Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 25 Sep 2002 02:13:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 25 Sep 2002 02:13:36 -0400 Received: from elin.scali.no ([62.70.89.10]:273 "EHLO elin.scali.no") by vger.kernel.org with ESMTP id ; Wed, 25 Sep 2002 02:13:35 -0400 Date: Wed, 25 Sep 2002 08:18:40 +0200 (CEST) From: Steffen Persvold X-X-Sender: sp@dpc-27.office.scali.no To: Lingli Zhang cc: linux-kernel@vger.kernel.org Subject: Re: mmap() failed on Linux 2.4.18-10smp with 4GB RAM In-Reply-To: <1032929970.3d9142b22bc55@webaccess.umail.ucsb.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2303 Lines: 59 On Tue, 24 Sep 2002, Lingli Zhang wrote: > Hi there, > > My machine is a 2-Processor Pentium 4 (Xeon) 2.4GHz e7500 Chipset with 4GB RAM. > I installed Redhat (kernel: Linux 2.4.18-10bigmem) on it. > > But when I run following piece of code: > ======================================== > #include > #include > int main(){ > mmap ((void *) 1090519040, 17000000, > PROT_READ | PROT_WRITE | PROT_EXEC, > MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0); > } > =========================================== > It gives out "segmentation fault". It works well if I change 17000000 > to 16000000. > > I have tried Linux 2.4.18-10smp kernel, same problem. > > Is there anyone have any idea what's going on here? Or do you have any > recommendation that which version of Linux I should use for my machine to work > around this problem? > Well, the problem is that you are forcing the mmap to create a virtual map starting at 0x41000000 and with 17000000 bytes that map is ending at 0x42036640, which is right in the middle of where glibc gets mapped : # cat /proc/2441/maps 08048000-08049000 r-xp 00000000 00:0c 163922 /home/sp/a.out 08049000-0804a000 rw-p 00000000 00:0c 163922 /home/sp/a.out 40000000-40013000 r-xp 00000000 08:02 416894 /lib/ld-2.2.5.so 40013000-40014000 rw-p 00013000 08:02 416894 /lib/ld-2.2.5.so 40014000-40015000 rw-p 00000000 00:00 0 40022000-40023000 rw-p 00000000 00:00 0 42000000-4212c000 r-xp 00000000 08:02 448959 /lib/i686/libc-2.2.5.so 4212c000-42131000 rw-p 0012c000 08:02 448959 /lib/i686/libc-2.2.5.so 42131000-42135000 rw-p 00000000 00:00 0 bfffe000-c0000000 rwxp fffff000 00:00 0 If you absolutely want to use this fixed address for your mmap, link your application statically, or maybe there's a way to tell the dynamic linker to put the libraries elsewhere ? Regards, -- Steffen Persvold | Scali AS mailto:sp@scali.com | http://www.scali.com Tel: (+47) 2262 8950 | Olaf Helsets vei 6 Fax: (+47) 2262 8951 | N0621 Oslo, NORWAY - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/