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From: Will Deacon <will@kernel.org>
To: Mark Salter <msalter@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	Khuong Dinh <khuong@os.amperecomputing.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drivers/perf: xgene_pmu: Fix uninitialized resource struct
Date: Mon, 7 Sep 2020 14:50:26 +0100	[thread overview]
Message-ID: <20200907135026.GC12551@willie-the-truck> (raw)
In-Reply-To: <20200902182729.27415-1-msalter@redhat.com>

On Wed, Sep 02, 2020 at 02:27:29PM -0400, Mark Salter wrote:
> diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c
> index edac28cd25dd..fdbbd0804b92 100644
> --- a/drivers/perf/xgene_pmu.c
> +++ b/drivers/perf/xgene_pmu.c
> @@ -1483,6 +1483,7 @@ xgene_pmu_dev_ctx *acpi_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu,
>  		return NULL;
>  
>  	INIT_LIST_HEAD(&resource_list);
> +	memset(&res, 0, sizeof(res));
>  	rc = acpi_dev_get_resources(adev, &resource_list,
>  				    acpi_pmu_dev_add_resource, &res);
>  	acpi_dev_free_resource_list(&resource_list);

Hmm, to be honest, I'm not sure we should be calling devm_ioremap_resource()
at all here. The resource is clearly bogus, even with this change: the name
and the resource hierarchy pointers will all be NULL. I think it would be
better to follow the TX2 PMU driver (drivers/perf/thunderx2_pmu.c) which
appears to assign the resource directly in tx2_uncore_pmu_init_dev().

Is there a reason we can't do that?

Will

WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will@kernel.org>
To: Mark Salter <msalter@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	Khuong Dinh <khuong@os.amperecomputing.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] drivers/perf: xgene_pmu: Fix uninitialized resource struct
Date: Mon, 7 Sep 2020 14:50:26 +0100	[thread overview]
Message-ID: <20200907135026.GC12551@willie-the-truck> (raw)
In-Reply-To: <20200902182729.27415-1-msalter@redhat.com>

On Wed, Sep 02, 2020 at 02:27:29PM -0400, Mark Salter wrote:
> diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c
> index edac28cd25dd..fdbbd0804b92 100644
> --- a/drivers/perf/xgene_pmu.c
> +++ b/drivers/perf/xgene_pmu.c
> @@ -1483,6 +1483,7 @@ xgene_pmu_dev_ctx *acpi_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu,
>  		return NULL;
>  
>  	INIT_LIST_HEAD(&resource_list);
> +	memset(&res, 0, sizeof(res));
>  	rc = acpi_dev_get_resources(adev, &resource_list,
>  				    acpi_pmu_dev_add_resource, &res);
>  	acpi_dev_free_resource_list(&resource_list);

Hmm, to be honest, I'm not sure we should be calling devm_ioremap_resource()
at all here. The resource is clearly bogus, even with this change: the name
and the resource hierarchy pointers will all be NULL. I think it would be
better to follow the TX2 PMU driver (drivers/perf/thunderx2_pmu.c) which
appears to assign the resource directly in tx2_uncore_pmu_init_dev().

Is there a reason we can't do that?

Will

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  reply	other threads:[~2020-09-07 17:19 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-02 18:27 [PATCH] drivers/perf: xgene_pmu: Fix uninitialized resource struct Mark Salter
2020-09-02 18:27 ` Mark Salter
2020-09-07 13:50 ` Will Deacon [this message]
2020-09-07 13:50   ` Will Deacon
2020-09-08 18:37   ` Mark Salter
2020-09-08 18:37     ` Mark Salter
2020-09-11 16:08     ` Will Deacon
2020-09-11 16:08       ` Will Deacon

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