From: Will Deacon <will.deacon@arm.com>
To: Julien Grall <julien.grall@arm.com>
Cc: mark.rutland@arm.com, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 2/3] drivers/perf: arm_pmu: Defer the setting of __oprofile_cpu_pmu
Date: Tue, 31 May 2016 17:28:34 +0100 [thread overview]
Message-ID: <20160531162834.GR24936@arm.com> (raw)
In-Reply-To: <1464694883-26298-3-git-send-email-julien.grall@arm.com>
On Tue, May 31, 2016 at 12:41:22PM +0100, Julien Grall wrote:
> The global variable __oprofile_cpu_pmu is set before the PMU is fully
> initialized. If an error occurs before the end of the initialization,
> the PMU will be freed and the variable will contain an invalid pointer.
>
> This will result in a kernel crash when perf will be used.
>
> Fix it by moving the setting of __oprofile_cpu_pmu when the PMU is fully
> initialized (i.e when it is no longer possible to fail).
>
> Signed-off-by: Julien Grall <julien.grall@arm.com>
> Acked-by: Mark Rutland <mark.rutland@arm.com>
> ---
> drivers/perf/arm_pmu.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
Should this one go to -stable too?
Will
> diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
> index 6401f0c..95614d2 100644
> --- a/drivers/perf/arm_pmu.c
> +++ b/drivers/perf/arm_pmu.c
> @@ -992,9 +992,6 @@ int arm_pmu_device_probe(struct platform_device *pdev,
>
> armpmu_init(pmu);
>
> - if (!__oprofile_cpu_pmu)
> - __oprofile_cpu_pmu = pmu;
> -
> pmu->plat_device = pdev;
>
> if (node && (of_id = of_match_node(of_table, pdev->dev.of_node))) {
> @@ -1030,6 +1027,9 @@ int arm_pmu_device_probe(struct platform_device *pdev,
> if (ret)
> goto out_destroy;
>
> + if (!__oprofile_cpu_pmu)
> + __oprofile_cpu_pmu = pmu;
> +
> pr_info("enabled with %s PMU driver, %d counters available\n",
> pmu->name, pmu->num_events);
>
> --
> 1.9.1
>
next prev parent reply other threads:[~2016-05-31 16:28 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-31 11:41 [PATCH 0/3] drivers/perf: arm_pmu: Small bug fixes in the driver Julien Grall
2016-05-31 11:41 ` [PATCH 1/3] drivers/perf: arm_pmu: Fix reference count of a device_node in of_pmu_irq_cfg Julien Grall
2016-05-31 11:41 ` [PATCH 2/3] drivers/perf: arm_pmu: Defer the setting of __oprofile_cpu_pmu Julien Grall
2016-05-31 16:28 ` Will Deacon [this message]
2016-05-31 17:29 ` Mark Rutland
2016-05-31 11:41 ` [PATCH 3/3] drivers/perf: arm_pmu: Avoid leaking pmu->irq_affinity on error Julien Grall
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