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| author | Sean Christopherson <[email protected]> | 2025-01-31 01:07:21 +0000 |
|---|---|---|
| committer | Peter Zijlstra <[email protected]> | 2025-02-08 14:47:26 +0000 |
| commit | c631a2de7ae48d50434bdc205d901423f8577c65 (patch) | |
| tree | f1ac30d7c119c241e6289e58bb71bca32033ad6c /tools/testing/selftests/net/lib/py/utils.py | |
| parent | perf/x86/intel: Fix ARCH_PERFMON_NUM_COUNTER_LEAF (diff) | |
| download | kernel-c631a2de7ae48d50434bdc205d901423f8577c65.tar.gz kernel-c631a2de7ae48d50434bdc205d901423f8577c65.zip | |
perf/x86/intel: Ensure LBRs are disabled when a CPU is starting
Explicitly clear DEBUGCTL.LBR when a CPU is starting, prior to purging the
LBR MSRs themselves, as at least one system has been found to transfer
control to the kernel with LBRs enabled (it's unclear whether it's a BIOS
flaw or a CPU goof). Because the kernel preserves the original DEBUGCTL,
even when toggling LBRs, leaving DEBUGCTL.LBR as is results in running
with LBRs enabled at all times.
Closes: https://lore.kernel.org/all/[email protected]
Reported-by: Maxim Levitsky <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Maxim Levitsky <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Diffstat (limited to 'tools/testing/selftests/net/lib/py/utils.py')
0 files changed, 0 insertions, 0 deletions