linux-kernel - [PATCH] drivers/acpi/processor

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Date:	Sat, 17 Mar 2012 16:38:11 +0100
From:	Julia Lawall <Julia.Lawall@...6.fr>
To:	Len Brown <lenb@...nel.org>, srivatsa.bhat@...ux.vnet.ibm.com,
	deepthi@...ux.vnet.ibm.com, venki@...gle.com, trenn@...e.de,
	bhelgaas@...gle.com
Cc:	kernel-janitors@...r.kernel.org, linux-acpi@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] drivers/acpi/processor_driver.c: add missing kfree

From: Julia Lawall <Julia.Lawall@...6.fr>

The function acpi_processor_add is stored in the ops.add field of a
acpi_driver structure.  This function is then called in
acpi_bus_driver_init.  On failure, this function clears the field
device->driver_data, but does not free its contents.  Thus the free has to
be done by the add function.  In acpi_processor_add, the corresponding
value is pr.  This value is currently freed on failure before storing it in
device->driver_data, but not after.  This free is added in the error
handling code at the end of the function.  The per_cpu variable
processors is also cleared so that it does not refer to a dangling pointer.

Signed-off-by: Julia Lawall <Julia.Lawall@...6.fr>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@...ux.vnet.ibm.com>
Acked-by: Deepthi Dharwar <deepthi@...ux.vnet.ibm.com>

---
v3: Added reviews and acks

 drivers/acpi/processor_driver.c |   15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 2801b41..c5ce91c 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -536,8 +536,8 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device)
 		return -ENOMEM;
 
 	if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
-		kfree(pr);
-		return -ENOMEM;
+		result = -ENOMEM;
+		goto err_free_pr;
 	}
 
 	pr->handle = device->handle;
@@ -577,7 +577,7 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device)
 	dev = get_cpu_device(pr->id);
 	if (sysfs_create_link(&device->dev.kobj, &dev->kobj, "sysdev")) {
 		result = -EFAULT;
-		goto err_free_cpumask;
+		goto err_clear_processor;
 	}
 
 	/*
@@ -595,9 +595,16 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device)
 
 err_remove_sysfs:
 	sysfs_remove_link(&device->dev.kobj, "sysdev");
+err_clear_processor:
+	/*
+	 * processor_device_array is not cleared to allow checks for buggy
+	 *  BIOSes
+	 */
+	per_cpu(processors, pr->id) = NULL;
 err_free_cpumask:
 	free_cpumask_var(pr->throttling.shared_cpu_map);
-
+err_free_pr:
+	kfree(pr);
 	return result;
 }
 
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