Re: [ros-dev] [ros-diffs] [gedmurphy] 70408: [NTOSKRNL] - Raise the IRQL when enumerating device lists so it doesn't get edited mid-listing - Don't hardcode the pointer size when checking the buffer size

[Thomas Faber]

Uhm... raising the IRQL is not a synchronization mechanism. Should
there be a spinlock involved?


On 2015-12-23 12:26, gedmurphy(a)svn.reactos.org wrote:
>   Author: gedmurphy
>  Date: Wed Dec 23 11:26:28 2015
>  New Revision: 70408
>  
>  URL: http://svn.reactos.org/svn/reactos?rev=70408&view=rev
>  Log:
>  [NTOSKRNL]
>  - Raise the IRQL when enumerating device lists so it doesn't get edited mid-listing
>  - Don't hardcode the pointer size when checking the buffer size
>  
>  Modified:
>      trunk/reactos/ntoskrnl/io/iomgr/device.c
>  
>  Modified: trunk/reactos/ntoskrnl/io/iomgr/device.c
>  URL:
> http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/io/iomgr/device.c…
>  ==============================================================================
>  --- trunk/reactos/ntoskrnl/io/iomgr/device.c	[iso-8859-1] (original)
>  +++ trunk/reactos/ntoskrnl/io/iomgr/device.c	[iso-8859-1] Wed Dec 23 11:26:28 2015
>  @@ -1088,6 +1088,10 @@
>   {
>       ULONG ActualDevices = 1;
>       PDEVICE_OBJECT CurrentDevice = DriverObject->DeviceObject;
>  +    KIRQL OldIrql;
>  +
>  +    /* Raise to dispatch level */
>  +    KeRaiseIrql(DISPATCH_LEVEL, &OldIrql);
>   
>       /* Find out how many devices we'll enumerate */
>       while ((CurrentDevice = CurrentDevice->NextDevice)) ActualDevices++;
>  @@ -1099,13 +1103,14 @@
>       *ActualNumberDeviceObjects = ActualDevices;
>   
>       /* Check if we can support so many */
>  -    if ((ActualDevices * 4) > DeviceObjectListSize)
>  +    if ((ActualDevices * sizeof(PDEVICE_OBJECT)) > DeviceObjectListSize)
>       {
>           /* Fail because the buffer was too small */
>  +        KeLowerIrql(OldIrql);
>           return STATUS_BUFFER_TOO_SMALL;
>       }
>   
>  -    /* Check if the caller only wanted the size */
>  +    /* Check if the caller wanted the device list */
>       if (DeviceObjectList)
>       {
>           /* Loop through all the devices */
>  @@ -1123,6 +1128,9 @@
>               DeviceObjectList++;
>           }
>       }
>  +
>  +    /* Return back to previous IRQL */
>  +    KeLowerIrql(OldIrql);
>   
>       /* Return the status */
>       return STATUS_SUCCESS;
>  
>