Messages in this thread | | | Date | Tue, 25 May 1999 18:39:16 +0200 (CEST) | From | Simon Richter <> | Subject | Re: Capabilities done right [diff against 2.3.1] |
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On Tue, 25 May 1999, Fred Reimer wrote:
[-EACCES, -ECAP or SIGCAP]
> Why not both? Why not return the syscall with failure (and appropriate > error code) AND send a signal. Signals are supposed to be async right? The > signal handler, for those cap aware future apps, could flip a flag that they > program can check after getting the failed syscall for more capability > specific information. Is this not doable? Or is it, just not desirable?
Returning -EPERM and sending SIGCAP (non-fatal signal) has the disadvantage that the program cannot tell at the time the syscall returns what has happened, because signals are asynchronous.
I see three options:
return -ECAP: disadvantage: Non-aware apps wouldn't know about this error and assume wild things (or even break). advantage: Aware apps could know what happened without too much overhead.
return -EACCES: advantage: Old apps know what happened. Disadvantage: New apps are unsure.
send SIGCAP: advantage: ? disadvantage: Causes strange things if not properly caught.
Simon
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