Messages in this thread | | | Date | Wed, 7 Apr 2004 13:49:25 -0700 | From | "Randy.Dunlap" <> | Subject | Re: help needed with acquire/release_console_sem() problem. |
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On Thu, 25 Mar 2004 10:35:28 -0500 Kirk Reiser wrote:
| Hello folks: I am hoping someone may be able to help me with a | problem I have been experiencing since the release of 2.6.3. It | appears that because of the likeliness of race conditions occuring | while accessing console services acquire_console_sem() and | release_console_sem() were placed around sections of code which could | lead to these races. | | In my speakup console code I tried to put the same functions around | possible problem code with the result that it locks up the computer to | the point of a hardware reset being necessary. I have placed the code | in my functions for cutting and pasting portions of screen memory | which is where the new changes address the problem to some extent in | the kernel code. The comments to release_console_sem() state that the | functions are safe and may be called from any context
release_console_sem() comment says that. acquire() does not.
| but either that | isn't true or because I am in kernelspace I cannot schedule() off. I
Why do you want to call schedule()?
| am not exactly sure what the reasoning is or how to get around the | situation so if anyone has any suggestions I'd love to hear about it.
Are you using preempt (CONFIG_PREEMPT)? Would it cause any scheduling or semaphore problems or differences?
| What I currently do is mark portions of screen memory and then call | set_selection and paste_selection with the marked region of memory | which is what other functions seem to do to provide copy and paste | facilities. I cannot just ignore the situation because the acquire | and release_console_sem() calls have been placed around portions of | that code as well such as clear_selection and paste_selection().
I suppose that you could post some real code to see if someone sees any problems in it.
-- ~Randy "We have met the enemy and he is us." -- Pogo (by Walt Kelly) (Again. Sometimes I think ln -s /usr/src/linux/.config .signature) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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