On 24/05/2022 18:03, Russell King (Oracle) wrote:
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. :(
Does it make sense to only print the message if/when the method changes
as opposed to every time the CPUs are brought online? That way, there
would still be at least one print showing the current method. I believe
that is what Ard had proposed.
Jon
--
nvpublic
