From: Arlet Ottens (arlet@ladybug.xs4all.nl)
Date: Tue Jan 30 2001 - 06:36:14 EST
Mahadev K Cholachagudda wrote: > I have some experience with m68k-coldfire 5206e code. The ColdFire do have > superuser/user mode. > > But the Linux should provide the protections for the kernel. If say > application programmer writes an application which directly update the > status of say interrupts, then the whole mechanism of protection is lost. This is going to be a problem, since uClinux doesn't use an MMU (even on ports that have user/supervisor mode), and there's no memory protection. Even if the user mode process can't change the interrupt status directly, it could still overwrite kernel data structures, and crash your system. Depending on your platform, it may be feasible to implement some form of memory protection in the uClinux kernel. For instance, if your CPU has support for user and supervisor memory spaces, you could protect the kernel from userspace interference. Although you may not be able to protect userspace applications from each other. Note that the kernel currently doesn't offer support for this kind of memory protection, so you need to add it yourself. -- Arlet Ottens / Talent Store / Seattle Torn / Art Teen Lost Very funny, Scotty ... now beam down my clothes. This message resent by the uclinux-dev@uclinux.org list server http://www.uClinux.org/
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