[PATCH] platform/x86: hp-bioscfg: Support allocation bios vars

[Artem Maksimov]

On HP systems with a large number of BIOS
attribute instances, the kzalloc_objs()
allocation in hp_alloc_ordered_list_data() and
hp_alloc_string_data() can fail when physical
memory is fragmented, leaving the driver
unable to register those attributes.

The same failure mode was already fixed for enumeration_data in
hp_alloc_enumeration_data() by commit 916727cfdb72 ("platform/x86:
hp-bioscfg: Support allocations of larger data"), reported on HP
Z2 Tower G9 and Z4 G5 Workstation systems:

  https://bugs.debian.org/1127612

order-list-attributes.c and string-attributes.c use
the identical allocation pattern and are still affected.
Apply the same fix: fall back to kvzalloc_objs()/kvfree()
instead of kzalloc_objs()/kfree(), and return -EINVAL
early when the instance count is zero.

Link: https://bugs.debian.org/1127612
Signed-off-by: Artem Maksimov <okuroshioffc@xxxxxxxxx>
---
 .../x86/hp/hp-bioscfg/order-list-attributes.c         | 11 ++++++++---
 .../platform/x86/hp/hp-bioscfg/string-attributes.c    | 11 ++++++++---
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
index 5bf8d40bdf81..80ac15435a18 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
@@ -98,8 +98,13 @@ int hp_alloc_ordered_list_data(void)
 {
 	bioscfg_drv.ordered_list_instances_count =
 		hp_get_instance_count(HP_WMI_BIOS_ORDERED_LIST_GUID);
-	bioscfg_drv.ordered_list_data = kzalloc_objs(*bioscfg_drv.ordered_list_data,
-						     bioscfg_drv.ordered_list_instances_count);
+
+	if (!bioscfg_drv.ordered_list_instances_count)
+		return -EINVAL;
+	bioscfg_drv.ordered_list_data =
+			kvzalloc_objs(*bioscfg_drv.ordered_list_data,
+						bioscfg_drv.ordered_list_instances_count);
+
 	if (!bioscfg_drv.ordered_list_data) {
 		bioscfg_drv.ordered_list_instances_count = 0;
 		return -ENOMEM;
@@ -438,6 +443,6 @@ void hp_exit_ordered_list_attributes(void)
 	}
 	bioscfg_drv.ordered_list_instances_count = 0;
 
-	kfree(bioscfg_drv.ordered_list_data);
+	kvfree(bioscfg_drv.ordered_list_data);
 	bioscfg_drv.ordered_list_data = NULL;
 }
diff --git a/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
index f3dfba270f7e..095201004d87 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
@@ -101,8 +101,13 @@ static const struct attribute_group string_attr_group = {
 int hp_alloc_string_data(void)
 {
 	bioscfg_drv.string_instances_count = hp_get_instance_count(HP_WMI_BIOS_STRING_GUID);
-	bioscfg_drv.string_data = kzalloc_objs(*bioscfg_drv.string_data,
-					       bioscfg_drv.string_instances_count);
+
+	if (!bioscfg_drv.string_instances_count)
+		return -EINVAL;
+	bioscfg_drv.string_data =
+			kvzalloc_objs(*bioscfg_drv.string_data,
+					bioscfg_drv.string_instances_count);
+
 	if (!bioscfg_drv.string_data) {
 		bioscfg_drv.string_instances_count = 0;
 		return -ENOMEM;
@@ -390,6 +395,6 @@ void hp_exit_string_attributes(void)
 	}
 	bioscfg_drv.string_instances_count = 0;
 
-	kfree(bioscfg_drv.string_data);
+	kvfree(bioscfg_drv.string_data);
 	bioscfg_drv.string_data = NULL;
 }
-- 
2.53.0