Messages in this thread | | | Date | Tue, 22 Apr 2008 22:37:26 -0700 | From | Chris Wright <> | Subject | Re: [PATCH 0/3] exporting capability name/code pairs (for 2.6.26) |
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* KaiGai Kohei (kaigai@ak.jp.nec.com) wrote: > [PATCH 2/3] exporting capability name/code pairs > > This patch enables to export code/name pairs of capabilities the running > kernel supported. > > A newer kernel sometimes adds new capabilities, like CAP_MAC_ADMIN > at 2.6.25. However, we have no interface to disclose what capabilities > are supported on the running kernel. Thus, we have to maintain libcap > version in appropriate one synchronously. > > This patch enables libcap to collect the list of capabilities at run time, > and provide them for users. It helps to improve portability of library. > > It exports these information as regular files under /sys/kernel/capability. > The numeric node exports its name, the symbolic node exports its code.
I do not understand why this is necessary. The capability bits are an ABI that shouldn't change in a non-backward compat way (i.e. only additions).
We typically don't export strings <-> number conversions for constants. I know you've explained this a few times before, but it still seems to me like a userspace only problem. What can userspace do with a capability it does not know about?
thanks, -chris
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