diff mbox

[2/3] drivers/perf: arm_pmu: Defer the setting of __oprofile_cpu_pmu

Message ID 1464694883-26298-3-git-send-email-julien.grall@arm.com
State Accepted
Commit 0f254c7671e851243412bce6c2e618732831d0f8
Headers show

Commit Message

Julien Grall May 31, 2016, 11:41 a.m. UTC 
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(-)

-- 
1.9.1

Comments

Will Deacon May 31, 2016, 4:28 p.m. UTC | #1 
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

>
diff mbox

Patch

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);