linux-kernel - munmap from inside kernel

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:	Thu, 21 Sep 2006 10:04:12 +0200
From:	"Andreas Block" <andreas.block@...-electronics.com>
To:	linux-kernel@...r.kernel.org
Subject: munmap from inside kernel

Hi,

following scenario:
Two linux systems connected via PCI.
I'd like to write a driver, which allows to map memory from the remote  
system into local user space and vice versa.
This works quite well utilizing mmap and respective vma_ops.
I do have one problem though. When the buffer on the remote side gets  
destroyed, I'd like to remove the mappings from local user space into this  
buffer (I do prefer a segfaulting application over an application writing  
into "I don't know where").
Under kernel 2.4.x I used "do_munmap()" in protection of "mm->mmap_sem"  
and it seemed to work quite well for me.
Now using kernel 2.6.x (I tested 2.6.8 and 2.6.15) this seemingly doesn't  
work anymore, because I do end up with a crash, when trying to manually  
unmap the memory.

Is there any safe way to "trigger munmap()" from inside the kernel?

Best regards,
Andreas
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/