PCI: hotplug: Drop superfluous NULL pointer checks in has_*_file()

The PCI hotplug core contains five has_*_file() functions to determine
whether a certain sysfs file shall be added (or removed) for a given
hotplug slot.

The functions perform NULL pointer checks for the hotplug_slot and its
hotplug_slot_ops.  However the callers already perform these checks:

  pci_hp_register()
    __pci_hp_register()
      __pci_hp_initialize()

  pci_hp_deregister()
    pci_hp_del()

The only way to actually trigger these checks is to call pci_hp_add()
without having called pci_hp_initialize().

Amend pci_hp_add() to catch that and drop the now superfluous NULL
pointer checks in has_*_file().

Drop the same superfluous checks from pci_hp_create_module_link(),
which is (only) called from pci_hp_add().

Link: https://lore.kernel.org/r/37d1928edf8c3201a8b10794f1db3142e16e02b9.1740501868.git.lukas@wunner.de
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/hotplug/pci_hotplug_core.c b/drivers/pci/hotplug/pci_hotplug_core.c
index de5b501b40beb8858efdd2bef0b9771bfe9541be..d4c12451570bce561b1630a3ceb6de9734988aaf 100644 (file)
--- a/drivers/pci/hotplug/pci_hotplug_core.c
+++ b/drivers/pci/hotplug/pci_hotplug_core.c
@@ -209,8 +209,6 @@ static bool has_power_file(struct pci_slot *pci_slot)
 {
        struct hotplug_slot *slot = pci_slot->hotplug;
 
-       if ((!slot) || (!slot->ops))
-               return false;
        if ((slot->ops->enable_slot) ||
            (slot->ops->disable_slot) ||
            (slot->ops->get_power_status))
@@ -222,8 +220,6 @@ static bool has_attention_file(struct pci_slot *pci_slot)
 {
        struct hotplug_slot *slot = pci_slot->hotplug;
 
-       if ((!slot) || (!slot->ops))
-               return false;
        if ((slot->ops->set_attention_status) ||
            (slot->ops->get_attention_status))
                return true;
@@ -234,8 +230,6 @@ static bool has_latch_file(struct pci_slot *pci_slot)
 {
        struct hotplug_slot *slot = pci_slot->hotplug;
 
-       if ((!slot) || (!slot->ops))
-               return false;
        if (slot->ops->get_latch_status)
                return true;
        return false;
@@ -245,8 +239,6 @@ static bool has_adapter_file(struct pci_slot *pci_slot)
 {
        struct hotplug_slot *slot = pci_slot->hotplug;
 
-       if ((!slot) || (!slot->ops))
-               return false;
        if (slot->ops->get_adapter_status)
                return true;
        return false;
@@ -256,8 +248,6 @@ static bool has_test_file(struct pci_slot *pci_slot)
 {
        struct hotplug_slot *slot = pci_slot->hotplug;
 
-       if ((!slot) || (!slot->ops))
-               return false;
        if (slot->ops->hardware_test)
                return true;
        return false;
@@ -439,9 +429,14 @@ EXPORT_SYMBOL_GPL(__pci_hp_initialize);
  */
 int pci_hp_add(struct hotplug_slot *slot)
 {
-       struct pci_slot *pci_slot = slot->pci_slot;
+       struct pci_slot *pci_slot;
        int result;
 
+       if (WARN_ON(!slot))
+               return -EINVAL;
+
+       pci_slot = slot->pci_slot;
+
        result = fs_add_slot(pci_slot);
        if (result)
                return result;

diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
index 36b44be0489d6230978461543bd20b7119e5c5ce..dd6e80b7db093c81914a6142a6c6b3b66517dc2b 100644 (file)
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -340,8 +340,6 @@ void pci_hp_create_module_link(struct pci_slot *pci_slot)
        struct kobject *kobj = NULL;
        int ret;
 
-       if (!slot || !slot->ops)
-               return;
        kobj = kset_find_obj(module_kset, slot->mod_name);
        if (!kobj)
                return;