proc-v7-bugs.c
> > @@ -288,6 +288,7 @@ void cpu_v7_ca15_ibe(void)
> > {
> > if (check_spectre_auxcr(this_cpu_ptr(&spectre_warned), BIT(0)))
> > cpu_v7_spectre_v2_init();
> > + cpu_v7_spectre_bhb_init();
> > }
> > void cpu_v7_bugs_init(void)
>
>
> Since this patch has been merged, I am seeing a ton of messages when booting
> Linux on tegra124-jetson-tk1 ...
>
> [ 1233.327547] CPU0: Spectre BHB: using loop workaround
> [ 1233.327795] CPU1: Spectre BHB: using loop workaround
> [ 1233.328270] CPU1: Spectre BHB: using loop workaround
Now that you mention this, I vaguely remember some email on the list a
while ago about this being caused by something like cpuidle - but I'm
unable to find it now.
> [0] https://lore.kernel.org/linux-arm-kernel/20220519161310.1489625-1-dmitry.osipenko@xxxxxxxxxxxxx/T/
That was probably it.
We can't really do this for the other print, because the system status
can change as a result of CPUs being brought online. :(
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