On Tue 2008-02-05 13:50:51, Jiri Kosina wrote: > On Tue, 5 Feb 2008, Pavel Machek wrote: > > > > Actually, this clearly shows that either prehistoric libc.so.5 or the > > > program itself are broken. > > I believe it shows clear regression in latest 2.6.25 kernel. > > I am still not completely sure. It might be a regression, but it also > might just trigger the bug in ancient version in libc.so.5 which might be > fixed in some later version -- are you able to verify that?
I'm in same position as you here. I only have few old binaries :-(. > > You say it is wrong. Manpages imply otherwise: > > > > int brk(void *end_data_segment); > > ... > > DESCRIPTION > > brk() sets the end of the data segment to the value > > specified by > > end_data_segment, when that value is reasonable, the system does > > have enough > > memory and the process does not exceed its max data size (see > > setrlimit(2)). > > Note it talks about data segment, not about heap, and that seems to > > imply that BSS and heap are actually one area. 2.6.25 broke that. > > Single Unix Specification talks only about manipulating the break section, > see http://opengroup.org/onlinepubs/007908775/xsh/brk.html SuS: # The brk() and sbrk() functions are used to change the amount of space # allocated for the calling process. It talks about "space for calling process". It does not talk about heap, and I think it implicitely assumes "bss and heap" are continuous... (It also says return 0 or success, and we return address). > > > Still, it will probably not fix your particular program crashes, just > > > because it will always assume that brk starts immediately after the end > > > of > > > the bss, which is plain wrong and has never been assured. Could you > > > please > > Can you quote docs that tells me it is plain wrong? > > See the Single Unix Specification. It doesn't seem to allow you to assume > *anything* about start_brk location, seems to me. I believe it implicitely assumes start_brk is well known, actually. Otherwise it should have told us how to get start_brk. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/
