Date: Wed, 27 Oct 2004 10:05:19 -0700 From: Peter Wemm <peter@wemm.org> To: freebsd-amd64@freebsd.org, obrien@freebsd.org Cc: "James R. Van Artsalen" <james@jrv.org> Subject: Re: two 4GB mallocs => SEGV Message-ID: <200410271005.19427.peter@wemm.org> In-Reply-To: <20041026213227.GA95016@dragon.nuxi.com> References: <20041026115041.GE2841@sivokote.iziade.m$> <417E8F7A.70009@jrv.org> <20041026213227.GA95016@dragon.nuxi.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tuesday 26 October 2004 02:32 pm, David O'Brien wrote: > On Tue, Oct 26, 2004 at 12:55:06PM -0500, James R. Van Artsalen wrote: > > David O'Brien wrote: > > >malloc.c:map_pages() calls brk(2) and this is where it goes to > > > la-la land. > > > > The brk() kernel call is probably failing due to ulimit being > > exceeded and not anything mysterious. > > # ulimit -a | grep virt > virtual memory (kbytes, -v) unlimited The data size limit is 8GB though. > BTW, a statically built binary (ie, using libc.a) just hangs in the > brk(2) call. Yes, and that is rather worrying. > > A few months ago I posted this bug in the libc brk(2) code - the > > stack is not balanced if the kernel returns an error. I'm not > > running current code at the moment but see if you brk.S has a stack > > issue at the err: label. Stick in this pop if so and report if > > malloc(3c) then returns NULL instead of crashing, then up your > > ulimit and try again and see if all works without error. > > > > --- lib/libc/amd64/sys/brk.S.~1~ Sat May 24 12:35:23 2003 > > +++ lib/libc/amd64/sys/brk.S Fri Apr 9 02:02:22 2004 > > @@ -78,6 +78,7 @@ > > popq %rdi > > ret > > err: > > + popq %rdi > > #ifdef PIC > > movq PIC_GOT(HIDENAME(cerror)),%rdx > > jmp *%rdx > > Today's code has: > > err: > addq $8, %rsp > #ifdef PIC > movq PIC_GOT(HIDENAME(cerror)),%rdx > jmp *%rdx > > > so the stack should be OK. Where do you see the addq? Its not in cvs that I can see.. Oh, its in sbrk.S - this patch is against brk.S. -- Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com "All of this is for nothing if we don't go to the stars" - JMS/B5
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200410271005.19427.peter>