[PATCH 0/3] perf/core: Assert PERF_EVENT_FLAG_ARCH is followed

[PATCH 0/3] perf/core: Assert PERF_EVENT_FLAG_ARCH is followed

[Anshuman Khandual]

This series ensures that PERF_EVENT_FLAG_ARCH mask is followed correctly,
while defining all the platform specific hardware event flags. But after
adding these checks, there are couple of build failures on x86 platform
like the following.

BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_AMD_BRS)
BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LAT_HYBRID)

This happens because both these flags PERF_X86_EVENT_AMD_BRS (0x10000) and
PERF_X86_EVENT_PEBS_LAT_HYBRID (0x20000) falls outside PERF_EVENT_FLAG_ARCH
(0x0000ffff). Given that x86 platform is already using up all available bit
positions, should this platform flags mask be extended to (0x000fffff) ?

This seires applies on v6.0-rc3.

Anshuman Khandual (3):
  perf/core: Assert PERF_EVENT_FLAG_ARCH does not overlap with generic flags
  arm64/perf: Assert all platform event flags are within PERF_EVENT_FLAG_ARCH
  x86/perf: Assert all platform event flags are within PERF_EVENT_FLAG_ARCH

 arch/arm64/kernel/perf_event.c  |  1 +
 arch/x86/events/amd/core.c      |  2 ++
 arch/x86/events/core.c          | 16 ++++++++++++++++
 drivers/perf/apple_m1_cpu_pmu.c |  1 +
 drivers/perf/arm_spe_pmu.c      |  1 +
 kernel/events/core.c            |  1 +
 6 files changed, 22 insertions(+)

-- 
2.25.1

[PATCH 1/3] perf/core: Assert PERF_EVENT_FLAG_ARCH does not overlap with generic flags

[Anshuman Khandual]

This just ensures that PERF_EVENT_FLAG_ARCH does not overlap with generic
hardware event flags.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-perf-users@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 kernel/events/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 2621fd24ad26..29c58de6c888 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -13429,6 +13429,7 @@ void __init perf_event_init(void)
 	 */
 	BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head))
 		     != 1024);
+	BUILD_BUG_ON(PERF_EVENT_FLAG_USER_READ_CNT & PERF_EVENT_FLAG_ARCH);
 }
 
 ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
-- 
2.25.1

[PATCH 2/3] arm64/perf: Assert all platform event flags are within PERF_EVENT_FLAG_ARCH

[Anshuman Khandual]

Ensure all platform specific event flags are within PERF_EVENT_FLAG_ARCH.

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-perf-users@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/arm64/kernel/perf_event.c  | 1 +
 drivers/perf/apple_m1_cpu_pmu.c | 1 +
 drivers/perf/arm_spe_pmu.c      | 1 +
 3 files changed, 3 insertions(+)

diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index cb69ff1e6138..cf9cedb07f92 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -1390,6 +1390,7 @@ static struct platform_driver armv8_pmu_driver = {
 
 static int __init armv8_pmu_driver_init(void)
 {
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & ARMPMU_EVT_64BIT);
 	if (acpi_disabled)
 		return platform_driver_register(&armv8_pmu_driver);
 	else
diff --git a/drivers/perf/apple_m1_cpu_pmu.c b/drivers/perf/apple_m1_cpu_pmu.c
index 979a7c2b4f56..9ec8c694d0f2 100644
--- a/drivers/perf/apple_m1_cpu_pmu.c
+++ b/drivers/perf/apple_m1_cpu_pmu.c
@@ -568,6 +568,7 @@ MODULE_DEVICE_TABLE(of, m1_pmu_of_device_ids);
 
 static int m1_pmu_device_probe(struct platform_device *pdev)
 {
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & ARMPMU_EVT_47BIT);
 	return arm_pmu_device_probe(pdev, m1_pmu_of_device_ids, NULL);
 }
 
diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index b65a7d9640e1..74344abf4b11 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -1276,6 +1276,7 @@ static int __init arm_spe_pmu_init(void)
 	if (ret)
 		cpuhp_remove_multi_state(arm_spe_pmu_online);
 
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & SPE_PMU_HW_FLAGS_CX);
 	return ret;
 }
 
-- 
2.25.1

[PATCH 3/3] x86/perf: Assert all platform event flags are within PERF_EVENT_FLAG_ARCH

[Anshuman Khandual]

Ensure all platform specific event flags are within PERF_EVENT_FLAG_ARCH.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: linux-perf-users@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/x86/events/amd/core.c |  2 ++
 arch/x86/events/core.c     | 16 ++++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 9ac3718410ce..7aee514285ba 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -1469,6 +1469,8 @@ __init int amd_pmu_init(void)
 	else
 		memcpy(hw_cache_event_ids, amd_hw_cache_event_ids, sizeof(hw_cache_event_ids));
 
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PAIR);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_AMD_BRS);
 	return 0;
 }
 
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index f969410d0c90..98fe13f50632 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2083,6 +2083,22 @@ static int __init init_hw_perf_events(void)
 
 	pr_info("Performance Events: ");
 
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LDLAT);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_ST);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_ST_HSW);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LD_HSW);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_NA_HSW);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_EXCL);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_DYNAMIC);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_EXCL_ACCT);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_AUTO_RELOAD);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_LARGE_PEBS);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_VIA_PT);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_LBR_SELECT);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_TOPDOWN);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_STLAT);
+	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LAT_HYBRID);
+
 	switch (boot_cpu_data.x86_vendor) {
 	case X86_VENDOR_INTEL:
 		err = intel_pmu_init();
-- 
2.25.1

Re: [PATCH 3/3] x86/perf: Assert all platform event flags are within PERF_EVENT_FLAG_ARCH

[James Clark]

On 29/08/2022 07:55, Anshuman Khandual wrote:
> Ensure all platform specific event flags are within PERF_EVENT_FLAG_ARCH.
> 
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: x86@kernel.org
> Cc: linux-perf-users@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
>  arch/x86/events/amd/core.c |  2 ++
>  arch/x86/events/core.c     | 16 ++++++++++++++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
> index 9ac3718410ce..7aee514285ba 100644
> --- a/arch/x86/events/amd/core.c
> +++ b/arch/x86/events/amd/core.c
> @@ -1469,6 +1469,8 @@ __init int amd_pmu_init(void)
>  	else
>  		memcpy(hw_cache_event_ids, amd_hw_cache_event_ids, sizeof(hw_cache_event_ids));
>  
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PAIR);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_AMD_BRS);
>  	return 0;
>  }
>  
> diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
> index f969410d0c90..98fe13f50632 100644
> --- a/arch/x86/events/core.c
> +++ b/arch/x86/events/core.c
> @@ -2083,6 +2083,22 @@ static int __init init_hw_perf_events(void)
>  
>  	pr_info("Performance Events: ");
>  
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LDLAT);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_ST);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_ST_HSW);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LD_HSW);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_NA_HSW);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_EXCL);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_DYNAMIC);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_EXCL_ACCT);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_AUTO_RELOAD);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_LARGE_PEBS);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_VIA_PT);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_LBR_SELECT);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_TOPDOWN);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_STLAT);
> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LAT_HYBRID);
> +

Hi Anshuman,

You can use static_assert() and then put them in the global scope. If
they're next to the definition of these it will be clearer and easier to
maintain.

Also, I'm assuming that this now causes a build failure, so I would
include the change to expand PERF_EVENT_FLAG_ARCH as the first commit in
the set. That way we can see at least one proposed solution.

Thanks
James

>  	switch (boot_cpu_data.x86_vendor) {
>  	case X86_VENDOR_INTEL:
>  		err = intel_pmu_init();

Re: [PATCH 3/3] x86/perf: Assert all platform event flags are within PERF_EVENT_FLAG_ARCH

[Anshuman Khandual]

On 8/30/22 15:30, James Clark wrote:
> 
> 
> On 29/08/2022 07:55, Anshuman Khandual wrote:
>> Ensure all platform specific event flags are within PERF_EVENT_FLAG_ARCH.
>>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Ingo Molnar <mingo@redhat.com>
>> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
>> Cc: Mark Rutland <mark.rutland@arm.com>
>> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
>> Cc: Jiri Olsa <jolsa@kernel.org>
>> Cc: Namhyung Kim <namhyung@kernel.org>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Borislav Petkov <bp@alien8.de>
>> Cc: x86@kernel.org
>> Cc: linux-perf-users@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>>  arch/x86/events/amd/core.c |  2 ++
>>  arch/x86/events/core.c     | 16 ++++++++++++++++
>>  2 files changed, 18 insertions(+)
>>
>> diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
>> index 9ac3718410ce..7aee514285ba 100644
>> --- a/arch/x86/events/amd/core.c
>> +++ b/arch/x86/events/amd/core.c
>> @@ -1469,6 +1469,8 @@ __init int amd_pmu_init(void)
>>  	else
>>  		memcpy(hw_cache_event_ids, amd_hw_cache_event_ids, sizeof(hw_cache_event_ids));
>>  
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PAIR);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_AMD_BRS);
>>  	return 0;
>>  }
>>  
>> diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
>> index f969410d0c90..98fe13f50632 100644
>> --- a/arch/x86/events/core.c
>> +++ b/arch/x86/events/core.c
>> @@ -2083,6 +2083,22 @@ static int __init init_hw_perf_events(void)
>>  
>>  	pr_info("Performance Events: ");
>>  
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LDLAT);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_ST);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_ST_HSW);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LD_HSW);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_NA_HSW);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_EXCL);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_DYNAMIC);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_EXCL_ACCT);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_AUTO_RELOAD);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_LARGE_PEBS);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_VIA_PT);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_LBR_SELECT);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_TOPDOWN);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_STLAT);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LAT_HYBRID);
>> +
> 
> Hi Anshuman,
> 
> You can use static_assert() and then put them in the global scope. If
> they're next to the definition of these it will be clearer and easier to
> maintain.

Right, will do the required change.

> 
> Also, I'm assuming that this now causes a build failure, so I would
> include the change to expand PERF_EVENT_FLAG_ARCH as the first commit in
> the set. That way we can see at least one proposed solution.

Sure, will expand PERF_EVENT_FLAG_ARCH into 0x000FFFFF.