On Thu, 2006-12-28 at 09:54 +0100, Jan Engelhardt wrote: > On Dec 27 2006 17:10, Pavel Machek wrote: > > >> Was just wondering if the _var_ in kfree(_var_) could be set to > >> NULL after its freed. It may solve the problem of accessing some > >> freed memory as the kernel will crash since _var_ was set to NULL. > >> > >> Does this make sense? If yes, then how about renaming kfree to > >> something else and providing a kfree macro that would do the > >> following: > >> > >> #define kfree(x) do { \ > >> new_kfree(x); \ > >> x = NULL; \ > >> } while(0) > >> > >> There might be other better ways too.
---- snip ---- (x) = NULL; \ ---- snip ---- ? > >No, that would be very confusing. Otoh having > >KFREE() do kfree() and assignment might be acceptable. > > What about setting x to some poison value from <linux/poison.h>? That depends on the decision/definition if (so called) "double free" is an error or not (and "free(NULL)" must work in POSIX-compliant environments). Personally I think it is pointless to disallow "kfree(NULL)" by using some poison value and force people to add a "we have to free that variable" variable to work around it instead of keeping it NULL (which makes the "kfree($variable)" a no-op). Former discussions are to be found in the archives ...... Bernd -- Firmix Software GmbH http://www.firmix.at/ mobil: +43 664 4416156 fax: +43 1 7890849-55 Embedded Linux Development and Services - 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/