The patch titled
Fix race in efi variable delete code
has been removed from the -mm tree. Its filename was
fix-race-in-efi-variable-delete-code.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: Fix race in efi variable delete code
From: Matt Domsch <Matt_Domsch@xxxxxxxx>
Fix race when deleting an EFI variable and issuing another EFI command on
the same variable. The removal of the variable from the efivars_list
should be done in efivar_delete and not delayed until the kobject release.
Furthermore, remove the item from the list at module unload time, and use
list_for_each_entry_safe() rather than list_for_each_safe() for
readability.
Tested on ia64.
Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx>
Signed-off-by: Matt Domsch <Matt_Domsch@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/firmware/efivars.c | 29 ++++++++++++-----------------
1 file changed, 12 insertions(+), 17 deletions(-)
diff -puN drivers/firmware/efivars.c~fix-race-in-efi-variable-delete-code drivers/firmware/efivars.c
--- a/drivers/firmware/efivars.c~fix-race-in-efi-variable-delete-code
+++ a/drivers/firmware/efivars.c
@@ -122,8 +122,6 @@ struct efivar_entry {
struct kobject kobj;
};
-#define get_efivar_entry(n) list_entry(n, struct efivar_entry, list)
-
struct efivar_attribute {
struct attribute attr;
ssize_t (*show) (struct efivar_entry *entry, char *buf);
@@ -386,9 +384,6 @@ static struct sysfs_ops efivar_attr_ops
static void efivar_release(struct kobject *kobj)
{
struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
- spin_lock(&efivars_lock);
- list_del(&var->list);
- spin_unlock(&efivars_lock);
kfree(var);
}
@@ -430,9 +425,8 @@ static ssize_t
efivar_create(struct subsystem *sub, const char *buf, size_t count)
{
struct efi_variable *new_var = (struct efi_variable *)buf;
- struct efivar_entry *search_efivar = NULL;
+ struct efivar_entry *search_efivar, *n;
unsigned long strsize1, strsize2;
- struct list_head *pos, *n;
efi_status_t status = EFI_NOT_FOUND;
int found = 0;
@@ -444,8 +438,7 @@ efivar_create(struct subsystem *sub, con
/*
* Does this variable already exist?
*/
- list_for_each_safe(pos, n, &efivar_list) {
- search_efivar = get_efivar_entry(pos);
+ list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
strsize2 = utf8_strsize(new_var->VariableName, 1024);
if (strsize1 == strsize2 &&
@@ -490,9 +483,8 @@ static ssize_t
efivar_delete(struct subsystem *sub, const char *buf, size_t count)
{
struct efi_variable *del_var = (struct efi_variable *)buf;
- struct efivar_entry *search_efivar = NULL;
+ struct efivar_entry *search_efivar, *n;
unsigned long strsize1, strsize2;
- struct list_head *pos, *n;
efi_status_t status = EFI_NOT_FOUND;
int found = 0;
@@ -504,8 +496,7 @@ efivar_delete(struct subsystem *sub, con
/*
* Does this variable already exist?
*/
- list_for_each_safe(pos, n, &efivar_list) {
- search_efivar = get_efivar_entry(pos);
+ list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
strsize2 = utf8_strsize(del_var->VariableName, 1024);
if (strsize1 == strsize2 &&
@@ -537,9 +528,9 @@ efivar_delete(struct subsystem *sub, con
spin_unlock(&efivars_lock);
return -EIO;
}
+ list_del(&search_efivar->list);
/* We need to release this lock before unregistering. */
spin_unlock(&efivars_lock);
-
efivar_unregister(search_efivar);
/* It's dead Jim.... */
@@ -768,10 +759,14 @@ out_free:
static void __exit
efivars_exit(void)
{
- struct list_head *pos, *n;
+ struct efivar_entry *entry, *n;
- list_for_each_safe(pos, n, &efivar_list)
- efivar_unregister(get_efivar_entry(pos));
+ list_for_each_entry_safe(entry, n, &efivar_list, list) {
+ spin_lock(&efivars_lock);
+ list_del(&entry->list);
+ spin_unlock(&efivars_lock);
+ efivar_unregister(entry);
+ }
subsystem_unregister(&vars_subsys);
firmware_unregister(&efi_subsys);
_
Patches currently in -mm which might be from Matt_Domsch@xxxxxxxx are
origin.patch
docbook-add-edd-firmware-interfaces.patch
-
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