lkml.org 
[lkml]   [2012]   [Jul]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5/6] drivers/pci/hotplug: ensure a consistent return value in error case
Date
From: Julia Lawall <Julia.Lawall@lip6.fr>

Typically, the return value desired for the failure of a function with an
integer return value is a negative integer. In these cases, the return
value is sometimes a negative integer and sometimes 0, due to a subsequent
initialization of the return variable within the loop.

A simplified version of the semantic match that finds this problem is:
(http://coccinelle.lip6.fr/)

//<smpl>
@r exists@
identifier ret;
position p;
constant C;
expression e1,e3,e4;
statement S;
@@

ret = -C
... when != ret = e3
when any
if@p (...) S
... when any
if (\(ret != 0\|ret < 0\|ret > 0\) || ...) { ... return ...; }
... when != ret = e3
when any
*if@p (...)
{
... when != ret = e4
return ret;
}
//</smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
drivers/pci/hotplug/cpqphp_core.c | 14 ++++++++++----
drivers/pci/hotplug/pcihp_skeleton.c | 14 ++++++++++----
drivers/pci/hotplug/shpchp_core.c | 14 ++++++++++----
3 files changed, 30 insertions(+), 12 deletions(-)
diff --git a/drivers/pci/hotplug/cpqphp_core.c b/drivers/pci/hotplug/cpqphp_core.c
index 187a199..c8eaeb4 100644
--- a/drivers/pci/hotplug/cpqphp_core.c
+++ b/drivers/pci/hotplug/cpqphp_core.c
@@ -611,7 +611,7 @@ static int ctrl_slot_setup(struct controller *ctrl,
u32 tempdword;
char name[SLOT_NAME_SIZE];
void __iomem *slot_entry= NULL;
- int result = -ENOMEM;
+ int result;

dbg("%s\n", __func__);

@@ -623,19 +623,25 @@ static int ctrl_slot_setup(struct controller *ctrl,

while (number_of_slots) {
slot = kzalloc(sizeof(*slot), GFP_KERNEL);
- if (!slot)
+ if (!slot) {
+ result = -ENOMEM;
goto error;
+ }

slot->hotplug_slot = kzalloc(sizeof(*(slot->hotplug_slot)),
GFP_KERNEL);
- if (!slot->hotplug_slot)
+ if (!slot->hotplug_slot) {
+ result = -ENOMEM;
goto error_slot;
+ }
hotplug_slot = slot->hotplug_slot;

hotplug_slot->info = kzalloc(sizeof(*(hotplug_slot->info)),
GFP_KERNEL);
- if (!hotplug_slot->info)
+ if (!hotplug_slot->info) {
+ result = -ENOMEM;
goto error_hpslot;
+ }
hotplug_slot_info = hotplug_slot->info;

slot->ctrl = ctrl;
diff --git a/drivers/pci/hotplug/pcihp_skeleton.c b/drivers/pci/hotplug/pcihp_skeleton.c
index b20ceaa..1f00b93 100644
--- a/drivers/pci/hotplug/pcihp_skeleton.c
+++ b/drivers/pci/hotplug/pcihp_skeleton.c
@@ -252,7 +252,7 @@ static int __init init_slots(void)
struct slot *slot;
struct hotplug_slot *hotplug_slot;
struct hotplug_slot_info *info;
- int retval = -ENOMEM;
+ int retval;
int i;

/*
@@ -261,17 +261,23 @@ static int __init init_slots(void)
*/
for (i = 0; i < num_slots; ++i) {
slot = kzalloc(sizeof(*slot), GFP_KERNEL);
- if (!slot)
+ if (!slot) {
+ retval = -ENOMEM;
goto error;
+ }

hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
- if (!hotplug_slot)
+ if (!hotplug_slot) {
+ retval = -ENOMEM;
goto error_slot;
+ }
slot->hotplug_slot = hotplug_slot;

info = kzalloc(sizeof(*info), GFP_KERNEL);
- if (!info)
+ if (!info) {
+ retval = -ENOMEM;
goto error_hpslot;
+ }
hotplug_slot->info = info;

slot->number = i;
diff --git a/drivers/pci/hotplug/shpchp_core.c b/drivers/pci/hotplug/shpchp_core.c
index 7414fd9..b6de307 100644
--- a/drivers/pci/hotplug/shpchp_core.c
+++ b/drivers/pci/hotplug/shpchp_core.c
@@ -99,22 +99,28 @@ static int init_slots(struct controller *ctrl)
struct hotplug_slot *hotplug_slot;
struct hotplug_slot_info *info;
char name[SLOT_NAME_SIZE];
- int retval = -ENOMEM;
+ int retval;
int i;

for (i = 0; i < ctrl->num_slots; i++) {
slot = kzalloc(sizeof(*slot), GFP_KERNEL);
- if (!slot)
+ if (!slot) {
+ retval = -ENOMEM;
goto error;
+ }

hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
- if (!hotplug_slot)
+ if (!hotplug_slot) {
+ retval = -ENOMEM;
goto error_slot;
+ }
slot->hotplug_slot = hotplug_slot;

info = kzalloc(sizeof(*info), GFP_KERNEL);
- if (!info)
+ if (!info) {
+ retval = -ENOMEM;
goto error_hpslot;
+ }
hotplug_slot->info = info;

slot->hp_slot = i;


\
 
 \ /
  Last update: 2012-07-14 19:21    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site