4.16-stable review patch. If anyone has any objections, please let me know.
------------------ From: Peter Zijlstra <[email protected]> commit e9088adda13cd23249d4b0abb97ff8a81bf5573a upstream. Don't leave the tsc-early clocksource registered if it errors out early. This was reported by Diego, who on his Core2 era machine got TSC invalidated while it was running with tsc-early (due to C-states). This results in keeping tsc-early with very bad effects. Reported-and-Tested-by: Diego Viola <[email protected]> Fixes: aa83c45762a2 ("x86/tsc: Introduce early tsc clocksource") Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Rafael J. Wysocki <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/kernel/tsc.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1205,7 +1205,7 @@ static void tsc_refine_calibration_work( /* Don't bother refining TSC on unstable systems */ if (tsc_unstable) - return; + goto unreg; /* * Since the work is started early in boot, we may be @@ -1258,11 +1258,12 @@ static void tsc_refine_calibration_work( out: if (tsc_unstable) - return; + goto unreg; if (boot_cpu_has(X86_FEATURE_ART)) art_related_clocksource = &clocksource_tsc; clocksource_register_khz(&clocksource_tsc, tsc_khz); +unreg: clocksource_unregister(&clocksource_tsc_early); } @@ -1272,8 +1273,8 @@ static int __init init_tsc_clocksource(v if (!boot_cpu_has(X86_FEATURE_TSC) || tsc_disabled > 0 || !tsc_khz) return 0; - if (check_tsc_unstable()) - return 0; + if (tsc_unstable) + goto unreg; if (tsc_clocksource_reliable) clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY; @@ -1289,6 +1290,7 @@ static int __init init_tsc_clocksource(v if (boot_cpu_has(X86_FEATURE_ART)) art_related_clocksource = &clocksource_tsc; clocksource_register_khz(&clocksource_tsc, tsc_khz); +unreg: clocksource_unregister(&clocksource_tsc_early); return 0; }
