alistair23-linux/drivers/misc/vmw_vmci/vmci_driver.c
Jorgen Hansen eb94cd68ab VMCI: Doorbell create and destroy fixes
This change consists of two changes:

1) If vmci_doorbell_create is called when neither guest nor
   host personality as been initialized, vmci_get_context_id
   will return VMCI_INVALID_ID. In that case, we should fail
   the create call.
2) In doorbell destroy, we assume that vmci_guest_code_active()
   has the same return value on create and destroy. That may not
   be the case, so we may end up with the wrong refcount.
   Instead, destroy should check explicitly whether the doorbell
   is in the index table as an indicator of whether the guest
   code was active at create time.

Reviewed-by: Adit Ranadive <aditr@vmware.com>
Signed-off-by: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28 08:26:21 -04:00

118 lines
3 KiB
C

/*
* VMware VMCI Driver
*
* Copyright (C) 2012 VMware, Inc. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation version 2 and no later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
#include <linux/vmw_vmci_defs.h>
#include <linux/vmw_vmci_api.h>
#include <linux/atomic.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include "vmci_driver.h"
#include "vmci_event.h"
static bool vmci_disable_host;
module_param_named(disable_host, vmci_disable_host, bool, 0);
MODULE_PARM_DESC(disable_host,
"Disable driver host personality (default=enabled)");
static bool vmci_disable_guest;
module_param_named(disable_guest, vmci_disable_guest, bool, 0);
MODULE_PARM_DESC(disable_guest,
"Disable driver guest personality (default=enabled)");
static bool vmci_guest_personality_initialized;
static bool vmci_host_personality_initialized;
/*
* vmci_get_context_id() - Gets the current context ID.
*
* Returns the current context ID. Note that since this is accessed only
* from code running in the host, this always returns the host context ID.
*/
u32 vmci_get_context_id(void)
{
if (vmci_guest_code_active())
return vmci_get_vm_context_id();
else if (vmci_host_code_active())
return VMCI_HOST_CONTEXT_ID;
return VMCI_INVALID_ID;
}
EXPORT_SYMBOL_GPL(vmci_get_context_id);
static int __init vmci_drv_init(void)
{
int vmci_err;
int error;
vmci_err = vmci_event_init();
if (vmci_err < VMCI_SUCCESS) {
pr_err("Failed to initialize VMCIEvent (result=%d)\n",
vmci_err);
return -EINVAL;
}
if (!vmci_disable_guest) {
error = vmci_guest_init();
if (error) {
pr_warn("Failed to initialize guest personality (err=%d)\n",
error);
} else {
vmci_guest_personality_initialized = true;
pr_info("Guest personality initialized and is %s\n",
vmci_guest_code_active() ?
"active" : "inactive");
}
}
if (!vmci_disable_host) {
error = vmci_host_init();
if (error) {
pr_warn("Unable to initialize host personality (err=%d)\n",
error);
} else {
vmci_host_personality_initialized = true;
pr_info("Initialized host personality\n");
}
}
if (!vmci_guest_personality_initialized &&
!vmci_host_personality_initialized) {
vmci_event_exit();
return -ENODEV;
}
return 0;
}
module_init(vmci_drv_init);
static void __exit vmci_drv_exit(void)
{
if (vmci_guest_personality_initialized)
vmci_guest_exit();
if (vmci_host_personality_initialized)
vmci_host_exit();
vmci_event_exit();
}
module_exit(vmci_drv_exit);
MODULE_AUTHOR("VMware, Inc.");
MODULE_DESCRIPTION("VMware Virtual Machine Communication Interface.");
MODULE_VERSION("1.1.5.0-k");
MODULE_LICENSE("GPL v2");