PCI: hotplug: ensure a consistent return value in error case

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>

[bhelgaas: squashed into one patch]
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Julia Lawall 2012-07-16 09:25:56 -06:00 committed by Bjorn Helgaas
parent cfaf025112
commit 83d0571073
4 changed files with 40 additions and 16 deletions

View file

@ -225,7 +225,7 @@ cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last)
struct hotplug_slot *hotplug_slot;
struct hotplug_slot_info *info;
char name[SLOT_NAME_SIZE];
int status = -ENOMEM;
int status;
int i;
if (!(controller && bus))
@ -237,18 +237,24 @@ cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last)
*/
for (i = first; i <= last; ++i) {
slot = kzalloc(sizeof (struct slot), GFP_KERNEL);
if (!slot)
if (!slot) {
status = -ENOMEM;
goto error;
}
hotplug_slot =
kzalloc(sizeof (struct hotplug_slot), GFP_KERNEL);
if (!hotplug_slot)
if (!hotplug_slot) {
status = -ENOMEM;
goto error_slot;
}
slot->hotplug_slot = hotplug_slot;
info = kzalloc(sizeof (struct hotplug_slot_info), GFP_KERNEL);
if (!info)
if (!info) {
status = -ENOMEM;
goto error_hpslot;
}
hotplug_slot->info = info;
slot->bus = bus;

View file

@ -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;

View file

@ -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;

View file

@ -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;