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ACPI: fix potential OOPS in power driver

PATCH Applied Dmitry Torokhov 2 participants 2 messages Aug 24, 2006 ACPI

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PATCH 1/1 ACPI: fix potential OOPS in power driver

Hi,

I am wondering what is the reason to have every local variable initialized, whether it is needed or not? Aside of increasing code size it also hides errors compiler would warn about otherwise.

The patch below fixes potential OOPS, I have more patches that remove unnecessary initializations, checks. Would you be interested in these?

Signature · 55 lines
Dmitry

ACPI: fix potential OOPS in power driver

ACPI is littered with useless itialization of _every_ variable
on the stack. Besides increasing code it also sometimes covers
real bugs.

Signed-off-by: Dmitry Torokhov <[email protected]>
---

 drivers/acpi/power.c |    9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

Index: work/drivers/acpi/power.c
===================================================================
--- work.orig/drivers/acpi/power.c
+++ work/drivers/acpi/power.c
@@ -216,10 +216,8 @@ static int acpi_power_off_device(acpi_ha
 {
 	int result = 0;
 	acpi_status status = AE_OK;
-	struct acpi_device *device = NULL;
 	struct acpi_power_resource *resource = NULL;
 
-
 	result = acpi_power_get_context(handle, &resource);
 	if (result)
 		return result;
@@ -230,13 +228,13 @@ static int acpi_power_off_device(acpi_ha
 	if (resource->references) {
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 				  "Resource [%s] is still in use, dereferencing\n",
-				  device->pnp.bus_id));
+				  resource->device->pnp.bus_id));
 		return 0;
 	}
 
 	if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) {
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n",
-				  device->pnp.bus_id));
+				  resource->device->pnp.bus_id));
 		return 0;
 	}
 
@@ -251,8 +249,7 @@ static int acpi_power_off_device(acpi_ha
 		return -ENOEXEC;
 
 	/* Update the power resource's _device_ power state */
-	device = resource->device;
-	device->power.state = ACPI_STATE_D3;
+	resource->device->power.state = ACPI_STATE_D3;
 
 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
 			  resource->name));
Applied
#1 lore raw
Quoted 7 lines · Dmitry Torokhov

I am wondering what is the reason to have every local variable initialized, whether it is needed or not? Aside of increasing code size it also hides errors compiler would warn about otherwise.

The patch below fixes potential OOPS, I have more patches that remove unnecessary initializations, checks. Would you be interested in these?

Style of the original author I guess.
If you'd like to send a patch to clean it up, I'm happy to accept it -- as long as cleanups are not mixed with functionality changes.

Quoted 1 line

ACPI: fix potential OOPS in power driver

Applied.

thanks,
-Len

Quoted 50 lines
 drivers/acpi/power.c |    9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

Index: work/drivers/acpi/power.c
===================================================================

drivers/acpi/power.c +3 -7
@@ -216,10 +216,8 @@ static int acpi_power_off_device(acpi_ha
 {
 	int result = 0;
 	acpi_status status = AE_OK;
-	struct acpi_device *device = NULL;
 	struct acpi_power_resource *resource = NULL;
 
-
 	result = acpi_power_get_context(handle, &resource);
 	if (result)
 		return result;
@@ -230,13 +228,13 @@ static int acpi_power_off_device(acpi_ha
 	if (resource->references) {
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 				  "Resource [%s] is still in use, dereferencing\n",
-				  device->pnp.bus_id));
+				  resource->device->pnp.bus_id));
 		return 0;
 	}
 
 	if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) {
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n",
-				  device->pnp.bus_id));
+				  resource->device->pnp.bus_id));
 		return 0;
 	}
 
@@ -251,8 +249,7 @@ static int acpi_power_off_device(acpi_ha
 		return -ENOEXEC;
 
 	/* Update the power resource's _device_ power state */
-	device = resource->device;
-	device->power.state = ACPI_STATE_D3;
+	resource->device->power.state = ACPI_STATE_D3;
 
 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
 			  resource->name));
-

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