On Fri, 10 Aug 2007 09:40:00 +0200 Ingo Molnar <[EMAIL PROTECTED]> wrote:
> > * Andrew Morton <[EMAIL PROTECTED]> wrote: > > > We seem to have made a mess in there. timer_list_show() ends up > > calling lookup_module_symbol_name(), which takes a mutex. However > > print_symbol() (which is called at oops time, interrupt time, etc) > > calls module_address_lookup(), which is basically the same, only it > > doesn't take the mutex. > > hm, current upstream does: > > static void print_name_offset(struct seq_file *m, void *sym) > { > char symname[KSYM_NAME_LEN]; > > if (lookup_symbol_name((unsigned long)sym, symname) < 0) > > why was that changed? It wasn't. lookup_symbol_name() calls lookup_module_symbol_name() which calls mutex_lock(). > I think symbol lookups for debug purposes have to > be lockless, fundamentally. > Sure, especially a sysrq thingy. It's a bit nasty to just go in there and start walking data structures without holding the needed lock though. - 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/