Check for mutex

NTDEV
1

Hello,

How can I check the existence of a mutex, created by an user level
application? If it’s possible, how safe it is to do something like this
from a kernel-mode driver?

–
Thank you,

Andrei Ciubotaru

2

ZwOpenMutant/NtOpenMutant which are undocumented. You can switch to
semaphores and call NtCreateSemaphore instead. You can get the prototype
from internet.

It is not unsafe to use mutants in kernel mode. They are not preferred
in kernel because of performance reasons.

3

I make this check only once in 2 seconds. It shouldn’t affect the
performance too much… i think.

Thank you for the quick answer.

Thank you,

Andrei Ciubotaru

Satya Das wrote:

ZwOpenMutant/NtOpenMutant which are undocumented. You can switch to
semaphores and call NtCreateSemaphore instead. You can get the prototype
from internet.

It is not unsafe to use mutants in kernel mode. They are not preferred
in kernel because of performance reasons.

Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256

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4

Hello,

Me again… It seems that “undocumented” is the best title for these
functions. I seem unable to find some usage sample (I’ve found the
definition…) of the Zw(Nt)OpenMutant. Does anyone worked with this
functions? Please help!

Thank you,

Andrei Ciubotaru [Hardwired]

Andrei Ciubotaru [Hardwired] wrote:

I make this check only once in 2 seconds. It shouldn’t affect the
performance too much… i think.

Thank you for the quick answer.

Thank you,

Andrei Ciubotaru

Satya Das wrote:

> ZwOpenMutant/NtOpenMutant which are undocumented. You can switch to
> semaphores and call NtCreateSemaphore instead. You can get the prototype
> from internet.
> It is not unsafe to use mutants in kernel mode. They are not preferred
> in kernel because of performance reasons.
> —
> Questions? First check the Kernel Driver FAQ at
> http://www.osronline.com/article.cfm?id=256
>
> You are currently subscribed to ntdev as: unknown lmsubst tag
> argument: ‘’
> To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
>

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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