two 4GB mallocs => SEGV
obrien at freebsd.org
Tue Oct 26 14:32:31 PDT 2004
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
BTW, a statically built binary (ie, using libc.a) just hangs in the
> 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
> + popq %rdi
> #ifdef PIC
> movq PIC_GOT(HIDENAME(cerror)),%rdx
> jmp *%rdx
Today's code has:
addq $8, %rsp
so the stack should be OK.
-- David (obrien at FreeBSD.org)
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