linux-kernel - Re: [Patch v3 5/7] perf/x86/intel: Change macro GLOBAL_CTRL_EN_PERF_METRICS to BIT

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CALC8CXdkpNtk7gd+jPhixU2irxfLae+rQRzORWXmKtNMzdyohg@mail.gmail.com>
Date: Thu, 2 Oct 2025 12:19:33 -0400
From: ChaosEsque Team <chaosesqueteam@...il.com>
To: Dapeng Mi <dapeng1.mi@...ux.intel.com>
Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>, 
	Arnaldo Carvalho de Melo <acme@...nel.org>, Namhyung Kim <namhyung@...nel.org>, Ian Rogers <irogers@...gle.com>, 
	Adrian Hunter <adrian.hunter@...el.com>, 
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Kan Liang <kan.liang@...ux.intel.com>, 
	Andi Kleen <ak@...ux.intel.com>, Eranian Stephane <eranian@...gle.com>, linux-kernel@...r.kernel.org, 
	linux-perf-users@...r.kernel.org, Dapeng Mi <dapeng1.mi@...el.com>, 
	Yi Lai <yi1.lai@...el.com>
Subject: Re: [Patch v3 5/7] perf/x86/intel: Change macro GLOBAL_CTRL_EN_PERF_METRICS
 to BIT_ULL(48)

"Tip bot"
Just the tip.
Wonder if this was sent to "menglongdong" (a kernel programmer)

On Tue, Aug 19, 2025 at 10:33 PM Dapeng Mi <dapeng1.mi@...ux.intel.com> wrote:
>
> Macro GLOBAL_CTRL_EN_PERF_METRICS is defined to 48 instead of
> BIT_ULL(48), it's inconsistent with other similar macros. This leads to
> this macro is quite easily used wrongly since users thinks it's a
> bit-mask just like other similar macros.
>
> Thus change GLOBAL_CTRL_EN_PERF_METRICS to BIT_ULL(48) and eliminate
> this potential misuse.
>
> Signed-off-by: Dapeng Mi <dapeng1.mi@...ux.intel.com>
> Tested-by: Yi Lai <yi1.lai@...el.com>
> ---
>  arch/x86/events/intel/core.c      | 8 ++++----
>  arch/x86/include/asm/perf_event.h | 2 +-
>  2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
> index 15da60cf69f2..f88a99d8d125 100644
> --- a/arch/x86/events/intel/core.c
> +++ b/arch/x86/events/intel/core.c
> @@ -5319,9 +5319,9 @@ static void intel_pmu_check_hybrid_pmus(struct x86_hybrid_pmu *pmu)
>                                                 0, x86_pmu_num_counters(&pmu->pmu), 0, 0);
>
>         if (pmu->intel_cap.perf_metrics)
> -               pmu->intel_ctrl |= 1ULL << GLOBAL_CTRL_EN_PERF_METRICS;
> +               pmu->intel_ctrl |= GLOBAL_CTRL_EN_PERF_METRICS;
>         else
> -               pmu->intel_ctrl &= ~(1ULL << GLOBAL_CTRL_EN_PERF_METRICS);
> +               pmu->intel_ctrl &= ~GLOBAL_CTRL_EN_PERF_METRICS;
>
>         intel_pmu_check_event_constraints(pmu->event_constraints,
>                                           pmu->cntr_mask64,
> @@ -5456,7 +5456,7 @@ static void intel_pmu_cpu_starting(int cpu)
>                 rdmsrq(MSR_IA32_PERF_CAPABILITIES, perf_cap.capabilities);
>                 if (!perf_cap.perf_metrics) {
>                         x86_pmu.intel_cap.perf_metrics = 0;
> -                       x86_pmu.intel_ctrl &= ~(1ULL << GLOBAL_CTRL_EN_PERF_METRICS);
> +                       x86_pmu.intel_ctrl &= ~GLOBAL_CTRL_EN_PERF_METRICS;
>                 }
>         }
>
> @@ -7790,7 +7790,7 @@ __init int intel_pmu_init(void)
>         }
>
>         if (!is_hybrid() && x86_pmu.intel_cap.perf_metrics)
> -               x86_pmu.intel_ctrl |= 1ULL << GLOBAL_CTRL_EN_PERF_METRICS;
> +               x86_pmu.intel_ctrl |= GLOBAL_CTRL_EN_PERF_METRICS;
>
>         if (x86_pmu.intel_cap.pebs_timing_info)
>                 x86_pmu.flags |= PMU_FL_RETIRE_LATENCY;
> diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
> index 70d1d94aca7e..f8247ac276c4 100644
> --- a/arch/x86/include/asm/perf_event.h
> +++ b/arch/x86/include/asm/perf_event.h
> @@ -430,7 +430,7 @@ static inline bool is_topdown_idx(int idx)
>  #define GLOBAL_STATUS_TRACE_TOPAPMI            BIT_ULL(GLOBAL_STATUS_TRACE_TOPAPMI_BIT)
>  #define GLOBAL_STATUS_PERF_METRICS_OVF_BIT     48
>
> -#define GLOBAL_CTRL_EN_PERF_METRICS            48
> +#define GLOBAL_CTRL_EN_PERF_METRICS            BIT_ULL(48)
>  /*
>   * We model guest LBR event tracing as another fixed-mode PMC like BTS.
>   *
> --
> 2.34.1
>
>