The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From eb50aaf960e3bedfef79063411ffd670da94b84b Mon Sep 17 00:00:00 2001
From: Andy Shevchenko andriy.shevchenko@linux.intel.com Date: Mon, 22 Mar 2021 18:31:00 +0200 Subject: [PATCH] ACPI: scan: Use unique number for instance_no
The decrementation of acpi_device_bus_id->instance_no in acpi_device_del() is incorrect, because it may cause a duplicate instance number to be allocated next time a device with the same acpi_device_bus_id is added.
Replace above mentioned approach by using IDA framework.
While at it, define the instance range to be [0, 4096).
Fixes: e49bd2dd5a50 ("ACPI: use PNPID:instance_no as bus_id of ACPI device") Fixes: ca9dc8d42b30 ("ACPI / scan: Fix acpi_bus_id_list bookkeeping") Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Cc: 4.10+ stable@vger.kernel.org # 4.10+ Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index e6a5d997241c..cb8f70842249 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -9,6 +9,8 @@ #ifndef _ACPI_INTERNAL_H_ #define _ACPI_INTERNAL_H_
+#include <linux/idr.h> + #define PREFIX "ACPI: "
int early_acpi_osi_init(void); @@ -96,9 +98,11 @@ void acpi_scan_table_handler(u32 event, void *table, void *context);
extern struct list_head acpi_bus_id_list;
+#define ACPI_MAX_DEVICE_INSTANCES 4096 + struct acpi_device_bus_id { const char *bus_id; - unsigned int instance_no; + struct ida instance_ida; struct list_head node; };
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index a184529d8fa4..84bb7c1929f1 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -479,9 +479,8 @@ static void acpi_device_del(struct acpi_device *device) list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) if (!strcmp(acpi_device_bus_id->bus_id, acpi_device_hid(device))) { - if (acpi_device_bus_id->instance_no > 0) - acpi_device_bus_id->instance_no--; - else { + ida_simple_remove(&acpi_device_bus_id->instance_ida, device->pnp.instance_no); + if (ida_is_empty(&acpi_device_bus_id->instance_ida)) { list_del(&acpi_device_bus_id->node); kfree_const(acpi_device_bus_id->bus_id); kfree(acpi_device_bus_id); @@ -631,6 +630,21 @@ static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id) return NULL; }
+static int acpi_device_set_name(struct acpi_device *device, + struct acpi_device_bus_id *acpi_device_bus_id) +{ + struct ida *instance_ida = &acpi_device_bus_id->instance_ida; + int result; + + result = ida_simple_get(instance_ida, 0, ACPI_MAX_DEVICE_INSTANCES, GFP_KERNEL); + if (result < 0) + return result; + + device->pnp.instance_no = result; + dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result); + return 0; +} + int acpi_device_add(struct acpi_device *device, void (*release)(struct device *)) { @@ -665,7 +679,9 @@ int acpi_device_add(struct acpi_device *device,
acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device)); if (acpi_device_bus_id) { - acpi_device_bus_id->instance_no++; + result = acpi_device_set_name(device, acpi_device_bus_id); + if (result) + goto err_unlock; } else { acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id), GFP_KERNEL); @@ -681,9 +697,16 @@ int acpi_device_add(struct acpi_device *device, goto err_unlock; }
+ ida_init(&acpi_device_bus_id->instance_ida); + + result = acpi_device_set_name(device, acpi_device_bus_id); + if (result) { + kfree(acpi_device_bus_id); + goto err_unlock; + } + list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list); } - dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
if (device->parent) list_add_tail(&device->node, &device->parent->children); diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 02a716a0af5d..f28b097c658f 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -233,6 +233,7 @@ struct acpi_pnp_type {
struct acpi_device_pnp { acpi_bus_id bus_id; /* Object name */ + int instance_no; /* Instance number of this object */ struct acpi_pnp_type type; /* ID type */ acpi_bus_address bus_address; /* _ADR */ char *unique_id; /* _UID */