Bug 152372 – app-emulation/dosemu error if /dev/shm is mounted "noexec"

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description norbert kamenicky 2006-10-22 06:45:49 UTC]

if /dev/shm is mounted "noexec" (which is default AFAIK)
dosemu-1.3.3 fails with this error:
ERROR: MAPPING: cannot map temp file pool, Operation not permitted

It's very interesting, because it fails on this system call: (output from strace)

mmap2(NULL, 15794176, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_SHARED, 6, 0) = -1 EPERM (Operation not permitted)

while trying to call mmap(2) with "PROT_EXEC" flag on noexec protected device

i.e. a patch is needed to make it work with /dev/shm mounted "noexec"

[Comment 1 Jakub Moc (RETIRED) 2006-10-22 08:06:23 UTC]

Change $_mapping from "auto" to "mapashm" in /etc/dosemu/dosemu.conf 

[Comment 2 Stefaan De Roeck (RETIRED) 2006-12-30 05:28:11 UTC]

Solution works for me at least

[Comment 3 norbert kamenicky 2006-12-30 14:38:12 UTC]

(In reply to comment #1)
> Change $_mapping from "auto" to "mapashm" in /etc/dosemu/dosemu.conf 
> 

Yes, this solution really works, so please do it default in /etc/dosemu/dosemu.conf and the bug can be closed.

Thanks

[Comment 4 John Lawless 2007-03-21 01:14:41 UTC]

> Change $_mapping from "auto" to "mapashm" in /etc/dosemu/dosemu.conf 

That did NOT work for me but remounting /dev/shm to exec did work.

[Comment 5 Hanno Böck 2007-04-02 21:34:40 UTC]

fixed in global dosemu.conf, though this might be overwritten by local config