Hi!
As some of you remember my partner and I have worked on implementing a TCP/IP Noise Simulator for Linux 2.4.x. Now, the simulator uses or replaces the IP-Queue mechanism of IP-Tables, and can be run as a kernel module or a standalone userland application. We noticed our kernel module OOPSified kernels that used the new VM by Andrea Archanageli, and we assumed it was still buggy, so we sticked with the older one (which is by Rik van Riel IIRC). Now, in the last IGLU meeting I had a talk with Moshe Bar who said, that it was not supposed to work. The reason is that we used kmalloc and if we don't touch the buffer we allocated for a long time, and then tried to access a pointer to a 5th or greater page after its start, it is not guaranteed to succeed. <rant> kmalloc is supposed to be similar to the malloc() userland function, which gives you a dynamically allocated buffer for life. Why does not kmalloc behaves that way in the new VM? Would it not break compatibility with many third-party modules, like our own? </rant> OK - now for a solution. I suppose I can replace kmalloc by any of the other kernel memory allocation mechanisms. Rubini and Corbet mention quite a few in the relevant chapter in Linux Device Drivers: http://www.xml.com/ldd/chapter/book/ch07.html But I don't really know what to choose. We will need to build an abstraction for it, that will default to malloc in user-land, but that's a lesser problem. Can anybody clarify this situation? Regards, Shlomi Fish ---------------------------------------------------------------------- Shlomi Fish [EMAIL PROTECTED] Home Page: http://t2.technion.ac.il/~shlomif/ Home E-mail: [EMAIL PROTECTED] "Let's suppose you have a table with 2^n cups..." "Wait a second - is n a natural number?" ================================================================= To unsubscribe, send mail to [EMAIL PROTECTED] with the word "unsubscribe" in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
