Re: 2.6 Series Mem Mgmt

[Brian Gerst <bgerst@didntduck.org>]

Chris Bookholt wrote:
> I'm hoping someone can help explain part of the layout of a process' 
> virtual address space in the 2.6 series kernel.
> 
> Below is the output of "cat /proc/self/maps" on Fedora Core 3 
> (2.6.9-1.6_FC2) with exec-shield[-randomize] disabled and 
> legacy_vm_layout enabled.
> 
> What is being mapped in at last line (ffffe000-fffff000 ---p)?  This is 
> always there, no matter what process I run.  To my knowledge, this 
> wasn't the case on 2.4.
> 
>  >$ cat /proc/self/maps
> 08048000-0804c000 r-xp 00000000 03:03 2490451    /bin/cat
> 0804c000-0804d000 rw-p 00003000 03:03 2490451    /bin/cat
> 0804d000-0806e000 rw-p 0804d000 00:00 0
> 42344000-42359000 r-xp 00000000 03:03 950351     /lib/ld-2.3.3.so
> 42359000-4235a000 r--p 00014000 03:03 950351     /lib/ld-2.3.3.so
> 4235a000-4235b000 rw-p 00015000 03:03 950351     /lib/ld-2.3.3.so
> 4235d000-42473000 r-xp 00000000 03:03 950450     /lib/tls/libc-2.3.3.so
> 42473000-42474000 r--p 00116000 03:03 950450     /lib/tls/libc-2.3.3.so
> 42474000-42477000 rw-p 00117000 03:03 950450     /lib/tls/libc-2.3.3.so
> 42477000-42479000 rw-p 42477000 00:00 0
> 55017000-55018000 rw-p 55017000 00:00 0
> 55018000-55218000 r--p 00000000 03:03 114690 /usr/lib/locale/locale-archive
> feffe000-ff000000 rw-p feffe000 00:00 0
> ffffe000-fffff000 ---p 00000000 00:00 0
> 
> I have not had much success in my search for information via Google & 
> IRC and the books I have are specific to the 2.4 series.  Any help would 
> be greatly appreciated.
> 

That is the vsyscall page.

--
				Brian Gerst