Re: [PATCH] perf/bts: Don't try handling BTS interrupt if BTS is not enabled

From: Alexander Shishkin
Date: Mon Sep 26 2016 - 17:05:37 EST


http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=f1e1c9e5e357c05253affb13be29285c5cb56bf0

On 26 September 2016 at 22:19, Boris Ostrovsky
<boris.ostrovsky@xxxxxxxxxx> wrote:
> Otherwise we will try to dereference ds which has not been allocated.
>
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> ---
> arch/x86/events/intel/bts.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c
> index bdcd651..1f5657f 100644
> --- a/arch/x86/events/intel/bts.c
> +++ b/arch/x86/events/intel/bts.c
> @@ -451,6 +451,9 @@ int intel_bts_interrupt(void)
> s64 old_head;
> int err = -ENOSPC, handled = 0;
>
> + if (!x86_pmu.bts)
> + return 0;
> +
> /*
> * The only surefire way of knowing if this NMI is ours is by checking
> * the write ptr against the PMI threshold.
> --
> 1.8.3.1
>