Messages in this thread | | | From | Mike Waychison <> | Date | Thu, 14 Jul 2011 13:38:35 -0700 | Subject | Re: [PATCH 2/2] x86: Allow disabling of sys_iopl, sys_ioperm |
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On Thu, Jul 14, 2011 at 1:37 PM, H. Peter Anvin <hpa@zytor.com> wrote: > On 07/14/2011 01:34 PM, Mike Waychison wrote: >> In some build environments, it is useful to allow disabling of IO >> accesses to hardware, without having to rely on CAP_SYS_RAWIO (which is >> already overloaded to mean many other things). One way that userland >> has access to IO accesses is via the iopl(2) and ioperm(2) system calls. >> >> Allow disabling of these system calls from ever being available via a >> configuration option, X86_SYS_IOPL. This is implemented by simply >> stubbing out the system calls and having them return ENOSYS when their >> functionality is disabled. >> >> Note that we default this option to 'y', so that existing kernel configs >> will continue to support sys_iopl and sys_ioperm as before. >> > > Wouldn't it be more useful for this to be a sysctl? In particular, like > many similar things it probably should be a lockable sysctl (three > states: enabled, disabled, and locked-disabled). > > Making it a compile-time option I'm very skeptical to.
Are there existing examples of this already in the tree? -- 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/
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