Re: [PATCH 0/8] perf/amd/ibs: Fix sample period computations

[Namhyung Kim]

On Mon, Oct 07, 2024 at 03:48:02AM +0000, Ravi Bangoria wrote:
> IBS Fetch and IBS Op pmus have constraints on supported sample period
> values. The IBS hw behavior could be undefined if they are not followed.
> Currently, IBS driver does not honor them correctly and thus a malicious
> event could cause issues to the system. Fortunately, the IBS hw is very
> resilient so far and IBS pmus are restricted to root only, so the attack
> vector is minimal. In any case, these are genuine bugs and must be fixed.
> 
> Patches are prepared on v6.11.
> 
> Ravi Bangoria (8):
>   perf/amd/ibs: Remove IBS_{FETCH|OP}_CONFIG_MASK macros
>   perf/amd/ibs: Remove pointless sample period check
>   perf/amd/ibs: Fix ->config to sample period calculation for OP pmu
>   perf/amd/ibs: Fix perf_ibs_op.cnt_mask for CurCnt
>   perf/amd/ibs: Don't allow freq mode event creation through ->config
>     interface
>   perf/amd/ibs: Add pmu specific minimum period
>   perf/amd/ibs: Add ->check_period() callback
>   perf/core: Introduce pmu->adjust_period() callback

Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>

Thanks,
Namhyung

> 
>  arch/x86/events/amd/ibs.c         | 97 +++++++++++++++++++++++--------
>  arch/x86/include/asm/perf_event.h |  1 +
>  include/linux/perf_event.h        |  5 ++
>  kernel/events/core.c              | 12 +++-
>  4 files changed, 88 insertions(+), 27 deletions(-)
> 
> -- 
> 2.46.2
>