On Mon, 2007-08-20 at 16:26 -0400, Mathieu Desnoyers wrote: > plain text document attachment (module.c-sort-module-list.patch) > A race that appears both in /proc/modules and in kallsyms: if, between the > seq file reads, the process is put to sleep and at this moment a module is > or removed from the module list, the listing will skip an amount of > modules/symbols corresponding to the amount of elements present in the > unloaded > module, but at the current position in the list if the iteration is located > after the removed module. > > The cleanest way I found to deal with this problem is to sort the module list. > We can then keep the old struct module * as the old iterator, knowing the it > may > be removed between the seq file reads, but we only use it as "get next". If it > is not present in the module list, the next pointer will be used. > > By doing this, removing a given module will now only fuzz the output related > to > this specific module, not any random module anymore. Since modprobe uses > /proc/modules, it might be important to make sure multiple concurrent running > modprobes won't interfere with each other.
You've reduced, but not eliminated, the problem. A new module inserted is quite likely to reuse the same address. I don't have a real problem with this patch, but I'm wondering if the problem is theoretical or demonstrated. Rusty. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
