4.18-stable review patch. If anyone has any objections, please let me know.
------------------ From: Vitaly Kuznetsov <[email protected]> commit 110d2a7fc39725d2c29d2fede4f34a35a4f98882 upstream. Commit 1268ed0c474a ("x86/hyper-v: Fix the circular dependency in IPI enlightenment") pre-filled hv_vp_index with VP_INVAL so it is now (theoretically) possible to observe hv_cpu_number_to_vp_number() returning VP_INVAL. We need to check for that in hyperv_flush_tlb_others(). Not checking for VP_INVAL on the first call site where we do if (hv_cpu_number_to_vp_number(cpumask_last(cpus)) >= 64) goto do_ex_hypercall; is OK, in case we're eligible for non-ex hypercall we'll catch the issue later in for_each_cpu() cycle and in case we'll be doing ex- hypercall cpumask_to_vpset() will fail. It would be nice to change hv_cpu_number_to_vp_number() return value's type to 'u32' but this will likely be a bigger change as all call sites need to be checked first. Fixes: 1268ed0c474a ("x86/hyper-v: Fix the circular dependency in IPI enlightenment") Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Michael Kelley <[email protected]> Cc: "K. Y. Srinivasan" <[email protected]> Cc: Haiyang Zhang <[email protected]> Cc: Stephen Hemminger <[email protected]> Cc: "Michael Kelley (EOSG)" <[email protected]> Cc: [email protected] Cc: "H. Peter Anvin" <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/hyperv/mmu.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/arch/x86/hyperv/mmu.c +++ b/arch/x86/hyperv/mmu.c @@ -95,6 +95,11 @@ static void hyperv_flush_tlb_others(cons } else { for_each_cpu(cpu, cpus) { vcpu = hv_cpu_number_to_vp_number(cpu); + if (vcpu == VP_INVAL) { + local_irq_restore(flags); + goto do_native; + } + if (vcpu >= 64) goto do_native; _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
